Control method based on cold-carrying circulation heat recovery oil gas recovery system
By adopting the cold-loaded cycle heat recovery control method in the oil and gas recovery system, the operation of valves and pumps is automatically controlled, and the problems of high energy consumption in the traditional system and complex refrigeration system are solved, and the efficiency of the oil and gas exhaust cooling is achieved, which improves the energy saving and environmental protection and reliability of the system.
Patent Information
- Application Number
- CN202411532218.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-30
- Publication Date
- 2025-03-04
AI Technical Summary
Traditional oil and gas recovery systems have problems such as high energy consumption, high pollution, complex refrigeration systems, high cost and low reliability, especially in terms of low efficiency in recycling high-grade refrigeration capacity of -70℃ oil and gas exhaust gas.
The control method based on the cold-circulation heat recovery oil and gas recovery system is adopted, and the central control module automatically controls the operation of oil and gas valves, refrigerant valves and refrigerant pumps based on actual data, so as to achieve efficient recovery of the cooling capacity of -70℃ oil and gas exhaust in the cold-circulation heat recovery subsystem.
Effectively recovering the cooling capacity of -70℃ oil and gas exhaust gas reduces dependence on compression mechanism cooling, reduces energy consumption, improves energy utilization, and simplifies the refrigeration system, reduces cost and complexity, and improves the reliability of the system.
Smart Images
Figure CN119554888A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of oil and gas recovery, and in particular to a control method for an oil and gas recovery system based on heat recovery from a cooling cycle. 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 around -70°C. They are used to condense and liquefy volatile organic compounds in oil and gas (VOCs gas) and 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 adding a heating device before being discharged into the atmosphere. However, the -70℃ oil and gas exhaust gas at the outlet of the final stage cold cycle heat recovery oil and gas recovery system has a lot 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 existing technology still needs to be improved and enhanced. Summary of the Invention
[0005] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a control method for an oil and gas recovery system based on a cold cycle heat 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 methods.
[0006] In order to achieve the above object, the present invention adopts the following technical solutions:
[0007] A control method for a heat recovery oil and gas recovery system based on a cold cycle, wherein the heat recovery oil and gas recovery system comprises: an electrical control subsystem, an oil and gas cooling liquefaction recovery subsystem and a cold cycle heat recovery subsystem; the electronic control subsystem comprises: an electrical control box (11), a sensor data acquisition module (113) arranged in the electrical control box (11) and electrically connected in sequence, a display operation module (114) and a central control module (115); a first pressure sensor (13), a first temperature sensor (14), a second pressure sensor (15), a second temperature sensor (16) electrically connected to the sensor data acquisition module (113) respectively. ), a third pressure sensor (17), a third temperature sensor (18), a fourth pressure sensor (19), a fourth temperature sensor (110), a fifth pressure sensor (111) and a fifth temperature sensor (112); a coolant pump speed regulator (12) electrically connected to the central control module (115); the oil and gas cooling liquefaction recovery subsystem includes a first-stage cooling module, a second-stage cooling module, a third-stage cooling module, and a fourth-stage heating module connected in sequence through an oil and gas connecting pipe; wherein the first-stage cooling module includes: an oil and gas inlet (21), a first-stage cooling box A (22), a first-stage 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 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); the cold cycle heat recovery subsystem includes: a first oil and gas condenser A (31) installed in the first cooling oil tank A (22) , a first-stage oil-gas condenser B (32) installed in a first-stage cooling oil tank B (23), a first coolant valve (33), a second coolant valve (34), a third coolant valve (35), a fourth coolant valve (36), a fifth coolant valve (37), a sixth coolant valve (38), a coolant pump (39) and a four-stage oil-gas heater (310); wherein the coolant outlet of the first-stage oil-gas condenser A (31) is divided into two paths, one path is connected to one end of the first coolant valve (33), and the other path is connected to one end of the second coolant valve (34); the other end of the first coolant valve (33) is connected to the coolant outlet of the first-stage oil-gas condenser B (32);The other end of the second coolant valve (34) is connected to one end of the coolant pump (39), and the other end of the coolant pump (39) is connected to the coolant inlet of the fourth-stage oil-gas heater (310). The coolant 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 coolant valve (36) and the other is connected to one end of the sixth coolant valve (38). The other end of the fourth coolant valve (36) is divided into two paths, one of which is connected to the coolant inlet of the first-stage oil-gas condenser A (31) and the other is connected to one end of the fifth coolant valve (37). The other end of the sixth coolant valve (38) is divided into two paths, one of which is connected to the coolant inlet of the first-stage oil-gas condenser A (31). The first pressure sensor (13) and the first temperature sensor (14) are arranged at the oil and gas inlet (21), and the second pressure sensor (15) and the second temperature sensor (16) are arranged at the first cooling module and the second cooling module. The invention relates to a method for controlling the cooling medium and the cooling medium in a cooling medium. The method comprises the following steps: a first oil-gas connecting pipe, a second oil-gas connecting pipe connecting the second-stage cooling module and the third-stage cooling module, a fourth oil-gas connecting pipe connecting the third-stage cooling module and the fourth-stage heating module, a fifth oil-gas connecting pipe connecting the third-stage cooling module and the fourth-stage heating module, and a fifth oil-gas connecting pipe connecting the fifth oil-gas connecting pipe. The method comprises the following steps: when the display operation module (114) is set to be turned on, the central control is used to control the cooling medium and the cooling medium. The module (115) controls the first oil and gas valve (24) to be opened, the second oil and gas valve (25) to be closed, the first coolant valve (33) to be opened, the second coolant valve (34) to be closed, the third coolant valve (35) to be opened, the fourth coolant valve (36) to be opened, the fifth coolant valve (37) to be closed, the sixth coolant valve (38) to be closed, and the coolant pump (39) to be opened; obtains the actual test pressure of the first pressure sensor (13) as P1, the actual test pressure of the second pressure sensor (15) as P2, and the actual test temperature of the second temperature sensor (16) as T2; and sets the pressure difference P on the display operation module (114); 1设定压差 , set the outlet temperature to T 2设定温度 , set the control temperature accuracy to T 2设定精度 ; When P1-P2≤P 1设定压差When P1-P2>P 1设定压差 When T 2设定温度 -T 2设定精度 ≤T2≤T 2设定温度 +T 2设定精度 When T2>T 2设定温度 +T 2设定精度 When T2 < T 2设定温度 -T 2设定精度 When the coolant pump speed regulator (12) is used to control the coolant pump (39) to reduce the speed, reduce the coolant flow rate until the machine stops; when the display operation module (114) is set to shut down, the central control module (115) controls the first oil and gas valve (24), the second oil and gas valve (25), the first coolant valve (33), the second coolant valve (34), the third coolant valve (35), the fourth coolant valve (36), the fifth coolant valve (37), the sixth coolant valve (38), and the coolant pump (39) to all be closed.
[0008] The control method of the oil and gas recovery system based on the heat recovery of the cold cycle, wherein 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), and the second oil and gas condenser B (28) is connected to one end of the third oil and gas valve (29). The other end 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); the control method further comprises the steps of: when the display operating system (114) is set to be turned on, controlling the third oil and gas valve (29) to be opened and the fourth oil and gas valve (210) to be closed through the central control module (115); obtaining the actual test pressure of the third pressure sensor (17) as P3, the actual test pressure of the second pressure sensor (15) as P2, setting P on the display operating system (114); 2设定压差 ; When P2-P3≤P 2设定压差 When P2-P3>P 2设定压差 When the display operating system (114) is set to shut down, the third oil and gas valve (29) and the fourth oil and gas valve (210) are controlled to be closed. When the display operating system (114) is set to shut down, the third oil and gas valve (29) and the fourth oil and gas valve (210) are controlled to be closed.
[0009] The control method of the oil and gas recovery system based on the heat recovery of the cooling cycle, wherein 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), and the three-stage oil and gas condenser B ( The other end of the fifth oil and gas valve (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); the control method further comprises the steps of: when the display operating system (114) is set to be turned on, controlling the fifth oil and gas valve (214) to be opened and the sixth oil and gas valve (215) to be closed through the central control module (115); obtaining the actual test pressure of the third pressure sensor (17) as P3, the actual test pressure of the fourth pressure sensor (19) as P4, setting P on the display operating system (114); 3设定压差 ; When P3-P4≤P 3设定压差 When P3-P4>P 3设定压差 When the display operating system (114) is set to be shut down, the fifth oil and gas valve (214) and the sixth oil and gas valve (215) are controlled to be closed. When the display operating system (114) is set to be shut down, the fifth oil and gas valve (214) and the sixth oil and gas valve (215) are controlled to be closed.
[0010] The control method of the oil and gas recovery system based on the heat recovery of the cold cycle, wherein the first-stage oil and gas condenser A and the first-stage oil and gas condenser B are respectively connected to a cold agent pump for cooling, the second-stage oil and gas condenser A and the second-stage oil and gas condenser B are respectively connected to a second-stage refrigeration compressor for cooling, and the third-stage oil and gas condenser A and the third-stage oil and gas condenser B are respectively connected to a third-stage refrigeration compressor for cooling; the control method further comprises the steps of: when the display operation module (114) is set to power on, synchronously starting the cold agent pump (39) and the second-stage refrigeration compressor; obtaining the actual test temperature T3 of the third temperature sensor (18), and setting the preset temperature T on the display operation module (114); 3预设温度 ; When T3>T 3预设温度 When T3≤T 3预设温度 When the display operation module (114) is set to shut down, the three-stage refrigeration compressor is first controlled to stop, then the two-stage refrigeration compressor is controlled to stop, and finally the refrigerant pump is controlled to stop.
[0011] The control method of the oil and gas recovery system based on the heat recovery of the cooling cycle further includes the steps of: obtaining the actual test temperature of the third temperature sensor (18) as T3, setting the outlet air temperature as T on the display operation module (114) 3设定温度 , set the control accuracy to T 3设定精度 When T 3设定温度 -T 3设定精度 ≤T3≤T 3设定温度 +T 3设定精度 When T3>T 3设定温度 +T 3设定精度 When T3<T 3设定温度 -T 3设定精度 When the secondary refrigeration compressor is controlled to unload.
[0012] The control method of the oil and gas recovery system based on the heat recovery of the cooling cycle further includes the steps of: obtaining the actual test temperature of the fourth temperature sensor (110) as T4, setting the outlet air temperature as T on the actual operation module (114) 4设定温度 , set the control accuracy to T 4设定精度 When T 4设定温度 -T 4设定精度 ≤T4≤T 4设定温度 +T 4设定精度 When T4>T 4设定温度 +T 4设定精度 When T4<T 4设定温度 -T 4设定精度 When the 3rd stage refrigeration compressor is controlled to unload.
[0013] Beneficial effects:
[0014] The present invention provides a control method for an oil and gas recovery system based on a cold cycle heat recovery. The central control module sets input requirements based on the start and stop of the display operation module, the oil and gas inlet and outlet temperatures at various levels, and the inlet and outlet pressure difference. The sensor data acquisition system collects data during actual operation, automatically calculates and controls each execution system, and controls the operation of the refrigeration system corresponding to each oil and gas valve, the refrigerant valve, the refrigerant pump, and the oil and gas condensers at various levels. The control method for an oil and gas recovery system based on a cold cycle heat recovery of the present invention can effectively recover the cooling capacity of oil and gas tail gas at about -70°C, and is used to replace the original use of 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. The control method for an oil and gas recovery system based on a cold cycle heat recovery provided by the present invention has the advantages of low energy consumption, energy saving and environmental protection, simple refrigeration system, low cost, and high reliability, which greatly improves the energy saving and environmental protection, cost performance, and operational reliability of the oil and gas recovery system. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 This is a structural diagram of the cooling cycle heat recovery oil and gas recovery system provided by the present invention.
[0016] Figure 2 This is a structural diagram of the electrical control subsystem provided by the present invention.
[0017] Figure 3 The present invention provides a flow chart of a control method for a heat recovery oil and gas recovery system based on a cooling cycle.
[0018] Main component symbols: 11-electrical control box, 12-coolant pump speed regulator, 13-first pressure sensor, 14-first temperature sensor, 15-second pressure sensor, 16-second temperature sensor, 17-third pressure sensor, 18-third temperature sensor, 19-fourth pressure sensor, 110-fourth temperature sensor, 111-fifth pressure sensor, 112-fifth temperature sensor, 113-sensor data acquisition module, 114-display operation module, 115-central control module, 21-oil and gas inlet, 22-first -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
[0019] The present invention provides a control method for an oil and gas recovery system based on a cold cycle heat recovery system. 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.
[0020] In the description of the present invention, it should be understood that the orientation or position relationship indicated by the terms "top" and "bottom" 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 of the present invention; in addition, the terms "installation" and "connection" should be understood in a broad sense. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0021] See also Figure 1-Figure 3The present invention provides a control method for a heat recovery oil and gas recovery system based on a cold cycle. As shown in the figure, the heat recovery oil and gas recovery system for a cold cycle comprises: an electrical control subsystem, an oil and gas cooling liquefaction recovery subsystem and a cold cycle heat recovery subsystem; the electronic control subsystem comprises: an electrical control box (11), a sensor data acquisition module (113) arranged in the electrical control box (11) and electrically connected in sequence, a display operation module (114) and a central control module (115); a first pressure sensor (13), a first temperature sensor (14), a second pressure sensor (15), a second temperature sensor (15) and a second pressure sensor (15) electrically connected to the sensor data acquisition module (113) respectively. A temperature sensor (16), a third pressure sensor (17), a third temperature sensor (18), a fourth pressure sensor (19), a fourth temperature sensor (110), a fifth pressure sensor (111), and a fifth temperature sensor (112); a coolant pump speed regulator (12) electrically connected to the central control module (115); the oil and gas cooling liquefaction recovery subsystem includes a first-stage cooling module, a second-stage cooling module, a third-stage cooling module, and a fourth-stage heating module connected in sequence through an oil and gas connecting pipe; wherein the first-stage cooling module includes: an oil and gas inlet (21), a first-stage cooling box A (22), a first-stage 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 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); the cold cycle heat recovery subsystem includes: a first oil and gas condenser A ( 31), a first-stage oil-gas condenser B (32) installed in a first-stage cooling oil tank B (23), a first coolant valve (33), a second coolant valve (34), a third coolant valve (35), a fourth coolant valve (36), a fifth coolant valve (37), a sixth coolant valve (38), a coolant pump (39) and a four-stage oil-gas heater (310); wherein the coolant outlet of the first-stage oil-gas condenser A (31) is divided into two paths, one path is connected to one end of the first coolant valve (33), and the other path is connected to one end of the second coolant valve (34); the other end of the first coolant valve (33) is connected to the coolant outlet of the first-stage oil-gas condenser B (32);The other end of the second coolant valve (34) is connected to one end of the coolant pump (39), the other end of the coolant pump (39) is connected to the coolant inlet of the fourth oil-gas heater (310), and the coolant outlet of the fourth oil-gas heater (310) is divided into two paths, one of which is connected to one end of the fourth coolant valve (36) and the other is connected to one end of the sixth coolant valve (38); the other end of the fourth coolant valve (36) is divided into two paths, one of which is connected to the coolant inlet of the first oil-gas condenser A (31) and the other is connected to one end of the fifth coolant valve (37); the other end of the sixth coolant valve (38) is divided into two paths, one of which is connected to the coolant inlet of the first oil-gas condenser B (32) and the other is connected to one end of the third coolant valve (35); the other end of the third coolant valve (35) is connected to the connecting pipe between the second coolant valve (34) and the coolant pump (39); the fifth coolant valve (37) is connected to the coolant inlet of the first oil-gas condenser B (32). ) is connected to the connecting pipe of the first coolant valve (33) and the coolant outlet of the first oil-gas condenser B (32); the first pressure sensor (13) and the first temperature sensor (14) are arranged at the oil-gas inlet (21); the second pressure sensor (15) and the second temperature sensor (16) are arranged on the first oil-gas connecting pipe connecting the first cooling module and the second cooling module; the third pressure sensor (17) and the third temperature sensor (18) are arranged on the second oil-gas connecting pipe connecting the second cooling module and the third cooling module; the fourth pressure sensor (19) and the fourth temperature sensor (110) are arranged on the third oil-gas connecting pipe connecting the third cooling module and the fourth heating module; the fifth pressure sensor (111) and the fifth temperature sensor (112) are arranged at the oil-gas outlet; the coolant pump (39) is electrically connected to the coolant pump speed regulator (12);
[0022] The control method comprises the steps of:
[0023] S100, when the display operation module (114) is set to be turned on, the central control module (115) controls the first oil and gas valve (24) to be opened, the second oil and gas valve (25) to be closed, the first coolant valve (33) to be opened, the second coolant valve (34) to be closed, the third coolant valve (35) to be opened, the fourth coolant valve (36) to be opened, the fifth coolant valve (37) to be closed, the sixth coolant valve (38) to be closed, and the coolant pump (39) to be turned on;
[0024] S200, obtaining the actual test pressure of the first pressure sensor (13) as P1, the actual test pressure of the second pressure sensor (15) as P2, and the actual test temperature of the second temperature sensor (16) as T2; setting the pressure difference P on the display operation module (114); 1设定压差 , set the outlet temperature to T 2设定温度 , set the control temperature accuracy to T2设定精度 ;
[0025] S300, when P1-P2≤P 1设定压差 When the first oil and gas valve (24), the second oil and gas valve (25), the first coolant valve (33), the second coolant valve (34), the third coolant valve (35), the fourth coolant valve (36), the fifth coolant valve (37), and the sixth coolant valve (38) are controlled to operate according to the original startup setting state;
[0026] S400, when P1-P2>P 1设定压差 When the first oil and gas valve (24) is closed, the second oil and gas valve (25) is opened, the first coolant valve (33) is closed, the second coolant valve (34) is opened, the third coolant valve (35) is closed, the fourth coolant valve (36) is closed, the fifth coolant valve (37) is opened, and the sixth coolant valve (38) is opened;
[0027] S500, when T 2设定温度 -T 2设定精度 ≤T2≤T 2设定温度 +T 2设定精度 When the speed of the refrigerant pump (39) is kept constant by controlling the refrigerant pump speed regulator (12);
[0028] S600, when T2>T 2设定温度 +T 2设定精度 When the load is 100%, the speed of the brine pump (39) is increased by controlling the brine pump speed regulator (12), thereby increasing the brine flow rate until the load is 100%;
[0029] S700, when T2<T 2设定温度 -T 2设定精度 When the coolant pump speed regulator (12) is used to control the coolant pump (39) to reduce the speed, thereby reducing the coolant flow rate until the machine stops;
[0030] S800, when the display operation module (114) is set to shut down, the central control module (115) controls the first oil and gas valve (24), the second oil and gas valve (25), the first coolant valve (33), the second coolant valve (34), the third coolant valve (35), the fourth coolant valve (36), the fifth coolant valve (37), the sixth coolant valve (38), and the coolant pump (39) to all be closed.
[0031] In traditional oil and gas recovery systems, the imported oil and gas undergo multi-stage cooling at around -70°C and are 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 many problems in traditional oil and gas recovery methods, such as high energy consumption, high pollution, complex refrigeration system, high cost, and low reliability.
[0032] To solve the problems of traditional oil and gas recovery methods, the central control module of the present invention sets input requirements based on the start and stop of the display operation module, the inlet and outlet temperatures of each level of oil and gas, and the inlet and outlet pressure difference. It collects data during actual operation through the sensor data acquisition system, automatically calculates and controls each execution subsystem, and controls the operation of the refrigeration system corresponding to each oil and gas valve, refrigerant valve, refrigerant pump, and each level of oil and gas condenser. The present invention adopts an innovative control method for the refrigeration cycle heat recovery oil and gas recovery system. The higher temperature refrigerant from the first-stage oil and gas condenser in the refrigeration cycle heat recovery subsystem is used to absorb the cold energy of the oil and gas exhaust gas at about -70°C through the four-stage oil and gas heater, and is cooled to become a lower temperature refrigerant. At the same time, the -70°C oil and gas exhaust gas is heated to about 10°C for discharge; the lower temperature refrigerant enters the first-stage oil and gas condenser, dissipates cold energy to reduce the inlet oil and gas temperature, absorbs the heat of the inlet oil and gas, and heats up to become a higher temperature refrigerant, and the cycle continues.
[0033] The present invention controls the opening and closing of corresponding oil and gas valves and refrigerant valves and adjusts the flow rate of the refrigerant pump based on the comparison between the actual pressure difference and the set pressure difference, as well as the comparison between the actual temperature and the set temperature, so as to achieve effective recovery of the cooling capacity of oil and gas exhaust gas at about -70°C through the refrigerant, which 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.
[0034] Specifically, when the display operation module is set to be turned on, the first oil and gas valve (24) is opened, the second oil and gas valve (25) is closed, the first coolant valve (33) is opened, the second coolant valve (34) is closed, the third coolant valve (35) is opened, the fourth coolant valve (36) is opened, the fifth coolant valve (37) is closed, the sixth coolant valve (38) is closed, and the coolant pump (39) is turned on. At this time, the high-temperature and high-pressure oil and gas only enters the first-stage oil and gas condenser A (31) from the oil and gas inlet (21), and in this process, the higher-temperature refrigerant coming out of the first-stage oil and gas condenser A (31) first passes through the first-stage oil and gas condenser B to heat the frosted first-stage oil and gas condenser B and defrost it; then it absorbs the cold energy of the oil and gas tail gas at about -70°C through the fourth-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 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 high-temperature and high-pressure oil and gas, and absorbs the heat of the inlet high-temperature and high-pressure oil and gas to heat it up to become a higher-temperature refrigerant.
[0035] In this process, the actual pressure difference between the first pressure sensor and the second pressure sensor is obtained in real time, and the actual pressure difference is compared with the preset pressure difference. If P1-P2≤P 1设定压差 , it means that the actual pressure difference between the first pressure sensor and the second pressure sensor is not large, and it is determined that the first-stage oil and gas condenser A (31) is temporarily not frosted. At this time, the first oil and gas valve (24), the second oil and gas valve (25), the first refrigerant valve (33), the second refrigerant valve (34), the third refrigerant valve (35), the fourth refrigerant valve (36), the fifth refrigerant valve (37), and the sixth refrigerant valve (38) are controlled by the central control module (115) to operate according to the original startup setting state.
[0036] If P1-P2>P 1设定压差, indicating that the actual pressure difference between the first pressure sensor and the second pressure sensor is large, that is, the wind resistance in the first-stage oil and gas condenser A (31) is large. At this time, it is determined that the first-stage oil and gas condenser A (31) is frosted, and the central control module (115) controls the first oil and gas valve (24) to be closed, the second oil and gas valve (25) to be opened, the first refrigerant valve (33) to be closed, the second refrigerant valve (34) to be opened, the third refrigerant valve (35) to be closed, the fourth refrigerant valve (36) to be closed, the fifth refrigerant valve (37) to be opened, and the sixth refrigerant valve (38) to be opened; at this time, the high-temperature and high-pressure oil and gas have switched the flow direction through the oil and gas valves, and the The high-temperature and high-pressure oil and gas only pass through the first-stage oil and gas condenser B (32). In this process, the higher-temperature refrigerant coming out of the first-stage oil and gas condenser B (32) first passes through the first-stage oil and gas condenser A to heat the frosted first-stage oil and gas condenser A and defrost it; then it absorbs the cold energy of the oil and gas tail gas at about -70°C through the fourth-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 before being discharged; the lower-temperature refrigerant enters the first-stage oil and gas condenser B again, dissipates the cold energy to reduce the temperature of the inlet high-temperature and high-pressure oil and gas, absorbs the heat of the inlet high-temperature and high-pressure oil and gas, and heats it up to become a higher-temperature refrigerant, and the cycle switches in this way.
[0037] In the present invention, when T 2设定温度 -T 2设定精度 ≤T2≤T 2设定温度 +T 2设定精度 When T2>T 2设定温度 +T 2设定精度 When T2 < T 2设定温度 -T 2设定精度 When the temperature of the high-temperature and high-pressure oil and gas is too high in the first-stage cooling module, the coolant pump (39) is controlled by the coolant pump speed regulator (12) to reduce the speed and reduce the coolant flow until the machine stops.
[0038] That is to say, in the present invention, for the refrigerant side, when the first-stage oil-gas condenser A is not frosted but the first-stage oil-gas condenser B is frosted, the refrigerant valve is used to control the refrigerant flow direction. The higher-temperature refrigerant coming out of the first-stage oil-gas condenser A in the refrigerant cycle heat recovery subsystem first passes through the first-stage oil-gas condenser B to heat the frosted first-stage oil-gas condenser B and defrost it; then it absorbs the cold energy of the oil and gas exhaust gas at about -70°C through the four-stage oil-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-gas condenser A again, dissipates the cold energy to reduce the temperature of the inlet oil and gas, and absorbs the heat of the inlet oil and gas to heat it up to become a higher-temperature refrigerant;
[0039] 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 heat recovery subsystem of the cooling soul ring first passes through the first-stage oil and gas condenser A to heat the frosted first-stage oil and gas condenser A and defrost it. Then, it 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 inlet oil and gas temperature, 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.
[0040] On the oil and gas side, when the first-stage oil and gas condenser A is not frosted and the first-stage 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-stage oil and gas cooling box A; when the first-stage oil and gas condenser A is frosted and the first-stage 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-stage oil and gas cooling box B.
[0041] The present invention, based on a cold-carrying cycle heat recovery subsystem, can effectively recover the cooling energy of oil and gas exhaust gas at around -70°C, replacing the original compressor refrigeration system used to provide cooling capacity for the first-stage oil and gas condenser. This reduces the number of compressors required for the first-stage oil and gas condenser and significantly improves the energy utilization rate of the oil and gas recovery unit. By cyclically switching the flow direction of the refrigerant, it cleverly implements cooling, frosting, and defrosting cycles, effectively ensuring the normal and stable operation of the cold-carrying cycle cold recovery system. The control method for the cold-carrying cycle heat recovery oil and gas recovery system provided by the present invention has the advantages of low energy consumption, energy conservation and environmental protection, a simple refrigeration system, low cost, and high reliability, significantly improving the energy conservation and environmental protection, cost-effectiveness, and operational reliability of the oil and gas recovery system.
[0042] In some embodiments, 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), and the other end of the secondary oil and gas condenser B (28) is connected to the fourth oil and gas valve The control method further comprises the steps of: when the display operating system (114) is set to be turned on, controlling the third oil and gas valve (29) to open and the fourth oil and gas valve (210) to close by the central control module (115); obtaining the actual test pressure of the third pressure sensor (17) as P3 and the actual test pressure of the second pressure sensor (15) as P2, setting P on the display operating system (114); and 2设定压差 ; When P2-P3≤P 2设定压差 When P2-P3>P 2设定压差 When the display operating system (114) is set to shut down, the third oil and gas valve (29) and the fourth oil and gas valve (210) are controlled to be closed. When the display operating system (114) is set to shut down, the third oil and gas valve (29) and the fourth oil and gas valve (210) are controlled to be closed.
[0043] In this embodiment, when the display operation module (114) is set to be turned on, the central control module (115) controls the third oil and gas valve (29) to be opened and the fourth oil and gas valve (210) to be closed. At this time, the oil and gas coming out of the first oil and gas connecting pipe (26) is further cooled by the secondary oil and gas condenser A (27). In this process, the actual pressure difference between the second pressure sensor (15) and the third pressure sensor (17) is obtained in real time, and the actual pressure difference is compared with the preset pressure difference. If it is monitored that P2-P3≤P 2设定压差 , indicating that the actual pressure difference between the second pressure sensor and the third pressure sensor is not large, and it is determined that the secondary oil and gas condenser A (27) is temporarily not frosted, so the third oil and gas valve (29) is controlled to open, and the fourth oil and gas valve (210) is operated according to the original startup setting state; if it is monitored that P2-P3>P 2设定压差, it means that the actual pressure difference between the second pressure sensor and the third pressure sensor is large, that is, the wind resistance in the secondary oil and gas condenser A (27) is large. At this time, it is determined that the secondary oil and gas condenser A (27) is frosted, and the central control module (115) controls the third oil and gas valve (29) to be closed and the fourth oil and gas valve (210) to be opened. At this time, the oil and gas have switched the flow direction through the oil and gas valve. At this time, the oil and gas are cooled through the secondary oil and gas condenser B (28). In this way, by cyclically switching the oil and gas flow direction, the oil and gas cooling, frosting, and defrosting cycle is efficiently achieved, thereby effectively ensuring the normal and stable operation of the variable flow direction cold cycle oil and gas recovery system.
[0044] In some embodiments, the three-stage cooling module includes a three-stage oil-gas condenser A (212), a three-stage oil-gas condenser B (213), a fifth oil-gas valve (214), a sixth oil-gas valve (215), and a third oil-gas connecting pipe (216); the other end of the second oil-gas connecting pipe (211) is divided into two paths, one path is connected to one end of the three-stage oil-gas condenser A (212), and the other path is connected to one end of the three-stage oil-gas condenser B (213); the other end of the three-stage oil-gas condenser A (212) is connected to one end of the fifth oil-gas valve (214), and the other end of the three-stage oil-gas condenser B (214) is connected to One end of the sixth oil and gas valve (215) is connected, and 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); the control method further comprises the steps of: when the display operating system (114) is set to be turned on, controlling the fifth oil and gas valve (214) to be opened and the sixth oil and gas valve (215) to be closed through the central control module (115); obtaining the actual test pressure of the third pressure sensor (17) as P3, the actual test pressure of the fourth pressure sensor (19) as P4, setting P on the display operating system (114); 3设定压差 ; When P3-P4≤P 3设定压差 When P3-P4>P 3设定压差 When the display operating system (114) is set to be shut down, the fifth oil and gas valve (214) and the sixth oil and gas valve (215) are controlled to be closed. When the display operating system (114) is set to be shut down, the fifth oil and gas valve (214) and the sixth oil and gas valve (215) are controlled to be closed.
[0045] In this embodiment, when the display operation module (114) is set to be turned on, the central control module (115) controls the fifth oil and gas valve (214) to be opened and the sixth oil and gas valve (215) to be closed. At this time, the oil and gas coming out of the second oil and gas connecting pipe (211) is further cooled by the three-stage oil and gas condenser A (212). In this process, the actual pressure difference between the third pressure sensor (17) and the fourth pressure sensor (19) is obtained in real time, and the actual pressure difference is compared with the preset pressure difference. If it is monitored that P3-P4≤P 3设定压差 , indicating that the actual pressure difference between the third pressure sensor and the fourth pressure sensor is not large, and it is determined that the third-stage oil-gas condenser A (212) is not frosted temporarily, and the fifth oil-gas valve (214) and the sixth oil-gas valve (215) are controlled to operate according to the original startup setting state; if it is monitored that P3-P4>P 3设定压差 When the actual pressure difference between the third pressure sensor and the fourth pressure sensor is large, that is, the wind resistance in the third-stage oil-gas condenser A (212) is large. At this time, it is determined that the second-stage oil-gas condenser A (212) is frosted, and the fifth oil-gas valve (214) is controlled to be closed and the sixth oil-gas valve (215) is opened through the central control module (115). At this time, the oil and gas have switched the flow direction through the oil and gas valve. At this time, the oil and gas are cooled through the third-stage oil-gas condenser B (214). In this way, by cyclically switching the oil and gas flow direction, the oil and gas cooling, frosting, and defrosting cycle is efficiently achieved, thereby effectively ensuring the normal and stable operation of the variable flow direction cold cycle oil and gas recovery system.
[0046] In some embodiments, the first-stage oil-gas condenser A and the first-stage oil-gas condenser B are connected to a coolant pump for cooling, the second-stage oil-gas condenser A and the second-stage oil-gas condenser B are connected to a second-stage refrigeration compressor for cooling, and the third-stage oil-gas condenser A and the third-stage oil-gas condenser B are connected to a third-stage refrigeration compressor for cooling; the control method further comprises the steps of: when the display operation module (114) is set to power on, synchronously starting the coolant pump (39) and the second-stage refrigeration compressor; obtaining the actual test temperature T3 of the third temperature sensor (18), and setting the preset temperature T on the display operation module (114); 3预设温度 ; When T3>T 3预设温度 When T3≤T 3预设温度 When the display operation module (114) is set to shut down, the third-stage refrigeration compressor is first controlled to stop, then the second-stage refrigeration compressor is controlled to stop, and finally the refrigerant pump is controlled to stop.
[0047] In some embodiments, the actual test temperature of the third temperature sensor (18) is obtained as T3, and the air outlet temperature is set as T on the display operation module (114). 3设定温度 , set the control accuracy to T 3设定精度 When T 3设定温度 -T 3设定精度 ≤T3≤T 3设定温度 +T 3设定精度 When T3>T 3设定温度 +T 3设定精度 When T3<T 3设定温度 -T 3设定精度 When , it means that the high-temperature and high-pressure oil and gas are cooling too fast in the secondary cooling module. At this time, the secondary refrigeration compressor can be controlled to unload.
[0048] In some embodiments, the actual test temperature of the fourth temperature sensor (110) is obtained as T4, and the outlet air temperature is set as T on the actual operation module (114). 4设定温度 , set the control accuracy to T 4设定精度 When T 4设定温度 -T 4设定精度 ≤T4≤T 4设定温度 +T 4设定精度 When T4>T 4设定温度 +T 4设定精度 When T4<T 4设定温度 -T 4设定精度 When , it means that the high-temperature and high-pressure oil and gas are cooling too fast in the three-stage cooling module. At this time, the three-stage refrigeration compressor can be controlled to unload.
[0049] In summary, the control method for a refrigerated heat recovery oil and gas recovery system provided by the present invention can effectively recover the cooling energy of oil and gas exhaust gases at around -70°C, replacing the original compressor refrigeration system used to provide cooling capacity for the first-stage oil and gas condenser. This reduces the number of compressors required for the first-stage oil and gas condenser and significantly improves the energy efficiency of the oil and gas recovery unit. The control method for a refrigerated heat recovery oil and gas recovery system based on a refrigerated heat recovery system provided by the present invention has the advantages of low energy consumption, energy conservation and environmental protection, a simple refrigeration system, low cost, and high reliability. This significantly improves the energy conservation and environmental protection, cost-effectiveness, and operational reliability of the oil and gas recovery system.
[0050] 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 such changes or substitutions should fall within the protection scope of the present invention.
Claims
1. A control method for an oil and gas recovery system based on a cooling cycle heat recovery system, characterized in that: The refrigeration cycle heat recovery oil and gas recovery system comprises: an electrical control subsystem, an oil and gas cooling liquefaction recovery subsystem and a refrigeration cycle heat recovery subsystem; The electronic control subsystem comprises: an electrical control box (11), a sensor data acquisition module (113) disposed in the electrical control box (11) and electrically connected in sequence, a display operation module (114), and a central control module (115); a first pressure sensor (13), a first temperature sensor (14), a second pressure sensor (15), a second temperature sensor (16), a third pressure sensor (17), a third temperature sensor (18), a fourth pressure sensor (19), a fourth temperature sensor (110), a fifth pressure sensor (111), and a fifth temperature sensor (112) electrically connected to the sensor data acquisition module (113); and a coolant pump speed regulator (12) electrically connected to the central control module (115); 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); The first pressure sensor (13) and the first temperature sensor (14) are arranged at the oil and gas inlet (21); the second pressure sensor (15) and the second temperature sensor (16) are arranged on the first oil and gas connecting pipe connecting the first cooling module and the second cooling module; the third pressure sensor (17) and the third temperature sensor (18) are arranged on the second oil and gas connecting pipe connecting the second cooling module and the third cooling module; the fourth pressure sensor (19) and the fourth temperature sensor (110) are arranged on the third oil and gas connecting pipe connecting the third cooling module and the fourth heating module; the fifth pressure sensor (111) and the fifth temperature sensor (112) are arranged at the oil and gas outlet; the coolant pump (39) is electrically connected to the coolant pump speed regulator (12); The control method comprises the steps of: When the display operation module (114) is set to start, the central control module (115) controls the first oil and gas valve (24) to open, the second oil and gas valve (25) to close, the first coolant valve (33) to open, the second coolant valve (34) to close, the third coolant valve (35) to open, the fourth coolant valve (36) to open, the fifth coolant valve (37) to close, the sixth coolant valve (38) to close, and the coolant pump (39) to start; The actual test pressure of the first pressure sensor (13) is obtained as P1, the actual test pressure of the second pressure sensor (15) is obtained as P2, and the actual test temperature of the second temperature sensor (16) is obtained as T2; the pressure difference P is set on the display operation module (114); 1设定压差 , set the outlet temperature to T 2设定温度 , set the control temperature accuracy to T 2设定精度 ; When P1-P2≤P 1设定压差 When the first oil and gas valve (24), the second oil and gas valve (25), the first refrigerant valve (33), the second refrigerant valve (34), the third refrigerant valve (35), the fourth refrigerant valve (36), the fifth refrigerant valve (37) and the sixth refrigerant valve (38) are controlled to operate according to the original startup setting state; When P1-P2>P 1设定压差 When the first oil and gas valve (24) is closed, the second oil and gas valve (25) is opened, the first coolant valve (33) is closed, the second coolant valve (34) is opened, the third coolant valve (35) is closed, the fourth coolant valve (36) is closed, the fifth coolant valve (37) is opened, and the sixth coolant valve (38) is opened; When T 2设定温度 -T 2设定精度 ≤T2≤T 2设定温度 +T 2设定精度 When the speed of the coolant pump (39) is kept constant by controlling the coolant pump speed regulator (12); When T2>T 2设定温度 +T 2设定精度 When the load is 100%, the speed of the brine pump (39) is increased by controlling the brine pump speed regulator (12), thereby increasing the brine flow rate until the load is 100%; When T2<T 2设定温度 -T 2设定精度 When the coolant pump speed regulator (12) is used to control the coolant pump (39) to reduce the speed, thereby reducing the coolant flow rate until the machine stops; When the display operation module (114) is set to shut down, the first oil and gas valve (24), the second oil and gas valve (25), the first coolant valve (33), the second coolant valve (34), the third coolant valve (35), the fourth coolant valve (36), the fifth coolant valve (37), the sixth coolant valve (38), and the coolant pump (39) are all controlled to be closed through the central control module (115).
2. The control method of the oil and gas recovery system based on the cooling cycle heat recovery 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); the control method further comprises the steps of: When the display operating system (114) is set to start up, the third oil and gas valve (29) is controlled to be opened and the fourth oil and gas valve (210) is controlled to be closed through the central control module (115); The actual test pressure of the third pressure sensor (17) is obtained as P3, the actual test pressure of the second pressure sensor (15) is obtained as P2, and P is set on the display operating system (114). 2设定压差 ; When P2-P3≤P 2设定压差 When the third oil and gas valve (29) and the fourth oil and gas valve (210) are controlled to operate according to the original startup setting state; When P2-P3>P 2设定压差 When the third oil and gas valve (29) is controlled to be closed, the fourth oil and gas valve (210) is controlled to be opened; When the display operating system (114) is set to shut down, the third oil and gas valve (29) and the fourth oil and gas valve (210) are controlled to be completely closed.
3. The control method of the oil and gas recovery system based on the cooling cycle heat recovery according to claim 2 is characterized in that: The three-stage cooling module comprises a three-stage oil-gas condenser A (212), a three-stage oil-gas condenser B (213), a fifth oil-gas valve (214), a sixth oil-gas valve (215), and a third oil-gas connecting pipe (216); the other end of the second oil-gas connecting pipe (211) is divided into two paths, one path is connected to one end of the three-stage oil-gas condenser A (212), and the other path is connected to one end of the three-stage oil-gas condenser B (213); the other end of the three-stage oil-gas condenser A (212) is connected to one end of the fifth oil-gas valve (214), the other end of the three-stage oil-gas condenser B (214) is connected to one end of the sixth oil-gas valve (215), the other end of the fifth oil-gas valve (214) is connected to the other end of the sixth oil-gas valve (215), and is connected to one end of the third oil-gas connecting pipe (216); the control method further comprises the steps of: When the display operating system (114) is set to start, the fifth oil and gas valve (214) is controlled to open and the sixth oil and gas valve (215) is controlled to close through the central control module (115); The actual test pressure of the third pressure sensor (17) is obtained as P3, the actual test pressure of the fourth pressure sensor (19) is obtained as P4, and P is set on the display operating system (114). 3设定压差 ; When P3-P4≤P 3设定压差 When the fifth oil and gas valve (214) and the sixth oil and gas valve (215) are controlled to operate according to the original startup setting state; When P3-P4>P 3设定压差 When the fifth oil and gas valve (214) is controlled to be closed, the sixth oil and gas valve (215) is controlled to be opened; When the display operating system (114) is set to shut down, the fifth oil and gas valve (214) and the sixth oil and gas valve (215) are controlled to be completely closed.
4. The control method of the oil and gas recovery system based on the cooling cycle heat recovery according to claim 3 is characterized in that: The first-stage oil-gas condenser A and the first-stage oil-gas condenser B are respectively connected with a refrigerant pump for cooling, the second-stage oil-gas condenser A and the second-stage oil-gas condenser B are respectively connected with a second-stage refrigeration compressor for cooling, and the third-stage oil-gas condenser A and the third-stage oil-gas condenser B are respectively connected with a third-stage refrigeration compressor for cooling; the control method further comprises the steps of: When the display operation module (114) is set to power on, the refrigerant pump (39) and the secondary refrigeration compressor are started synchronously; The actual test temperature of the third temperature sensor (18) is obtained as T3, and a preset temperature T is set on the display operation module (114). 3预设温度 ; When T3>T 3预设温度 When , the three-stage refrigeration compressor is controlled to start; When T3≤T 3预设温度 When , the three-stage refrigeration compressor is controlled not to start; When the display operation module (114) is set to shut down, the third-stage refrigeration compressor is first controlled to shut down, then the second-stage refrigeration compressor is controlled to shut down, and finally the refrigerant pump is controlled to shut down.
5. The control method of the oil and gas recovery system based on the cooling cycle heat recovery according to claim 1 is characterized in that: Also includes the steps: The actual test temperature of the third temperature sensor (18) is obtained as T3, and the air outlet temperature is set as T on the display operation module (114). 3设定温度 , set the control accuracy to T 3设定精度 ; When T 3设定温度 -T 3设定精度 ≤T3≤T 3设定温度 +T 3设定精度 When the load of the secondary refrigeration compressor is controlled to remain unchanged; When T3>T 3设定温度 +T 3设定精度 When the secondary refrigeration compressor is loaded, When T3<T 3设定温度 -T 3设定精度 When the secondary refrigeration compressor is controlled to unload.
6. The control method of the oil and gas recovery system based on the heat recovery of the cooling cycle according to claim 4 is characterized in that: Also includes the steps: The actual test temperature of the fourth temperature sensor (110) is obtained as T4, and the outlet air temperature is set as T on the actual operation module (114). 4设定温度 , set the control accuracy to T 4设定精度 ; When T 4设定温度 -T 4设定精度 ≤T4≤T 4设定温度 +T 4设定精度 When the load of the three-stage refrigeration compressor is controlled to remain unchanged; When T4>T 4设定温度 +T 4设定精度 When the load of the three-stage refrigeration compressor is controlled; When T4<T 4设定温度 -T 4设定精度 When the 3rd stage refrigeration compressor is controlled to unload.