Arrangement for generating heat and cold

Abstract

The invention relates to the field of refrigeration and cryogenic engineering. An arrangement for generating heat and cold contains a cooling loop with an expander-compressor unit, and a loop containing a medium to be cooled, which is connectable to the cooling loop by means of heat exchange apparatus, the arrangement further containing regulation, protection, control, actuation and monitoring systems. The expander-compressor unit may have an electric generator drive and a two-stage configuration, and the cooling loop may have a closed or an open configuration. A coolant outlet of each stage of the expander is connected to a corresponding heat exchanger, wherein in an open cooling loop, the coolant outlet is in direct communication with the medium to be cooled. Regenerative heat exchange may be carried out between the stages of the expander, and the loops may be connected to a single source of gas. The invention makes it possible to increase the efficiency of refrigeration and cryogenic systems.

Description

[0001] Installation of heat and cold generation

[0002] The invention relates to the field of refrigeration and cryogenic engineering and can be used in refrigeration and cryogenic units, in heat pumps, in gas liquefaction units, in air separation units, in gas separation units, etc.

[0003] A gas refrigeration machine is known which can also be used as a heat pump. "Refrigeration Machines" by N.N. Koshkin and others. Moscow, Food Industry, 1973. Pp. 359-380.

[0004] The disadvantages of such a design are the low cooling coefficient and productivity.

[0005] The technical result achieved in this invention is an increase in the efficiency and productivity of refrigeration and cryogenic systems, including heat pumps and gas liquefaction plants, at least partially operating on a gas refrigeration cycle.

[0006] The specified technical result is achieved in that the heat and cold generation unit, containing a cooling circuit with a cold generation device in the form of an expander, for example with an electric generator drive, or made in the form of an expander-compressor unit and a cooled medium circuit connected by means of heat exchange devices to the cooling circuit, a regulation, protection, control, start-up, and monitoring system, is characterized in that it contains a cooling circuit that is at least one open or closed circuit for the circulation of a refrigerant in the form of a gas or vapor, or a mixture of gaseous refrigerants, with suitable thermophysical properties, wherein the cooling circuit includes at least one quasi-isothermal expansion device, for example, at least one, at least, two-stage or two-cascade quasi-isothermal expander made with the possibility of partial heat supply to the refrigerant during expansion,for example, a turboexpander, wherein in an open cooling circuit, the outlet of the refrigerant from each stage, or from each cascade, of at least the high pressure of the quasi-isothermal expander is connected to a heat exchanger, with the possibility of supplying heat to the refrigerant and removing heat from the cooled medium, for example, to a counter-current one, and the outlet of the low-pressure refrigerant from the last stage of the quasi-isothermal expander is supplied directly to the cooled medium, wherein in a closed cooling circuit, the outlets of the refrigerant from at least the first stage and from the last stage of the quasi-isothermal expander are separately connected to the same heat exchanger for cooling the cooled medium, including a separate line of at least the low-pressure refrigerant, made with the possibility of supplying heat to the low and higher pressure refrigerant. or the outlets of the stages of the quasi-isothermal expander are connected to different ones,at least two heat exchangers for supplying heat to the coolant, and the circuit of the cooled medium is divided into at least two parts, one of which is connected, with the possibility of removing heat from it, to a heat exchanger, for example a counter-current one, made between the stages or cascades of at least a two-stage quasi-isothermal expander, and the other part is connected, with the possibility of removing heat from it, to a heat exchanger, for example a counter-current one. made after the release of the coolant from the last stage or cascade of at least a two-stage quasi-isothermal expander.,

[0007] In addition, the installation is distinguished by the fact that the regenerative, or recuperative, refrigerant heat exchanger, for example a counter-current one, is designed with the possibility of supplying heat to the low-pressure refrigerant and removing heat from the high-pressure refrigerant in the cooling circuit, in the part before the inlet to the first stage of the quasi-isothermal expander.

[0008] In addition, the installation is distinguished by the fact that in the circuit of the cooled medium, and possibly in the cooling circuit, at least one pre-cooling heat exchanger is provided, connected to at least one external cooling circuit, for example with a vapor compression refrigeration cycle.

[0009] In addition, the installation is distinguished in that it contains at least two cooling stages connected in parallel to the high- and low-pressure refrigerant mains and connected in series by temperature to the heat exchangers of the cooled medium circuit, wherein each of the cooling stages contains at least one quasi-isothermal expander. In addition, the installation is distinguished in that the supply of high-pressure refrigerant to the first stage of the quasi-isothermal expander of at least the second, lower-temperature cooling stage in the cooling circuit is connected, with the possibility of removing heat from the high-pressure refrigerant, to a regenerative or recuperative refrigerant heat exchanger, for example a counter-current one, on the heat supply side, connected to the removal of low-pressure refrigerant from at least the second, lower-temperature cascade of the cooling circuit, for example to a compressor.

[0010] In addition, the installation is characterized in that both circuits, the cooling circuit and the circuit of the cooled medium, are connected simultaneously, for example through a gas preparation device, to a high- or medium-pressure gas main, for example natural gas, wherein at the inlet to the cooling circuit, the high- or medium-pressure natural gas is connected by a pipeline to the inlet of a compressor, for example, at least a two-stage compressor with intermediate and final gas coolers, possibly implemented on the shaft of at least one quasi-isothermal expander, the outlet of the cooled gas from the compressor is connected to the inlet of the first expansion stage of the quasi-isothermal expander and, further, to the heat exchanger for cooling the cooled medium, and the outlet of the low-pressure refrigerant from the last expansion stage of the quasi-isothermal expander is connected through a heat exchanger in the circuit of the cooled medium, for example to the compressor and, or to the medium or low-pressure natural gas main.the outlet of high or medium pressure natural gas from the lowest temperature heat exchanger in the circuit of the cooled medium is connected to an expansion device, for example, in the form of a throttle, the outlet of which is connected to a liquefied gas separator, the outlet of condensed gas from which, possibly through a series of heat exchangers of the circuit of the cooled medium with the possibility of sequentially supplying heat to it, is connected to the consumer and, or to the compressor and, or to the low pressure natural gas main.

[0011] In addition, the installation is characterized in that both circuits, the refrigerant circuit and the circuit of the cooled medium, are connected simultaneously, for example through a gas preparation device, to a high- or medium-pressure gas main, for example natural gas, wherein at the inlet to the cooling circuit, the high- or medium-pressure natural gas is connected to the inlet of at least one quasi-isothermal expander, and the outlet of, for example, uncondensed gas from the liquefied gas separator and the outlet of the low-pressure refrigerant in the cooling circuit from the last expansion stage of at least one quasi-isothermal expander, through, for example, a series of heat exchangers of the cooled medium circuit with the possibility of sequentially supplying heat to the natural gas - and, for example, to the low-pressure stripping gas are connected to a compressor, for example to the first stage of a two-stage compressor with intermediate and final gas coolers, possibly implemented on the shaft of at leastone quasi-isothermal expander, with the outlet of compressed and cooled gas from the compressor connected to at least a high- or medium-pressure natural gas pipeline.

[0012] In addition, the installation is characterized in that the refrigerant circuit and the circuit of the cooled medium are connected simultaneously to the same source of gas, for example air, wherein in the refrigerant circuit the air is connected to the inlet, for example, of a two-stage or two-cascade compressor with intermediate and final air coolers, possibly implemented on the shaft of at least one quasi-isothermal expander, wherein the outlet from the final cooler of the compressor is divided by pipelines, for example, into three parts, one part, for example the first, as a cooled and liquefied medium, is connected through a pre-cooling heat exchanger, with the possibility of removing heat to a cooling heat exchanger, after which the pipeline with this part of the gas can be mounted in a low-temperature heat exchanger, also with the possibility of removing heat. after which the circuit of the cooled medium can contain a regenerative or recuperative heat exchanger for additional cooling,at the outlet of which the pipeline with the first part of the gas is connected to an expansion device, for example in the form of a throttle valve, the outlet of which is connected to a liquefied gas separator, wherein the outlet of uncondensed gas is sequentially supplied by a pipeline with the possibility of supplying heat, first, to a regenerative or recuperative heat exchanger for additional cooling, after which it is connected to a low-temperature heat exchanger, then to a cooling heat exchanger, then to a pre-cooling heat exchanger, after the outlet from which the heated uncondensed gas is connected to the outlet from the cycle, or is connected to the inlet of a compressor, wherein the second part of the gas, for example high-pressure air, as a refrigerant of the first, high-temperature cooling circuit is connected to the first stage of one quasi-isothermal expander, the outlet of the cooled refrigerant from which is connected by a pipeline, with the possibility of supplying heat to the refrigerant,to a pre-cooling heat exchanger, the outlet of heated refrigerant from which is fed to the second stage of this quasi-isothermal expander, the outlet of cooled refrigerant from which is connected by a pipeline to a low-pressure refrigerant line formed in the pre-cooling heat exchanger, the outlet of heated refrigerant from which is fed to the inlet of the compressor, or to the outlet of gas from the cycle, wherein a third portion of the gas, for example high-pressure air, as a refrigerant of the second, low-temperature cooling circuit, is fed to a recuperative or regenerative refrigerant heat exchanger, with the possibility of removing heat from the high-pressure refrigerant, after which this portion of the refrigerant, for example air, is connected to the inlet of the first stage of another, at least one quasi-isothermal expander, as part of at least a second low-temperature cooling circuit, the outlet of cooled refrigerant from which the pipeline is supplied,for example, in a low-temperature heat exchanger, with the ability to remove heat from the cooled medium, the outlet of the heated refrigerant from which is fed into the second stage of the same quasi-isothermal expander, the outlet of the cooled low-pressure refrigerant from which is fed into a recuperative or regenerative refrigerant heat exchanger, with the ability to remove heat from the high-pressure refrigerant, while the outlet of the heated low-pressure refrigerant from this heat exchanger is connected to the compressor inlet, or to the outlet of the gas from the cycle.

[0013] In addition, the installation is distinguished in that both circuits, the refrigerant circuit and the circuit of the cooled medium, are connected simultaneously to a high- or medium-pressure gas main, for example natural gas, wherein the outlet from the high- or medium-pressure gas main is divided into three parts, one part, as a cooled and / or liquefied medium, is supplied to the circuit of the cooled medium, the other part, as a refrigerant, is supplied to the first, high-temperature cooling circuit, including at least a pre-cooling heat exchanger, and the third part of the gas, as a refrigerant of the second, lower-temperature cooling circuit, is connected, possibly through a regenerative refrigerant heat exchanger, to another, lower-temperature quasi-isothermal expander and to at least one low-temperature heat exchanger.

[0014] In addition, the installation is distinguished by the fact that the cooling circuit contains two circuits, for example with their own compressors, wherein one cooling circuit with a refrigerant or a mixture of refrigerants, for example in the form of methane gas, after being released from the end cooler of the methane compressor, possibly through a pre-cooling heat exchanger with an external, for example vapor-compression cooling cycle, is connected to the inlet of the first stage of one quasi-isothermal expander, the outlet of the refrigerant from which is supplied, with the possibility of removing heat from the cooled medium, for example from pre-treated natural gas, to a heat exchanger for deeper cooling, and possibly partial liquefaction, of the cooled medium, the outlet of the heated refrigerant (methane) from which is supplied to the second expansion stage of the same quasi-isothermal expander, the outlet of the cooled refrigerant from which is connected by a low-pressure refrigerant line.for example, into the same heat exchanger, with the ability to remove heat from the cooled medium, the outlet of the heated low-pressure refrigerant from this low-pressure refrigerant line, possibly through a pre-cooling heat exchanger, is connected to the inlet of the methane compressor, while in the second cooling circuit the refrigerant, for example nitrogen, after the aftercooler of the nitrogen compressor is supplied by a pipeline, for example through a pre-cooling heat exchanger, into a recuperative or regenerative refrigerant heat exchanger, with the ability to remove heat from the refrigerant, for example high-pressure nitrogen.after which the cooled high-pressure refrigerant is connected to the inlet of the first stage of the second, low-temperature quasi-isothermal expander, the outlet of the cooled refrigerant from which is fed into a low-temperature heat exchanger with the ability to remove heat from the cooled medium, the outlet of the heated refrigerant from which is fed into the second stage of the same low-temperature quasi-isothermal expander, the outlet of the cooled low-pressure refrigerant from this stage is fed into a recuperative (regenerative) refrigerant heat exchanger, with the ability to remove heat from the high-pressure refrigerant, while the outlet of the low-pressure refrigerant heated in it, for example nitrogen, possibly through a pre-cooling heat exchanger, is connected to the inlet of the nitrogen compressor, while in the circuit of the cooled medium, in the part of the circuit with a temperature corresponding to the condensation temperature of low-boiling gases, or lower, a condensate separator.

[0015] The drawings show

[0016] Figure 1. Installation for generating heat and cold as a gas refrigeration unit and / or heat pump with two cooling heat exchangers.

[0017] Figure 2. Installation for generating heat and cold as a refrigeration plant with a closed gas refrigeration cycle.

[0018] Figure 3. Installation for generating heat and cold as an air refrigeration plant with an open gas refrigeration cycle.

[0019] Figure 4. Gas refrigeration and / or heat pump unit with four stages of refrigerant expansion in a quasi-isothermal expansion device with four stages of refrigerant expansion and compression, forming four cooling circuits in a heat exchanger for cooling the cooled medium.

[0020] Figure 5. Installation for generating heat and cold as an installation for liquefying natural gas using the energy of gas pressure in the gas pipeline.

[0021] Figure 6. Installation for generating heat and cold as an installation for liquefying natural gas using the energy of gas pressure in the gas pipeline, in an expander-compressor unit. Figure 7. Installation for generating heat and cold as an installation for liquefying low-boiling gas, for example, hydrogen.

[0022] Figure 8. Schematic diagram of a heat and cold generation plant as a gas liquefaction plant, such as air.

[0023] Figure 9. Schematic diagram of a heat and cold generation plant as a natural gas liquefaction plant with methane (left) and nitrogen (right) external cooling circuits.

[0024] The heat and cold generation unit comprises a circuit of a cooled medium 1 and a cooling circuit 2, including a quasi-isothermal expander 3, the first expansion stage 4 of which is connected via a cooling heat exchanger 5 of the cooled medium to a second expansion stage 6, the outlet of the gas - refrigerant from which is connected, also with the possibility of supplying heat to the refrigerant, via a low-pressure line 7 to the same cooling heat exchanger 5, or to an additional cooling heat exchanger 8, or to a regenerative refrigerant heat exchanger 9, or is directly directed into the circuit of the cooled medium 1.may also contain a compressor 10, for example with an intermediate 11 and an aftercooler 12, a heat exchanger for preliminary cooling of the cooled medium 13, a low-temperature heat exchanger 14, the circuit of the cooled medium 1 may contain a throttle valve 15, possibly through a regenerative heat exchanger for additional cooling 16, connected to a liquefied gas separator 17, may also contain a preliminary cooling circuit with a vapor-compression refrigeration cycle 18, a second cooling circuit 19 with a compressor 20, a separator 21, a high- or medium-pressure natural gas main 22, a gas preparation device 23, an engine 24, a low-temperature quasi-isothermal expander 25, a low-pressure gas main 26, a refrigeration chamber 27, a circulation fan 28.

[0025] The heat and cold generation plant operates as follows.

[0026] When the unit operates as a refrigeration unit and / or a heat pump (Fig. 1) with a closed gas refrigeration cycle, in the cooling circuit 2, a gaseous refrigerant, for example nitrogen, helium, methane, etc., is fed to the input of the first stage of the compressor 10, is compressed in it, after which it is cooled in the intermediate cooler 1 1, is then compressed in the second stage of the compressor 10 and is cooled in the aftercooler 12, after which the refrigerant is fed to the quasi-isothermal expander 3, expands in the first expansion stage 4, for example, rotating the compressor 10, while the refrigerant is cooled and enters the cooling heat exchanger 5, in which the refrigerant is heated, removing heat from part of the cooled medium.after which the refrigerant heated in this way is fed to the second stage 6 of the expansion of the quasi-isothermal expander 3, expands in it, for example, rotating the compressor 10 and at the same time cools again, after which it is fed to the additional cooling heat exchanger 8, heats up in it, cooling the second part of the cooled medium in the circuit of the cooled medium 1 and is fed to the input of the compressor 10, in which it is compressed again. Then the cycle is repeated. The heat taken from the refrigerant in the intermediate 1 1 and final 12 coolers of the compressor 10 can be usefully used for various purposes.

[0027] From the second stage 6 of the quasi-isothermal expander 3, the cooled refrigerant can be supplied to the low-pressure refrigerant line 7, made in the cooling heat exchanger 5 (Fig. 2), where the refrigerant is heated and supplied to the compressor 10. The refrigerant expanded in the first stage 4 of the quasi-isothermal expander 3 is also heated in this cooling heat exchanger 5 and enters the second expansion stage 6. In this case, while maintaining the previous refrigeration capacity, the refrigerant flow through the compressor 10 decreases, and the power of the second expansion stage 6 of the quasi-isothermal expander 3 increases, which increases the efficiency and refrigeration capacity of the plant.

[0028] The unit can operate on an open gas refrigeration cycle (Fig. 3). During operation of the unit, after expansion of the refrigerant, for example air, in the first expansion stage 4 of the quasi-isothermal expander 3, the cooled air is fed to the cooling heat exchanger 5, is heated in it, cooling part of the air supplied, due to the operation of the circulation fan 28, from the refrigeration chamber 27, after which it enters the second expansion stage 6 of the quasi-isothermal expander 3, finally expands, rotating the load - compressor 10, after which the newly cooled refrigerant - air is fed to the refrigeration chamber 27. At the same time, part of the low-pressure refrigerant from the refrigeration chamber 27 is fed to the regenerative heat exchanger 9, cools the return flow of refrigerant - high-pressure air in it, after which it is fed to the compressor 10 and compressed. Then the cycle is repeated.

[0029] The installation may contain a quasi-isothermal expansion device with several, for example, four, cascades of expansion / compression of the refrigerant, formed by four quasi-isothermal expander-compressors 3 (Fig. 4) installed in series as the refrigerant expands. In this case, during operation of the installation, the refrigerant is compressed in the compressor 10 due to the operation of the engine 24, cooled in the intermediate cooler 11, after which the refrigerant is compressed in a cascade of compressors with intermediate coolers 11 and one final cooler 12, made as part of the quasi-isothermal expander-compressors 3. The refrigerant compressed in this way is fed to the first expansion stage 4 of the high-pressure quasi-isothermal expander-compressor 3. Next, cooled during expansion, with the work of compression performed, the refrigerant is fed into the cooling heat exchanger 5, where it is heated by the flow of the cooled medium.After which the refrigerant expands and cools in the second and subsequent expansion stages formed by the next three quasi-isothermal expander-compressors 3. In this case, 3 additional cooling circuits 2 are formed in the cooling heat exchanger 5, which reduces the refrigerant consumption in the cycle and reduces the size of the regenerative heat exchanger 9. The coolant heated in the intermediate coolers 11 and the final cooler 12 can be used for heating and hot water supply in the heat pump cycle.

[0030] The release of the refrigerant from the second stage 6 of the expansion of the quasi-isothermal expander 3 can be supplied via the low-pressure main 7 to the cooling heat exchanger 5 formed between the stages of the quasi-isothermal expander 3 (Fig. 5). In this case, the entire flow of the cooled medium in the circuit of the cooled medium 1 passes through the cooling heat exchanger 5. Each quasi-isothermal expander 3 and 25 in the installation, for example, for liquefying natural gas (Fig. 5) can be connected, via the gas preparation device 23, to the high- or medium-pressure main 22 of natural gas. In this case, part of the natural gas is fed to the cooling circuit 2 as a refrigerant, where it is divided into two parts, one part of the refrigerant expands in the quasi-isothermal expander 3 of the first, higher-temperature cooling cascade.The other part of the refrigerant is fed through the regenerative refrigerant heat exchanger 9 to the low-temperature quasi-isothermal expander 25 of the second, lower-temperature cascade of the cooling circuit 2. And part of the natural gas, received from the main line 22 into the circuit of the cooled medium 1, is successively cooled in heat exchangers 5 by the return flows of the refrigerant of the first and second stages of the cooling circuit 2, then fed through the regenerative heat exchanger of additional cooling 16, where it is additionally cooled, into the throttle valve 15, expands in it, while being cooled again and fed into the liquefied gas separator 17, from where the liquid fraction of the gas is fed to the consumer, and the uncondensed part of the natural gas (boil-off gas) can be successively heated, first in the regenerative heat exchanger of additional cooling 16, and then in other heat exchangers of the circuit of the cooled medium 1.Natural gas from cooling circuit 2 (possibly also stripping gas), expanded in quasi-isothermal expanders 3 and 25, and heated in heat exchangers 5 of the cooled medium circuit 1, enters the compressor inlet 10, is compressed and fed into high- or medium-pressure natural gas main 22.

[0031] Quasi-isothermal expanders 3 and 25, executed on the shaft of the compressor 10, constitute the expander-compressor unit (Fig. 6). In this case, gas from the high- or medium-pressure natural gas main 22 is fed to the inlet of the compressor 10, is compressed in it and fed to the inlet of the quasi-isothermal expanders 3 and 25 of the first and second cooling stages, in the cooling circuit 2, in which it expands with the performance of work and is cooled. After which the natural gas as a refrigerant is heated in the cooling circuit 2, taking heat from another part of the natural gas, in the circuit of the cooled medium 1 and is fed to the low-pressure gas main 26 and, further, to the consumer of natural gas, possibly together with uncondensed (boiling) gas, or is again compressed in the compressor (not shown in the drawing) and fed to the high- or medium-pressure natural gas main 22.The installation may contain several, for example, three cooling circuits 2, 18 and 19, sequentially, as the temperature decreases, connected via heat exchangers to the circuit of the cooled medium 1 (Fig. 7). In this case, the cooled medium. for example, gaseous hydrogen is fed to the pre-cooling heat exchanger 13, where it is cooled by a refrigerant, for example propane, circulating in the vapor compression cycle of the pre-cooling circuit 18, after which it enters the cooling heat exchanger 5 as part of the cooling circuit 2, where it is additionally cooled, for example by nitrogen, which is cooled during expansion in the cascade of quasi-isothermal expanders 3 and in the throttle valve 15. Final cooling and liquefaction occurs in the low-temperature heat exchanger 14, connected to the cascade of low-temperature quasi-isothermal expanders 25, in which the low-boiling refrigerant, for example helium, is expanded.After which the hydrogen expands in the expansion device and is separated in the separator 17.

[0032] In the air liquefaction unit (Fig. 8), air through the gas preparation device 23, for example in the form of a filter, is fed to the input of the first stage of the compressor 10 and is compressed, then cooled in the intermediate cooler 11 and divided into two parts, one part enters the circuit of the cooled medium 1, is cooled in the pre-cooling heat exchanger 13, after which it is cooled in the cooling heat exchanger 5, then cooled in the low-temperature heat exchanger 15, after which it is cooled in the regenerative heat exchanger of additional cooling 16, then it expands in the throttle valve 15 and is fed to the liquefied gas separator 17, from which the liquefied gas is fed to the consumer, and the uncondensed gas is successively heated in the heat exchangers of the circuit of the cooled medium and removed from the cycle, or is fed to the input of the compressor 10.In this case, another part of the air is compressed to a higher pressure in the second stage of the compressor 10, cooled in the aftercooler 12 and fed to the cooling circuit 2, in the form of a refrigerant. Then, the refrigerant is divided into two parts. One part of the refrigerant is fed to the pre-cooling circuit, in which it expands in the quasi-isothermal expander 3 and cools the air in the pre-cooling heat exchanger 13, after which the refrigerant (air) heated to a temperature close to the ambient temperature enters the input of the second stage of the compressor 10 and is again compressed in it.Another portion of the refrigerant from the aftercooler 12 of the compressor 10 is fed to the regenerative refrigerant heat exchanger 9, cooled in it and fed to the first expansion stage 4 of another low-temperature quasi-isothermal expander 25, expanded in it with the performance of work and cooled, after which it is fed to the low-temperature heat exchanger 14, takes heat from the cooled medium (air) in the cooling circuit 1, is heated and fed to the second expansion stage 6 of the quasi-isothermal expander 3, performing work and cooling. Then the low-pressure refrigerant (air) enters the regenerative refrigerant heat exchanger 9, cools the return flow of the high-pressure refrigerant (air) and with a temperature close to the ambient temperature is fed to the input of the second compression stage of the compressor 10 and is again compressed in it. Then the cycle repeats.

[0033] In the natural gas liquefaction plant (Fig. 9), pre-treated natural gas is fed into the pre-cooling heat exchanger 13 and cooled as a result of heat removal, into the pre-cooling circuit with the vapor compression refrigeration cycle 18, after which it is cooled in the cooling heat exchanger 5, as a result of heat removal from the natural gas to the return flow of the refrigerant, for example methane, after the expansion and cooling of the methane in the first 4 and second 6 expansion stages of the quasi-isothermal expander 3 in the second external cooling circuit 19, connected to its own methane compressor 20. In this case, the refrigerant (methane) can also pass through the pre-cooling heat exchanger 13.Natural gas cooled to the condensation temperature of heavy hydrocarbons, after being released from cooling heat exchanger 5, is fed to heavy hydrocarbon separator 21, heavy hydrocarbon condensate from which is fed to the consumer, and uncondensed natural gas is fed to low-temperature heat exchanger 14, where heat is removed from it by a reverse flow of refrigerant, for example nitrogen, circulating in cooling circuit 2. After which natural gas is fed through regenerative additional cooling heat exchanger 16, where it is additionally cooled, to throttle valve 15, expands in it, cooling again, and enters liquefied gas separator 17. from where the liquid fraction of natural gas is fed to the consumer, and the uncondensed portion of natural gas (stripping gas) can be successively heated in heat exchangers of cooled medium circuit 1 and then used for its intended purpose.In the nitrogen circuit of external cooling 2, the refrigerant (nitrogen) from the aftercooler 12 of the compressor 10 is fed, possibly through the precooling heat exchanger 13, to the regenerative refrigerant heat exchanger 9, is cooled in it by the return flow of low-pressure nitrogen and is fed to the first expansion stage 4 of the low-temperature quasi-isothermal expander 25 of the nitrogen circuit of cooling 2. In this case, the nitrogen expands with the performance of work and is cooled, after which it is fed to the low-temperature heat exchanger 14, takes heat from the cooled medium (natural gas) in the cooling circuit 1, is heated and is fed to the second expansion stage 6 of the low-temperature quasi-isothermal expander 25, performing work and cooling. The low pressure nitrogen then enters the regenerative refrigerant heat exchanger 9, cools the return flow of high pressure refrigerant (nitrogen), and can then be heated in the pre-cooling heat exchanger 13.Next, low-pressure nitrogen with a temperature close to the ambient temperature is fed to the compressor input 10 and is compressed again in it. Then the cycle is repeated.

[0034] The use of this invention will increase the efficiency and cooling capacity of refrigeration and heat pump units, installations for liquefying various gases, including hydrogen, air separation units, etc., at least in part of the cycle using a gaseous refrigerant or a mixture of refrigerants.

Claims

Invention formula A heat and cold generation plant comprising a cooling circuit with a cold generation device in the form of an expander, for example with an electric generator drive, or made in the form of an expander-compressor unit and a cooled medium circuit connected by means of heat exchangers to the cooling circuit, a regulation, protection, control, start-up, and monitoring system, characterized in that it comprises a cooling circuit that is at least one open or closed circuit for the circulation of a refrigerant in the form of a gas or vapor, or a mixture of gaseous refrigerants, with suitable thermophysical properties, wherein the cooling circuit includes at least one quasi-isothermal expansion device, for example, at least one, at least, two-stage or two-cascade quasi-isothermal, made with the possibility of partially supplying heat to the refrigerant during expansion, an expander, for example a turbo expander,wherein in the open cooling circuit the outlet of the refrigerant from each stage, or from each cascade, of at least the high pressure of the quasi-isothermal expander is connected to a heat exchanger, with the possibility of supplying heat to the refrigerant and removing heat from the cooled medium, for example, to a counter-current , and the outlet of the low-pressure refrigerant from the last stage of the quasi-isothermal expander is supplied directly to the cooled medium , wherein in the closed cooling circuit the outlets of the refrigerant from at least the first stage and from the last stage of the quasi-isothermal expander are separately connected to the same heat exchanger for cooling the cooled medium , including a separate line of at least the low-pressure refrigerant, made with the possibility of supplying heat to the low and higher pressure refrigerant , or the outlets of the stages of the quasi-isothermal expander are connected to different, to at least two heat exchangers supplying heat to the refrigerant,and the circuit of the cooled medium is divided into at least two parts, one of which is connected, with the possibility of removing heat from it to a heat exchanger, for example a counter-current one, made between the stages, or cascades, of at least a two-stage quasi-isothermal expander, and the other part is connected, with the possibility of removing heat from it to a heat exchanger, for example a counter-current one, performed after the release of the refrigerant from the last stage or cascade of at least a two-stage quasi-isothermal expander.

2. The installation according to item 1, characterized in that the regenerative or recuperative heat exchanger of the refrigerant, for example a counter-current one, is designed with the possibility of supplying heat to the low-pressure refrigerant and removing heat from the high-pressure refrigerant in the cooling circuit, in the part before the inlet to the first stage of the quasi-isothermal expander.

3. An installation according to paragraph 1 or 2, characterized in that in the circuit of the cooled medium, and possibly also in the cooling circuit, at least one pre-cooling heat exchanger is provided, connected to at least one external cooling circuit, for example with a vapor compression refrigeration unit.

4. The installation according to item 1 or 2, characterized in that it contains at least two cooling stages connected in parallel to the high- and low-pressure refrigerant lines and connected in series by temperature to the heat exchangers of the cooled medium circuit, wherein each of the cooling stages contains at least one quasi-isothermal expander.

5. The installation according to claim 4, characterized in that the supply of high-pressure refrigerant to the first stage of the quasi-isthermal expander, at least of the second, lower-temperature cooling stage, in the cooling circuit, is connected, with the possibility of removing heat from the high-pressure refrigerant, to a regenerative or recuperative refrigerant heat exchanger, for example, to a counter-current one, on the heat supply side, connected to the removal of low-pressure refrigerant from at least the second, lower-temperature stage of the cooling circuit, for example to a compressor.

6. The installation according to item 1 or 2, characterized in that both circuits, the cooling circuit and the circuit of the cooled medium, are connected simultaneously, for example through a gas preparation device, to a high- or medium-pressure gas main, for example natural gas, while at the inlet to the cooling circuit, natural gas high or medium pressure is connected by a pipeline to the inlet of a compressor, for example, at least a two-stage compressor with intermediate and final gas coolers, possibly implemented on the shaft of at least one quasi-isothermal expander, the outlet of cooled gas from the compressor is connected to the inlet of the first expansion stage of the quasi-isothermal expander and, further, to a heat exchanger for cooling the cooled medium, and the outlet of low-pressure refrigerant from the last expansion stage of the quasi-isothermal expander is connected through a heat exchanger in the circuit of the cooled medium, for example to the compressor and, or to a medium or low pressure natural gas main, the outlet of high or medium pressure natural gas from the lowest temperature heat exchanger in the circuit of the cooled medium is connected to an expansion device, for example, in the form of a throttle, the outlet of which is connected to a liquefied gas separator.the release of non-condensed gas from which, possibly through a series of heat exchangers of the cooled medium circuit with the possibility of sequentially supplying heat to it, is connected to the consumer and / or to the compressor and / or to the low-pressure natural gas main.

7. The installation according to claim 1 or 2, characterized in that both circuits, the refrigerant circuit and the circuit of the medium to be cooled, are connected simultaneously, for example through a gas preparation device, to a high- or medium-pressure gas main, for example natural gas, wherein at the inlet to the cooling circuit, high- or medium-pressure natural gas is connected to the inlet of at least one quasi-isothermal expander, and the outlet, for example, of uncondensed gas from the liquefied gas separator and the outlet of low-pressure refrigerant in the cooling circuit from the last expansion stage of at least one quasi-isothermal expander, through, for example, a series of heat exchangers of the circuit of the medium to be cooled with the possibility of sequentially supplying heat to the natural gas - and, for example, to the low-pressure stripping gas are connected to a compressor, for example to the first stage of a two-stage compressor with intermediate and final gas coolers.possibly implemented on the shaft of at least one quasi-isothermal expander, wherein the outlet of compressed and cooled gas from the compressor is connected to at least a high- or medium-pressure natural gas main.

8. The installation according to claim 1 or 2, characterized in that the refrigerant circuit and the circuit of the cooled medium are connected simultaneously to the same source of gas, for example air, wherein in the refrigerant circuit the air is connected to the inlet, for example, of a two-stage or two-cascade compressor with intermediate and final air coolers, possibly implemented on the shaft of at least one quasi-isothermal expander, wherein the outlet from the final cooler of the compressor is divided by pipelines, for example, into three parts, one part, for example the first, as a cooled and liquefied medium, is connected through a pre-cooling heat exchanger, with the possibility of removing heat to a cooling heat exchanger, after which the pipeline with this part of the gas can be mounted in a low-temperature heat exchanger, also with the possibility of removing heat, after which the circuit of the cooled medium can contain a regenerative or recuperative heat exchanger for additional cooling,at the outlet of which the pipeline with the first part of the gas is connected to an expansion device, for example in the form of a throttle valve, the outlet of which is connected to a liquefied gas separator. In this case, the outlet of uncondensed gas is successively supplied by a pipeline with the possibility of supplying heat, first, to a regenerative or recuperative additional cooling heat exchanger, after which it is connected to a low-temperature heat exchanger, then to a cooling heat exchanger, then to a pre-cooling heat exchanger, after the outlet from which the heated uncondensed gas is connected to the outlet from the cycle, or is connected to the inlet of a compressor, in which case the second part of the gas, for example high-pressure air, as a refrigerant of the first, high-temperature cooling circuit is connected to the first stage of one quasi-isothermal expander, the outlet of the cooled refrigerant from which is connected by a pipeline, with the possibility of supplying heat to the refrigerant,to the pre-cooling heat exchanger, the outlet of the heated refrigerant from which is fed into the second stage of this quasi-isothermal expander, the outlet of the cooled refrigerant from which is connected by a pipeline to the low-pressure refrigerant line made in the pre-cooling heat exchanger, the outlet of the heated refrigerant from, which is supplied to the compressor inlet or to the gas outlet from the cycle, wherein the third part of the gas, for example high-pressure air, as a refrigerant of the second, low-temperature cooling circuit, is supplied to a recuperative or regenerative refrigerant heat exchanger, with the possibility of removing heat from the high-pressure refrigerant, after which this part of the refrigerant, for example air, is connected to the inlet of the first stage of another, at least one quasi-isothermal expander, as part of at least a second low-temperature cooling circuit, the outlet of the cooled refrigerant from which is supplied by a pipeline, for example to a low-temperature heat exchanger, with the possibility of removing heat from the cooled medium, the outlet of the heated refrigerant from which is supplied to the second stage of the same quasi-isothermal expander, the outlet of the cooled low-pressure refrigerant from which is supplied to a recuperative or regenerative refrigerant heat exchanger,with the ability to remove heat from the high-pressure refrigerant, while the outlet of the heated low-pressure refrigerant from this heat exchanger is connected to the compressor inlet, or to the gas outlet from the cycle., 9. The installation according to paragraph 1 or 2, characterized in that both circuits, the refrigerant circuit and the circuit of the cooled medium, are connected simultaneously to a high- or medium-pressure gas main, for example natural gas, wherein the outlet from the high- or medium-pressure gas main is divided into three parts, one part, as a cooled and / or liquefied medium, is supplied to the circuit of the cooled medium, the other part, as a refrigerant, is supplied to the first, high-temperature cooling circuit, including at least a pre-cooling heat exchanger, and the third part of the gas, as a refrigerant of the second, lower-temperature cooling circuit, is connected, possibly through a regenerative refrigerant heat exchanger, to another, lower-temperature quasi-isothermal expander and to at least one low-temperature heat exchanger.

10. The installation according to item 1 or 2, characterized in that the cooling circuit contains two circuits, for example with their own compressors, wherein one cooling circuit with a refrigerant or a mixture of refrigerants, for example in the form of methane gas, after being released from the end cooler of the methane compressor, possibly through a pre-cooling heat exchanger with an external, for example vapor-compression cooling cycle, is connected to the inlet of the first stage of one quasi-isothermal expander, the outlet of the refrigerant from which is supplied, with with the possibility of removing heat from a cooled medium, for example from pre-treated natural gas, to a heat exchanger for deeper cooling, and possibly partial liquefaction, of the cooled medium, and the release of heated refrigerant (methane) from which it is supplied to the second expansion stage of the same quasi-isohermic expander, the outlet of the cooled refrigerant from which is connected by a low-pressure refrigerant line, for example, to the same heat exchanger, with the possibility of removing heat from the cooled medium, the outlet of the heated low-pressure refrigerant from this low-pressure refrigerant line, possibly through a pre-cooling heat exchanger, is connected to the inlet of the methane compressor, while in the second cooling circuit the refrigerant, for example nitrogen, after the aftercooler of the nitrogen compressor is supplied by a pipeline, for example through a pre-cooling heat exchanger, to a recuperative or regenerative refrigerant heat exchanger, with the possibility of removing heat from the refrigerant, for example high-pressure nitrogen, after which the cooled high-pressure refrigerant is connected to the inlet of the first stage of the second, low-temperature quasi-isohermic expander,the outlet of the cooled refrigerant from which is fed into a low-temperature heat exchanger with the possibility of removing heat from the cooled medium, the outlet of the heated refrigerant from which is fed into the second stage of the same low-temperature quasi-isothermal expander, the outlet of the cooled low-pressure refrigerant from this stage is fed into a recuperative (regenerative) refrigerant heat exchanger, with the possibility of removing heat from the high-pressure refrigerant, while the outlet of the low-pressure refrigerant heated in it, for example nitrogen, possibly through a pre-cooling heat exchanger, is connected to the inlet of the nitrogen compressor, while in the circuit of the cooled medium, in the part of the circuit with a temperature corresponding to the condensation temperature of low-boiling gases, or lower, a condensate separator can be made.

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