C4F7N / CO2 mixed gas recovery and purification device

Abstract

The C4F7N / CO2 mixed gas recovery and purification device includes a recovery and purification gas circuit and a tank filling circuit; the air inlet end of the recovery and purification gas circuit is provided with an air inlet interface, and the air outlet end is connected to the air inlet end of the tank filling circuit, and the first pressure sensor, the first solenoid valve, and the adsorption module are sequentially provided from the air inlet end to the air outlet end; the air outlet end of the tank filling circuit is provided with an air outlet interface, and the tank filling circuit is sequentially provided with a first pressure reducing and stabilizing valve, a compressor, a one-way valve, and a second pressure sensor from the air inlet end to the air outlet end, and the air outlet of the one-way valve is connected to the air outlet interface. It also includes an exhaust gas recovery branch, an online sampling branch, and a mixed gas concentration correction gas circuit. The exhaust gas recovery branch releases the high-pressure gas retained in the connecting pipeline into the built-in storage tank, and the online sampling branch and the mixed gas concentration correction gas circuit cooperate to correct the concentration of the mixed gas so that it can be recycled.

Description

Technical Field

[0001] The invention belongs to the technical field of recovery and purification of insulating gas, and in particular relates to a C4F7N / CO2 mixed gas recovery and purification device. Background Art

[0002] Perfluoroisobutyronitrile (molecular formula C4F7N, hereinafter referred to as C4 gas) is a new type of insulating gas with better insulation performance than sulfur hexafluoride (SF6) gas. Under the same gas pressure, the insulation strength of C4F7N is nearly twice that of SF6, and the greenhouse effect of C4F7N is much smaller than that of SF6 gas. It is easier to decompose than SF6 gas in the natural state.

[0003] However, C4F7N has a high liquefaction temperature of −4.7°C at normal pressure, and cannot be used alone. It needs to be mixed with diluent gases (such as CO2, N2 or air). According to relevant literature, the power industry generally uses C4F7N and CO2 as mixed insulating gases, and the concentration of C4F7N in the mixed gas is generally around 10%.

[0004] During the type test and maintenance of electrical equipment, the mixed gas (hereinafter referred to as mixed gas) needs to be recovered. The recovered mixed gas can be repeatedly recycled after being purified by purification equipment. The purification equipment needs to purify the micro-water, solid particles and decomposition products generated by discharge in the mixed gas. Before recycling, the concentration of the mixed gas needs to be adjusted to meet the requirements of gas recycling. Summary of the invention

[0005] In order to solve the deficiencies in the prior art, the present invention provides a C4F7N / CO2 mixed gas recovery and purification device.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions: a C4F7N / CO2 mixed gas recovery and purification device, including a recovery and purification gas path and a tank charging path;

[0007] The air inlet end of the recovery and purification gas circuit is provided with an air inlet interface, and the air outlet end is connected to the air inlet end of the tank charging circuit. The recovery and purification gas circuit is also provided with a first pressure sensor, a first solenoid valve, and an adsorption module in sequence from the air inlet end to the air outlet end;

[0008] An outlet interface is provided at the outlet end of the tank inflation circuit. A first pressure reducing and stabilizing valve, a compressor, a one-way valve and a second pressure sensor are sequentially provided on the tank inflation circuit from the air inlet end to the air outlet end. The outlet of the one-way valve is connected to the outlet interface.

[0009] It also includes an online sampling branch, the air inlet end of the online sampling branch is also connected to the air outlet end of the recovery and purification air circuit, the air outlet end is connected to the online sampling interface, and the online sampling branch is also provided with a second solenoid valve and a second pressure reducing and stabilizing valve.

[0010] It also includes an exhaust gas recovery branch, the outlet end of the exhaust gas recovery branch is connected to the inlet end of the first pressure reducing and stabilizing valve on the tank charging circuit, the inlet end of the exhaust gas recovery branch is connected to the tank charging circuit between the one-way valve and the outlet interface, and the fourth solenoid valve, the second manual valve, the storage tank, the first manual valve, and the third solenoid valve are connected in series in sequence from the inlet end to the outlet end on the exhaust gas recovery branch, and a third pressure sensor is provided on the storage tank.

[0011] It also includes a gas mixture concentration correction gas circuit, the outlet end of the gas mixture concentration correction gas circuit is arranged on the tank filling path between the one-way valve and the gas outlet interface, the inlet end of the gas mixture concentration correction gas circuit is connected to the sample gas storage bottle, and the gas mixture concentration correction gas circuit is sequentially connected in series from the inlet end to the outlet end with a third pressure reducing and stabilizing valve, an ITV electrical proportional valve, a ball valve and a fifth solenoid valve.

[0012] The measuring range of the first pressure sensor is -0.1~1.6MPa; the measuring range of the second pressure sensor is 0~5MPa.

[0013] ITV electric proportional valve uses ITV2020.

[0014] Adsorption module 9 is filled with 4A molecular sieve.

[0015] Working principle:

[0016] In the mixed gas recovery and tank filling process, open the first solenoid valve, close the second solenoid valve, the third solenoid valve, the fourth solenoid valve and the fifth solenoid valve, connect the air inlet interface to the electrical equipment to be recovered through a pipeline, and connect the air outlet interface to the external gas storage tank through a pipeline. Start the recovery process, the mixed gas flows through the first solenoid valve, enters the adsorption module, and then passes through the first pressure reducing and stabilizing valve and the compressor to compress the mixed gas into the external gas storage tank. The adsorption module is filled with 4A molecular sieve, which can adsorb trace water, solid particles, decomposition products generated by discharge, and part of CO2 gas in the mixed gas, but does not adsorb C4 gas. After the mixed gas is recovered, close the external valve of the electrical equipment to be recovered and close the valve of the external gas storage tank.

[0017] Exhaust gas recovery. Open the fourth solenoid valve to release the high-pressure gas retained in the connecting pipeline into the built-in storage tank. The second pressure sensor can monitor the mixed gas pressure. The pipeline that releases the pressure is easier to disassemble and reduces gas discharge. The next time you use it, open the third solenoid valve and the compressor, close the fourth and fifth solenoid valves, and you can first recover the gas in the built-in storage tank, and then recover the gas to be recovered in the electrical equipment.

[0018] Before recycling, the concentration of the mixed gas needs to be adjusted to meet the requirements of gas recycling. The principle of concentration correction is the law of partial pressure. The concentration of the mixed gas can be measured through the online sampling interface, and the second pressure sensor can measure the mixed gas pressure. The corrected concentration, that is, the final preparation concentration, can be known. The partial pressure of the dilution gas A, that is, CO2 gas, can be calculated. The partial pressure of the sample gas A entering can be controlled by the ITV electrical proportional valve to achieve the purpose of diluting the gas concentration. The corrected mixed gas can be used directly next time.

[0019] By adopting the above technical scheme, the present invention can not only realize the recovery and purification of C4F7N / CO2 mixed gas, but also adjust the concentration of the mixed gas to meet the requirements of recycling. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the present invention. DETAILED DESCRIPTION

[0021] like Figure 1 As shown, the C4F7N / CO2 mixed gas recovery and purification device of the present invention comprises a recovery and purification gas circuit (1) and a tank filling circuit (2);

[0022] The air inlet end of the recovery and purification gas circuit (1) is provided with an air inlet interface (6), and the air outlet end is connected to the air inlet end of the tank charging circuit. The recovery and purification gas circuit (1) is also provided with a first pressure sensor (7), a first solenoid valve (8), and an adsorption module (9) in sequence from the air inlet end to the air outlet end;

[0023] An outlet port (14) is provided at the outlet end of the tank inflation path (2), and a first pressure reducing and stabilizing valve (10), a compressor (11), a one-way valve (12) and a second pressure sensor (13) are provided in sequence on the tank inflation path from the inlet end to the outlet end, and the outlet of the one-way valve (12) is connected to the outlet port (14).

[0024] It also includes an online sampling branch (3), the air inlet end of the online sampling branch (3) is also connected to the air outlet end of the recovery and purification air circuit (1), and the air outlet end is connected to the online sampling interface (17). The online sampling branch (3) is also provided with a second solenoid valve (15) and a second pressure reducing and stabilizing valve (16).

[0025] The invention also comprises an exhaust gas recovery branch (4), wherein the outlet end of the exhaust gas recovery branch (4) is connected to the inlet end of the first pressure reducing and stabilizing valve (10) on the tank charging circuit (2), the inlet end of the exhaust gas recovery branch (4) is connected to the tank charging circuit (2) between the one-way valve (12) and the outlet interface (14), and the exhaust gas recovery branch (4) is connected in series with a fourth solenoid valve (22), a second manual valve (20), a storage tank (18), a first manual valve (19), and a third solenoid valve (21) in sequence from the inlet end to the outlet end, and the storage tank (18) is provided with a third pressure sensor (23).

[0026] The invention also comprises a mixed gas concentration correction gas circuit (5), wherein the gas outlet end of the mixed gas concentration correction gas circuit (5) is arranged on the tank filling circuit (2) between the one-way valve (12) and the gas outlet interface (14), the gas inlet end of the mixed gas concentration correction gas circuit (5) is connected to the sample gas storage bottle (24), and the mixed gas concentration correction gas circuit (5) is provided with a third pressure reducing and stabilizing valve (25), an ITV electrical proportional valve (26), a ball valve (27), and a fifth solenoid valve (28) in series from the gas inlet end to the gas outlet end.

[0027] The measuring range of the first pressure sensor (7) is -0.1 to 1.6 MPa; the measuring range of the second pressure sensor (13) is 0 to 5 MPa.

[0028] The ITV electric proportional valve (26) adopts ITV2020.

[0029] The adsorption module (9) is filled with 4A molecular sieve.

[0030] Working principle:

[0031] Mixed gas recovery and tank filling process. Open the first solenoid valve 8, close the second solenoid valve 15, the third solenoid valve 21, the fourth solenoid valve 22 and the fifth solenoid valve 28, the air inlet interface 6 is connected to the electrical equipment to be recovered through a pipeline, and the air outlet interface 14 is connected to the external gas storage tank through a pipeline. Start the recovery process, the mixed gas flows through the first solenoid valve 8, enters the adsorption module 9, and then passes through the first pressure reducing and stabilizing valve 10 and the compressor 11 to compress the mixed gas into the external gas storage tank. The adsorption module 9 is filled with 4A molecular sieve, which can adsorb trace water, solid particles, decomposition products produced by discharge, and part of the CO2 gas in the mixed gas, but does not adsorb C4 gas. After the mixed gas is recovered, close the external valve of the electrical equipment to be recovered, and close the valve of the external gas storage tank.

[0032] Exhaust gas recovery. Open the fourth solenoid valve 22 to release the high-pressure gas retained in the connecting pipeline into the built-in storage tank 18. The second pressure sensor can monitor the mixed gas pressure. The pipeline that releases the pressure is easier to disassemble and reduces gas discharge. When used next time, open the third solenoid valve 21 and the compressor 11, close the fourth solenoid valve 22, and you can first recover the gas in the built-in storage tank 18, and then recover the gas to be recovered in the electrical equipment.

[0033] Before recycling, the concentration of the mixed gas needs to be adjusted to meet the requirements of gas recycling. The principle of concentration correction is the law of partial pressure. The concentration of the mixed gas can be measured through the online sampling interface 17, and the second pressure sensor 13 can measure the pressure of the mixed gas. The corrected concentration, that is, the final preparation concentration, can be known to calculate the partial pressure of the dilution gas A, that is, CO2 gas that needs to be added. The partial pressure of the sample gas A entering can be controlled by the ITV electrical proportional valve to achieve the purpose of diluting the gas concentration. The corrected mixed gas can be used directly next time.

[0034] By adopting the above technical scheme, the present invention can not only realize the recovery and purification of C4F7N / CO2 mixed gas, but also adjust the concentration of the mixed gas to meet the requirements of recycling.

[0035] The above embodiments are only used to illustrate rather than limit the technical solutions of the present invention. Although the present invention is described in detail with reference to the above embodiments, those skilled in the art should understand that the present invention can still be modified or replaced by equivalents. Any modification or partial replacement that does not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. C4F7N / CO2 mixed gas recovery and purification device, characterized by: It includes a recovery and purification gas circuit (1) and a tank filling circuit (2); The air inlet end of the recovery and purification gas circuit (1) is provided with an air inlet interface (6), and the air outlet end is connected to the air inlet end of the tank charging circuit. The recovery and purification gas circuit (1) is also provided with a first pressure sensor (7), a first solenoid valve (8), and an adsorption module (9) in sequence from the air inlet end to the air outlet end; An outlet port (14) is provided at the outlet end of the tank inflation path (2); a first pressure reducing and stabilizing valve (10), a compressor (11), a one-way valve (12) and a second pressure sensor (13) are provided in sequence on the tank inflation path from the inlet end to the outlet end; and an outlet of the one-way valve (12) is connected to the outlet port (14); It also includes an online sampling branch (3), the air inlet end of the online sampling branch (3) is also connected to the air outlet end of the recovery and purification air path (1), and the air outlet end is connected to the online sampling interface (17). The online sampling branch (3) is also provided with a second solenoid valve (15) and a second pressure reducing and stabilizing valve (16); It also includes an exhaust gas recovery branch (4), the outlet end of the exhaust gas recovery branch (4) is connected to the inlet end of the first pressure reducing and stabilizing valve (10) on the tank charging path (2), the inlet end of the exhaust gas recovery branch (4) is connected to the tank charging path (2) between the one-way valve (12) and the outlet interface (14), the fourth solenoid valve (22), the second manual valve (20), the storage tank (18), the first manual valve (19), and the third solenoid valve (21) are connected in series in sequence from the inlet end to the outlet end of the exhaust gas recovery branch (4), and the storage tank (18) is provided with a third pressure sensor (23); The invention also comprises a mixed gas concentration correction gas circuit (5), wherein the gas outlet end of the mixed gas concentration correction gas circuit (5) is arranged on the tank filling circuit (2) between the one-way valve (12) and the gas outlet interface (14), the gas inlet end of the mixed gas concentration correction gas circuit (5) is connected to the sample gas storage bottle (24), and the mixed gas concentration correction gas circuit (5) is provided with a third pressure reducing and stabilizing valve (25), an ITV electrical proportional valve (26), a ball valve (27) and a fifth solenoid valve (28) in series from the gas inlet end to the gas outlet end.

2. The C4F7N / CO2 mixed gas recovery and purification device according to claim 1, characterized in that: The measuring range of the first pressure sensor (7) is -0.1 to 1.6 MPa.

3. The C4F7N / CO2 mixed gas recovery and purification device according to claim 1, characterized in that: The measuring range of the second pressure sensor (13) is 0-5 MPa.

4. The C4F7N / CO2 mixed gas recovery and purification device according to claim 1, characterized in that: The ITV electric proportional valve (26) adopts ITV2020.

5. The C4F7N / CO2 mixed gas recovery and purification device according to claim 1, characterized in that: The adsorption module (9) is filled with 4A molecular sieve.

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