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
  • F25B39/00—Evaporators; Condensers
  • F25B39/02—Evaporators
• • 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
  • F25B43/00—Arrangements for separating or purifying gases or liquids; Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat
  • F25B43/003—Filters
• • 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
  • F25B2339/00—Details of evaporators; Details of condensers
  • F25B2339/02—Details of evaporators
  • F25B2339/024—Evaporators with refrigerant in a vessel in which is situated a heat exchanger
  • F25B2339/0241—Evaporators with refrigerant in a vessel in which is situated a heat exchanger having plate-like elements
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
  • F28D21/00—Heat-exchange apparatus not covered by any of the groups F28D1/00 - F28D20/00
  • F28D21/0017—Flooded core heat exchangers

Definitions

• TITLE Evaporator for refrigeration installation delimiting two evaporation enclosures respectively at high pressure and low pressure and separated by a filtration screen
• the present invention relates firstly to an evaporator for a refrigeration installation where the refrigeration installation comprises a circuit in which a working fluid circulates, the evaporator comprising a main enclosure containing a working fluid where a gaseous phase and a liquid phase of said fluid coexist, said main enclosure comprising a supply inlet intended to be connected to the circuit to supply the main enclosure with working fluid in the liquid state and an extraction outlet intended to extract from the main enclosure the working fluid in the gaseous state to the circuit, the evaporator comprising a heat exchange device capable of heating the working fluid contained in the main enclosure.
• the invention also relates to a refrigeration installation comprising such an evaporator.
• the invention finds an application in particular in refrigeration installations intended for the production of artificial snow, in refrigeration installations intended for the production of ice, for example for the food industry, or even in refrigeration installations intended to be integrated into a air conditioning and cold production system, for example for cooling data management computer centres.
• a refrigeration installation comprises a circuit in which a working fluid circulates and the following elements staggered along the circuit and through which the working fluid circulates successively: an evaporator for heat exchange with a cold source, the fluid of work undergoing a loss of calories due to evaporation, a compression machine and a condenser with possibly an exchanger for heat exchange with a hot source.
• Such a refrigeration installation corresponds, for example, to the teachings of document WO2019/020940A1 in the name of the Applicant.
• the volume ratio between gas and liquid can be greater than 200,000 and evaporation in the evaporator can be very explosive, with a very high risk of seeing droplets being carried towards the compression machine. This may cause malfunctions or maintenance problems of the compression machine and this is not satisfactory.
• the purpose of the present invention is to propose an evaporator and a refrigeration installation which respond to the problems presented above in connection with the state of the art.
• the object of the invention is to propose a solution which meets at least one of the following objectives: to be economical and efficient, to limit internal pressure drops, to avoid any risk of damage to the compression machine due to of the evaporator, be operational and efficient in the case where the working fluid is essentially water-based.
• an evaporator for a refrigeration installation where the refrigeration installation comprises a circuit in which a working fluid circulates, the evaporator comprising a main enclosure containing a working fluid where a gaseous phase and a liquid phase of said working fluid coexist, said main enclosure comprising a supply inlet intended to be connected to the circuit to supply the main enclosure with working fluid in the liquid state and an extraction outlet intended to extract from the main enclosure of the working fluid in the gaseous state towards the circuit, the evaporator comprising a heat exchange device capable of heating the working fluid contained in the main enclosure, noteworthy in that the evaporator comprises: a high pressure enclosure delimited within the main enclosure, at the level of which the supply inlet is arranged so that the high-pressure enclosure is supplied with working fluid in the liquid state by the circuit, the high-pressure enclosure containing working fluid in the gaseous phase at a first value of pressure and working fluid in the liquid phase, the high-pressure enclosure delimiting at least one tank containing the working fluid in the liquid phase present in the
• the communication duct is an overflow-type overflow system arranged at the level of said at least one tank of the high-pressure enclosure.
• the overflow system is configured to act as a siphon between the working fluid in the liquid phase of at least one tank of the high pressure vessel and the working fluid in the liquid phase of at least a tank of the low pressure enclosure.
• the ratio between the evaporation surface of the working fluid in the liquid phase contained in the low pressure enclosure and the evaporation surface of the working fluid in the liquid phase contained in the high pressure enclosure is greater than 2 and preferably greater than or equal to 5.
• the communication of working fluid in the gaseous phase from the low pressure enclosure to the circuit is free, devoid of filtration.
• the ratio between the mass flow rate of working fluid evaporated in the high pressure enclosure and the mass flow rate of working fluid evaporated in the low pressure enclosure is between 5 and 10.
• the ratio between the mass flow rate of working fluid in the gas phase circulating through the filtration screen and the mass flow rate of working fluid in the gas phase circulating in the communication conduit is greater than 100.
• the high-pressure enclosure comprises at least two stacked tanks that are successively supplied with working fluid in the liquid phase by gravity flow through a pouring device fitted to at least one tank of the high-pressure enclosure.
• the low-pressure enclosure comprises at least two superposed tanks which are fed successively with working fluid in the liquid phase by gravity flow through a pouring device fitted to at least one tank of the low-pressure enclosure.
• the filtration screen is a wall, having through pores adapted to allow the working fluid to pass into the gaseous phase on either side of this wall, and presenting undulations along the height of the wall.
• the invention also relates to a refrigeration installation comprising a circuit in which a working fluid circulates, the refrigeration installation comprising the following elements staggered along said circuit and through which the working fluid circulates successively: an evaporator as mentioned above in which the working fluid in the liquid phase undergoes a loss of calories due to the evaporation occurring in the high pressure enclosure and in the low pressure enclosure, a compression machine, a condenser.
• the working fluid mainly contains water.
• the working fluid may be of another nature, such as for example methyl ethylene glycol.
• the mass flow rate of the gaseous phase of the working fluid circulating in the circuit is between 15 g/s and 15 kg/s.
• the low pressure enclosure of the evaporator includes an evacuation outlet for extracting out of the main enclosure the working fluid in the liquid phase from the at least one tank of the low pressure enclosure.
• the high-pressure enclosure of the evaporator comprises an inlet pipe making it possible to supply at least one tank of the high-pressure enclosure with working fluid in the liquid phase previously extracted from the low-pressure enclosure via the outlet evacuation.
• the refrigeration installation comprises a second circuit in which circulates an operational fluid separate from the working fluid and a heat exchanger between the operational fluid circulating in the second circuit and working fluid in the liquid phase present in, or resulting from, the main enclosure of the evaporator.
• it may be a refrigeration installation of the air conditioning system type, comprising an evaporator previously described and in which the working fluid which circulates in the evaporator being maintained at a pressure of between 5 and 100 mbar performs a decontamination against predetermined bacteria, in particular Legionella.
• FIG. 1 is a schematic sectional view of an example of a refrigeration installation comprising a first example of an evaporator according to the invention.
• FIG. 2 is a schematic sectional view of an example of a refrigeration installation comprising a second example of an evaporator according to the invention.
• the invention relates first to an evaporator 10 for a refrigeration installation 100 where the refrigeration installation 100 comprises a circuit 50 in which a working fluid circulates, the evaporator 10 comprising a main enclosure 11 containing a working fluid where a gaseous phase and a liquid phase of the working fluid coexist.
• the main enclosure 11 comprises a supply inlet 12 intended to be connected to the circuit 50 to supply the main enclosure 11 with working fluid in the liquid state and an extraction outlet 13 intended to extract from the enclosure main 11 of the working fluid in the gaseous state to the circuit 50, in order to supply the compression machine 60.
• the evaporator 10 also includes a heat exchange device 70 capable of heating the working fluid contained in the main enclosure 11.
• the refrigeration installation 100 with which the evaporator 10 described in this document is associated is a refrigeration installation corresponding to the teachings of document WO2019/020940A1 in the name of the Applicant.
• the invention finds an application in particular in refrigeration installations intended for the production of artificial snow, in refrigeration installations intended for the production of ice, for example for the food industry, or even in refrigeration installations intended to be integrated into a air conditioning system, for example for cooling data management computer centres.
• the evaporator 10 comprises a high-pressure enclosure 14 delimited within the main enclosure 11, at the level of which the supply inlet 12 is arranged so that the high-pressure enclosure 14 is supplied with working fluid in the liquid state by the circuit 50.
• the high pressure enclosure 14 contains working fluid in the gaseous phase 15 at a first pressure value and working fluid in the liquid phase 16.
• this first pressure value is between 6 and 7 mbar, typically 6.5 mbar, which advantageously makes it possible to provide strong boiling of the liquid (which mixes it and helps heat transfer) but the projections remain contained by the filtration screen 24 detailed below.
• One of the goals is to be close to the low pressure enclosure 17 so as not to be boiling in the low pressure enclosure 17.
• the high pressure enclosure 14 delimits at least one tank 20 containing the working fluid in the liquid phase 16 present in the high pressure enclosure 14.
• the at least one tank 20 of the high pressure enclosure provides a surface evaporation 21 of the working fluid in the liquid phase 16 contained in the high pressure enclosure 14, this evaporation taking place at a first evaporation pressure value.
• the working fluid thus evaporated mixes with the rest of the working fluid in the gaseous phase 15.
• the evaporation surface 21 corresponds at the interface between the working fluid in the liquid phase 16 and the working fluid in the gaseous phase 15.
• this first evaporation pressure value is between 6 and 7 mbar, typically of the order of 6 .5 mbar.
• the evaporator 10 also comprises a low-pressure enclosure 17 delimited within the main enclosure 11, containing working fluid in the gaseous phase 18 at a second pressure value strictly lower than the first pressure value and working in the liquid phase 19.
• this second pressure value is of the order of 6.11 mbar, in order to avoid boiling and therefore avoid having any projection.
• the extraction outlet 13 is arranged at the level of the low-pressure enclosure 17 so that the working fluid in the gaseous phase 18 contained in the low-pressure enclosure 17 is extracted in the direction of the circuit 50 until it is supplied the compression machine 60.
• the compression machine 60 makes it possible on the one hand to transfer the material with a certain volume flow, on the other hand to maintain a pressure ratio between the delivery pressure and the suction pressure.
• the nature of the compression machine 60 is not limiting, comprising one or more compression stages and possibly a compression ratio greater than, equal to, or greater than 10.
• the low-pressure enclosure 17 delimits at least one tank 22 containing the working fluid in the liquid phase 19 present in the low-pressure enclosure 17.
• the at least one tank 22 of the low-pressure enclosure 17 confers a evaporation surface 23 of the working fluid in the liquid phase 19 contained in the low pressure enclosure 17, this evaporation taking place at a second evaporation pressure value strictly different from the first evaporation pressure value.
• the working fluid thus evaporated mixes with the rest of the working fluid in the gas phase 18.
• the evaporation surface 23 corresponds to the interface between the working fluid in the liquid phase 19 and the working fluid in the gas phase 18.
• this second evaporation pressure value is of the order of 6.11 mbar.
• the evaporator 10 also includes a filtration screen 24 interposed between the high pressure enclosure 14 and the low pressure enclosure 17.
• the filtration screen 24 is configured so as to allow the working fluid to pass into the gaseous phase. 15 from the high pressure enclosure 14 to the low pressure enclosure 17 so that it mixes with the working fluid in the gaseous phase 18, and to block the passage of the working fluid into the liquid phase 16 of the high pressure enclosure 14 to the low pressure enclosure 17.
• the filtration screen 24 acts to prevent splashes of working fluid in the liquid phase 16 from reaching the compression machine 60 and ensures that the liquid thus blocked falls back by gravity into the tank 20 from which it was projected during the evaporation.
• the skilled person is able, according to his general knowledge, to design a filtration screen 24 that meets these functions, the structure of the filtration screen 24 not being limiting in itself.
• the evaporator 10 comprises a communication conduit 25 connecting the high pressure enclosure 14 to the low pressure enclosure 17.
• the communication conduit 25 is configured so as to essentially allow the working fluid to pass into the liquid phase 16 of the high pressure enclosure 14 to the low pressure enclosure 17 and to oppose free passage of the working fluid in the gaseous phase 15 from the high pressure enclosure 14 to the low pressure enclosure 17 and to oppose a free passage of the working fluid in the gaseous phase 18 from the low pressure enclosure 17 to the high pressure enclosure 14.
• a person skilled in the art is able, based on his general knowledge, to design a communication conduit 25 that meets these functions, the structure of the communication conduit 25 not being limiting in itself.
• the ratio between the mass flow rate of working fluid in the gas phase flowing through the filtration screen 24 and the mass flow rate of working fluid in the gas phase flowing in the communication conduit 25 is greater than 100, or even preferably greater than 1000, or even more preferably greater than 10,000.
• the mass flow rate of working fluid in the gaseous phase which would possibly circulate through the communication conduit 25 is in fact considered as an unsought leak, even harmful. It is therefore sought a mass flow rate of working fluid in the gaseous phase which would possibly circulate through the communication conduit 25 as close to 0 as possible.
• the communication conduit 25 is an overflow-type overflow system arranged at the level of at least one tank 20 of the high-pressure enclosure 14, suitable for pour the excess working fluid into the liquid phase 16 contained in this at least one tank 20 into the at least one tank 22 arranged in the low-pressure enclosure 17.
• this overflow system is configured to act like a siphon between the working fluid in the liquid phase 16 of at least one tank 20 of the enclosure at high pressure 14 and the working fluid in the liquid phase 19 of at least one tank 22 of the low pressure enclosure.
• This can be obtained by arranging a simple tube, an upper end of which opens into this tray 20 and a lower end of which is arranged in the volume of this tray 22.
• the positioning of the upper end of the tube fixes the height of the working fluid in the liquid phase 16 in the tank 20 concerned and the lower end fixes the height of the working fluid is embedded in the working fluid in the liquid phase 19 contained in the tank 22 concerned.
• the working fluid communication in the gas phase 18 of the low pressure enclosure 17 to the circuit 50 is free and devoid of filtration. This makes it possible to reduce internal pressure drops as much as possible, thereby improving operating efficiency. It is possible to afford this type of arrangement due to the very organization of the evaporator 10 with the filtration screen
• the ratio between the mass flow rate of working fluid evaporated in the high-pressure enclosure 14 at the level of the evaporation surface 21 and the mass flow rate of working fluid evaporated in the enclosure at low pressure 17 at the level of the evaporation surface 23 is between 5 and 10.
• the choice and adaptation of this ratio results from a compromise between the dimensions of the enclosure, the size of the filtration screen 24 and risks of boiling in the low pressure enclosure 17.
• the high pressure enclosure 14 comprises at least two tanks 20 (for example three in number as shown) superposed and successively fed in cascade with working fluid in the liquid phase 16 by gravity flow through a pouring device 26 fitted to each tank 20 of the high pressure enclosure 14 except the furthest downstream. Boiling is then only possible on the top (a few centimeters) of the liquid because below, the hydrostatic pressure prevents boiling. Boiling acts as an agitator in heat transfer.
• the low-pressure enclosure 17 comprises a single tank 22 arranged in its lower part at the manner of a simple gravity receptacle for liquid
• the low pressure enclosure 17 can comprise at least two tanks 20 (for example three in number as shown) superimposed and feeding successively in cascade with working fluid in the liquid phase 19 by gravity flow through a pouring device 27 fitted to each tank 22 of the low-pressure enclosure 17 except the furthest downstream.
• the exchange surface is then increased for the same diameter of the tank (this in relation to the ratio between the evaporation surface 23 of the working fluid in the liquid phase 19 contained in the low pressure enclosure 17 and the surface evaporation 21 of the working fluid in the liquid phase 16 contained in the high pressure enclosure 14).
• the high pressure enclosure 14 may optionally include a single tank 20 while the low pressure enclosure 17 would include several tanks 22 organized as described above.
• the low pressure enclosure 17 may optionally include a single tank 22 while the high pressure enclosure 14 would include several tanks 20 organized as described above.
• the filtration screen 24 is a wall, having through pores (not shown in detail) adapted to allow the working fluid to pass into the gaseous phase 15, 18 on either side of this wall, and having undulations 28 along the height of the wall.
• the wall can be vertical, horizontal, or oblique. According to one possible embodiment, it is possible to integrate metal or plastic straw to agglomerate the drops and then baffles to stop them.
• the invention also relates to a refrigeration installation 100 comprising a circuit 50 in which the working fluid circulates, the refrigeration installation 100 comprising the following elements staggered along the circuit 50 and through which the working fluid circulates successively: an evaporator 10 as previously described in which the working fluid in the liquid phase undergoes a loss of calories due to the evaporation occurring in the high pressure enclosure 14 and in the low pressure enclosure 17, a compression machine 60 , a condenser 80 where the working fluid undergoes liquefaction, the condensates 90 being sent, via the circuit 50, to the supply input 12.
• the working fluid contains at least one aqueous fluid, essentially water, optionally with some additives such as glycol.
• the mass flow rate of the gaseous phase of the working fluid circulating in the circuit 50 is between 15 g/s and 15 kg/s.
• the low-pressure enclosure 17 of the evaporator 10 comprises an evacuation outlet 29 making it possible to extract from the main enclosure 11 working fluid in the liquid phase. 19 from at least one tray 22 of the low-pressure enclosure 14.
• the liquid working fluid previously extracted at the discharge outlet 29 is reinjected into the high pressure enclosure 14.
• the high pressure enclosure 14 of the evaporator 10 comprises an inlet pipe 30 for supplying at least one tank 20 of the high-pressure enclosure 14 with working fluid in the liquid phase 16 previously extracted from the low-pressure enclosure 17 via the evacuation outlet 29 .
• the working fluid is the fluid intended to be used by the customer
• the liquid working fluid previously extracted at the evacuation outlet 29 is directly exploited by the customer, the latter using the advantage of the fact that it has been previously cooled in the evaporator 10.
• the cooling of the working fluid which circulates in the evaporator 10 while being maintained at a pressure level of between 5 and 100 mbar ensures a decontamination function against predetermined bacteria, in particular Legionella. It is the very low pressure (between 5 and 100 mbar) in the evaporator 10 which ensures the destruction of the bacteria. Indeed, a pressure level contained in this range typically corresponds to a temperature between 25° C. and 45° C., this temperature range being favored for the development of the Legionella bacterium.
• the refrigeration installation 100 comprises a second circuit (not shown) in which circulates an operational fluid distinct from the working fluid and a heat exchanger (not shown) between the operational fluid circulating in the second circuit and fluid working in the liquid phase present in, or coming from, the main enclosure 11 of the evaporator 10.
• a heat exchanger can therefore be arranged inside or outside the main enclosure 11 of the evaporator 10.
• the invention which has just been described has the advantage of being economical and efficient, of limiting the pressure drops internal to the evaporator 10 and to the refrigeration installation 100, of avoiding any risk of damage to the compression machine 60 due to the evaporator 10, and to be operational and efficient in the event that the working fluid is essentially water-based.

Landscapes

• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• Thermal Sciences (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• Power Engineering (AREA)
• Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)
• Sorption Type Refrigeration Machines (AREA)
• Filling Or Discharging Of Gas Storage Vessels (AREA)
• Separation By Low-Temperature Treatments (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=74347356

Family Applications (1)

Country Status (8)

Family Cites Families (7)

• 2020
  • 2020-12-04 FR FR2012719A patent/FR3117199B1/fr active Active
• 2021
  • 2021-12-01 US US18/255,980 patent/US20240027111A1/en not_active Abandoned
  • 2021-12-01 CN CN202180093045.6A patent/CN116829887A/zh active Pending
  • 2021-12-01 JP JP2023533598A patent/JP2023551718A/ja active Pending
  • 2021-12-01 WO PCT/FR2021/052172 patent/WO2022117956A1/fr not_active Ceased
  • 2021-12-01 AU AU2021393068A patent/AU2021393068A1/en not_active Abandoned
  • 2021-12-01 EP EP21845085.6A patent/EP4256252A1/de not_active Withdrawn
  • 2021-12-01 CA CA3200912A patent/CA3200912A1/fr active Pending

Also Published As

Similar Documents

Legal Events