Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B6/00—Compression machines, plants or systems, with several condenser circuits
  • F25B6/02—Compression machines, plants or systems, with several condenser circuits arranged in parallel
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B6/00—Compression machines, plants or systems, with several condenser circuits
  • F25B6/04—Compression machines, plants or systems, with several condenser circuits arranged in series
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B7/00—Compression machines, plants or systems, with cascade operation, i.e. with two or more circuits, the heat from the condenser of one circuit being absorbed by the evaporator of the next circuit
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B9/00—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point
  • F25B9/002—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the refrigerant
  • F25B9/004—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the refrigerant the refrigerant being air
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B2309/00—Gas cycle refrigeration machines
  • F25B2309/003—Gas cycle refrigeration machines characterised by construction or composition of the regenerator
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B2400/00—Component parts or details not otherwise provided for in this subclass
  • F25B2400/23—Separators

Definitions

• the present invention relates to a device and a method for heating then expanding a gas. It applies, in particular, to gas transport networks and in particular to the gas supply to a distribution network from a transport network. State of the art
• the transport of natural gas requires in particular the use of transport networks with arteries operated at different pressure ranges between 20 and 85 barg, and lower pressure distribution networks between 4 barg and 10 barg.
• the supply of a distribution network from a transport network as well as the passage from a high pressure artery to a medium pressure artery require gas expansion. However, during expansion, the gas is considerably cooled. Under certain pressure conditions, low temperatures can lead to the formation of organic condensates and/or free water, which leads to the formation of natural gas hydrates. These solid compounds are responsible for damaging not only the regulator but also equipment downstream of the regulator. These low temperatures also lead to a risk of brittle rupture of the pipes downstream of the regulator.
• the term “cold risk” refers to all the consequences listed above, linked to low temperatures. Thus, major difficulties are present in the low temperature expanded gas network.
• the minimum acceptable temperature depends in particular on the water content and the pressure of the gas in the network. For example, the minimum acceptable temperature is set by default at 0°C for a pipe whose age no longer allows its brittle fracture temperature to be determined. In other examples, the TMA is equal to -20°C or -29°C when the material constituting the distribution network is polyethylene or steel respectively.
• Prior art solutions describe the use of a gas heating device upstream of the expansion.
• a gas heating device upstream of the expansion implements the use of an urban heat network drawing thermal energy from a geothermal source. The presence of such a heat source close to the device constitutes a technical constraint which limits the use of such a device.
• this device requires the use of a thermal and electrical energy cogeneration unit in order to produce the additional thermal energy necessary for heating the gas.
• Another gas heating device upstream of the expansion implements the use of a gas combustion boiler.
• the implementation of such a device requires gas consumption and leads to greenhouse gas emissions constituting a source of pollution.
• Other prior art solutions describe the use of a gas heating device downstream of the expansion.
• the implementation of such a device involves operating at low temperature and within the limit of the TMA. This in particular constrains the device to perform expansion in at least two stages with inter-stage heating, in order to maintain the temperature above the TMA at each expansion stage. Despite this precaution, expansions operated at gas temperatures close to TMA induce a risk for equipment and the downstream network in the event of disturbance or failure. The increase in the number of floors also implies an increase in costs.
• EP 2 751 500 discloses a device for heating water included in a first circuit by means of a second similar to a heat pump.
• the heated water is, for example, used for domestic use.
• the device combining these two circuits does not allow the heating and circulation of a gas coming from a transport network to a distribution network at a lower pressure.
• the present invention aims to remedy all or part of these drawbacks.
• the present invention relates to a device for expanding a gas according to claim 1. Thanks to these provisions, the device allows the heating of the gas upstream of the expansion and therefore to maintain the gas at a temperature above the minimum acceptable temperature during the expansion. In addition, the device makes it possible to maintain gas pressure and temperature conditions far removed from the conditions for the formation of hydrates and condensates. Thus, the cold risk inherent in relaxation is avoided.
• the main thermodynamic system allows the use of a calorific fluid carrying out a cycle of transformation and heat exchange adaptable to the different temperature constraints of the gas circulating in the transport and distribution networks.
• the main thermodynamic system allows in particular the use of an energy necessary for the realization of the cycle coming from numerous energy sources of varied nature, for example renewable and/or free and/or fatal heat sources.
• the heating of the gas carried out by the main thermodynamic system makes it possible in particular to use an external heat source whose temperature would not allow direct heating of the gas.
• the external heat source is a stream. The need for the presence of a high temperature heat source near the device is therefore avoided, which eliminates an installation constraint conditioning the implantation of the device.
• the main expander is a turbine coupled to a generator producing electrical energy. Thanks to these provisions, the device allows the production of electrical energy generated by the expansion of the gas. Thus, a production of recoverable electrical energy is achieved.
• the main compressor is powered, at least in part, by the electrical energy produced by the generator. Thanks to these arrangements, the device achieves at least partial energy self-supply. In addition, the device makes it possible to use the electrical energy produced by the generator. Thus, an energy optimization is achieved.
• the evaporator is powered, at least in part, by a waste heat source. Thanks to these provisions, the device makes it possible to use the recovery heat sources whose temperature is insufficient for direct heating of the gas to a predetermined temperature.
• the main thermodynamic system further comprises a second heat exchanger disposed downstream of the first exchanger, between the calorific fluid at the outlet of the first exchanger and the gas to be expanded from the first gas network, preheating the gas to be expanded. expanding and subcooling the calorific fluid. Thanks to these arrangements, the device allows pre-heating of the gas upstream of the heating of the gas in the first heat exchanger. The quantity of heat necessary for heating the gas is therefore reduced. The reduction in the quantity of heat makes it possible in particular to reduce the flow rate of calorific fluid and therefore the energy, in particular electrical energy, consumed by the main compressor. Thus, a reduction in the size of the main thermodynamic system is achieved and the overall energy consumption balance of the device is reduced.
• the main expander is a turbine coupled to a generator
• the overall energy production achieved by the device is increased since the electrical energy transmitted to the main compressor is reduced.
• the device allows sub-cooling of the calorific fluid upstream of the secondary expansion valve.
• the calorific fluid is used as a cold source in the heat exchanger, the quantity of refrigeration transmitted is increased.
• the secondary expander is an expander coupled to the main compressor. Thanks to these arrangements, the device makes it possible to carry out an energy transfer from the expansion turbine to the main compressor. The energy, in particular electricity, consumed by the main compressor is therefore reduced. Thus, the overall energy consumption balance of the device is reduced. Furthermore, when electrical energy is produced in the device by a generator coupled to a turbine, the overall production of electrical energy is increased since the electrical energy transmitted to the compressor is reduced.
• the main thermodynamic system further comprises a secondary compressor pre-compressing the calorific gas upstream of the evaporator, the evaporator upstream of the injection into the main compressor being configured to carry out an exchange heat and cool the pre-compressed calorific gas. Thanks to these arrangements, the calorific gas leaving the secondary compressor is cooled before being compressed in the main compressor.
• the device therefore makes it possible to achieve two-stage compression with inter-stage cooling. Thus, the compression isentropic efficiency is increased, which leads to an improvement in the overall efficiency of the device.
• the device includes additional thermal integration to reduce the energy consumed from from the heat source. This reduction thus contributes to improving the overall efficiency of the device.
• the device further comprises a secondary thermodynamic system using a second calorific fluid, comprising heat transfer means configured to perform a heat exchange in the evaporator between the second calorific fluid and the calorific liquid to be evaporated .
• the secondary thermodynamic system carries out, for example, a second transformation and heat exchange cycle. This second cycle draws heat from lower temperature sources. In particular, the heat is drawn from sources at very low temperatures, for example below 0°C. Thus, an optimization of heat transfers is achieved by the device.
• the use of the secondary thermodynamic system makes it possible to increase the capacity of this air evaporator. Thus, the efficiency of the device is improved.
• the secondary thermodynamic system produces the second cold calorific fluid used as a cold source. Thanks to these provisions, the device makes it possible to recover a cold source, and therefore cold temperatures, at the level of the evaporator.
• the cold temperatures produced by the device are, for example, recovered in a cooling network.
• the use of the secondary thermodynamic system, carrying out a second cycle of transformation and heat exchanges, makes it possible in particular to widen the range of application temperature of the cooling network. Thus, the number of application cases is increased.
• the device comprises a second heat exchanger arranged downstream of the first exchanger, the quantity of cold calories present in the cold source is increased.
• the secondary thermodynamic system is powered, at least in part, by the electrical energy produced by the generator. Thanks to these provisions, the self-supply and therefore the energy independence of the device comprising the secondary thermodynamic system are reinforced. In addition, the device also makes it possible to recover the electrical energy produced by the generator.
• the device further comprises a subsidiary heat exchanger disposed downstream of the main expander, configured to recover cold temperatures from the gas expanded by the main expander. Thanks to these provisions, when low temperatures at the outlet of the main expansion valve are targeted, a production and a transfer of cold temperatures are carried out. For example, cold storage is transferred to a cooling network.
• the present invention relates to a process for expanding a gas, which comprises at least one main expansion step between a first gas network at a first pressure and a second gas network at a second pressure lower than the first pressure, the method further comprising, upstream of the main expansion step:
• Figures 1 to 6 represent, respectively and schematically, six first particular embodiments of the device that is the subject of the invention.
• FIG. 7 represents, in the form of a flowchart, a succession of particular steps of the method which is the subject of the invention.
• FIG. 8 represents, schematically, a seventh particular embodiment of the device which is the subject of the invention.
• FIG. 9 graphically represents a sensitivity study of different particular embodiments of the device that is the subject of the invention as a function of temperature
• FIG. 10 represents, schematically, a particular embodiment of a compressor that can be used in the device that is the subject of the invention.
• FIG. 11 represents, schematically, a piston booster of a compressor of the device which is the subject of the invention
• Figures 12 to 15 represent, respectively and, schematically, four operating phases of a free-piston and through-opening blower
• FIG. 16 represents, schematically, an eighth particular embodiment of the device which is the subject of the invention.
• FIG. 17 schematically represents a ninth particular embodiment of the device which is the subject of the invention.
• upstream and downstream to designate the position of the elements depend on the choice of fluid whose circulation is observed.
• the fluid is, for example, either a natural gas to be heated before expansion, or a calorific fluid present in a thermodynamic system. When elements of a thermodynamic system are described, the fluid corresponds to the calorific fluid.
• first gas network refers to a network, for example, for transporting natural gas.
• the pressure in a first gas network is, for example, between 20 and 85 barg.
• second gas network refers to a network, for example, for the distribution of natural gas.
• the pressure in a second gas network is, for example, between 4 barg and 40 barg.
• natural gas refers to a gaseous mixture of compounds belonging to the hydrocarbon family.
• a natural gas notably comprises a volume proportion of methane of at least 80% compared to the total volume of the gas.
• a natural gas has a volume proportion of methane equal to 95% relative to the total volume of the gas.
• waste heat refers to heat generated by a production site, the primary objective of this site not being to produce this heat. This heat produced is not recovered and therefore lost. In other words, waste heat is subsidiary heat produced during a main process and not consumed in this main process. We also speak of fatal energy. For example, a fatal energy of a renewable energy corresponds to a part of the renewable energy not exploited.
• global warming potential refers to a relative potency of a greenhouse gas.
• a calorific fluid is likely to concern a greenhouse gas.
• a GWP of a heat transfer fluid is calculated based on the time the heat transfer fluid will remain active in the atmosphere. It should be noted that a global warming potential is notably calculated over 100 years and the acronym used for such a GWP is "GWP 100".
• carbon dioxide is the reference greenhouse gas with a GWP 100 equal to 1.
• the unit of measurement "barg” is used to indicate in particular a gauge pressure.
• the unit of measurement “kWe” refers to the electrical kilowatt.
• FIG. 1 a schematic view of a first embodiment of the device 100 object of the invention.
• the device 100 for expanding a gas comprises:
• thermodynamic system 120 comprising:
• the main regulator 105 is arranged between a first gas network 110 at a first pressure and a second gas network 115 at a second pressure. It is noted that the gas in the second network has a pressure lower than the pressure of the gas in the first network.
• the main expander 105 is a turbine (not shown) coupled to a generator 101.
• the generator 101 produces electrical energy. Thus, part of the relaxation energy is transformed into electricity.
• the electrical efficiency of the generator 101 is at least equal to 95%. It is noted that the electrical energy produced is, for example, used to supply a power plant or an electrical network.
• the turbine 105 is fixed speed or variable speed.
• the use of a fixed-speed turbine requires the addition of an expansion valve upstream of the turbine to maintain the turbine on its operating curve according to the operating conditions set by, in particular, the flow rate, the pressure and the temperature. .
• a pressure drop is present in the valve and represents a non-negligible loss for the expansion stage, in particular linked to a distance of the operating conditions from the optimal operating point.
• the isentropic efficiency of the turbine decreases with a decrease in flow.
• the turbine 105 is variable speed.
• optimal efficiencies, in particular isentropic are maintained over the operating range of the device.
• the turbine 105 performs a thermodynamic cycle with isentropic efficiency at least equal to 90%.
• thermodynamic system 120 is arranged upstream of the main regulator 105, when following the circulation of the gas to be heated. It is noted that the main thermodynamic system 120 uses a calorific fluid 125 to heat the gas to be expanded in the first network 110.
• the calorific fluid 125 of the main thermodynamic system 120 has the following physico-chemical characteristics:
• the evaporation temperature of the calorific fluid at low pressure that is to say downstream of the expansion carried out by the secondary expansion valve 135, is lower than the temperature of the heat source and
• the high pressure condensation temperature i.e. downstream of the compression, is higher than the heating temperature of the gas to be expanded.
• the device 100 performs an optimal thermodynamic cycle, in line with the heat transfer, physical transformation and yield constraints predetermined by the operator.
• the calorific fluid 125 of the main thermodynamic system 120 comprises at least one compound chosen, for example, from carbon dioxide, ethane, propane, propylene, butane or ammonia.
• the calorific fluid of the main thermodynamic system comprises at least one compound chosen from propane, propylene and ammonia. It is noted that the GWP 100 of carbon dioxide, propane, propylene and ammonia is respectively equal to 1; 3; 1, 8 and 0.
• calorific fluids belonging to the family of halocarbons such as hydrofluorocarbons with the acronym “H FC”, hydrochlorofluorocarbons with the acronym “HCFC” or chlorofluorocarbons with the acronym “CFC”, have GWP 100 between 120 and 10,000.
• Each calorific fluid chosen from carbon dioxide, ethane, propane, propylene, butane or ammonia therefore has a reduced GWP 100 compared to calorific fluids belonging to the family halocarbons.
• these calorific fluids, with a reduced GWP 100 comply with the “F-GAS number 517/2014/UE” regulation.
• the calorific fluid has reduced toxicity, pollutant character and global warming potential compared to a conventionally used calorific fluid, belonging in particular to the halocarbon family. It is observed, in Figure 1, that the heat exchanger 130 of the main thermodynamic system 120 transfers heat from the calorific fluid 125 to the gas to be expanded present in the first gas network 110.
• the calorific fluid 125 condenses at a temperature higher than a predetermined temperature of the gas upstream of the expansion carried out by the main expansion valve 105.
• the predetermined temperature of the natural gas before the expansion is equal to 27° C.
• the condensation temperature of the calorific fluid 125 is greater than 27°C.
• the target temperature of the natural gas downstream of the expansion valve is equal to 0°C.
• Calorific fluids such as propane, propylene and ammonia notably have condensation temperatures equal to 60°C respectively at pressures equal to 20 barg; 24 barg and 26 barg. These calorific fluids can therefore be used in the device, for example, for heating natural gas, having a temperature equal to 27° C. upstream of the main regulator 105 and a target temperature equal to 0° C. downstream of the main regulator 105 .
• the temperature of the calorific fluid 125 is higher than the temperature of the heated gas.
• the temperature of the calorific fluid 125 is equal to its boiling point. The consideration of the fluid 125 at its boiling temperature is important in order to optimize the efficiency of the transfer of latent heat of condensation of the calorific fluid 125.
• the heat exchange carried out in the heat exchanger 130 corresponds at a minimized difference between the temperatures, at the outlet of the heat exchanger 130, of the calorific fluid and of the heated gas.
• the temperature difference is between 2°C and 3°C.
• the secondary expansion valve 135 is arranged downstream of the heat exchanger 130 when the circulation of the calorific fluid 125 is followed.
• the secondary expansion valve 135 expands the calorific fluid to a pressure and a temperature of 'evaporation.
• the secondary regulator 135 is an expansion valve.
• FIG. 5 A schematic view of a fifth embodiment of the device 500 object of the invention is observed in FIG. 5, in which the secondary expander 135 of the main thermodynamic system 520 is an expansion turbine coupled to the main compressor 160.
• the secondary expansion turbine 135 is also called "turboexpander" in English.
• the separator 140 is arranged downstream of the secondary expansion valve 135.
• the separator 140 separates the flow of calorific fluid into a flow of liquid calorific 145 and a flow of calorific gas 150.
• the separator 140 is a separator known to the person skilled in the art. For example, separator 140 is a flash balloon.
• the flow of calorific liquid 145 is then transferred to the evaporator 155.
• the evaporator 155 evaporates the calorific liquid 145 into calorific gas 150.
• the separator 140 and the evaporator 155 are combined.
• the separator 140 and the evaporator 155 are combined into a single piece of equipment.
• This equipment is, for example, a Kettle exchanger known to those skilled in the art.
• the evaporator 155 is powered, at least in part, by a heat source.
• the difference between the temperatures, at the outlet of the evaporator 155, of the vaporized calorific fluid 150 and of the fluid coming from the heat source is preferably between 2° C. and 3° C. It is noted that the value of such a temperature difference varies according to the nature of the evaporator 140 and the heat source. In addition, the value of such a temperature difference conditions the evaporation temperature and therefore the evaporation equilibrium pressure of the calorific fluid at the outlet of the secondary expansion valve 135.
• the evaporator 155 is powered, at least in part, by a recovery heat source 102.
• the recovery heat sources correspond to so-called “fatal” or “free” heat sources.
• the heat sources are selected based on the location of the device 100. Table 1 shows examples of recovery heat sources based on the location of the device. [Table 1]
• the recovery heat sources set out above are also valid for the devices 200, 300, 400, 500, and 600 described previously or subsequently. It is noted that, when the evaporator 155 is powered by a recovery heat source 102, the evaporation temperature of the calorific fluid 125 at the outlet of the expander secondary 135 is lower than the temperature of the heat source 102. In other words, the calorific fluid 125 evaporates at a temperature lower than the temperature of the heat source
• the evaporation temperature of the calorific fluid is lower than 0°C.
• Calorific fluids such as propane, propylene and ammonia have evaporation temperatures equal to -10°C respectively at pressures equal to 2.5 barg; 3.3 barg and 2.9 barg.
• These calorific fluids can therefore be used in the device, for example, during a heat exchange in the evaporator 155 with in particular a recovery heat source 102 having a temperature substantially equal to 0°C.
• these initially liquid calorific fluids are heated and therefore vaporized in the evaporator 155 by transfer of heat originating in particular from the recovery heat source 102.
• the device 100 further comprises a secondary thermodynamic system using a second calorific fluid, comprising a heat transfer means carrying out a heat exchange in the evaporator 155 between the second calorific fluid and the calorific liquid 145 to be evaporated.
• the secondary thermodynamic system produces the second cold calorific fluid then used as a cold source 103.
• the evaporator 155 is an exchanger which transmits the negative calories to the second calorific fluid then used as a cold source
• the transfer of cold temperatures is carried out directly or via a secondary loop (not shown) comprising, for example, a second calorific fluid comprising glycol water.
• the calorific fluid leaving the evaporator 155 for example also mixed with the flow of calorific gas 150, is superheated upstream of the injection into the main compressor 160.
• the superheating of the flow of calorific gas corresponds to a temperature increase of between 1°C and 2°C.
• the superheating of the calorific gas is carried out by any means known to those skilled in the art. Thus, the injection of drops into the main compressor 160 is avoided.
• the main compressor 160 is arranged downstream of the evaporator 155 and upstream of the heat exchanger 130.
• the main compressor 160 compresses the calorific gas 150 coming from the separator 140 and coming from the evaporator 155.
• the calorific gas upstream of the compression initially at an equilibrium pressure of evaporation, is compressed up to an equilibrium pressure of condensation.
• the main compressor 160 when the main expander 105 is a turbine coupled to a generator 101, the main compressor 160 is powered, at least in part, by the electrical energy produced by the generator 101. In these embodiments, the main compressor 160 carries out a thermodynamic cycle with isentropic efficiency at least equal to 75%.
• the compression ratio influences the compression efficiency and the temperature of the calorific fluid downstream of the compression.
• the compression ratio is to minimize in order to improve the overall efficiency of the device.
• a reduction in the compression ratio is obtained in particular by reducing the condensation temperature of the calorific fluid 125 at the outlet of the heat exchanger 130 and by increasing the evaporation temperature of the calorific fluid 125 at the outlet of the secondary expansion valve 135.
• the compression rate is greater than a limit value predetermined by the user, the compression of the flow of calorific gas is divided into several stages.
• the calorific fluid 125 is in a state of superheated vapor.
• the difference between the temperature at the outlet of the heat exchanger 130 of the calorific fluid and the temperature of the natural gas to be expanded is preferably between 2°C and 3°C. Such a preferential temperature difference is justified by the following explanation.
• the calorific fluid 125 is in a state of superheated vapor and enters the heat exchanger 130. The calorific fluid 125 leaves the heat exchanger 130 at its boiling temperature corresponding to the temperature at the outlet of the heat exchanger 130.
• An increase in the temperature at the outlet of the heat exchanger 130 of the calorific fluid causes an increase in the pressure of the same calorific fluid, having the consequence of increasing the need for compression performed by the main compressor 160
• An increase in the need for compression results in a decrease in the overall efficiency of the device.
• a reduction in the temperature of the calorific fluid at the outlet of the heat exchanger 130 is, for example, carried out in order to reduce the need for compression. This decrease in temperature corresponds to a decrease in the temperature difference stated above.
• thermodynamic cycle For example, the calorific fluid of the main thermodynamic system 120 carries out the following thermodynamic cycle:
• the calorific fluid is compressed by the main compressor 160 at high pressure.
• the main compressor 160 consumes electrical energy produced by the generator 101 coupled to the turbine 105;
• the compressed calorific fluid is condensed by transmitting its calories to the gas to be expanded in the heat exchanger 130.
• the calorific fluid At the heat exchanger outlet, the calorific fluid is at its boiling temperature and at high pressure;
• the condensed calorific fluid is expanded at low pressure by the secondary expander 135.
• the calorific fluid has two phases, a liquid phase 145 and a vapor phase 150;
• the flow of calorific liquid 145 is evaporated in the evaporator 155.
• the steam obtained is collected with the flow of calorific vapor 150, the calorific fluid obtained is ejected to the main compressor 160 for a new cycle.
• thermodynamic cycle described above for the main thermodynamic system 120 is also valid for each main thermodynamic system 320, 420, 520, respectively of the devices 200, 320, 420 and 520.
• FIG. 2 A schematic view of a second embodiment of the device 200 object of the invention is observed in FIG. 2, in which the main thermodynamic system 220 comprises a second heat exchanger 231 disposed downstream of the first exchanger 130, between the calorific fluid 125 at the outlet of the first exchanger 130 and the gas to be expanded present in the first gas network 110, preheating the gas to be expanded.
• the second heat exchanger 231 is also called a “booster”. It is noted that the second heat exchanger 231 subcools the calorific fluid.
• the heat exchange carried out in the second heat exchanger 231 corresponds to a minimized difference between the temperature of the calorific fluid at the outlet of the second heat exchanger 231, and the temperature of the gas 110 to be heated.
• the temperature difference is between 8°C and 10°C.
• the temperature difference is between 3°C and 5°C.
• the first heat exchanger 130 and the second heat exchanger 231 are combined.
• the condensation and sub-cooling functions are performed by a single element.
• the calorific fluid 125 of the main thermodynamic system 220 carries out the following thermodynamic cycle:
• the calorific fluid is compressed by the main compressor 160 at high pressure, the main compressor 160 consumes electrical energy produced by the generator 101 coupled to the turbine 105;
• the compressed calorific fluid is condensed in the first heat exchanger 130 by transmitting its calories to the gas to be expanded preheated;
• the condensed calorific fluid is sub-cooled in the second heat exchanger 231 by transmitting its calories to the gas to be pre-heated coming from the first network 110;
• the subcooled calorific fluid is expanded at low pressure by the secondary expander 135, it is noted that at the output of the secondary expander 135 the calorific fluid has two phases, a liquid phase 145 and a vapor phase 150;
• the flow of calorific liquid 145 is evaporated in the evaporator 155, the steam obtained is collected with the flow of calorific vapor 150, the calorific fluid obtained is ejected to the main compressor 160 to carry out a new cycle.
• FIG. 3 A schematic view of a third embodiment of the device 300 object of the invention is observed in FIG. 3, which comprises a secondary thermodynamic system 321 using a second calorific fluid 326.
• the secondary thermodynamic system 321 comprises a means of heat transfer carrying out a heat exchange in the evaporator 155 between the second calorific fluid 326 and the calorific liquid 145 to be evaporated.
• the secondary thermodynamic system 321 corresponds to a second refrigeration loop.
• the evaporator 155 of the main thermodynamic system 320 is supplied with calories by the secondary thermodynamic system 321.
• the second calorific fluid 326 of the secondary thermodynamic system 321 operates at a lower temperature.
• the secondary thermodynamic system 321 further comprises:
• a second secondary expansion valve 336 which expands the secondary calorific fluid downstream of the evaporator 155, and being, for example, of the same nature as the secondary expansion valve 135;
• auxiliary separator 341 disposed downstream of the second secondary expander 336, which separates the flow of secondary calorific fluid into a flow of secondary calorific gas 351 and a flow of secondary calorific liquid 346, and being, for example, of the same nature as the separator 140;
• auxiliary evaporator 356 arranged downstream of the auxiliary separator 341 and evaporating the secondary calorific liquid 346 into secondary calorific gas 351, and being, for example, of the same nature as the evaporator 155;
• the secondary thermodynamic system 321 produces the secondary calorific liquid 346 used as a cold source 103.
• the transfer of cold temperatures from the secondary calorific liquid 346 is carried out directly or via a tertiary loop (not shown) comprising, for example, a third calorific fluid comprising glycol water.
• the auxiliary evaporator 356 is a heat exchanger transmitting the negative calories of the secondary calorific liquid 346 to a third calorific fluid subsequently used as another cold source 103.
• the secondary thermodynamic system 321 is powered, at least in part, by the electrical energy produced by the generator 101.
• the auxiliary compressor 356 is powered, at least in part , by the electrical energy produced by the generator 101.
• the auxiliary evaporator 356 is powered, at least in part, by a recovery heat source 102.
• the secondary thermodynamic system 321 recovers calories from a heat source, for example recovery 102, that is colder, that is to say having a temperature lower than the temperature of another heat source.
• recovery heat used directly by the evaporator 155 of the main thermodynamic system 320.
• the evaporator 155 is an air-cooled evaporator, the recovery heat source 102 being air, the use of a thermodynamic system secondary 321 makes it possible to increase the capacities of this air evaporator.
• thermodynamic transformations of the first liquid calorific fluid 145 carried out by the evaporator 155 of the main thermodynamic system 320, and of the secondary calorific liquid 346 carried out by the auxiliary evaporator 356 of the thermodynamic system secondary 321 are shown in Table 2.
• the first liquid calorific fluid 145 is propane
• the second calorific fluid 346 is carbon dioxide
• the recovery heat source 102 is air.
• the use of the secondary thermodynamic system 321 makes it possible in particular to increase, compared to the use of a single main thermodynamic system 320, the difference between the temperature of the carbon dioxide in the auxiliary evaporator 356 and ambient air temperature.
• carbon dioxide as the second calorific fluid 326, more efficiently recovers calories present in the ambient air, compared to the use of a single main thermodynamic system 320.
• a schematic view of a fourth embodiment of the device 400 object of the invention is observed in FIG. 4, in which the expansion of the natural gas is carried out, at least, in two stages.
• a trigger ratio is defined by a pressure upstream of the trigger divided by a pressure downstream of the trigger.
• a trigger is performed in two stages when the trigger ratio is greater than a predetermined limit value set by the user.
• the value of the expansion ratio increases, the temperature of the heated natural gas increases, as well as the temperature and the equilibrium pressure of condensation of the calorific fluid 125. Consequently, the compression ratio and the power of the main compressor 160 increase, and the isentropic efficiency of the main compressor 160 decreases.
• a multi-stage trigger is, for example, achieved.
• the determination of the number of expansion stages depends on the operating conditions and the technology of the equipment. For example, for this purpose and with a view to optimizing the device 400, a technical-economic study is carried out. Preferably, an expansion ratio is constant between two stages. Thus, the economic and energy optimum of an expansion is achieved.
• the main thermodynamic system 420 further comprises an auxiliary heat exchanger 431.
• the auxiliary heat exchanger 431 is arranged downstream of the first main expansion valve 105 and upstream of the second main expansion valve 406, and heats the pre-expanded natural gas at the outlet of the first main regulator 105 and coming from the second network 115.
• the natural gas present in the first network 110 performs the following thermodynamic steps: - the natural gas of the first gas network 110 is pre-heated by the first heat exchanger 130,
• the pre-heated natural gas from the network 111 is pre-expanded by the first main regulator 105,
• the heated natural gas from the network 112 is expanded by the second main regulator 406 to form, for example, an expanded natural gas from a distribution network 113.
• the first main expander 105 and the second main expander 406 are turbines coupled to electricity generators, 101 and 407.
• the calorific fluid 125 heating the natural gas from the network 111 in the auxiliary heat exchanger 431 comes from the main compressor 160.
• the compressed calorific fluid is divided into two streams.
• a flow of calorific fluid heats, in the auxiliary heat exchanger 431, the flow of natural gas from the second network 115.
• Another flow of calorific fluid heats, in the first heat exchanger 130, the flow of natural gas from the first network 110.
• the flows of calorific fluid, originating respectively from the first heat exchanger 130 and from the auxiliary heat exchanger 431 are then gathered upstream of the expansion carried out by the secondary expansion valve 135.
• the compression ratio of the main compressor 160 has an influence on the compression efficiency and the temperature of the compressed calorific gas.
• the compression rate should be minimized in order to improve the overall performance of the device.
• a decrease in the compression ratio corresponds to a decrease in the condensation temperature of the calorific fluid at the outlet of the heat exchanger 130 and to an increase in the evaporation temperature of the calorific fluid at the outlet of the secondary expansion valve 135.
• the rate of compression is greater than a limit value predetermined by the user, the compression of the calorific fluid is carried out, for example, in several stages, as represented in FIG. 6.
• FIG. 6 a schematic view of a sixth embodiment of the device 600 object of the invention, in which the main thermodynamic system 620 comprises a secondary compressor 661 upstream of the main compressor 160, pre-compressing the calorific gas 150.
• the evaporator 155 upstream of the injection into the main compressor 160 performs a heat exchange and cools the precompressed calorific gas.
• the calorific fluid of the main thermodynamic system 620 carries out the following thermodynamic cycle:
• the calorific fluid is compressed by the main compressor 160 at high pressure, the main compressor 160 consumes electrical energy produced by the generator 101 coupled to the turbine 105; - the compressed calorific fluid is condensed in the heat exchanger 130 by transmitting its calories to the gas to be expanded pre-heated;
• the condensed calorific fluid is expanded at low pressure by the secondary expander 135, and at the output of the secondary expander 135 the calorific fluid has two phases, a liquid phase 145 and a vapor phase 150;
• the flow of calorific gas is pre-compressed in the secondary compressor 661 to form the pre-compressed calorific gas 662, the secondary compressor 661 being, for example, of the same nature as the main compressor 160;
• the flow of pre-compressed calorific gas 662 is cooled by heating the flow of calorific liquid 145 in the evaporator 155
• a heat source for example recovery 102, is used in addition to supply, at least in part, the evaporator 155 and carry out the evaporation of the calorific liquid 145;
• the cooled calorific gas 663 is injected into the main compressor 160 to perform a new cycle.
• the main compressor 160 and the secondary compressor 661 are powered, at least in part, by the electrical energy produced by the generator 101 .
• a compression stage 720 which compresses the calorific gas at the outlet of the separation stage and/or at the outlet of the evaporation stage and which forms the compressed calorific fluid.
• the devices 100, 200, 300, 400, 500, 600, 800, 4000 or 5000 are configured to implement the steps of the method 700 and their embodiments as described above.
• Examples 1, 2, 3 and 4 described below are examples of application of the device which is the subject of the invention.
• the calorific fluid is propane
• the turbine isentropic efficiency is equal to 90%
• generator efficiency is equal to 96%
• compressor motor efficiency is equal to 96%
• compressor isentropic efficiency is equal to 75%.
• calorific fluid propane
• the net production of electrical energy by the device 100 object of the invention, under the conditions of Example 1, is equal to 18.7 kWe.
• the power required for the evaporator 155 is equal to 19.0 kW, thus the use of an air or surface geothermal evaporator 155 can be envisaged under these conditions.
• the use of air or superficial geothermal energy does not make it possible to directly heat the natural gas to a temperature equal to 44.7° C. upstream of the expansion.
• a device of the prior art comprising a thermodynamic system for recovering the negative temperatures of the gas downstream of the expansion, produces a gas downstream of the expansion having a temperature of -30°C.
• the temperature of the gas downstream of the expansion is lower than the hydrate formation temperature equal to -19°C.
• the use of the device of the prior art limits the recovery of energy or requires the implementation of several expansion stages.
• an expansion of 300,000 Nm3/h of natural gas from 58 to 38 barg is carried out.
• the natural gas is heated from 7°C to 27°C.
• the device 100 which is the subject of the invention is compared with a device of the prior art mentioned previously implementing the use of an urban heat network drawing thermal energy from a geothermal source.
• Tables 5 and 6 detail the pressure and temperature conditions applied to the natural gas and to the calorific fluid in the device 100:
• calorific fluid propane
• table 7 summarizes the production of electricity and the heat purchased during the use of the device 100 object of the invention and the device of the prior art mentioned above: [Table 7]
• the device 100 which is the subject of the invention consumes, under the conditions applied, a zero quantity of purchased heat, and therefore less than the device of the prior art.
• the purchased heat associated with device 100 is zero since device 100 consumes waste or free heat.
• Example 3 an expansion of 600,000 Nm3/h of natural gas from 58 to 38 barg is carried out.
• the natural gas is heated from 7°C to 27°C.
• the device 100 object of the invention is compared to a device of the prior art mentioned above implementing the use of an urban heating network drawing thermal energy from a geothermal source.
• the devices of Example 3 are used to perform a heat transfer with an urban heating network with the acronyms "RCU”.
• the device of the prior art has:
• a first heat exchanger comprising a first calorific fluid and heating the natural gas to be expanded
• a second heat exchanger comprising a second fluid, for example water, circulating in the district heating network and configured to heat the first calorific fluid.
• Table 8 illustrates an embodiment of the device of the prior art, with the temperature conditions of each fluid:
• the device of the prior art has constraints, in particular concerning the transfer of heat from the RCU to the natural gas.
• the heat transfer from the RCU to the natural gas is limited by the temperature of the natural gas at 8°C and the temperature differences of the various flows between the first and the second exchanger.
• Tables 9 and 10 detail the pressure and/or temperature conditions applied to the natural gas, to the calorific fluid in the device 100: [Table 9]
• a heat exchange is carried out between the fluid, for example water, present in the RCU and the calorific liquid 145 of the device 100.
• the RCU corresponds to a recovery heat source 102.
• the fluid present in the RCU heats the calorific liquid 145 which evaporates into calorific gas.
• the fluid present in the RCU has:
• a temperature equal to 2°C is predetermined to prevent freezing of the water circulating in the RCU.
• table 11 summarizes the production of electricity and the heat purchased during the use of the device 100 object of the invention and the device of the prior art mentioned above: [Table 11]
• the device 100 object of the invention using as recovery heat source 102 an RCU makes it possible to overcome the constraints mentioned above in the device of the prior art carrying out a heat transfer with a fluid from an RCU.
• the advantages are:
• the treatment capacity of the unit increases from 300,000 to 600,000 Nm3/h and the net electricity production increases from 2.0 to 4.3 MWe compared to device 100 cited in example 2 above.
• an expansion of 35.0 KNm3/h of natural gas from 16 to 3.9 barg is carried out.
• the natural gas is heated from 4°C to 75°C.
• the device 200 object of the invention is compared to a device of the prior art.
• the prior art device has two expansion stages. It is noted that the device of the prior art comprises the following elements performing the staged expansion of the natural gas:
• the calorific fluid heating the natural gas used in the first heat exchanger and the second heat exchanger, has a temperature upstream and downstream of the heat exchange respectively equal to 7.5° C. and 1.0°C.
• Table 12 details the pressure and temperature conditions applied to the natural gas used in the device of the prior art: [Table 12]
• table 15 summarizes the production of electricity and the production of cold during the use of a device of the prior art and of the device 200 object of the invention: [Table 15]
• the device 200 object of the invention has the following additional advantages compared to the device of the prior art:
• the cold production of the device 200 increases by 25% when the evaporator 155 of the device 200 is coupled to a secondary thermodynamic system generating a second cold calorific fluid used as a cold source.
• the performance of the device 200 is further improved when the target temperature at the outlet of the expander increases. This increase has the following advantages:
• table 16 summarizes the production of electricity and the production of cold during the use of a device of the prior art and two devices 200 objects of the invention each having an output temperature of turbine equal to 0°C or 15°C: [Table 16]
• the total energy gain is increased for a device 200 with a turbine outlet temperature equal to 15°C, compared to a device 200 with a turbine outlet temperature equal to 0°C. It is also noted that a greater production of cold is obtained for a device 200 with a temperature at the outlet of the turbine equal to 15°C.
• the device further comprises an adaptation automaton.
• the adaptation automaton adjusts the operating conditions of the device according to the temperature of the gas to be expanded.
• the operating conditions such as flow, pressure and temperature
• the operating conditions are subject to strong daily and seasonal variations.
• gas consumption is higher in winter with consumption peaks in the morning and evening. It is noted that these high flow rates represent a significant potential for upgrading the expansion energy.
• the temperature of the gas can drop to 5°C, which increases the need for heat before expansion.
• summer consumption is reduced with gas temperatures that can reach 25°C. The need for reheating is lower but the recovery potential is also reduced due to the low throughput.
• the device adapts to the operating conditions with a Programmable Logic Controller (acronym “API”).
• the API is able to set operating instructions and adjust parameters such as: - the flow rate of calorific fluid,
• the action levers of the API are, for example: the power of the compressor, the level of liquid in the evaporator and the percentage of opening of the secondary expansion valve. It is also possible to install a recirculation line with a regulation valve between the compressor discharge and the evaporator inlet in order to increase the operating range of the device.
• the compressor can operate at its lowest power and only part of the flow of calorific fluid circulates towards the natural gas heater. The other part runs in circles between the compressor and the evaporator.
• the API adjusts in particular the operating variables from instructions determined by an operator.
• An additional level of automation is therefore integrated into the device to optimize overall efficiency through automatic management of setpoints and system configuration.
• Table 17 summarizes the benefits and losses of the process for two cases: with or without recovery of the negative calories in the evaporator.
• a technical and economic optimization calculation carried out by a management automaton makes it possible to direct the operating instructions in real time towards one extreme or another.
• the operating instructions are modified in real time.
• This automaton also takes into consideration the technical constraints and the parameters of the equipment, such as the compressor efficiency as a function of the pressure ratio, the TMA linked to a hydrate formation temperature as a function of the water content and the pressure.
• a variability of the operating conditions on the transport network implies in particular a need to adapt the device for recovering the expansion energy.
• This adaptation is carried out in certain embodiments, for example, by an API optionally coupled to a management automaton performing technical and economic calculations in real time, adjusting the operating instructions and modifying the configuration of the device, for example by short-circuiting (or deriving, in English "by-pass") the finisher.
• FIG. 8 A diagrammatic view of a seventh embodiment of the device 800 object of the invention is observed in FIG. 8, which further comprises a subsidiary heat exchanger 801 arranged downstream of the main regulator 105.
• the subsidiary heat exchanger 801 is configured to recover cold temperatures 104 from the gas present in the second network 115 and expanded by the main expander 105.
• the subsidiary heat exchanger is also called a finisher.
• a subsidiary calorific fluid heats the expanded gas 115.
• the subsidiary calorific fluid recovers the negative calories 104 from the expanded gas. By recovering these negative calories 104, the subsidiary calorific fluid becomes a subsidiary refrigerating fluid.
• the subsidiary heat exchanger 801 of the device 800 transfers the cold temperatures from the expanded gas present in the second network 115 to a cold network via, for example, the subsidiary refrigerant.
• the graph 900 represented in FIG. 9 shows a study of the sensitivity of certain examples of the device which is the subject of the invention as a function of the target temperature at the outlet of a turbine 105.
• the ordinate axis corresponds to the power in kilowatts (kW) and the x-axis corresponds to the temperature at the turbine outlet in degrees Celsius (°C).
• the heat source is 0°C.
• the net production of electricity and the production of cold temperatures are represented as a function of the target temperature at the outlet of the expansion turbine 105 coupled to a generator 101 .
• the terms “upper” and “lower” are also used for a relative description of two curves in order to distinguish them.
• the curve with points 901 corresponds to the cold balance for an example of the device with booster and with finisher
• - the upper curve in broken line 902 corresponds to the cold balance for an example of the device with booster and without finisher, comparable to an embodiment of the device 200;
• - the curve alternating with a line followed by two points 903 corresponds to the cold balance for an example of the device without booster and with finisher, comparable to an embodiment of the device 800;
• the upper curve in solid line 904 corresponds to the cold balance for an example of the device without booster and without finisher, comparable to the device 100;
• the lower curve in solid line 906 corresponds to the electrical balance for an example of the device without booster.
• the booster significantly improves the electrical balance. It is noted that this improvement is greater when the turbine outlet temperature decreases.
• This study also shows that to maximize the production of cold temperatures, it is particularly necessary to operate at low temperature with a paver, at the risk of approaching the TMA. The other possibility is to operate at high temperature without a paver, but at the expense of electricity production.
• the main compressor 160 is a pneumatic booster 1000 having a free piston.
• the embodiments of the main compressor 1000 with a free piston are represented in FIGS. 10 to 17. It is recalled that, in a free piston supercharger, the movement of the piston responds only to the pressure of the gas, without a connecting rod actuates where retains it. A person skilled in the art knows how to easily replace this free piston with a pneumatic diaphragm booster, for example.
• the main compressor 160 is a pneumatic membrane booster.
• FIGS. 10 to 15 mentions the general operation of a booster 1000, as well as different variants of the booster 1000. This operation and these variants are applicable to the embodiments of the devices 4000 and 5000 represented respectively in figures 16 and 17.
• the booster allows, by recovering the expansion energy of a gas, therefore without energy expenditure, to compress the calorific fluid 125 then injected into the heat exchanger 130, close to a gas network 1200 at pressure Pa and a gas network 1300 at pressure Pb, where Pa is greater than Pb.
• the gas from the upstream network 1200 is taken through a first pipe 3100 to an inlet 1800 of an expansion chamber of a free-piston booster 3000 1100. Once the gas is expanded, it joins the downstream gas network 1300 via a second pipe 3200.
• elements are added for the automation of suppressor operation.
• a valve 3150 controlled by a flowmeter and positioned on the first pipe 3100 controls the gas flow to the free piston 1100 and positioned on the first pipe 3100. It is noted that such a valve is configured to adjust the power of the piston free 1100.
• a recycling of the calorific gas 125 is carried out.
• the recycling of the calorific gas 125 is carried out by reinjecting the calorific gas 125 into the pipe arranged between the evaporator 155 and the booster 3000.
• FIG 11 shows a booster, i.e. a 7000 expander pair, on the left, and 7200 compressor, on the right, with free piston.
• the regulator 7000 comprises a chamber 7500 provided with a high pressure gas inlet coming from the first conduit 3100 and a low pressure gas outlet in the second conduit 3200.
• an expansion piston 7400 is placed in movement by gas pressure and transmits this pressure, via a shaft 7600 to a compression piston 7700 which compresses the calorific fluid 125 in a second chamber 7800.
• the set of pistons 7400 and 7700 and the shaft 7600 constitutes a free piston.
• Valves 1500 and 1600 ensure the sealing and the direction of movement of the calorific fluid 125 from the third conduit 3300 for inlet of calorific fluid 125 at low pressure gas to the fourth conduit 3400 for outlet of calorific fluid 125 at high pressure gas. pressure.
• the gas inlet control system in chamber 7500 and gas outlet in chamber 7500 is not described here, being well known to those skilled in the art.
• a free piston is moved in a first chamber 7500 by the gas and compresses the calorific fluid 125 in a second chamber 7800.
• the drive of the compressor by a turbine is done with very limited mechanical losses.
• the pressure of the fluid at the outlet of the compressor can be higher than the pressure of the gas at the inlet of the expansion station, depending on the ratio of the surfaces of the pistons 7400 and 7700.
• the free piston is replaced by membranes , similar to membrane boosters known to those skilled in the art.
• the free piston 1100 of the suppressor has a through opening 2400.
• the arrows in broken lines represent the movements of gas.
• the free piston 1100 includes an expansion head 2000 and a compression head 2200 connected by a shaft.
• a through opening 2400 opens, on the one hand, into the expansion head 2000 on the side opposite the compression head 2200 and, on the other hand, into a side wall of the shaft.
• the first gas line 3100 opens into the part 2100 of the expansion chamber 1700 facing the shaft. Consequently, the mouth of the through opening 2400 is only in the part 2100 when the free volume of the compression chamber 2300 is maximum.
• the output of the expansion chamber 1700 to which the second pipe 3200 is connected is located on a side face of the expansion chamber 1700 and is obstructed by the expansion head 2000 only when the through opening 2400 does not open into the part 2100 of the expansion chamber 1700. More particularly, the outlet of the expansion chamber 1700 is obstructed by the expansion head 2000 except in the position of the free piston where the free volume of the compression chamber 2300 is minimal.
• the free volume of the compression chamber is intermediate between its extreme values.
• the pressure in the part 1700 of the expansion chamber opposite the compression chamber 2300 is at the value Pb of the downstream network 3200.
• the gas coming from the first pipe 3100 enters the intermediate part 2100 of the expansion chamber, at a pressure Pa.
• the pressure ratio Pa/Pb is greater than the ratio of the surfaces of the trigger head 2000 in the part 1700 and in the part 2100.
• the free piston 1100 therefore moves to the left, as illustrated in FIG. 13. This movement of the free piston 1100 causes the aspiration of gaseous calorific fluid 125 coming from the third conduit 3300 through the inlet valve 1500.
• the through opening 2400 opens into the part 2100 of the expansion chamber and the gas coming from the first line 3100 passes through the expansion head.
• the pressure in the part 1700 of the expansion chamber then reaches Pa, which causes the movement of the free piston 1100 towards the compression chamber 2300, as illustrated in FIG. 14.
• This movement obstructs the through opening 2400 and compresses the calorific fluid 125 gas present in the compression chamber 2300.
• the calorific fluid 125 compressed gas passes through the outlet valve 1600 then the fourth pipe 3400.
• the part 1700 of the expansion chamber is pneumatically connected to the second pipe 3200, as illustrated in FIG. 15.
• this free-piston booster 1100 operates without an external moving part and as long as there is a sufficient pressure difference between the first line and the second line.
• FIG. 16 a schematic view of an eighth embodiment of the device 4000 which is the subject of the invention, in which the thermodynamic system 4020 of the device 4000 has a 3000 free-piston suppressor 1100.
• the 3000 free-piston booster 1100 has a 2300 compression chamber similar to the main compressor 160.
• a gaseous calorific fluid 125 to be compressed downstream of the evaporator is injected into the booster 3000.
• the injection of the calorific gas 125 to be compressed is carried out by the use of an inlet 1500.
• the inlet 1500 of the calorific gas 125 to be compressed is provided with a valve.
• the calorific gas 125 to be compressed is injected into the compression chamber 2300 via the inlet 1500.
• the calorific gas 125 compressed in the compression chamber 2300 is injected into a network 3400 of calorific gas 125 compressed.
• the network 3400 of compressed calorific gas 125 is arranged upstream of the main heat exchanger 130.
• the compressed calorific gas 125 circulating in the network 3400 has characteristics similar to the calorific gas 125 previously described.
• the injection of the 125 compressed calorific gas into the 3400 network is carried out by the use of an outlet 1600 of compressed 125 calorific gas.
• the compressed calorific gas 125 is evacuated from the compression chamber 2300 to the network 3400 of compressed calorific gas 125 via an outlet 1600. It is noted, in FIG.
• the natural gas network 1200 is a network of heated natural gas downstream of the heat exchanger 130. It can be seen that the network of heated gas 1200 is a so-called "annex" gas network to the network of heated gas upstream of the turbine 105. This auxiliary network of gas natural gas 1200 is obtained, for example, by a flow separator (not shown) arranged downstream of the heat exchanger 130. The heated natural gas from the network 1200 undergoes additional expansion by being injected into the additional expansion chamber 1700 of the booster 3000 by an 1800 entry.
• the natural gas network 1300 is a natural gas network having undergone an additional expansion in the additional expansion chamber 1700 of the booster 3000.
• the expanded natural gas is injected into the network 1300 through an outlet 1900 of the expansion chamber 1700.
• the annex expansion energy of the natural gas is transferred in full to the piston carrying out the compression of the calorific gas 125 in the compression chamber 2300 thus allowing an optimal and efficient transfer of energy.
• the expanded natural gas circulating in the network 1300 is injected into the second network 115.
• the second network 115 is a natural gas distribution network.
• the expanded natural gas flowing in the network 1300 undergoes other thermodynamic transformations before injection into the second network 115.
• the expanded natural gas flowing in the network 1300 is not injected into the second network 115.
• the device 4000 comprises a main regulator 105 between a first gas network 110 at a first pressure and a second gas network 115 at a second press lower than first press.
• the main regulator 105 is a turbine coupled to a generator 101 producing electrical energy.
• FIG. 17 A diagrammatic view of a ninth embodiment of the device 5000 object of the invention is observed in FIG. 17, in which the thermodynamic system 5020 comprises a suppressor 3000 with free piston 1100.
• the booster 3000 with free piston 1100 has :
• an expansion chamber 1700 similar to the main regulator 105 and being a turbine coupled to a generator 101 producing electrical energy.
• a network 3300 of calorific gas 125 to be compressed downstream of the evaporator 155 is injected into the booster 3000.
• the injection of the calorific gas 125 to be compressed into the booster 3000 is carried out by the use an inlet 1500.
• the inlet 1500 of the calorific gas 125 to be compressed is provided with a valve.
• the calorific gas 125 to be compressed circulating in the network 3300 is injected into the compression chamber 2300 via the inlet 1500.
• the calorific gas 125 compressed in the compression chamber 2300 is injected into a network 3400 of compressed calorific gas 125.
• the network 3400 of compressed calorific gas 125 is arranged upstream of the heat exchanger 130. It is also noted that the calorific gas 125 circulating in the network 3400 has characteristics similar to the calorific gas 125 previously described.
• the injection of the compressed calorific gas 125 into the network 3400 is carried out by the use of an outlet 1600 of compressed calorific gas. In other words, the compressed calorific gas 125 is evacuated from the compression chamber 2300 to the network 3400 of compressed calorific gas 125 via an outlet 1600.
• the natural gas network 1200 is a heated natural gas network downstream of the heat exchanger 130.
• the heated natural gas from the network 1200 undergoes a main expansion in the expansion chamber 1700 of the booster 3000
• the heated natural gas circulating in the network 1200 is injected into the expansion chamber 1700 through an inlet 1800.
• the natural gas network 1300 is similar to a second natural gas network 115.
• the second network 115 is a natural gas distribution network.
• the expanded natural gas is injected into the network 1300 through an outlet 1900 of the expansion chamber 1700.
• the expansion chamber 1700 is a turbine coupled to a generator 101 producing electrical energy.
• part of the expansion energy of the natural gas generated in the expansion chamber 1700 is converted into electrical energy through the use of a generator 101.
• the use of the booster 3000 in the device 5000 allows to carry out a compression of the calorific gas 125 and to generate electrical energy.
• main compressor 160 can also be transposed to the secondary compressor 661 of the device 600 and to the auxiliary compressor 361 of the device 300.

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• 2022
  • 2022-01-14 FR FR2200300A patent/FR3131952B1/fr active Active
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