Cold-carrying circulation heat recovery oil gas recovery system

Abstract

The invention relates to the technical field of oil gas recovery, and discloses a cold-carrying circulation heat recovery oil gas recovery system which comprises an oil gas cooling liquefaction recovery subsystem and a cold-carrying circulation heat recovery subsystem. The oil gas cooling, liquefying and recycling subsystem comprises a first-stage cooling module, a second-stage cooling module, a third-stage cooling module and a fourth-stage heating module which are sequentially communicated through oil gas connecting pipes; the secondary refrigerant circulation heat recovery subsystem comprises a first-stage oil gas condenser A, a first-stage oil gas condenser B, a first secondary refrigerant valve, a second secondary refrigerant valve, a third secondary refrigerant valve, a fourth secondary refrigerant valve, a fifth secondary refrigerant valve, a sixth secondary refrigerant valve, a secondary refrigerant pump and a fourth-stage oil gas heater. The cold-carrying circulation heat recovery oil gas recovery system has the advantages of being low in energy consumption, energy-saving, environment-friendly, simple in refrigerating system, low in cost, high in reliability and the like, and the energy-saving and environment-friendly performance, the cost performance and the operation reliability of the oil gas recovery system are greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas recovery, and in particular to a cooling cycle heat recovery oil and gas recovery system. Background Art

[0002] At present, there are common oil and gas recovery systems that can be used for multi-stage deep cooling, with the lowest temperature reaching about -70°C. They are used to condense and liquefy volatile organic compounds in oil and gas (VOCs gas) to recover them. While reducing environmental pollution, the recovered volatile organic compounds can also generate considerable economic benefits.

[0003] However, this type of ordinary oil and gas recovery system will cool the imported oil and gas to -70℃ after multi-stage cooling. The -70℃ oil and gas exhaust gas after cooling and recovery is generally discharged directly into the atmosphere, or heated to about 10℃ by an additional heating device before being discharged into the atmosphere. However, the -70℃ oil and gas exhaust gas at the outlet of the final-stage refrigeration cycle heat recovery oil and gas recovery system has a large amount of high-grade refrigeration capacity, which is discharged into the atmosphere in vain or requires energy to be consumed for heating the low-temperature oil and gas before being discharged. This method makes the traditional oil and gas recovery system have many problems such as high energy consumption, high pollution, complex refrigeration system, high cost, low reliability, etc., which seriously restricts the development of oil and gas condensation equipment.

[0004] Therefore, the prior art still needs to be improved and enhanced. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a refrigeration cycle heat recovery oil and gas recovery system, aiming to solve the problems of high energy consumption, high pollution, complex refrigeration system, high cost and low reliability of traditional oil and gas recovery systems.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A cooling cycle heat recovery oil and gas recovery system, characterized by comprising: an oil and gas cooling liquefaction recovery subsystem and a cooling cycle heat recovery subsystem;

[0008] The oil and gas cooling liquefaction recovery subsystem comprises a primary cooling module, a secondary cooling module, a tertiary cooling module, and a quaternary heating module which are sequentially connected via an oil and gas connecting pipe; wherein the primary cooling module comprises: an oil and gas inlet (21), a primary cooling box A (22), a primary cooling box B (23), a first oil and gas valve (24), a second oil and gas valve (25), and a first oil and gas connecting pipe (26); the oil and gas inlet (21) is divided into two paths, one path is connected to one end of the primary cooling box A (22), and the other end of the cooling box A (22) is connected to one end of the first oil and gas valve (24); the other path is connected to one end of the primary cooling box B (23), and the other end of the primary cooling box B (23) is connected to one end of the second oil and gas valve (25); the other end of the first oil and gas valve (24) is connected to the other end of the second oil and gas valve (25), and is connected to one end of the first oil and gas connecting pipe (26);

[0009] The secondary cooling cycle heat recovery subsystem comprises: a primary oil-gas condenser A (31) installed in a primary cooling oil tank A (22), a primary oil-gas condenser B (32) installed in a primary cooling oil tank B (23), a first secondary cooling agent valve (33), a second secondary cooling agent valve (34), a third secondary cooling agent valve (35), a fourth secondary cooling agent valve (36), a fifth secondary cooling agent valve (37), a sixth secondary cooling agent valve (38), a secondary cooling agent pump (39) and a four-stage oil-gas heater (310); wherein the secondary cooling agent outlet of the primary oil-gas condenser A (31) is divided into two paths, one path is connected to one end of the first secondary cooling agent valve (33), and the other path is connected to one end of the second secondary cooling agent valve (34); the other end of the first secondary cooling agent valve (33) is connected to the secondary cooling agent outlet of the primary oil-gas condenser B (32); the other end of the second secondary cooling agent valve (34) is connected to one end of the secondary cooling agent pump (39), and the secondary cooling agent pump (39) is connected to the secondary cooling agent outlet of the primary oil-gas condenser B (32). The other end is connected to the refrigerant inlet of the fourth-stage oil-gas heater (310); the refrigerant outlet of the fourth-stage oil-gas heater (310) is divided into two paths, one of which is connected to one end of the fourth refrigerant valve (36), and the other is connected to one end of the sixth refrigerant valve (38); the other end of the fourth refrigerant valve (36) is divided into two paths, one of which is connected to the refrigerant inlet of the first-stage oil-gas condenser A (31), and the other is connected to one end of the fifth refrigerant valve (37); the sixth refrigerant valve (38) is connected to the refrigerant inlet of the first-stage oil-gas condenser A (31). The other end of the valve (38) is divided into two paths, one of which is connected to the refrigerant inlet of the first-stage oil-gas condenser B (32), and the other is connected to one end of the third refrigerant valve (35); the other end of the third refrigerant valve (35) is connected to the connecting pipe of the second refrigerant valve (34) and the refrigerant pump (39); the other end of the fifth refrigerant valve (37) is connected to the connecting pipe of the first refrigerant valve (33) and the refrigerant outlet of the first-stage oil-gas condenser B (32).

[0010] The described refrigeration cycle heat recovery oil and gas recovery system, wherein the described secondary cooling module includes a secondary oil and gas condenser A (27), a secondary oil and gas condenser B (28), a third oil and gas valve (29), a fourth oil and gas valve (210), and a second oil and gas connecting pipe (211); the other end of the first oil and gas connecting pipe (26) is divided into two paths, one path is connected to one end of the secondary oil and gas condenser A (27), and the other path is connected to one end of the secondary oil and gas condenser B (28); the other end of the secondary oil and gas condenser A (27) is connected to one end of the third oil and gas valve (29), the other end of the secondary oil and gas condenser B (28) is connected to one end of the fourth oil and gas valve (210), the other end of the third oil and gas valve (29) is connected to the other end of the fourth oil and gas valve (210), and is connected to one end of the second oil and gas connecting pipe (211).

[0011] The described refrigeration cycle heat recovery oil and gas recovery system, wherein the described three-stage cooling module includes a three-stage oil and gas condenser A (212), a three-stage oil and gas condenser B (213), a fifth oil and gas valve (214), a sixth oil and gas valve (215), and a third oil and gas connecting pipe (216); the other end of the second oil and gas connecting pipe (211) is divided into two paths, one path is connected to one end of the three-stage oil and gas condenser A (212), and the other path is connected to one end of the three-stage oil and gas condenser B (213); the other end of the three-stage oil and gas condenser A (212) is connected to one end of the fifth oil and gas valve (214), the other end of the three-stage oil and gas condenser B (214) is connected to one end of the sixth oil and gas valve (215), the other end of the fifth oil and gas valve (214) is connected to the other end of the sixth oil and gas valve (215), and is connected to one end of the third oil and gas connecting pipe (216).

[0012] The described refrigeration cycle heat recovery oil and gas recovery system, wherein the described four-stage heating module comprises a four-stage heating box (217) connected to the other end of the described third oil and gas connecting pipe (216), and the other end of the described four-stage heating box (217) is connected to an oil and gas outlet (218); the described four-stage oil and gas heater (310) is installed in the described four-stage heating box (217).

[0013] The refrigeration cycle heat recovery oil and gas recovery system, wherein, further comprises a liquid oil outlet pipe (219), and the liquid oil outlet of the first-stage cooling box A (22), the liquid oil outlet of the first-stage cooling box B (23), the liquid oil outlet of the second-stage oil and gas condenser A (27), the liquid oil outlet of the second-stage oil and gas condenser B (28), the liquid oil outlet of the third-stage oil and gas condenser A (212), and the liquid oil outlet of the third-stage oil and gas condenser B (213) are all connected to the liquid oil outlet pipe (219).

[0014] Beneficial effects:

[0015] The present invention provides a cooling cycle heat recovery oil and gas recovery system, which uses a relatively high temperature cooling agent from a primary oil and gas condenser in a cooling cycle heat recovery subsystem, absorbs the cold of oil and gas tail gas at about -70°C through a four-stage oil and gas heater, cools down to become a relatively low temperature cooling agent, and heats the -70°C oil and gas tail gas to about 10°C for discharge; the relatively low temperature cooling agent enters the primary oil and gas condenser again, dissipates the cold to reduce the temperature of the imported oil and gas, absorbs the heat of the imported oil and gas to heat up to become a relatively high temperature cooling agent, and operates in a cycle; based on the cooling cycle heat recovery subsystem, the present invention can effectively recover the cold of oil and gas tail gas at about -70°C, and is used to replace the original compressor refrigeration to provide cooling capacity for the primary oil and gas condenser, reduce the compressor configuration of the primary oil and gas condenser, and greatly improve the energy utilization rate of the oil and gas recovery unit. The cooling cycle heat recovery oil and gas recovery system provided by the present invention has the advantages of low energy consumption, energy saving and environmental protection, simple refrigeration system, low cost, high reliability, etc., and greatly improves the energy saving and environmental protection, cost performance and operation reliability of the oil and gas recovery system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a structural diagram of the refrigeration cycle heat recovery oil and gas recovery system provided by the present invention.

[0017] Explanation of main component symbols: 21-oil and gas inlet, 22-first-stage cooling box A, 23-first-stage cooling box B, 24-first oil and gas valve, 25-second oil and gas valve, 26-first oil and gas connecting pipe, 27-second-stage oil and gas condenser A, 28-second-stage oil and gas condenser B, 29-third oil and gas valve, 210-fourth oil and gas valve, 211-second oil and gas connecting pipe, 212-third-stage oil and gas condenser A, 213-third-stage oil and gas condenser B, 214-fifth oil and gas valve, 215-sixth oil and gas valve, 216-third oil and gas connecting pipe, 217-fourth-stage heating box, 218-oil and gas outlet, 219-liquid oil outlet pipe. DETAILED DESCRIPTION

[0018] The present invention provides a cooling cycle heat recovery oil and gas recovery system. In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail below with reference to the accompanying drawings and examples.

[0019] In the description of the present invention, it should be understood that the orientation or position relationship indicated by the terms "top", "bottom", etc. is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, and cannot be understood as a limitation on the present invention; in addition, the terms "installation", "connection", etc. should be understood in a broad sense, and for ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0020] In traditional oil and gas recovery systems, the imported oil and gas are subjected to multi-stage cooling at around -70°C, and then discharged into the atmosphere in vain or even require energy to heat the low-temperature oil and gas before being discharged. The high-quality refrigeration capacity of the -70°C oil and gas exhaust gas is not effectively recovered and utilized, resulting in the traditional oil and gas recovery system having many problems such as high energy consumption, high pollution, complex refrigeration system, high cost, and low reliability.

[0021] In order to solve the problems of the traditional oil and gas recovery system, the present invention provides a cooling cycle heat recovery oil and gas recovery system, such as Figure 1 As shown, it comprises: an oil and gas cooling liquefaction recovery subsystem and a cooling circulation heat recovery subsystem; the oil and gas cooling liquefaction recovery subsystem comprises a primary cooling module, a secondary cooling module, a tertiary cooling module, and a quaternary heating module which are sequentially connected through an oil and gas connecting pipe; wherein the primary cooling module comprises: an oil and gas inlet (21), a primary cooling box A (22), a primary cooling box B (23), a first oil and gas valve (24), a second oil and gas valve (25), and a first oil and gas connecting pipe (2 6); the oil and gas inlet (21) is divided into two paths, one path is connected to one end of the first cooling box A (22), and the other end of the cooling box A (22) is connected to one end of the first oil and gas valve (24); the other path is connected to one end of the first cooling box B (23), and the other end of the first cooling box B (23) is connected to one end of the second oil and gas valve (25); the other end of the first oil and gas valve (24) is connected to the other end of the second oil and gas valve (25), and is connected to one end of the first oil and gas connecting pipe (26);

[0022] The secondary cooling cycle heat recovery subsystem comprises: a primary oil-gas condenser A (31) installed in a primary cooling oil tank A (22), a primary oil-gas condenser B (32) installed in a primary cooling oil tank B (23), a first secondary cooling agent valve (33), a second secondary cooling agent valve (34), a third secondary cooling agent valve (35), a fourth secondary cooling agent valve (36), a fifth secondary cooling agent valve (37), a sixth secondary cooling agent valve (38), a secondary cooling agent pump (39) and a four-stage oil-gas heater (310); wherein the secondary cooling agent outlet of the primary oil-gas condenser A (31) is divided into two paths, one path is connected to one end of the first secondary cooling agent valve (33), and the other path is connected to one end of the second secondary cooling agent valve (34); the other end of the first secondary cooling agent valve (33) is connected to the secondary cooling agent outlet of the primary oil-gas condenser B (32); the other end of the second secondary cooling agent valve (34) is connected to one end of the secondary cooling agent pump (39), and the secondary cooling agent pump (39) is connected to the secondary cooling agent outlet of the primary oil-gas condenser B (32). The other end is connected to the refrigerant inlet of the fourth-stage oil-gas heater (310); the refrigerant outlet of the fourth-stage oil-gas heater (310) is divided into two paths, one of which is connected to one end of the fourth refrigerant valve (36), and the other is connected to one end of the sixth refrigerant valve (38); the other end of the fourth refrigerant valve (36) is divided into two paths, one of which is connected to the refrigerant inlet of the first-stage oil-gas condenser A (31), and the other is connected to one end of the fifth refrigerant valve (37); the sixth refrigerant valve (38) is connected to the refrigerant inlet of the first-stage oil-gas condenser A (31). The other end of the valve (38) is divided into two paths, one of which is connected to the refrigerant inlet of the first-stage oil-gas condenser B (32), and the other is connected to one end of the third refrigerant valve (35); the other end of the third refrigerant valve (35) is connected to the connecting pipe of the second refrigerant valve (34) and the refrigerant pump (39); the other end of the fifth refrigerant valve (37) is connected to the connecting pipe of the first refrigerant valve (33) and the refrigerant outlet of the first-stage oil-gas condenser B (32).

[0023] In the present invention, for the refrigerant side, when the first-stage oil and gas condenser A is not frosted, but the first-stage oil and gas condenser B is frosted, a refrigerant valve is used to control the flow direction of the refrigerant, and the higher-temperature refrigerant coming out of the first-stage oil and gas condenser A in the refrigerant cycle heat recovery subsystem first passes through the first-stage oil and gas condenser B to heat the frosted first-stage oil and gas condenser B to defrost it; then it absorbs the cold energy of the oil and gas tail gas at about -70°C through the four-stage oil and gas heater, cools it down to become a lower-temperature refrigerant, and heats the -70°C oil and gas tail gas to about 10°C for discharge; the lower-temperature refrigerant enters the first-stage oil and gas condenser A again, dissipates the cold energy to reduce the temperature of the inlet oil and gas, absorbs the heat of the inlet oil and gas to heat it up to become a higher-temperature refrigerant;

[0024] When the first-stage oil and gas condenser A is frosted and the first-stage oil and gas condenser B is not frosted, the refrigerant valve is used to switch the refrigerant flow direction. The higher-temperature refrigerant coming out of the first-stage oil and gas condenser B in the cooling cycle heat recovery subsystem first passes through the first-stage oil and gas condenser A to heat the frosted first-stage oil and gas condenser A to defrost it, and then absorbs the cold energy of the oil and gas exhaust gas at about -70°C through the four-stage oil and gas heater, cools it down to become a lower-temperature refrigerant, and at the same time heats the -70°C oil and gas exhaust gas to about 10°C for discharge; the lower-temperature refrigerant enters the first-stage oil and gas condenser B, dissipates the cold energy to reduce the temperature of the inlet oil and gas, absorbs the heat of the inlet oil and gas to heat it up to become a higher-temperature refrigerant, and the cycle switching operation is repeated.

[0025] For the oil and gas side, when the first-level oil and gas condenser A is not frosted but the first-level oil and gas condenser B is frosted, the oil and gas valve is used to control the oil and gas to pass through the first-level oil and gas cooling box A; when the first-level oil and gas condenser A is frosted but the first-level oil and gas condenser B is not frosted, the oil and gas valve is used to switch the oil and gas to pass through the first-level oil and gas cooling box B.

[0026] The present invention is based on a cold-carrying cycle heat recovery subsystem, which can effectively recover the cold of oil and gas tail gas at about -70°C, and is used to replace the original compressor refrigeration to provide cooling capacity for the first-stage oil and gas condenser, reduce the compressor configuration of the first-stage oil and gas condenser, and greatly improve the energy utilization rate of the oil and gas recovery unit; by cyclically switching the flow direction of the refrigerant, the cooling, frosting, and defrosting cycles are cleverly realized, thereby effectively ensuring the normal and stable operation of the cold-carrying cycle cold recovery system. The cold-carrying cycle heat recovery oil and gas recovery system provided by the present invention has the advantages of low energy consumption, energy saving and environmental protection, simple refrigeration system, low cost, high reliability, etc., which greatly improves the energy saving and environmental protection, cost performance and operation reliability of the oil and gas recovery system.

[0027] In some embodiments, Figure 1 As shown, the secondary cooling module includes a secondary oil and gas condenser A (27), a secondary oil and gas condenser B (28), a third oil and gas valve (29), a fourth oil and gas valve (210), and a second oil and gas connecting pipe (211); the other end of the first oil and gas connecting pipe (26) is divided into two paths, one path is connected to one end of the secondary oil and gas condenser A (27), and the other path is connected to one end of the secondary oil and gas condenser B (28); the other end of the secondary oil and gas condenser A (27) is connected to one end of the third oil and gas valve (29), the other end of the secondary oil and gas condenser B (28) is connected to one end of the fourth oil and gas valve (210), the other end of the third oil and gas valve (29) is connected to the other end of the fourth oil and gas valve (210), and is connected to one end of the second oil and gas connecting pipe (211).

[0028] In this embodiment, the high-temperature and high-pressure oil and gas are partially liquefied after being cooled by the primary cooling module, and the remaining oil and gas continue to enter the secondary cooling module through the first oil and gas connecting pipe (26) for further cooling. By controlling the switching of the third oil and gas valve (29) and the fourth oil and gas valve (210), the remaining oil and gas can be further cooled and liquefied through the secondary oil and gas condenser A (27) or the secondary oil and gas condenser B (28) alone. Specifically, by controlling the third oil and gas valve (29) to open and the fourth oil and gas valve (210) to close, the remaining oil and gas is cooled and liquefied through the secondary oil and gas condenser A (27). During this process, if it is detected that the secondary oil and gas condenser A (27) is frosted, the third oil and gas valve (29) is controlled to close and the fourth oil and gas valve (210) is controlled to open, so that the remaining oil and gas is cooled and liquefied through the secondary oil and gas condenser B (28). In this way, by cyclically switching the oil and gas flow direction, the cooling, frosting and defrosting cycles can be cleverly achieved, thereby effectively ensuring the normal and stable operation of the cold-carrying circulating oil and gas recovery system.

[0029] In some embodiments, Figure 1 As shown, the three-stage cooling module includes a three-stage oil and gas condenser A (212), a three-stage oil and gas condenser B (213), a fifth oil and gas valve (214), a sixth oil and gas valve (215), and a third oil and gas connecting pipe (216); the other end of the second oil and gas connecting pipe (211) is divided into two paths, one path is connected to one end of the three-stage oil and gas condenser A (212), and the other path is connected to one end of the three-stage oil and gas condenser B (213); the other end of the three-stage oil and gas condenser A (212) is connected to one end of the fifth oil and gas valve (214), the other end of the three-stage oil and gas condenser B (214) is connected to one end of the sixth oil and gas valve (215), the other end of the fifth oil and gas valve (214) is connected to the other end of the sixth oil and gas valve (215), and is connected to one end of the third oil and gas connecting pipe (216).

[0030] In this embodiment, the remaining oil and gas after being cooled by the secondary cooling module can enter the tertiary cooling module through the second oil and gas connecting pipe (211) for further cooling. By controlling the switching of the fifth oil and gas valve (214) and the sixth oil and gas valve (215), the remaining oil and gas can be further cooled and liquefied through the tertiary oil and gas condenser A (212) or the tertiary oil and gas condenser B (213) alone. Specifically, by controlling the fifth oil and gas valve (214) to open and the sixth oil and gas valve (215) to close, the remaining oil and gas is cooled and liquefied through the three-stage oil and gas condenser A (212). During this process, if it is detected that the three-stage oil and gas condenser A (212) is frosted, the fifth oil and gas valve (214) is controlled to close and the sixth oil and gas valve (215) is controlled to open, so that the remaining oil and gas is cooled and liquefied through the three-stage oil and gas condenser B (213). In this way, by cyclically switching the oil and gas flow direction, the cooling, frosting and defrosting cycles can be cleverly achieved, thereby effectively ensuring the normal and stable operation of the cold-carrying circulation oil and gas recovery system.

[0031] In some embodiments, Figure 1 As shown, the four-stage heating module includes a four-stage heating box (217) connected to the other end of the third oil and gas connecting pipe (216), and the other end of the four-stage heating box (217) is connected to the oil and gas outlet (218); the four-stage oil and gas heater (310) is installed in the four-stage heating box (217).

[0032] In this embodiment, the low-temperature (about -70°C) oil and gas tail gas cooled by the three-stage cooling module enters the four-stage heating box (217) equipped with the four-stage oil and gas heater (310) through the third oil and gas connecting pipe (216). At this time, since the refrigerant cools the high-temperature and high-pressure oil and gas in the first-stage oil and gas condenser to become a higher-temperature refrigerant, the higher-temperature refrigerant can absorb the cold of the oil and gas tail gas of about -70°C through the four-stage oil and gas heater, cool down to become a lower-temperature refrigerant, and heat the -70°C oil and gas tail gas. The oil and gas exhaust gas is discharged at about 10°C; the relatively low-temperature refrigerant enters the primary oil and gas condenser, dissipates the cold energy to reduce the temperature of the inlet oil and gas, absorbs the heat of the inlet oil and gas to heat up to become a relatively high-temperature refrigerant, and operates in this cycle; this embodiment is based on the refrigeration cycle heat recovery subsystem, which can effectively recover the cold energy of the oil and gas exhaust gas at about -70°C, and is used to replace the original compressor refrigeration to provide refrigeration capacity for the primary oil and gas condenser, reduce the compressor configuration of the primary oil and gas condenser, and greatly improve the energy utilization rate of the oil and gas recovery unit.

[0033] In some embodiments, Figure 1As shown, it also includes a liquid oil outlet pipe (219), and the liquid oil outlet of the first-stage cooling box A (22), the liquid oil outlet of the first-stage cooling box B (23), the liquid oil outlet of the second-stage oil-gas condenser A (27), the liquid oil outlet of the second-stage oil-gas condenser B (28), the liquid oil outlet of the third-stage oil-gas condenser A (212), and the liquid oil outlet of the third-stage oil-gas condenser B (213) are all connected to the liquid oil outlet pipe (219).

[0034] In this embodiment, during the cooling process of the high-temperature and high-pressure oil and gas at different stages, the volatile organic matter therein is condensed and liquefied and then recovered through the liquid oil outlet pipe (219).

[0035] In summary, the present invention uses the higher temperature refrigerant from the first-stage oil and gas condenser in the refrigeration cycle heat recovery subsystem, absorbs the cold of the oil and gas tail gas at about -70°C through the four-stage oil and gas heater, cools down to become a lower temperature refrigerant, and heats the -70°C oil and gas tail gas to about 10°C for discharge; the lower temperature refrigerant enters the first-stage oil and gas condenser again, dissipates the cold to reduce the temperature of the imported oil and gas, absorbs the heat of the imported oil and gas to heat up to become a higher temperature refrigerant, and operates in this cycle; based on the refrigeration cycle heat recovery subsystem, the present invention can effectively recover the cold of the oil and gas tail gas at about -70°C, which is used to replace the original compressor refrigeration to provide refrigeration for the first-stage oil and gas condenser, reduce the compressor configuration of the first-stage oil and gas condenser, and greatly improve the energy utilization rate of the oil and gas recovery unit. The refrigeration cycle heat recovery oil and gas recovery system provided by the present invention has the advantages of low energy consumption, energy saving and environmental protection, simple refrigeration system, low cost, high reliability, etc., which greatly improves the energy saving and environmental protection, cost performance and operation reliability of the oil and gas recovery system.

[0036] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of the present invention, and all these changes or substitutions should fall within the protection scope of the present invention.

Claims

1. A cooling cycle heat recovery oil and gas recovery system, characterized in that: include: Oil and gas cooling liquefaction recovery subsystem and cooling cycle heat recovery subsystem; The oil and gas cooling liquefaction recovery subsystem comprises a primary cooling module, a secondary cooling module, a tertiary cooling module, and a quaternary heating module which are sequentially connected via an oil and gas connecting pipe; wherein the primary cooling module comprises: an oil and gas inlet (21), a primary cooling box A (22), a primary cooling box B (23), a first oil and gas valve (24), a second oil and gas valve (25), and a first oil and gas connecting pipe (26); the oil and gas inlet (21) is divided into two paths, one path is connected to one end of the primary cooling box A (22), and the other end of the cooling box A (22) is connected to one end of the first oil and gas valve (24); the other path is connected to one end of the primary cooling box B (23), and the other end of the primary cooling box B (23) is connected to one end of the second oil and gas valve (25); the other end of the first oil and gas valve (24) is connected to the other end of the second oil and gas valve (25), and is connected to one end of the first oil and gas connecting pipe (26); The secondary cooling cycle heat recovery subsystem comprises: a primary oil-gas condenser A (31) installed in a primary cooling oil tank A (22), a primary oil-gas condenser B (32) installed in a primary cooling oil tank B (23), a first secondary cooling agent valve (33), a second secondary cooling agent valve (34), a third secondary cooling agent valve (35), a fourth secondary cooling agent valve (36), a fifth secondary cooling agent valve (37), a sixth secondary cooling agent valve (38), a secondary cooling agent pump (39) and a four-stage oil-gas heater (310); wherein the secondary cooling agent outlet of the primary oil-gas condenser A (31) is divided into two paths, one path is connected to one end of the first secondary cooling agent valve (33), and the other path is connected to one end of the second secondary cooling agent valve (34); the other end of the first secondary cooling agent valve (33) is connected to the secondary cooling agent outlet of the primary oil-gas condenser B (32); the other end of the second secondary cooling agent valve (34) is connected to one end of the secondary cooling agent pump (39), and the secondary cooling agent pump (39) is connected to the secondary cooling agent outlet of the primary oil-gas condenser B (32). The other end is connected to the refrigerant inlet of the fourth-stage oil-gas heater (310); the refrigerant outlet of the fourth-stage oil-gas heater (310) is divided into two paths, one of which is connected to one end of the fourth refrigerant valve (36), and the other is connected to one end of the sixth refrigerant valve (38); the other end of the fourth refrigerant valve (36) is divided into two paths, one of which is connected to the refrigerant inlet of the first-stage oil-gas condenser A (31), and the other is connected to one end of the fifth refrigerant valve (37); the sixth refrigerant valve (38) is connected to the refrigerant inlet of the first-stage oil-gas condenser A (31). The other end of the valve (38) is divided into two paths, one of which is connected to the refrigerant inlet of the first-stage oil-gas condenser B (32), and the other is connected to one end of the third refrigerant valve (35); the other end of the third refrigerant valve (35) is connected to the connecting pipe of the second refrigerant valve (34) and the refrigerant pump (39); the other end of the fifth refrigerant valve (37) is connected to the connecting pipe of the first refrigerant valve (33) and the refrigerant outlet of the first-stage oil-gas condenser B (32).

2. The refrigeration cycle heat recovery oil and gas recovery system according to claim 1 is characterized in that: The secondary cooling module comprises a secondary oil and gas condenser A (27), a secondary oil and gas condenser B (28), a third oil and gas valve (29), a fourth oil and gas valve (210), and a second oil and gas connecting pipe (211); the other end of the first oil and gas connecting pipe (26) is divided into two paths, one path is connected to one end of the secondary oil and gas condenser A (27), and the other path is connected to one end of the secondary oil and gas condenser B (28); the other end of the secondary oil and gas condenser A (27) is connected to one end of the third oil and gas valve (29), the other end of the secondary oil and gas condenser B (28) is connected to one end of the fourth oil and gas valve (210), the other end of the third oil and gas valve (29) is connected to the other end of the fourth oil and gas valve (210), and is connected to one end of the second oil and gas connecting pipe (211).

3. The refrigeration cycle heat recovery oil and gas recovery system according to claim 2 is characterized in that: The three-stage cooling module comprises a three-stage oil and gas condenser A (212), a three-stage oil and gas condenser B (213), a fifth oil and gas valve (214), a sixth oil and gas valve (215), and a third oil and gas connecting pipe (216); the other end of the second oil and gas connecting pipe (211) is divided into two paths, one path is connected to one end of the three-stage oil and gas condenser A (212), and the other path is connected to one end of the three-stage oil and gas condenser B (213); the other end of the three-stage oil and gas condenser A (212) is connected to one end of the fifth oil and gas valve (214), the other end of the three-stage oil and gas condenser B (214) is connected to one end of the sixth oil and gas valve (215), the other end of the fifth oil and gas valve (214) is connected to the other end of the sixth oil and gas valve (215), and is connected to one end of the third oil and gas connecting pipe (216).

4. The refrigeration cycle heat recovery oil and gas recovery system according to claim 3 is characterized in that: The four-stage heating module comprises a four-stage heating box (217) connected to the other end of the third oil and gas connecting pipe (216), and the other end of the four-stage heating box (217) is connected to an oil and gas outlet (218); the four-stage oil and gas heater (310) is installed in the four-stage heating box (217).

5. The refrigeration cycle heat recovery oil and gas recovery system according to claim 1 is characterized in that: It also includes a liquid oil outlet pipe (219), and the liquid oil outlet of the first-stage cooling box A (22), the liquid oil outlet of the first-stage cooling box B (23), the liquid oil outlet of the second-stage oil-gas condenser A (27), the liquid oil outlet of the second-stage oil-gas condenser B (28), the liquid oil outlet of the third-stage oil-gas condenser A (212), and the liquid oil outlet of the third-stage oil-gas condenser B (213) are all connected to the liquid oil outlet pipe (219).

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