RU2638579C2 - Recovery of heat from high-pressure flow - Google Patents

Abstract

FIELD: machine engineering.

SUBSTANCE: method includes the use of hot separator to create high pressure vapour flow; generating of medium pressure water vapour flow and low pressure water vapour flow from said high pressure vapour flow as a result of heat extraction from said high pressure vapour flow; directing said flow of medium pressure water vapour into steaming plant, where said flow of medium pressure vapour is used as water vapour for steaming; and directing said low pressure vapour flow to at least one plant which is selected from the product fractionation unit and remote plant for diesel fuel stripping, where said low pressure vapour flow is used as water steam for steaming.

EFFECT: method makes it possible to recover heat more efficiently and minimize the use of supply utilities.

10 cl, 1 dwg

Description

This application claims priority to US Application No. 14 / 026,470, which was filed September 13, 2013, the entire contents of which are hereby incorporated by reference in their entirety.

FIELD OF THE INVENTION

The present invention generally relates to hydroprocessing units, and, more specifically, to a method for recovering heat from a high pressure stream. In one embodiment, the high-pressure heat generating stream is a vapor stream from a hot separator that is used to generate both medium-pressure water vapor and low-pressure water vapor, each of which can be used in further processing such as when used as steam for steaming in components such as a steaming unit, a product fractionation unit and / or a remote steaming unit for diesel opliva.

State of the art

Energy optimization for hydroprocessing units, such as hydrocracking units, has become very important and there is a desire to minimize utilization of utilities and maximize heat recovery. As the authors of the present invention have realized, one way to achieve this is realized by generating water vapor using hot separator vapors. However, as the authors of the present invention have also realized, since the hot side is the effluent of the reactor, which has a very high pressure, safety is a big problem. Thus, the production of water vapor becomes important with the necessary inherent safety. The achievement of this requirement allows you to achieve the scheme developed by the authors of the present invention, one example of which is described below.

Disclosure of invention

In short, in certain embodiments, the present invention is a method for recovering heat from a high pressure stream during a hydroprocessing, where one embodiment of the method comprises sequentially introducing a high pressure stream from a hot separator into a first steam generator and a second steam generator; using the first steam generator to generate a medium-pressure water vapor stream, and then using a medium-pressure water vapor stream as steam for steaming. The method also includes using a second steam generator to generate a low pressure water vapor stream, and then using a low pressure water vapor stream as steam for steaming.

In addition, in certain embodiments, the present method of recovering heat from a high pressure stream during hydroprocessing includes the steps of using a hot separator to create a high pressure vapor stream, and then removing heat from the high pressure vapor stream to generate both medium pressure water vapor and low pressure water vapor. In certain embodiments, the medium pressure steam is sent to a steaming unit, where the medium pressure steam is used as steam for steaming, and the low pressure steam is sent to at least one unit selected from a product fractionation unit and a remote steam setting for diesel fuels where water vapor of low pressure is used as steam for steaming.

In conclusion, certain embodiments of the present method of recovering heat from high pressure water vapor during hydroprocessing include the direction of the high pressure stream to the first process vessel and the direction of the first feed water stream to the first process vessel. The method is continued as a result of heat extraction from the high pressure stream in the first process vessel to create a medium pressure water vapor stream from the first feed water stream. The method also includes the direction of the high pressure stream from the first process vessel to the second process vessel and the direction of the second feed water stream to the second vessel. In conclusion, the method includes taking heat from a high pressure stream in a second process vessel to create a low pressure water vapor stream from a second feed water stream.

Brief Description of the Drawing

One preferred embodiment of the present invention is described herein when referring to the drawing, where:

Figure 1 is one example of an embodiment of the present method for recovering heat from a high pressure stream in a hydrocracking unit.

The implementation of the invention

In short, in certain embodiments of the present method that can be used in a hydroprocessing unit (such as a hydrocracking unit), two different levels of water vapor pressure are generated using hot separator vapors, where one of the water vapor streams is intended to be used as water vapor for steaming in a steaming unit (medium pressure steam) MLP, and the other of the steam flows is intended to be used as steam for steam ripping in a product fractionation unit and a remote steaming unit for diesel fuel (low pressure water vapor). Each steam generator will produce exactly the amount that is necessary for steaming at the required level. To feed the demand for medium pressure steam, they will use additional high pressure steam from the manifold, and to feed the demand for low pressure steam will use additional medium pressure steam from the manifold, when necessary, for example, during start-up and in other cases when the production of water vapor is insufficient for technological needs. In the case of the resulting generation of water vapor, greater than required, the pressure regulator will close the flow of make-up water vapor from the collector.

However, this closure causes an increase in pressure in the steam generator (s), which increases the temperature of the generated water vapor. The result is to reduce the temperature difference between the hot side fluid and the water from which water vapor is generated, and less water vapor will be generated. This will tend to self-regulate the production of water vapor. Typically, steam generators operate at a pressure lower than in the corresponding manifold, which delivers water vapor during startup. In order to prevent contamination of the corresponding supply manifold in case of increase in water vapor pressure above a certain level, the high pressure switch will close the isolation valve, preventing the water vapor from flowing back into the collector. This type of valve closure will prevent contamination of the steam manifold if the pipe ruptures or leaks from the high pressure side. Such leakage or destruction of the pipe could otherwise cause hydrogen sulfide and other non-condensable components to enter the steam manifold, thereby polluting it.

In the event of a pipe rupture, the pressure in the steam drum will increase and a high pressure switch will be activated, which will then close the shut-off valves in the boiler feed water (BFW) line and the purge line, thereby ensuring that fluid is captured from the destroyed pipe in the generator itself and minimizing pollution of the boiler feedwater collector. The response pressure at which the relay becomes activated is the shutdown pressure of the BFW pump. In certain embodiments, the design pressure of the steam generator is preferably set to 10/13 of the design pressure (high pressure) of the pipe space. After the steam generator is cut off from the BFW line, the water vapor outlet line, the make-up line, and the purge line, the steam generator is isolated and the pressure relief valve (PSV) on the generator opens when the set pressure for the PSV valve is reached. The line from the PSV valve is sent to the discharge manifold, and not to the atmosphere, since hydrocarbon and hydrogen sulfide will be present in the discharged vapors if the pipe is broken. Since the PSV valve line is routed to the discharge manifold, there is the possibility of water vapor leaking into the flare manifold during normal operation, and thus, a burst disk is also provided to prevent upstream leakage in relation to the PSV valve. Otherwise, if water vapor leaks during lower temperatures, the result may be clogging of the discharge manifold due to the formation of ice deposits.

In one example of one embodiment, as shown in FIG. 1, the present method is illustrated as being included in a hydrocracking unit. Since hydrocracking units are known to those skilled in the art, only those process streams and components that are relevant to the present method are demonstrated and described, since it should be clear to those skilled in the art how the present method can be incorporated into a hydrocracking unit. It should also be noted that the present method is not limited to hydrocracking units, but can instead be provided in other types of hydro-processing units as well as in processing units of other types in which heat recovery from a high pressure stream is desired.

As can be said when referring again to Figure 1, this figure shows one embodiment in which a high-pressure vapor stream 10 is supplied from a hot separator 12 to a first process vessel used as a first steam generator, such as a first refrigerator 22. Also provided other embodiments, such as embodiments comprising shell-and-tube heat exchangers arranged in parallel, which heat exchange with boiler feed water flowing as a result those natural circulation from vessel mounted above the tube bundle heat exchangers. This tank serves as a separation space for separating the generated water vapor from the circulating boiler feed water. In this way, many engineering systems that produce water vapor at the same pressure share a common separation tank.

In one example embodiment of Figure 1 the pressure of stream 10 could be in the range of 500 lb / ⁱⁿ² (g.) (34.5 bar (g.)) To 2800 lb / ⁱⁿ² (g.) (154 bar (g .)), and the temperature could range from 400 ° F (200 ° C) to 700 ° F (370 ° C). It goes without saying that in other configurations the flow will have different pressures and temperatures.

Before reaching the first cooler 22, stream 10 may be passed through other components, for example, through one or a series of heat exchangers, in order to remove some heat for use in other parts of the process. In this example, stream 10 first passes through a heat exchanger 14 (such as a shell-and-tube heat exchanger) that heats one of the process streams, such as a fresh feed stream; then it passes through another heat exchanger (such as another shell-and-tube heat exchanger) 16, which heats another process stream, such as recycle gas; and finally, it passes through a heat exchanger 20, which heats another process stream, such as a feed stream to the fractionation section. It goes without saying that depending on various parameters in temperature and pressure and other components of the processing plant, other configurations are also provided.

After flow 10 passes through heat exchangers 14, 16 and 20, the resulting stream 29 is sent to the first refrigerator 22, as mentioned above, where it is used to provide heat in order to generate water vapor from the boiler feed water, which enters the refrigerator 22 through the boiler line 25 feed water (BFW). The liquid level in the first refrigerator 22 is monitored using a liquid level sensor (LIC) 17, which is coupled to a flow indicator controller 19 and a valve 21, for regulating and controlling the amount of boiler feed water directed to the refrigerator 22 through the boiler feed water line (BFW) 25 .

Boiler feed water is converted to water vapor in the first refrigerator 22 as a result of heat extraction from stream 29, which results in a resulting stream 24 of saturated water vapor. The resulting stream 24 could, for example, have a pressure in the range of 100 to 400 lb / ⁱⁿ² (g.) (7 to 28 bar (g.)) In other embodiments. After leaving the first refrigerator 22 as the resultant stream 24, this stream is fed to the superheater 26. As water vapor passes through the superheater 26, saturated water vapor overheats and exits as a stream 27, which, ultimately, can be fed to a steaming unit (not shown) through line 31 after passing through the flow control valve 30. The valve 30 is controlled by using a paired flow indicator controller, which controls and monitors the flow rate to the stripper of the stripping unit.

However, before passing through line 31 for use as steam for steaming in a steaming unit, superheated steam is mixed with high-pressure steam stream 33 from the manifold. In order to achieve the desired pressure for the steam setting (which in this case corresponds to medium-pressure water vapor), in this embodiment, a control valve 35 coupled to a pressure indicator controller (PIC) 37 and an additional control valve 39 coupled to the additional controller 41 are used Pic. In particular, the PIC controller 37 monitors the pressure of stream 27 at a point after this stream passes through superheater 26, but before combining with another stream, and if necessary, increase (or decrease) the pressure of stream 27 in order to achieve the desired pressure for entering the stripping unit through line 31 of the PIC controller 37 opens (or partially or completely closes) the valve 35 so that a larger (or smaller) amount of high pressure stream 33 is mixed with stream 27.

In this embodiment, the medium-pressure flow line 31 could be of any preselected pressure value in the range of 100 lb / ⁱⁿ² (g.) (7 bar (g.)) To 400 lb / ⁱⁿ² (g.) (28 bar (hut)).

In the case of determining controller 41 PIC that the pressure in the line 43 is greater than a predetermined value, such as, e.g., a predetermined value in the range of 140 lb / ⁱⁿ² (g.) (10 bar (g.)) To 300 lb / ⁱⁿ² (g.) (21 bar (g.)), high pressure switch 39 closes the isolation valve to prevent the flow of water vapor in the high pressure manifold. This configuration prevents contamination of the steam manifold in the event of leakage or destruction of the pipe on the high pressure side, since without closing the isolation valve 39, hydrogen sulfide and other non-condensable components could enter the steam manifold during leakage or destruction of the pipe, thereby polluting the manifold.

With the first refrigerator 22 (the first steam generator), an alarm system for increasing pressure 100 is connected, which in this case is a pressure switch (extremely high level) or RAN. As is known in the art, such pressure alarm systems, as well as other regulators and controllers mentioned in this document, are usually paired with a computer processor. This first overpressure alarm system 100 includes a pressure indicator (PI) 102, which monitors the pressure of flow 24 at a position between the first refrigerator 22 and superheater 26, and also includes shut-off valves 104, 106, and 108. In the event of pipe failure in the first refrigerator 22, the pressure in the first refrigerator 22 will increase, and such an increase will be detected by the pressure indicator 102. Once the pressure reaches a predetermined level (such as, e.g., a predetermined value in the range of 140 lb / ⁱⁿ² (g.) (10 bar (g.)) To 300 lb / ⁱⁿ² (g.) (21 bar ( g.)), the regulator will activate the high-pressure switch, which closes the following shut-off valves: (a) shut-off valve 104 (coupled to stream 27), (b) shut-off valve 106 (coupled to purge line 23) and (c) shut-off valve valve 108 (interfaced with boiler feed water line 25). Thus, with these valve closures, fluid food from a broken pipe is safely captured in the very first steam generator.

In addition, when the shutoff valves 104, 106, and 108 are closed and the first steam generator (including the first cooler 22 in this embodiment) is isolated, the pressure relief valve 110 (PSV) is configured and configured to open when the pressure of the PSV valve is reached . The flow from the pressure relief valve 110 upon opening is directed through stream 112 to a discharge manifold (not shown), since in this embodiment, both hydrocarbon and hydrogen sulfide will be released during pipe failure. However, since in this embodiment, the stream 112 is directed to a discharge manifold (not shown), it is possible for water vapor to leak into the discharge manifold, and accordingly, this embodiment also preferably includes a burst disk 114 or other equivalent device connected in series with PSV valve 110 to prevent such a leakage of water vapor. In the event of such a leakage of water vapor during the action of lower temperatures, the result may be a clogging of the flare collector.

The design pressure of the steam generator, which is the same as the response pressure of the PSV valve for this first steam generator (including the first cooler 22), is preferably set to 10/13 of the design pressure of the pipe space in this embodiment.

The present embodiment of FIG. 1 also includes a second steam generator, such as a second refrigerator 32. The effluent 60 from the feather cooler 22 is used as a heat source to generate water vapor in the second refrigerator 32. It goes without saying that the temperature of the stream 60 leaving the first the refrigerator 22 will be lower than the temperature of the stream 29 entering the first refrigerator 22, since a certain amount of heat was taken to create a stream 24 of water vapor from the boiler feed water.

After flow 60 passes through the second cooler 32 and uses it to generate water vapor in the second cooler, the effluent 62 from the second cooler 32 can be passed through one or more heat exchangers or other components before directing the resulting flow 64 to the product condenser for further processing, where Recycling is known to those skilled in the art. In the embodiment of FIG. 1, stream 62 is first directed to a heat exchanger 66, which can be coupled to a recycle gas stream, and then to a heat exchanger 68, which receives a feed stream from a cold evaporator drum (not shown). It goes without saying that depending on various temperature and pressure parameters and other components of the processing plant, other configurations are also provided.

In conclusion, the line associated with the purge stream 23 from the first refrigerator 22 includes a valve 76 in addition to the valve 106 of the first pressurization alarm system 100 discussed above. This valve 106 is used to control the flow rate of purge stream 23, which is then referred to as stream 77 after passing through valve 106, and stream 77 is directed to a purge drum (not shown). In this example, the refinery purge network is designed for low pressure, so the purge drum will function as a reservoir with a PSV valve where pressure relief can be achieved.

The second steam generator (second cooler) 32 functions in a similar way with the first steam generator (first cooler) 22 and, therefore, will not be described in detail except for the discussion of any significant differences between the two steam generators (coolers). In addition, the components and flows associated with the second refrigerator 32, which correspond to what occurs for the first refrigerator 22, will be denoted by similar reference numbers except that the characteristics associated with the second refrigerator will include a single-bar symbol. (') or double stroke (' ').

One difference between the steam flows generated by using the second cooler 32 and the steam flows associated with the first cooler 22 is that instead of the resulting medium pressure stream 31 being passed to the steaming unit (as in the case of the first steam generator with the first refrigerator 22), the resulting stream from the second steam generator (with the second refrigerator 32) is sent in parallel along two streams, referred to as low pressure stream 31 'and low pressure stream 31''. In this embodiment, stream 31 ′ is directed to a product fractionation unit (not shown), and stream 31 ″ is directed to a steaming unit for diesel fuel (not shown). Water vapor streams 31 'and 31''are used as steam for steaming, respectively, in a product fractionation unit and a steaming unit for diesel fuel. In this embodiment, the flows 31 'and 31''are preferably configured to show a specific predetermined pressure which is in the range from 15 to 20 lb / ⁱⁿ² (1 to 1.4 bar), but depending on the intended use of streams other pressures are also provided.

One additional difference between the flows conjugated with the first and second steam generators relates to additional water vapor supplied to receive at the desired pressure for the medium pressure stream 31 (conjugated to the first steam generator including the first cooler 22) and low flows 31 'and 31' ' pressure (associated with a second steam generator, including a second refrigerator 32). In particular, with regard to medium pressure stream 31, this stream may be mixed with an appropriate amount of high pressure water vapor from the manifold through stream 33 to be supplied at a predetermined pressure through various valves and regulators, as discussed above. A similar control method is followed for low pressure streams 31 'and 31' 'except that instead of receiving additional high pressure steam from the manifold through stream 33, as necessary, low pressure streams 31' and 31 '' in this embodiment as necessary, medium pressure additional water vapor is taken from the collector.

Except for the differences noted above, the components associated with the second steam generator (including the second refrigerator 32), such as the second pressure alarm system 101 ', the second superheater 26', and the like, operate essentially in the same way as the corresponding components of the first a steam generator (including a first refrigerator 22). Accordingly, such components need not be discussed further.

Specific Embodiments

Despite the description of the following in connection with specific embodiments, it should be understood that this description is intended to illustrate and not limit the scope of the preceding description of the invention and the attached claims.

A first embodiment of the invention is a method for recovering heat from a high pressure stream during hydroprocessing, the method comprising sequentially introducing a high pressure stream from a hot separator into a first steam generator and a second steam generator; using the first steam generator to generate a medium pressure water vapor stream, and then using the medium pressure water vapor stream as steam for steaming; and using a second steam generator to generate a low pressure water vapor stream, and then using a low pressure water vapor stream as steam for steaming. One embodiment of the invention is one, any or all of the representatives selected from the preceding embodiments in this paragraph up to and including the first embodiment in this paragraph, further comprising a medium pressure steam flow direction to the steaming unit; and the direction of the flow of low-pressure water vapor in at least one installation selected from the installation of fractionation of the product and the remote installation of steaming for diesel fuel. One embodiment of the invention is one, any or all of the representatives selected from the preceding embodiments in this paragraph up to and including the first embodiment in this paragraph, where part of the low pressure water vapor stream is sent to the product fractionation unit and part of the water vapor stream low pressure is sent to a remote unit for steaming for diesel fuel.

A second embodiment of the invention is a method for recovering heat from a high pressure stream during hydroprocessing, the method comprising using a hot separator to create a high pressure vapor stream; production of both a medium pressure water vapor stream and a low pressure water vapor stream from a high pressure vapor stream as a result of heat extraction from a high pressure vapor stream; the direction of the medium-pressure steam flow to the steaming unit, where the medium-pressure steam flow is used as steam for steaming; and directing the low pressure water vapor stream to at least one unit selected from a product fractionation unit and a remote steaming unit for diesel fuel, where the low pressure water vapor stream is used as steam for steam. One embodiment of the invention is one, any or all of the representatives selected from the preceding embodiments in this paragraph up to and including the second embodiment in this paragraph, where part of the low pressure water vapor stream is sent to the product fractionation unit and part of the water vapor stream low pressure is sent to a remote unit for steaming for diesel fuel. One embodiment of the invention is one, any or all of the representatives selected from the preceding embodiments in this paragraph up to and including the second embodiment in this paragraph, further including the direction of flow of the high pressure vapor from the hot separator to the first steam generator and heat removal from the stream high pressure to obtain a medium-pressure steam flow; the direction of the high-pressure vapor flow, from which heat was taken in the first steam generator, to the second steam generator; and using a second steam generator to select additional heat from the high pressure stream, thereby obtaining a low pressure water vapor stream. One embodiment of the invention is one, any or all of the representatives selected from the preceding embodiments in this paragraph up to and including the second embodiment in this paragraph, further comprising providing at least one first heat exchanger between the hot separator and the first steam generator and heat removal from the high pressure stream using the specified at least one first heat exchanger; and providing at least one second heat exchanger after the second steam generator and extracting additional heat from the high pressure stream using said at least one second heat exchanger. One embodiment of the invention is one, any or all of the representatives selected from the previous embodiments in this paragraph up to and including the second embodiment in this paragraph, further comprising providing a medium pressure steam superheater in the gap between the first steam generator and the stripper and direction medium pressure steam flow from the first steam generator through a medium pressure steam superheater; and providing a low pressure water vapor superheater after the second steam generator and directing a low pressure water vapor stream from the second steam generator through the low pressure water vapor superheater. One embodiment of the invention is one, any or all of the representatives selected from the preceding embodiments in this paragraph up to and including the second embodiment in this paragraph, further comprising providing a pressure alarm system that is configured and configured to activate a valve coupled with the boiler feed water line, at a predefined high pressure value, where the specified boiler feed water line provides t supplying boiler feed water in the first steam generator and the second steam generator; and activating a valve coupled to the boiler feed water line, if the alarm system detects an increase in pressure, the pressure reaches a predetermined high pressure value to stop the flow of boiler feed water to both the first steam generator and the second steam generator. One embodiment of the invention is one, any or all of the representatives selected from the preceding embodiments in this paragraph up to and including the second embodiment in this paragraph, further comprising adjusting using a computer processor configured and configured to control at least one valve , the pressure stream of medium-pressure water vapor entering the steaming unit, to maintain it at the level of the first pre of a certain pressure of 130 lb / ⁱⁿ² (g.) (9 bar (g).); and regulation, using a computer processor configured and configured to control at least one valve, the pressure of the low-pressure water vapor stream entering at least one unit selected from a product fractionation unit and a steaming unit for diesel fuel to maintain it at a level the second predetermined pressure in the range of 15 lb / ⁱⁿ² (g.) (1 bar (g.)) to 20 lb / ⁱⁿ² (g.) (1.4 bar (g).). One embodiment of the invention is one, any or all of the representatives selected from the preceding embodiments in this paragraph up to and including the second embodiment in this paragraph, where, during the regulation of the pressure of the medium pressure water vapor stream, the medium pressure water vapor stream is controllably combined an additional high pressure stream in the form of high pressure water vapor to achieve a first predetermined pressure; and while adjusting the pressure of the low pressure water vapor stream with the low pressure water vapor stream, a secondary medium pressure stream in the form of medium pressure water vapor is controllably combined to achieve a second predetermined pressure. One embodiment of the invention is one, any or all of the representatives selected from the preceding embodiments in this paragraph up to and including the second embodiment in this paragraph, further comprising combining the medium pressure water vapor stream with the high pressure manifold water vapor to provide a steam stripping unit at a predetermined pressure; combining a low-pressure steam stream with steam of a medium-pressure manifold to provide a stream at a predetermined pressure to a steaming unit for diesel fuel; and combining the low pressure water vapor stream with the steam of the medium pressure manifold to provide a fractionated product stream at a predetermined pressure. One embodiment of the invention is one, any or all of the representatives selected from the previous embodiments in this paragraph up to and including the second embodiment in this paragraph, where the first steam generator includes a first refrigerator; and the second steam generator includes a second refrigerator.

A third embodiment of the invention is a method for recovering heat from a high pressure stream during hydroprocessing, the method including directing the high pressure stream to a first process vessel; the direction of the first flow of feed water into the first process vessel; heat removal from the high pressure stream in the first process vessel to create a medium pressure water vapor stream from the first feed water stream, directing the high pressure stream from the first process vessel to the second process vessel; the direction of the second flow of feed water into the second process vessel; and heat removal from the high pressure stream in the second process vessel to create a low pressure water vapor stream from the second feed water stream. One embodiment of the invention is one, any or all of the representatives selected from the previous embodiments in this paragraph up to and including the third embodiment in this paragraph, further comprising providing a first pressure alarm system that is triggered by a pressure greater than than the first predefined level, where the first pressure alarm system isolates the first process vessel as a result of terminated I first flow of feedwater flow in the first process tank and the resulting flow stream cease medium pressure steam; and providing a second pressure alarm system that is triggered by a pressure greater than the second predetermined level, where the second pressure alarm system isolates the second process vessel by stopping the flow of the second feed water stream into the second process vessel and by terminating the flow of water vapor low pressure. One embodiment of the invention is one, any or all of the representatives selected from the preceding embodiments in this paragraph up to and including the third embodiment in this paragraph, further including the medium pressure steam flow direction to the first superheater to create a first superheated water vapor stream medium pressure; using the first superheated stream as steam for steaming; directing a low pressure steam stream to a second superheater to create a second superheated stream; and using a second superheated stream as steam for steaming. One embodiment of the invention is one, any or all of the representatives selected from the previous embodiments in this paragraph up to and including the third embodiment in this paragraph, further comprising using the first pressure alarm system to stop the flow of the first purge stream from the first process capacity; and using a second pressure alarm system to stop the flow of the second purge stream from the second process vessel. One embodiment of the invention is one, any or all of the representatives selected from the previous embodiments in this paragraph up to and including the third embodiment in this paragraph, further comprising providing a first pressure alarm system that is triggered by a pressure greater than than the first predefined level, where the first pressure alarm system isolates the first process vessel as a result of terminated I first flow of feedwater flow in the first process tank and the resulting flow stream cease medium pressure steam; determining the first pressure of the medium-pressure water vapor stream between the first process vessel and the first superheater and comparing the first pressure with the first predetermined pressure; activation of the first pressure alarm system if the first pressure exceeds the first predetermined pressure; providing a second pressure alarm system that is triggered by a pressure greater than the second predetermined level, where the second pressure alarm system isolates the second process vessel by stopping the flow of the second feed water stream to the second process vessel and by stopping the flow low pressure water vapor flow; determining a second pressure of the low-pressure water vapor stream between the second process vessel and the second superheater and comparing the second pressure with the second predetermined pressure; and activating a second pressure alarm system if the second pressure exceeds a second predetermined pressure. One embodiment of the invention is one, any or all of the representatives selected from the previous embodiments in this paragraph up to and including the third embodiment in this paragraph, further comprising providing a line for directing the first effluent from the first process vessel to the discharge manifold; providing a first safety valve configured and configured to be in a normally closed state, but allowing the flow of the first effluent to the discharge manifold when activated; providing a line for directing a second effluent from the second process vessel to a discharge manifold; providing a second safety valve, configured and configured to be in a normally closed state, but allowing the flow of the second outlet stream to the discharge manifold when activated. One embodiment of the invention is one, any or all of the representatives selected from the preceding embodiments in this paragraph up to and including the third embodiment in this paragraph, where the first safety valve is activated to ensure the flow of the first exit stream in case of activation of the first alarm system about increasing pressure and when the pressure of the safety valve constituting the first predetermined pressure is reached; and the second safety valve is activated to provide a flow of the second effluent in the event of activation of the second pressure alarm system and in case pressure of the safety valve constituting the second predetermined pressure is reached.

It can be assumed that without further elaboration, specialists in the relevant technical fields, using the preceding description of the invention, can use the present invention to its fullest extent and easily determine the essential characteristics of this invention without deviating from its scope and essence for making various changes and modifications of the invention and adapting it to different use cases and conditions. Therefore, the foregoing preferred specific embodiments are to be taken as merely an illustration and not limitation of the rest of the description of the invention in any way, and it is intended to encompass various modifications and equivalent arrangements included within the scope of the appended claims.

In the foregoing discussion, all temperatures are presented in degrees Celsius, and all parts and percentages are obtained by weight, unless otherwise indicated.

Claims (31)

1. A method of recovering heat from a high pressure stream [10] during hydroprocessing, which includes: the use of a hot separator [12] to create a high pressure vapor stream [10]; the generation of both medium pressure steam stream [31] and low pressure steam [31 ', 31ʺ] from said high pressure vapor stream as a result of heat extraction from said high pressure vapor stream; directing said medium-pressure steam stream [31] to a steaming unit, wherein said medium-pressure steam stream is used as steam for steaming; and directing said low pressure steam [31 ', 31'] to at least one unit selected from a product fractionation unit and a remote steaming unit for diesel fuel, wherein said low pressure steam is used as steam for steaming. 2. The method according to claim 1, where part [31 '] of said low pressure water vapor stream is sent to a product fractionation unit, and part [31ʺ] of said low pressure water vapor stream is sent to a remote steaming unit for diesel fuel. 3. The method according to claim 1, further comprising: the direction of the specified stream [10] of high pressure vapors from the specified hot separator [12] to the first steam generator [22] and the selection of heat from the specified stream of high pressure to obtain the specified stream [31] of medium pressure steam; the direction of the specified stream of high-pressure vapor, from which heat was taken in the first steam generator [22], in the second steam generator [32]; and the use of a second steam generator [32] to select additional heat from the specified high pressure stream, thereby obtaining the specified stream of water vapor low pressure. 4. The method according to p. 3, further comprising: providing at least one first heat exchanger [14] in the gap between said hot separator and said first steam generator [22] and taking heat from said high pressure stream using said at least one first heat exchanger [14]; and providing at least one second heat exchanger [66] after the second steam generator [32] and selecting additional heat from said high pressure stream using said at least one second heat exchanger [66]. 5. The method according to p. 3, further comprising: providing a superheater [26] of medium-pressure water vapor in the gap between said first steam generator [22] and said stripping column and directing said medium-pressure water vapor stream from the first steam generator [22] through said medium-pressure water superheater [26]; and providing a superheater [32] of low pressure steam after the second steam generator and directing said low pressure steam from the second steam generator [32] through said low pressure steam superheater [26 ']. 6. The method according to p. 1, further comprising: providing a pressure increase alarm system [100, 100 '] that is configured and configured to activate a valve [108] associated with the boiler feed water line [25] at a predetermined high pressure value, where the indicated boiler feed water line [25] provides the supply of boiler feed water to both the first steam generator [22] and the second steam generator [32]; and activation of the valve [108] associated with the indicated line [25] of the boiler feed water, if the indicated system [100, 100 '] detects an alarm about pressure increase when the pressure reaches the specified predetermined high pressure to stop the flow of boiler feed water as in the first steam generator [22], and the second steam generator [32]. 7. The method according to p. 1, further comprising: adjusting, using a computer processor configured and configured to control at least one valve [39], the pressure of said medium-pressure steam stream [31] to a specified steam setting to maintain it at a first predetermined pressure of 130 psi ² (g.) (9 bar (g.)); and regulation when using a computer processor configured and configured to control at least one valve [39 '], the pressure of the specified stream [31', 31ʺ] of low-pressure water vapor entering at least one installation selected from the product fractionation unit and installation stripping for diesel fuel for keeping it at a second predetermined pressure in the range of 15 lb / ⁱⁿ² (g.) (1 bar (g.)) to 20 lb / ⁱⁿ² (g.) (1.4 bar ( huts)). 8. The method according to claim 7, wherein during said pressure control of said medium-pressure water vapor stream [31], said medium-pressure water vapor stream [31] combines the additional high-pressure stream [33] in the form of high-pressure water vapor for achieving said first predetermined pressure; and during said pressure control of said low pressure water vapor stream [31 ′, 31 водя] with said low pressure water vapor stream [31 ', 31ʺ], the secondary medium pressure stream [33'] in the form of medium pressure water vapor is controllably combined to achieve said second predefined pressure. 9. The method according to p. 1, further comprising: combining said medium-pressure steam stream [31] with steam [33] a high-pressure manifold to provide steam to the said steam stripping unit at a predetermined pressure; combining said low-pressure water vapor stream [31ʺ] with water vapor [33 '] a medium-pressure manifold to provide a stream to a specified external diesel fuel stripping unit at a predetermined pressure; and combining the specified stream [31 '] of water vapor of low pressure with water vapor of a medium pressure collector to ensure supply to the specified installation fractionation of the product stream at a predetermined pressure. 10. The method according to p. 3, in which: said first steam generator includes a first refrigerator [22]; but the specified second steam generator includes a second refrigerator [32].

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