Compressor double-gas-seal system and automatic control method

Abstract

The invention discloses a compressor double-gas-seal system and an automatic control method, which can accurately monitor, regulate and control a compressor sealing system in real time according to the actual operation condition of a compressor. Comprising a compressor, an inlet and an outlet of the compressor are provided with a temperature sensor and a pressure sensor respectively, the transmission side of the compressor is provided with a double-gas-seal device, and the double-gas-seal device is provided with a seal gas inlet connector, an isolation gas inlet connector and a discharge outlet. A sealing gas inlet connector of the double-gas sealing device is sequentially connected with a sealing gas adjusting device and a sealing gas source pipeline network, an inlet and an outlet of the sealing gas adjusting device are provided with a temperature sensor and a pressure sensor respectively, and an isolation gas inlet connector of the double-gas sealing device is sequentially connected with an isolation gas pressure adjusting valve and an isolation gas pipeline. An inlet and an outlet of the isolation gas pressure regulating valve are respectively provided with a pressure sensor, and after sealing gas and isolation gas enter the double-gas sealing device, mixed gas is discharged through a discharge port.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical engineering, and in particular to a compressor double air sealing system and an automatic control method. Background Art

[0002] Centrifugal compressors have operating characteristics such as large flow, high pressure ratio, and wide operating conditions. They are currently widely used in modern large-scale chemical production enterprises. Therefore, they compress many types of gases and have complex operating conditions. Some media are flammable or toxic. Therefore, precise control of the compressor sealing system is particularly important for the normal operation and safe production operations of the unit.

[0003] Currently, the sealing system of the compressor is mostly controlled by manual adjustment, which has poor stability and cannot be accurately controlled, increasing the risk of compressed medium leakage, affecting the normal operation of the unit and safe production. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a compressor double air sealing system and an automatic control method, which can accurately monitor and regulate the compressor sealing system in real time according to the actual operating conditions of the compressor.

[0005] The object of the present invention is achieved like this: A compressor double air seal system comprises a compressor (1), wherein the inlet and outlet of the compressor (1) are respectively equipped with a temperature sensor and a pressure sensor, and the transmission side of the compressor (1) is equipped with a double air seal device (2). The double-gas sealing device (2) is provided with a sealing gas inlet interface, an isolation gas inlet interface, and an exhaust port. The sealing gas inlet interface of the double-gas sealing device (2) is connected to the sealing gas regulating device (5) and the sealing gas source pipeline network in sequence. The inlet and outlet of the sealing gas regulating device (5) are respectively equipped with a temperature sensor and a pressure sensor. The sealing gas regulating device (5) is used to regulate the temperature and pressure of the sealing gas. The isolation gas inlet interface of the double-gas sealing device (2) is connected to the isolation gas pressure regulating valve (7) and the isolation gas pipeline in sequence. The inlet and outlet of the isolation gas pressure regulating valve (7) are respectively equipped with pressure sensors. The isolation gas pressure valve is used to regulate the isolation gas pressure entering the double-gas sealing device. After the sealing gas and the isolation gas enter the double-gas sealing device (2) and complete the sealing effect, the mixed gas is discharged through the exhaust port of the double-gas sealing device.

[0006] Preferably, the transmission side of the compressor (1) is connected to the compressor, the sealing gas inlet interface is close to the compressor casing side, and the isolation gas inlet interface is far away from the compressor casing.

[0007] Preferably, the inlet of the sealing gas regulating device (5) is also connected to a cooling water pipeline, and a temperature sensor and a pressure sensor (11) and (12) are installed on the cooling water pipeline. A regulating valve is provided on the sealing gas source pipeline network and the cooling water pipeline respectively. The sealing gas regulating device (5) regulates the temperature and pressure of the sealing gas entering the double gas sealing device through the cooling water.

[0008] Preferably, the dual-gas sealing device (2) is provided with a pressure inlet, the pressure inlet is connected to a sealing cavity pressure sensor (26), and the sealing cavity pressure sensor (26) is used to monitor the sealing cavity pressure between the sealing gas and the isolation gas in the dual-gas sealing device.

[0009] Preferably, the discharge port of the double gas sealing device is connected to the inlet of the mixed gas separation device (23), and the mixed gas separation device (23) separates the mixed gas into sealing gas and isolation gas. The mixed gas separation device (23) has a sealing gas outlet and an isolation gas outlet. The sealing gas outlet of the mixed gas separation device (23) is connected to the inlet of the sealing gas boosting device (18), the outlet of the sealing gas boosting device (18) is connected to the sealing gas source pipeline network, and the inlet and outlet of the sealing gas boosting device (18) are respectively equipped with a temperature sensor and a pressure sensor; The isolation gas outlet of the mixed gas separation device (23) is connected to the inlet of the isolation gas boosting device (15), and the outlet of the isolation gas boosting device (15) is connected to the isolation gas source pipeline network. The inlet and outlet of the isolation gas boosting device (15) are respectively equipped with a temperature sensor and a pressure sensor.

[0010] Preferably, the sealing gas is water vapor and the isolation gas is nitrogen.

[0011] Preferably, the mixed gas separation device (23) condenses and separates the water vapor, and the condensed water evaporates again into water vapor and outputs it through the sealing gas outlet.

[0012] A method for automatically controlling a compressor double gas seal system comprises the following steps: S1, after the compressor (1) start-up conditions are met, start the compressor (1); S2, the compressor (1) heats and pressurizes the main steam and outputs it through the outlet of the compressor (1); according to the outlet pressure of the compressor (1), the sealing gas regulating device (5) regulates in real time the pressure (10) of the sealing gas of the sealing steam entering the double-gas sealing device (2); the sealing gas regulating device (5) regulates the temperature of the sealing gas entering the double-gas sealing device (2) according to the design temperature required by the double-gas sealing device (2); S3, according to the pressure of the double air sealing cavity, the isolation gas pressure regulating valve (7) is used to adjust the isolation gas pressure entering the double air sealing device in real time; S4, the double gas sealing device (2) outputs a mixed gas formed by water vapor and nitrogen through the discharge port, and the mixed gas is transported to the mixed gas separation device (23); S5, the mixed gas separation device (23) separates the mixed gas and transports the separated mixed gas to the sealing gas pressurizing device (15) and the isolation gas pressurizing device (18); S6. According to the pressure of the sealing gas source network, the steam booster device boosts the pressure of the separated steam and then inputs it into the steam source network for recycling; according to the pressure of the isolation gas source network, the nitrogen booster device boosts the pressure of the separated nitrogen and then inputs it into the nitrogen source network for recycling.

[0013] Due to the adoption of the above technical solution, the present invention has the following beneficial effects: The present invention solves the problems of poor stability of the existing compressor sealing system through manual adjustment, inability to perform precise control, increased leakage of the compressed medium, affecting the normal operation of the unit and causing risks in safe production.

[0014] The present invention can accurately monitor and regulate the compressor sealing system in real time according to the actual operating conditions of the compressor, reduce the risk of medium leakage in the compressor unit, improve the stability of the sealing system and the unit, and at the same time recycle the gas in the sealing system to reduce unnecessary waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a flow chart of a compressor double gas sealing system and automatic control method provided by the present invention; Figure 2 This is the compressor startup logic diagram provided by the present invention; Figure 3 This is an automatic control logic diagram of a compressor double gas sealing system and automatic control method provided by the present invention; Figure 4 It is a structural schematic diagram of a compressor double air sealing system provided by the present invention.

[0016] Reference numerals In the accompanying drawings, 1- compressor, 2- double air sealing device, 3- sealing gas temperature and pressure regulating device outlet temperature sensor, 4- sealing gas temperature and pressure regulating device outlet pressure sensor, 5- sealing gas temperature and pressure regulating device, 6- isolating gas pressure regulating valve outlet pressure sensor, 7- isolating gas pressure regulating valve, 8- isolating gas pressure regulating valve inlet pressure sensor, 9- sealing gas temperature and pressure regulating device inlet temperature sensor, 10- sealing gas temperature and pressure regulating device inlet pressure sensor, 11- sealing gas cooling water temperature sensor, 12- sealing gas cooling water pressure sensor, 13- steam boosting device outlet temperature sensor, 14- steam boosting device outlet pressure sensor, 15- steam boosting device, 1 6-Nitrogen booster outlet temperature sensor, 17-Nitrogen booster outlet pressure sensor, 18-Nitrogen booster, 19-Nitrogen booster inlet temperature sensor, 20-Nitrogen booster inlet pressure sensor, 21-Steam booster inlet temperature sensor, 22-Steam booster inlet pressure sensor, 23-Steam nitrogen mixed gas separation device, 24-Steam nitrogen mixed gas separation device inlet temperature sensor, 25-Steam nitrogen mixed gas separation device inlet pressure sensor, 26-Sealed chamber pressure sensor, 27-Compressor inlet temperature sensor, 28-Compressor inlet pressure sensor, 29-Compressor outlet temperature sensor, 30-Compressor outlet pressure sensor. DETAILED DESCRIPTION

[0017] A compressor double gas seal system includes a double gas seal device, a seal cavity pressure sensor, a centrifugal compressor, compressor inlet and outlet temperature and pressure sensors, a seal gas temperature and pressure regulating device, a seal gas desuperheating water temperature and pressure sensor, an isolation gas pressure regulating valve, a seal gas temperature and pressure regulating device inlet and outlet temperature and pressure sensors, an isolation gas temperature and pressure regulating valve pressure sensor, a steam and nitrogen mixed gas separation device, a steam boosting device, a nitrogen boosting device, a steam boosting device inlet and outlet temperature and pressure sensors, a nitrogen boosting device inlet and outlet temperature and pressure sensors, and a monitoring and control center.

[0018] The double air sealing device is installed on a centrifugal compressor, and temperature and pressure sensors are installed at the inlet and outlet of the compressor.

[0019] The double air sealing device has two air inlet interfaces, one discharge port and one pressure inlet port. The air inlet interface close to the compressor compressor casing is a sealing air inlet interface, and the air inlet interface farther from the compressor compressor casing is an isolation air inlet interface.

[0020] The sealing gas inlet interface is connected to the sealing gas temperature and pressure regulating device, the inlet and outlet of the sealing gas temperature and pressure regulating device are installed with temperature and pressure sensors, and the sealing gas cooling water pipeline is installed with a temperature and pressure sensor.

[0021] The isolation gas inlet interface is connected to the isolation gas pressure regulating valve, and pressure sensors are installed at the inlet and outlet of the isolation gas pressure regulating valve.

[0022] The pressure inlet is connected to the sealed cavity pressure sensor.

[0023] The discharge port of the double gas sealing device is connected to the inlet of the steam-nitrogen mixed gas separation device. The steam-nitrogen mixed gas separation device has two outlets, one for steam and the other for nitrogen.

[0024] The steam outlet of the steam-nitrogen mixed gas separation device is connected to the inlet of the steam booster device, the outlet of the steam booster device is connected to the steam gas source pipeline network, and the inlet and outlet of the steam booster device are installed with steam booster device inlet and outlet temperature and pressure sensors.

[0025] The nitrogen outlet of the steam-nitrogen mixed gas separation device is connected to the inlet of the nitrogen booster device, the outlet of the nitrogen booster device is connected to the nitrogen gas source pipeline network, and the inlet and outlet of the nitrogen booster device are installed with nitrogen booster device inlet and outlet temperature and pressure sensors.

[0026] The compressor inlet and outlet temperature and pressure sensors, the sealing gas temperature and pressure regulating device inlet and outlet temperature and pressure sensors, the isolation gas pressure regulating valve inlet and outlet temperature and pressure sensors, the steam booster device inlet and outlet temperature and pressure sensors, and the nitrogen booster device inlet and outlet temperature and pressure sensors are all connected to the monitoring and control center.

[0027] A method for automatically controlling a compressor double gas seal system comprises the following steps: The sealing gas is connected to the double gas sealing device of the compressor unit through the sealing inlet pipeline. The sealing gas here is water vapor. A temperature and pressure regulating device is installed between the water vapor inlet pipeline and the interface of the double gas sealing device of the unit. The temperature and pressure regulating device can adjust the temperature and pressure of the steam entering the double gas sealing device of the unit by adjusting the opening of the sealing steam and cooling water regulating valves. The sealing steam regulating valve and cooling water regulating valve have an adjustable range of 0-100%. Pressure sensors and temperature sensors are installed at the inlet and outlet of the steam temperature and pressure regulating device to monitor the sealing gas pressure and temperature before and after adjustment.

[0028] The isolation gas is connected to the double gas sealing device of the compressor unit through a pipeline. Nitrogen is used as the isolation gas here. An isolation gas pressure regulating valve is installed between the isolation gas inlet pipeline and the interface of the double gas sealing device of the unit. The pressure of the isolation gas entering the double gas sealing device can be adjusted by adjusting the opening of the isolation gas pressure valve. The adjustable range of the isolation gas pressure regulating valve is 0-100%. Pressure sensors are installed at both ends of the isolation gas pressure regulating valve to monitor the isolation gas pressure before and after adjustment.

[0029] The double-gas sealing device of the unit is provided with a sealing cavity pressure inlet, from which a pipeline can be led out for installing a pressure sensor to monitor the sealing cavity pressure between the sealing gas and the isolation gas in the double-gas sealing device.

[0030] By monitoring the pressure of the sealing chamber, adjusting the inlet pressure of the isolation gas, ensuring that the inlet pressure of the isolation gas is greater than the pressure in the sealing chamber, the sealing gas and a small amount of compressed medium that may exist are prevented from escaping from the double gas sealing device 2 to the atmosphere or the compressor gearbox.

[0031] The double-gas sealing device is provided with a discharge port, and the sealing gas and the isolation gas enter the gas seal to complete the sealing effect on the unit and are discharged through the discharge port of the double-gas sealing device.

[0032] The discharge port pipeline of the double air sealing device is connected to the steam-nitrogen mixed gas separation device. The separation device can evaporate the condensed water formed by part of the water vapor in the pipeline through the air seal, pipeline, etc. into water vapor again, and at the same time separate the nitrogen and water vapor and discharge them into the nitrogen and water vapor recovery pipelines respectively.

[0033] The nitrogen and water vapor separated by the mixed gas separation device are connected to the nitrogen and water vapor supercharging devices respectively through recovery pipelines, wherein pressure sensors are installed before the nitrogen and water vapor enter their respective supercharging devices to monitor the gas pressure entering the supercharging devices.

[0034] The outlets of the nitrogen and steam booster devices are connected to the nitrogen and water vapor gas source pipelines respectively. Similarly, pressure sensors are installed at the outlets of the nitrogen and water vapor booster devices to monitor the gas pressure after the booster devices boost the gas. After the nitrogen and water vapor boosted by the booster devices are merged with their respective gas source pipelines, the unit is sealed again.

[0035] The nitrogen and water vapor boosting device can boost the pressure of the recovered sealing gas and isolation gas according to the gas source pressure required by the nitrogen and water vapor of the sealing system, so as to reach the pressure at which each gas enters the gas source network; The system is equipped with a monitoring and control center. All temperature and pressure sensors are connected to the monitoring and control center, which can observe the system operation status in real time and automatically adjust the sealing system according to the actual working conditions of the compressor.

[0036] Specifically: See also Figure 4The present invention provides a compressor double gas sealing system, comprising a compressor 1, a double gas sealing device 2, a sealing gas temperature and pressure regulating device outlet temperature sensor 3, a sealing gas temperature and pressure regulating device outlet pressure sensor 4, a sealing gas temperature and pressure regulating device 5, an isolation gas pressure regulating valve outlet pressure sensor 6, an isolation gas pressure regulating valve 7, an isolation gas pressure regulating valve inlet pressure sensor 8, a sealing gas temperature and pressure regulating device inlet temperature sensor 9, a sealing gas temperature and pressure regulating device inlet pressure sensor 10, a sealing gas cooling water temperature sensor 11, a sealing gas cooling water pressure sensor 12, a steam booster outlet temperature sensor 13, a steam booster outlet pressure sensor 14, a steam booster outlet pressure sensor 15, a steam booster outlet pressure sensor 16, a steam booster outlet pressure sensor 17, a steam booster outlet pressure sensor 18, a steam booster outlet pressure sensor 19, a steam booster outlet pressure sensor 20, a steam booster outlet pressure sensor 21, a steam booster outlet pressure sensor 22, a steam booster outlet pressure sensor 23, a steam booster outlet pressure sensor 24, a steam booster outlet pressure sensor 25, a steam booster outlet pressure sensor 26, a steam booster outlet pressure sensor 27, a steam booster outlet pressure sensor 28, a steam booster outlet pressure sensor 29, a steam booster outlet pressure sensor 30, a steam booster outlet pressure sensor 31, a steam booster outlet pressure sensor 32, a steam booster outlet pressure sensor 33, a steam booster outlet pressure sensor 34, a steam booster outlet pressure sensor 35, a steam booster outlet pressure sensor 36, a steam booster outlet pressure sensor 37, a steam booster outlet pressure sensor 38, a steam booster outlet pressure sensor Pressure device 15, nitrogen booster device outlet temperature sensor 16, nitrogen booster device outlet pressure sensor 17, nitrogen booster device 18, nitrogen booster device inlet temperature sensor 19, nitrogen booster device inlet pressure sensor 20, steam booster device inlet temperature sensor 21, steam booster device inlet pressure sensor 22, steam-nitrogen mixed gas separation device 23, steam-nitrogen mixed gas separation device inlet temperature sensor 24, steam-nitrogen mixed gas separation device inlet pressure sensor 25, sealed chamber pressure sensor 26, compressor inlet temperature sensor 27, compressor inlet pressure sensor 28, compressor outlet temperature sensor 29, 30 - compressor outlet pressure sensor 30.

[0037] The double air sealing device 2 is installed on the centrifugal compressor 1, and the inlet and outlet of the compressor 1 are installed with temperature and pressure sensors 27, 28, 29, and 30. The double air sealing device 2 has two air inlet interfaces, a discharge port, and a pressure inlet. The air inlet interface close to the compressor compressor casing is a sealing air inlet interface, and the air inlet interface farther from the compressor compressor casing is an isolation air inlet interface. The sealing air inlet interface is connected to the sealing air temperature and pressure regulating device 5, and the inlet and outlet of the sealing air temperature and pressure regulating device 5 are installed with temperature and pressure sensors 3, 4, 9, and 10. The sealing gas cooling water pipeline is installed with temperature and pressure sensors 11 and 12, the isolation gas inlet interface is connected to the isolation gas pressure regulating valve 7, the isolation gas pressure regulating valve 7 inlet and outlet are installed with pressure sensors 6 and 8, the pressure inlet is connected to the sealing cavity pressure sensor 26, the double gas sealing device 5 discharge port is connected to the steam nitrogen mixed gas separation device 23 inlet, the steam nitrogen mixed gas separation device 23 has two outlets, one is a steam outlet, the other is a nitrogen outlet, the steam outlet of the steam nitrogen mixed gas separation device 23 is connected to the steam boosting device 18 inlet is connected, the steam booster device 18 outlet is connected to the steam gas source pipeline network, the steam booster device 18 inlet and outlet are installed with steam booster device inlet and outlet temperature and pressure sensors 16, 17, 19, 20, the steam nitrogen mixed gas separation device 23 nitrogen outlet is connected to the nitrogen booster device 15 inlet, the nitrogen booster device 15 outlet is connected to the nitrogen gas source pipeline network, the nitrogen booster device 15 inlet and outlet are installed with nitrogen booster device inlet and outlet temperature and pressure sensors 13, 14, 21, 22, the compressor inlet and outlet temperature and pressure sensors 27, 28, 29, 30, the inlet and outlet temperature and pressure sensors 3, 4, 9, 10 of the sealing gas temperature and pressure regulating device 5, the inlet and outlet pressure sensors 6, 8 of the isolation gas pressure regulating valve 7, the inlet and outlet temperature and pressure sensors 16, 17, 19, 20 of the steam booster device, and the inlet and outlet temperature and pressure sensors 13, 14, 21, 22 of the nitrogen booster device are all connected to the monitoring and control center, solving the problem of poor stability of the manual adjustment compressor sealing system, inability to perform precise control, increased leakage of the compressed medium, affecting the normal operation of the unit and causing risks such as safe production. See also Figures 1 to 3 In a first aspect, the present invention provides a method for automatically controlling a compressor double gas seal system, comprising the following steps: S1. After the compressor 1 start-up conditions are met, press Figure 2 The compressor start logic starts compressor 1; Specifically, the start-up conditions of compressor 1 are determined by the initial design parameters, and the compressor is not allowed to start if the start-up conditions are not met; S2, the compressor 1 heats and pressurizes the secondary steam and outputs it through the outlet of the compressor 1. The sealing steam is adjusted in real time by the sealing gas temperature and pressure regulating device 5 according to the detection of the outlet pressure sensor 30 of the compressor 1, and the temperature 9 and pressure 10 of the sealing gas entering the double gas sealing device 2; Specifically, after the compressor 1 is started, as the frequency of the main motor of the compressor 1 increases, the outlet pressure of the compressor 1 also increases. At this time, the required sealing steam pressure will also increase. The sealing steam pressure is adjusted by the sealing steam regulating valve in the sealing gas temperature and pressure regulating device 5 (the sealing steam pressure can be greater than the outlet pressure of the compressor 1, which is specifically set according to the actual design parameters). If the sealing steam temperature 9 from the gas source is greater than the design temperature required by the dual gas sealing device 2 (determined by the actual design parameters), the cooling water regulating valve in the sealing gas temperature and pressure regulating device 5 can be adjusted to reduce the temperature to the set value. S3, the isolation gas pressure entering the double gas sealing device is adjusted in real time through the isolation gas pressure regulating valve 7 according to the pressure of the double gas sealing cavity; Specifically, to prevent the sealing gas and a small amount of compressed medium that may exist from escaping from the double-gas sealing device 2 to the atmosphere or the compressor gearbox, isolation gas (here, nitrogen) is required for isolation. The pressure of the isolation gas must be greater than the double-gas sealing chamber pressure plus a set value (determined by the actual design) ΔP. The isolation gas pressure regulating valve 7 is used to adjust the isolation gas pressure entering the double-gas sealing device 2 in real time. S4, the double gas sealing device 2 transports the mixed gas formed by the sealing gas and the isolation gas to the steam-nitrogen mixed gas separation device 23 through the discharge port; Specifically, the gas discharged from the discharge port of the double-gas sealing device 2 is a mixture of water vapor and nitrogen. In order to recover the sealing gas and isolation gas discharged by the double-gas sealing device 2, the mixed gas is introduced into the steam-nitrogen mixed gas separation device 23 for separation (if other gases are used for the sealing gas and isolation gas, other separation devices are required); S5, the steam-nitrogen mixed gas separation device 23 separates steam and nitrogen, and transports them to the steam booster device 15 and the nitrogen booster device 18 respectively; Specifically, the nitrogen and water vapor separated by the steam nitrogen mixed gas separation device 23 will be recycled and transported to the steam booster device 15 and the nitrogen booster device 18. S6. The steam booster device boosts the pressure of the separated steam according to the pressure of the sealing gas source network and inputs it into the steam source network for recycling. The nitrogen booster device boosts the pressure of the separated nitrogen according to the pressure of the isolation gas source network and inputs it into the nitrogen source network for recycling. Specifically, by monitoring the pressure of nitrogen and water vapor separated by the steam-nitrogen mixed gas separation device 23, if it is less than the sealing gas water vapor pressure and the isolation gas nitrogen water vapor pressure of the double gas sealing device 2, by adjusting the motor frequency of the steam booster device 15 and the nitrogen booster device 18, the motor frequency can be adjusted in the range of 0-50Hz to reach the required gas source pressure respectively, and transport it to the gas source pipeline network of the sealing gas and isolation gas.

[0038] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A compressor double gas seal system, comprising a compressor, characterized in that: The inlet and outlet of the compressor are respectively equipped with a temperature sensor and a pressure sensor, and the transmission side of the compressor is equipped with a double air sealing device. The double-gas sealing device is provided with a sealing gas inlet interface, an isolation gas inlet interface, and an exhaust port. The sealing gas inlet interface of the double-gas sealing device is connected in sequence to a sealing gas regulating device and a sealing gas source pipeline network. The inlet and outlet of the sealing gas regulating device are respectively installed with a temperature sensor and a pressure sensor. The sealing gas regulating device is used to regulate the temperature and pressure of the sealing gas. The isolation gas inlet interface of the double-gas sealing device is connected in sequence to an isolation gas pressure regulating valve and an isolation gas pipeline. The inlet and outlet of the isolation gas pressure regulating valve are respectively installed with pressure sensors. The pressure of the isolation gas entering the double-gas sealing device is regulated by the isolation gas pressure valve. After the sealing gas and isolation gas enter the double-gas sealing device and complete the sealing effect, the mixed gas is discharged through the exhaust port of the double-gas sealing device.

2. A compressor double air seal system according to claim 1, characterized in that: The transmission side of the compressor is connected to the compressor, the sealing gas inlet interface is close to the compressor casing side, and the isolation gas inlet interface is far away from the compressor casing.

3. The compressor double air seal system according to claim 1, characterized in that: The inlet of the sealing gas regulating device is also connected to the cooling water pipeline, on which temperature sensors and pressure sensors are installed. Regulating valves are respectively provided on the sealing gas source pipeline network and the cooling water pipeline. The sealing gas regulating device adjusts the temperature and pressure of the sealing gas entering the double gas sealing device through the cooling water.

4. The compressor double air seal system according to claim 1, characterized in that: The double-gas sealing device is provided with a pressure inlet, which is connected to a sealing cavity pressure sensor. The sealing cavity pressure sensor is used to monitor the sealing cavity pressure between the sealing gas and the isolation gas in the double-gas sealing device.

5. The compressor double air seal system according to claim 1, characterized in that: The discharge port of the double gas sealing device is connected to the inlet of the mixed gas separation device, and the mixed gas separation device separates the mixed gas into sealing gas and isolation gas. The mixed gas separation device has a sealing gas outlet and an isolation gas outlet. The sealing gas outlet of the mixed gas separation device is connected to the inlet of the sealing gas booster device, the outlet of the sealing gas booster device is connected to the sealing gas source pipeline network, and the inlet and outlet of the sealing gas booster device are respectively installed with a temperature sensor and a pressure sensor; The isolation gas outlet of the mixed gas separation device is connected to the inlet of the isolation gas booster device, and the outlet of the isolation gas booster device is connected to the isolation gas source pipeline network. The inlet and outlet of the isolation gas booster device are respectively equipped with temperature sensors and pressure sensors.

6. A compressor double air seal system according to claim 5, characterized in that: The sealing gas is water vapor and the isolation gas is nitrogen.

7. A compressor double air seal system according to claim 6, characterized in that: The mixed gas separation device condenses and separates the water vapor, and the condensed water evaporates into water vapor again and outputs it through the sealed gas outlet.

8. An automatic control method for a compressor double air-sealing system according to claim 1, characterized in that: The following steps are involved: S1. After the compressor start-up conditions are met, start the compressor; S2, the compressor heats and pressurizes the main steam and outputs it through the compressor outlet. The sealing gas regulating device adjusts the pressure of the sealing steam entering the double-gas sealing device in real time according to the outlet pressure of the compressor. The sealing gas regulating device adjusts the temperature of the sealing gas entering the double-gas sealing device according to the design temperature required by the double-gas sealing device. S3. According to the pressure of the double gas sealing cavity, the isolation gas pressure entering the double gas sealing device is adjusted in real time through the isolation gas pressure regulating valve; S4, the double gas sealing device outputs a mixed gas formed by water vapor and nitrogen through the discharge port, and the mixed gas is transported to the mixed gas separation device; S5, the mixed gas separation device separates the mixed gas and transports it to the sealing gas boosting device and the isolation gas boosting device respectively; S6. According to the pressure of the sealing gas source network, the steam booster device boosts the pressure of the separated steam and then inputs it into the steam source network for recycling; according to the pressure of the isolation gas source network, the nitrogen booster device boosts the pressure of the separated nitrogen and then inputs it into the nitrogen source network for recycling.

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