A catalytic oxidation hydrogen removal device for radioactive waste gas in a nuclear power plant with controllable gas concentration

Abstract

The present invention relates to a catalytic oxidation hydrogen removal device for radioactive waste gas in a nuclear power plant with controllable gas concentration, comprising: an oxygen supply system, a nitrogen supply system, a hydrogen-containing waste gas inlet system, a pipeline mixer, a gas buffer tank, a preheater, an electric heater, a catalytic bed, a cooler, a trap, a fan and a central control system; the central control system is electrically connected to the rest; the central control system controls the nitrogen supply amount of the nitrogen supply system, controls the oxygen supply amount of the oxygen supply system, controls the waste gas inlet amount of the hydrogen-containing waste gas inlet system, and obtains the hydrogen content at different positions on the gas pipeline after the pipeline mixer. The beneficial effects of the present invention are as follows: the catalytic oxidation hydrogen removal device of the present invention is used for large-flow dilution of radioactive hydrogen-containing waste gas in a nuclear power plant to ensure that the hydrogen concentration in the catalytic oxidation reaction device is lower than the lower explosion limit and guarantee the safety of the device; it can make the distribution of various gases uniform, and the concentrations of hydrogen and oxygen are controllable, ensuring the stable and reliable operation of the equipment.

Description

Technical Field

[0001] The present invention belongs to the technical field of radioactive hydrogen-containing waste gas dilution in nuclear power plants, and particularly relates to a catalytic oxidation hydrogen removal device for radioactive waste gas in a nuclear power plant with controllable gas concentration. Background Art

[0002] The hydrogen concentration in the radioactive hydrogen-containing waste gas of a nuclear power plant is relatively high, and it is necessary to dilute the radioactive hydrogen-containing waste gas in a large flow rate to ensure that the hydrogen concentration in the catalytic oxidation reaction device is lower than the lower explosion limit and ensure the safety of the device. Under the condition of large-flow nitrogen dilution, it increases the difficulty of controlling the oxygen and hydrogen concentrations. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a catalytic oxidation hydrogen removal device for radioactive waste gas in a nuclear power plant with controllable gas concentration.

[0004] This catalytic oxidation hydrogen removal device for radioactive waste gas in a nuclear power plant with controllable gas concentration includes: an oxygen supply system, a nitrogen supply system, a hydrogen-containing waste gas inlet system, a pipeline mixer, a gas buffer tank, a preheater, an electric heater, a catalytic bed, a cooler, a trap, a fan, and a central control system; the central control system is electrically connected to the rest;

[0005] The gas supply pipelines of the oxygen supply system, the nitrogen supply system, and the hydrogen-containing waste gas inlet system are all connected to the inlet of the pipeline mixer, and the outlet of the pipeline mixer is connected to the inlet of the gas buffer tank; the outlet of the gas buffer tank is connected to the inlet of the preheater, and the outlet of the preheater is respectively connected to two outlet pipelines, one of the outlet pipelines is connected to the inlet of the electric heater, and the other outlet pipeline is connected to the inlet of the cooler; a condensate water outlet pipeline is provided at the bottom of the gas buffer tank; the outlet of the electric heater is connected to the inlet on the catalytic bed; the outlet on the catalytic bed is respectively connected to two outlet pipelines, one of the outlet pipelines is connected to the inlet on the preheater, and the other outlet pipeline is connected to the inlet of the cooler; the cooler is provided with an outlet, a circulating chilled water inlet, and a circulating chilled water outlet, the circulating chilled water inlet is connected to the circulating chilled water inlet pipeline, the circulating chilled water outlet is connected to the circulating chilled water outlet pipeline, the outlet on the cooler is connected to the inlet of the trap, and a condensate water outlet pipeline is provided at the bottom of the trap; the outlet of the trap is connected to the inlet of the fan, the outlet of the fan is respectively connected to the tail gas discharge main pipe and the tail gas circulation pipeline, the tail gas discharge main pipe communicates with the external environment, the tail gas circulation pipeline is connected to the inlet of the pipeline mixer, and a condensate water outlet is also provided on the trap, and the condensate water outlet is connected to the condensate water outlet pipeline;

[0006] The central control system is used to control the nitrogen supplement amount of the nitrogen supplement system, regulate the gas pressure in the gas buffer tank, control the oxygen supplement amount of the oxygen supplement system, control the waste gas intake amount of the hydrogen-containing waste gas intake system, obtain the hydrogen content at different positions on the gas pipeline after the pipeline mixer; control the pressure in the gas pipeline after the fan; issue an alarm instruction when the temperature in the gas pipeline after the electric heater exceeds the set value; obtain the temperature values on the gas pipeline after the preheater, on the gas pipeline after the electric heater, on the chilled water inlet pipeline of the cooler and on the chilled water outlet pipeline of the cooler in the catalytic bed, and regulate the gas pressure and flow rate in the gas pipeline between the catalytic bed and the preheater.

[0007] Preferably:

[0008] The oxygen supplement system includes an oxygen cylinder, a pressure reducing valve, a regulating valve, and a flow measurement display and control device; the pressure reducing valve, the regulating valve, and the flow measurement display and control device are successively arranged on the gas pipeline connecting the oxygen cylinder.

[0009] The nitrogen supplement system includes a nitrogen cylinder, a pressure reducing valve, a regulating valve, and a flow measurement display and control device; the pressure reducing valve, the regulating valve, and the flow measurement display and control device are successively arranged on the gas pipeline connecting the nitrogen cylinder; the regulating valve in the nitrogen supplement system is electrically connected to the central control system.

[0010] The hydrogen-containing waste gas intake system includes a waste gas cylinder, a pressure reducing valve, a regulating valve, and a flow measurement display and control device; the pressure reducing valve, the regulating valve, and the flow measurement display and control device are successively arranged on the gas pipeline connecting the waste gas cylinder.

[0011] Preferably:

[0012] A pressure sensing device is provided on the gas buffer tank, and the pressure sensing device is electrically connected to the central control system. The pressure sensing device is used to feedback the actual pressure value of the gas buffer tank to the central control system; the flow measurement display and control device in the oxygen supplement system is electrically connected to the central control system, and the flow measurement display and control device is used to feedback the oxygen concentration to the central control system; the regulating valve in the oxygen supplement system is used to adjust its own opening degree according to the instruction of the central control system to control the input amount of oxygen; the flow measurement display and control device in the hydrogen-containing waste gas intake system is electrically connected to the central control system, and the flow measurement display and control device is used to feedback the input amount of hydrogen-containing waste gas to the central control system.

[0013] The central control system is used to receive the actual pressure value in the gas buffer tank sent by the pressure sensing device, and issue a control instruction to control the opening degree of the regulating valve in the nitrogen supplement system to control the nitrogen supply amount, so as to maintain the pressure stability of the entire gas buffer tank and ensure that the pressure in the buffer tank does not exceed the upper limit value; it is used to receive the oxygen concentration feedback by the flow measurement display and control device in the oxygen supplement system, and issue a control instruction to control the opening degree of the regulating valve in the oxygen supplement system to control the oxygen supply amount, ensuring that the oxygen concentration in the system is sufficient to support the consumption of hydrogen-oxygen recombination; it is used to receive the input amount of hydrogen-containing waste gas in the hydrogen-containing waste gas intake system, and issue a control instruction to control the opening degree of the regulating valve in the hydrogen-containing waste gas intake system to prevent the hydrogen concentration in the hydrogen-containing waste gas from exceeding the set value.

[0014] Preferably:

[0015] The flow measurement display and control device includes a flow indicator, a flow transmitter and a flow control valve;

[0016] In the nitrogen supplement system, the oxygen supplement system and the hydrogen-containing waste gas intake system, a ball valve is provided between the pressure reducing valve and the regulating valve. The ball valve is used to open and close the gas pipeline connecting the pressure reducing valve and the regulating valve, adding an extra safeguard; a temperature sensor is also provided on the gas pipeline behind the regulating valve; in the hydrogen-containing waste gas intake system, a flow control alarm is also provided on the gas pipeline behind the regulating valve.

[0017] The pressure sensing device provided on the gas buffer tank includes a pressure sensor, a pressure indicator and a pressure transmitter; the pressure sensor is used to obtain the actual pressure in the gas buffer tank; the pressure indicator is used to display the actual pressure in the gas buffer tank; the pressure transmitter is used to upload the actual pressure obtained by the pressure sensor to the central control system.

[0018] Preferably:

[0019] Multiple analysis transmitters and air insulation switches are provided on the gas pipeline behind the pipeline mixer. The analysis transmitter is electrically connected to the central control system and is also electrically connected to the air insulation switch; multiple analysis transmitters are also provided on the gas pipeline behind the fan; the analysis transmitter is used to obtain the hydrogen content at different positions of the gas pipeline and upload the value to the central control system; the air insulation switch is used to protect the electrical circuit of the analysis transmitter from overloading or short-circuiting; a pressure controller is also provided on the gas pipeline behind the fan. The pressure controller is electrically connected to the central control system and is used to control the pressure in the gas pipeline behind the fan according to the instruction of the central control system; a choke orifice is also provided on the main exhaust pipe connected to the fan outlet; the multiple analysis transmitters provided on the gas pipeline behind the fan are also electrically connected to the analog relay unit; a heating cable corresponding to the fan is provided; a liquid level control valve is also provided on the tail gas circulation pipeline connected to the fan.

[0020] Preferably:

[0021] Temperature indicators and temperature detectors are provided on the gas pipeline inside the catalytic bed, after the preheater, after the electric heater, on the chilled water inlet pipeline of the cooler, and on the chilled water outlet pipeline of the cooler; both the temperature indicator and the temperature detector are electrically connected to the central control system for displaying and uploading the temperature values at the corresponding positions.

[0022] A temperature control alarm is also provided on the gas pipeline after the electric heater. The temperature control alarm is electrically connected to the central control system for temperature alarm according to the alarm instruction issued by the central control system; both the electric heater and the temperature control alarm are electrically connected to the control transformer.

[0023] On the gas pipeline between the catalytic bed and the preheater, a pneumatic diaphragm control valve is provided. The pneumatic diaphragm control valve is electrically connected to the central control system for controlling the pressure and flow rate of the gas in the gas pipeline according to the instruction of the central control system.

[0024] Preferably:

[0025] Two-position control valves are provided on both the outlet pipeline of the gas buffer tank and the condensate water outlet pipeline; a two-position control valve is also provided on the condensate water outlet pipeline of the trap; a liquid level signal converter is further provided on the condensate water outlet pipeline of the trap.

[0026] Both the two-position control valve and the air isolating switch are electrically connected to the potentiometer isolator, and the potentiometer isolator is also electrically connected to the frequency converter.

[0027] The working method of this nuclear power plant radioactive waste gas catalytic oxidation hydrogen removal device with controllable gas concentration specifically includes the following steps:

[0028] When the oxygen concentration in the oxygen supply system is within the set range, the central control system interlocks and controls the regulating valve and the flow measurement display and control device in the oxygen supply system to control the oxygen flow supplied by the oxygen cylinder in the oxygen supply system within the set value; when the oxygen concentration in the oxygen supply system exceeds the set range, the ball valve and the regulating valve in the oxygen supply system are interlocked and controlled by the central control system to control the oxygen concentration in the whole device within the set value.

[0029] When the nitrogen concentration in the nitrogen supply system is within the set range, the central control system interlocks and controls the regulating valve and the flow measurement display and control device in the nitrogen supply system to control the oxygen flow supplied by the oxygen cylinder in the nitrogen supply system within the set value; when the nitrogen concentration in the nitrogen supply system exceeds the set range, the ball valve and the regulating valve in the nitrogen supply system are interlocked and controlled by the central control system to control the nitrogen concentration in the whole device within the set value.

[0030] The central control system obtains the hydrogen content at different positions on the gas pipeline after the pipeline mixer, and controls the intake air volumes of the oxygen supply system, nitrogen supply system, and hydrogen-containing waste gas intake system to control the hydrogen concentration in the entire device below the set value.

[0031] Preferably, when the oxygen concentration in the oxygen supply system exceeds the set range, the ball valve and regulating valve in the oxygen supply system are interlocked and controlled by the central control system to control the oxygen concentration in the entire device within 2%.

[0032] Preferably, the hydrogen concentration in the hydrogen-containing waste gas does not exceed 4%.

[0033] The beneficial effects of the present invention are:

[0034] The catalytic oxidation hydrogen removal device of the present invention is used to greatly dilute the radioactive hydrogen-containing waste gas in a nuclear power plant to ensure that the hydrogen concentration in the catalytic oxidation reaction device is lower than the lower explosion limit and ensure the safety of the device; it can make various gases evenly distributed, and the hydrogen and oxygen concentrations can be controlled to ensure the stable and reliable operation of the equipment.

[0035] The central control system receives the actual pressure value in the gas buffer tank sent by the pressure sensing device, and issues a control instruction to control the opening of the regulating valve in the nitrogen supply system to control the nitrogen supply volume to maintain the pressure stability of the entire gas buffer tank and ensure that the pressure in the buffer tank does not exceed the upper limit value; it receives the oxygen concentration fed back by the flow measurement display and control device in the oxygen supply system, and issues a control instruction to control the opening of the regulating valve 10 in the oxygen supply system to control the oxygen supply volume to ensure that the oxygen concentration in the system is sufficient to support the consumption of hydrogen-oxygen recombination; the ball valve is used to open and close the gas pipeline connecting the pressure reducing valve and the regulating valve, adding an extra safeguard. Description of the Drawings

[0036] Figure 1 It is a schematic diagram of a catalytic oxidation hydrogen removal device for radioactive waste gas in a nuclear power plant with controllable gas concentration.

[0037] Description of the reference numerals: pipeline mixer 1, gas buffer tank 2, preheater 3, electric heater 4, catalytic bed 5, cooler 6, trap 7, fan 8, pressure reducing valve 9, regulating valve 10, ball valve 11, flow indicator 12, flow transmitter 13, flow control alarm 14, flow control valve 15, analysis transmitter 16, pressure indicator 17, pressure transmitter 18, temperature control alarm 19, temperature indicator 20, temperature detector 21, pneumatic diaphragm control valve 22, temperature sensor 24, pressure controller 25, orifice plate 26, two-position control valve 27, air isolation switch 28, potentiometer isolator 29, control transformer 30, frequency converter 31, analog relay unit 32, heating cable 33, liquid level signal converter 34, liquid level control valve 35. Detailed implementation mode

[0038] The present invention will be further described below in conjunction with embodiments. The description of the following embodiments is only used to help understand the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several modifications can still be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0039] Embodiment 1

[0040] As Figure 1 shown, a catalytic oxidation hydrogen removal device for radioactive waste gas in a nuclear power plant with controllable gas concentration includes: an oxygen supply system, a nitrogen supply system, a hydrogen-containing waste gas inlet system, a pipeline mixer 1, a gas buffer tank 2, a preheater 3, an electric heater 4, a catalytic bed 5, a cooler 6, a trap 7, a fan 8 and a central control system; the central control system is electrically connected to the rest;

[0041] The gas supply pipelines of the oxygen supply system, the nitrogen supply system and the hydrogen-containing waste gas inlet system are all connected to the inlet of the pipeline mixer 1, and the outlet of the pipeline mixer 1 is connected to the inlet of the gas buffer tank 2; the outlet of the gas buffer tank 2 is connected to the inlet of the preheater 3, and the outlet of the preheater 3 is respectively connected to two outlet pipelines, one of which is connected to the inlet of the electric heater 4, and the other is connected to the inlet of the cooler 6; a condensate outlet pipeline is provided at the bottom of the gas buffer tank 2; the outlet of the electric heater 4 is connected to the inlet on the catalytic bed 5; the outlet on the catalytic bed 5 is respectively connected to two outlet pipelines, one of which is connected to the inlet on the preheater 3, and the other is connected to the inlet of the cooler 6; the cooler 6 is provided with an outlet, a circulating chilled water inlet and a circulating chilled water outlet, the circulating chilled water inlet is connected to the circulating chilled water inlet pipeline, the circulating chilled water outlet is connected to the circulating chilled water outlet pipeline, the outlet on the cooler 6 is connected to the inlet of the trap 7, and a condensate outlet pipeline is provided at the bottom of the trap 7; the outlet of the trap 7 is connected to the inlet of the fan 8, the outlet of the fan 8 is respectively connected to the tail gas discharge main pipe and the tail gas circulation pipeline, the tail gas discharge main pipe communicates with the external environment, the tail gas circulation pipeline is connected to the inlet of the pipeline mixer 1, and a condensate outlet is also provided on the trap 7, and the condensate outlet is connected to the condensate outlet pipeline;

[0042] The oxygen supply system includes an oxygen cylinder, a pressure reducing valve 9, a regulating valve 10 and a flow metering, displaying and controlling device; the pressure reducing valve 9, the regulating valve 10 and the flow metering, displaying and controlling device are successively arranged on the gas pipeline connecting the oxygen cylinder;

[0043] The nitrogen replenishment system includes a nitrogen cylinder, a pressure reducing valve 9, a regulating valve 10, and a flow rate metering, displaying and controlling device; the pressure reducing valve 9, the regulating valve 10, and the flow rate metering, displaying and controlling device are successively arranged on the gas pipeline connecting the nitrogen cylinder; the regulating valve 10 in the nitrogen replenishment system is electrically connected to the central control system;

[0044] The hydrogen-containing waste gas inlet system includes a waste gas cylinder, a pressure reducing valve 9, a regulating valve 10, and a flow rate metering, displaying and controlling device; the pressure reducing valve 9, the regulating valve 10, and the flow rate metering, displaying and controlling device are successively arranged on the gas pipeline connecting the waste gas cylinder;

[0045] A pressure sensing device is provided on the gas buffer tank 2, and the pressure sensing device is electrically connected to the central control system. The pressure sensing device is used to feedback the actual pressure value of the gas buffer tank 2 to the central control system; the flow rate metering, displaying and controlling device in the oxygen replenishment system is electrically connected to the central control system, and the flow rate metering, displaying and controlling device is used to feedback the oxygen concentration to the central control system; the regulating valve 10 in the oxygen replenishment system is used to adjust its own opening degree according to the instruction of the central control system to control the input amount of oxygen; the flow rate metering, displaying and controlling device in the hydrogen-containing waste gas inlet system is electrically connected to the central control system, and the flow rate metering, displaying and controlling device is used to feedback the input amount of hydrogen-containing waste gas to the central control system;

[0046] The flow rate metering, displaying and controlling device includes a flow indicator 12, a flow transmitter 13, and a flow control valve 15;

[0047] In the nitrogen replenishment system, the oxygen replenishment system, and the hydrogen-containing waste gas inlet system, a ball valve 11 is provided between the pressure reducing valve 9 and the regulating valve 10. The ball valve is used to open and close the gas pipeline connecting the pressure reducing valve and the regulating valve, adding an extra safeguard; a temperature sensor 24 is also provided on the gas pipeline behind the regulating valve 10; in the hydrogen-containing waste gas inlet system, a flow control alarm 14 is also provided on the gas pipeline behind the regulating valve 10;

[0048] The pressure sensing device provided on the gas buffer tank 2 includes a pressure sensor, a pressure indicator 17, and a pressure transmitter 18; the pressure sensor is used to obtain the actual pressure inside the gas buffer tank 2; the pressure indicator 17 is used to display the actual pressure inside the gas buffer tank 2; the pressure transmitter 18 is used to upload the actual pressure obtained by the pressure sensor to the central control system;

[0049] There are multiple analytical transmitters 16 and air-insulated switches 28 installed on the gas pipeline after the pipeline mixer 1. The analytical transmitter 16 is electrically connected to the central control system and is also electrically connected to the air-insulated switch 28; there are also multiple analytical transmitters 16 installed on the gas pipeline after the fan 8; the analytical transmitter 16 is used to obtain the hydrogen content at different positions of the gas pipeline and upload the values to the central control system; the air-insulated switch 28 is used to protect the electrical circuit of the analytical transmitter 16 from overloading or short-circuiting; there is also a pressure controller 25 installed on the gas pipeline after the fan 8. The pressure controller 25 is electrically connected to the central control system and is used to control the pressure in the gas pipeline after the fan 8 according to the instructions of the central control system; there is also a flow-limiting orifice plate 26 installed on the main exhaust gas pipeline connected to the outlet of the fan 8; the multiple analytical transmitters 16 installed on the gas pipeline after the fan 8 are also electrically connected to the analog relay unit 32; there is a heating cable 33 corresponding to the fan 8; there is also a liquid level control valve 35 installed on the exhaust gas circulation pipeline connected to the fan 8;

[0050] Temperature indicators 20 and temperature detectors 21 are installed on the gas pipeline after the catalytic bed 5, after the preheater 3, after the electric heater 4, on the chilled water inlet pipeline of the cooler 6, and on the chilled water outlet pipeline of the cooler 6; both the temperature indicator 20 and the temperature detector 21 are electrically connected to the central control system and are used to display and upload the temperature values at the corresponding positions;

[0051] There is also a temperature control alarm 19 installed on the gas pipeline after the electric heater 4. The temperature control alarm 19 is electrically connected to the central control system and is used to give a temperature alarm according to the alarm instructions issued by the central control system; both the electric heater 4 and the temperature control alarm 19 are electrically connected to the control transformer 30;

[0052] On the gas pipeline between the catalytic bed 5 and the preheater 3, there is a pneumatic diaphragm control valve 22. The pneumatic diaphragm control valve 22 is electrically connected to the central control system and is used to control the pressure and flow rate of the gas in the gas pipeline according to the instructions of the central control system;

[0053] Two-position control valves 27 are installed on both the outlet gas pipeline and the condensate outlet pipeline of the gas buffer tank 2; two-position control valves 27 are also installed on the condensate outlet pipeline of the trap 7; there is also a liquid level signal converter 34 installed on the condensate outlet pipeline of the trap 7;

[0054] Both the two-position control valve 27 and the air-insulated switch 28 are electrically connected to the potentiometer isolator 29, and the potentiometer isolator 29 is also electrically connected to the frequency converter 31;

[0055] The central control system is used to control the nitrogen supplement amount of the nitrogen supplement system, regulate the gas pressure in the gas buffer tank 2, control the oxygen supplement amount of the oxygen supplement system, control the waste gas intake amount of the hydrogen-containing waste gas intake system, obtain the hydrogen content at different positions on the gas pipeline after the pipeline mixer 1; control the pressure in the gas pipeline after the fan 8; issue an alarm instruction when the temperature in the gas pipeline after the electric heater 4 exceeds the set value; obtain the temperature values on the gas pipeline after the preheater 3, on the gas pipeline after the electric heater 4, on the chilled water inlet pipeline of the cooler 6 and on the chilled water outlet pipeline of the cooler 6 in the catalytic bed 5, and regulate the gas pressure and flow rate in the gas pipeline between the catalytic bed 5 and the preheater 3.

[0056] Example 2

[0057] On the basis of Example 1, the working method of the nuclear power plant radioactive waste gas catalytic oxidation hydrogen removal device with controllable gas concentration is as follows:

[0058] The radioactive waste gas hydrogen removal device will discharge tail gas. To maintain the stability of the system pressure, nitrogen will be supplemented to make up for the discharged tail gas. The hydrogen-oxygen recombination reaction will consume oxygen, and the oxygen consumption is related to the hydrogen content in the waste gas. Oxygen will be supplemented to maintain the stability of the oxygen concentration in the system. There are fluctuations in the hydrogen and nitrogen contents in the waste gas components:

[0059] When the oxygen concentration in the oxygen supplement system is within the set range, the central control system interlocks and controls the regulating valve 10 and the flow measurement display and control device in the oxygen supplement system, and controls the oxygen flow supplied by the oxygen cylinder in the oxygen supplement system within the set value; when the oxygen concentration in the oxygen supplement system exceeds the set range, the ball valve 11 and the regulating valve 10 in the oxygen supplement system are interlocked and controlled by the central control system to control the oxygen concentration in the whole device within the set value;

[0060] When the nitrogen concentration in the nitrogen supplement system is within the set range, the central control system interlocks and controls the regulating valve 10 and the flow measurement display and control device in the nitrogen supplement system, and controls the oxygen flow supplied by the oxygen cylinder in the nitrogen supplement system within the set value; when the nitrogen concentration in the nitrogen supplement system exceeds the set range and exceeds the tail gas emission amount, the system pressure will increase. When the nitrogen concentration reaches the upper limit value, the ball valve 11 and the regulating valve 10 in the nitrogen supplement system are interlocked and controlled by the central control system to reduce or even close the opening of the regulating valve 10 and control the nitrogen concentration in the whole device within the set value;

[0061] The central control obtains the hydrogen content at different positions on the gas pipeline after the pipeline mixer 1, and controls the hydrogen concentration in the whole device to be lower than the set value by regulating the intake amounts of the oxygen supplement system, the nitrogen supplement system and the hydrogen-containing waste gas intake system.

[0062] Set the oxygen concentration control range to 2.5 - 3.0%, and set the oxygen input flow rate to 1.0 Nm 3 / h. When the system starts running, the flow indicator 12 shows that the oxygen concentration is 2.6%, and at this time the oxygen input flow rate is 1.0 Nm 3 / h, and the opening of the regulating valve 10 in the oxygen supply system is 30%; the flow indicator 12 shows that the oxygen concentration is 2.3%, and at this time the oxygen input flow rate is 1.5 Nm 3 / h, and the opening of the regulating valve 10 in the oxygen supply system is 46%; the flow indicator 12 shows that the oxygen concentration is 3.2%, and at this time the oxygen input flow rate is 0.7 Nm 3 / h, and the opening of the regulating valve 10 in the oxygen supply system is 24%.

[0063] Nitrogen input control: Set the pressure of the gas buffer tank 2 to 5.0 - 6.0 Kpa, and set the nitrogen input flow rate to 1.0 Nm 3 / h. When the system starts running, the pressure value of the gas buffer tank 2 shows 5.2 Kpa, and at this time the actual nitrogen input flow rate is 1.0 Nm 3 / h, and the opening of the regulating valve 10 in the nitrogen supply system is 35%; the pressure value of the gas buffer tank 2 shows 6.2 Kpa, and at this time the actual nitrogen input flow rate is 0.7 Nm 3 / h, and the opening of the regulating valve 10 in the nitrogen supply system is 28%; the pressure value of the gas buffer tank 2 shows 4.8 Kpa, and at this time the actual nitrogen input flow rate is 1.3 Nm 3 / h, and the opening of the regulating valve 10 in the nitrogen supply system is 39%.

[0064] Exhaust gas input control: Set the upper limit value of the pressure of the gas buffer tank 2 to 7.5 Kpa, and set the upper limit value of the hydrogen concentration to 3.5%. When the system starts running, the exhaust gas input flow rate is 2.5 Nm 3 / h, the reading of the flow transmitter 13 in the hydrogen-containing exhaust gas inlet system is 1.8%. The moment the pressure of the gas buffer tank 2 reaches 7.5 Kpa, the opening of the regulating valve 10 in the hydrogen-containing exhaust gas inlet system drops directly from 30% to 0%. The moment the pressure drops from 7.5 Kpa to 5.0 Kpa, the opening of the regulating valve 10 in the hydrogen-containing exhaust gas inlet system rises from 0% to 30%, and the flow value of the flow transmitter 13 in the hydrogen-containing exhaust gas inlet system rises from 0 to 2.5 Nm 3 / h; when the system starts running, the exhaust gas input flow rate is 5.0 Nm 3 / h, when the pressure display of the gas buffer tank 2 is 6.0 Kpa and the reading of the flow transmitter 13 in the hydrogen-containing waste gas inlet system reaches 3.5% instantaneously, the opening of the regulating valve 10 in the hydrogen-containing waste gas inlet system drops directly from 60% to 0%, and the pressure drops from 6.0 Kpa to 5.0 Kpa. When the reading of the flow transmitter 13 in the hydrogen-containing waste gas inlet system gradually drops to 2.0% instantaneously, the opening of the regulating valve 10 in the hydrogen-containing waste gas inlet system gradually rises from 0% to 60%, and the flow value of the flow transmitter 13 in the hydrogen-containing waste gas inlet system rises from 0 to 5 Nm 3 / h.

Claims

1. A catalytic oxidation hydrogen removal device for radioactive waste gas in a nuclear power plant with controllable gas concentration, characterized in that, Including: An oxygen supply system, a nitrogen supply system, a hydrogen-containing waste gas inlet system, a pipeline mixer, a gas buffer tank, a preheater, an electric heater, a catalytic bed, a cooler, a trap, a fan, and a central control system; the central control system is electrically connected to the rest; The supply pipelines of the oxygen supply system, the nitrogen supply system, and the hydrogen-containing waste gas inlet system are all connected to the inlet of the pipeline mixer, and the outlet of the pipeline mixer is connected to the inlet of the gas buffer tank; the outlet of the gas buffer tank is connected to the inlet of the preheater, and the outlet of the preheater is respectively connected to two outlet pipelines, one of the outlet pipelines is connected to the inlet of the electric heater, and the other outlet pipeline is connected to the inlet of the cooler; a condensate water outlet pipeline is provided at the bottom of the gas buffer tank; the outlet of the electric heater is connected to the inlet on the catalytic bed; the outlet on the catalytic bed is respectively connected to two outlet pipelines, one of the outlet pipelines is connected to the inlet on the preheater, and the other outlet pipeline is connected to the inlet of the cooler; the cooler is provided with an outlet, a circulating chilled water inlet, and a circulating chilled water outlet, the circulating chilled water inlet is connected to the circulating chilled water inlet pipeline, the circulating chilled water outlet is connected to the circulating chilled water outlet pipeline, the outlet on the cooler is connected to the inlet of the trap, and a condensate water outlet pipeline is provided at the bottom of the trap; the outlet of the trap is connected to the inlet of the fan, the outlet of the fan is respectively connected to the main exhaust gas pipe and the exhaust gas circulation pipeline, the main exhaust gas pipe communicates with the external environment, the exhaust gas circulation pipeline is connected to the inlet of the pipeline mixer, and a condensate water outlet is also provided on the trap, and the condensate water outlet is connected to the condensate water outlet pipeline; The central control system is used to control the nitrogen supply amount of the nitrogen supply system, to adjust the gas pressure in the gas buffer tank, to control the oxygen supply amount of the oxygen supply system, to control the waste gas inlet amount of the hydrogen-containing waste gas inlet system, to obtain the hydrogen content at different positions on the gas pipeline after the pipeline mixer; to control the pressure in the gas pipeline after the fan; to issue an alarm instruction when the temperature in the gas pipeline after the electric heater exceeds the set value; to obtain the temperature values on the catalytic bed, on the gas pipeline after the preheater, on the gas pipeline after the electric heater, on the chilled water inlet pipeline of the cooler, and on the chilled water outlet pipeline of the cooler, and to regulate the gas pressure and flow rate in the gas pipeline between the catalytic bed and the preheater.

2. The catalytic oxidation hydrogen removal device for radioactive waste gas in a nuclear power plant with controllable gas concentration according to claim 1, characterized in that: The oxygen supply system includes an oxygen cylinder, a pressure reducing valve, a regulating valve, and a flow metering display and control device; the pressure reducing valve, the regulating valve, and the flow metering display and control device are successively arranged on the gas pipeline connecting the oxygen cylinder; The nitrogen supply system includes a nitrogen cylinder, a pressure reducing valve, a regulating valve, and a flow metering display and control device; the pressure reducing valve, the regulating valve, and the flow metering display and control device are successively arranged on the gas pipeline connecting the nitrogen cylinder; the regulating valve in the nitrogen supply system is electrically connected to the central control system; The hydrogen-containing waste gas inlet system includes a waste gas cylinder, a pressure reducing valve, a regulating valve, and a flow rate measurement display and control device; the pressure reducing valve, the regulating valve, and the flow rate measurement display and control device are successively arranged on the gas pipeline connecting the waste gas cylinder.

3. The hydrogen catalytic oxidation removal device for radioactive waste gas in a nuclear power plant with controllable gas concentration according to claim 2, characterized in that: A pressure sensing device is provided on the gas buffer tank, the pressure sensing device is electrically connected to the central control system, and the pressure sensing device is used to feedback the actual pressure value of the gas buffer tank to the central control system; the flow rate measurement display and control device in the oxygen supply system is electrically connected to the central control system, and the flow rate measurement display and control device is used to feedback the oxygen concentration to the central control system; the regulating valve in the oxygen supply system is used to adjust its own opening degree according to the instruction of the central control system to control the input amount of oxygen; the flow rate measurement display and control device in the hydrogen-containing waste gas inlet system is electrically connected to the central control system, and the flow rate measurement display and control device is used to feedback the input amount of hydrogen-containing waste gas to the central control system; The central control system is used to receive the actual pressure value in the gas buffer tank sent by the pressure sensing device, and issue a control instruction to control the opening degree of the regulating valve in the nitrogen supply system to control the nitrogen supply amount; used to receive the oxygen concentration feedback by the flow rate measurement display and control device in the oxygen supply system, and issue a control instruction to control the opening degree of the regulating valve in the oxygen supply system to control the oxygen supply amount; used to receive the input amount of hydrogen-containing waste gas in the hydrogen-containing waste gas inlet system, and issue a control instruction to control the opening degree of the regulating valve in the hydrogen-containing waste gas inlet system to prevent the hydrogen concentration in the hydrogen-containing waste gas from exceeding the set value.

4. The hydrogen catalytic oxidation removal device for radioactive waste gas in a nuclear power plant with controllable gas concentration according to claim 2, characterized in that: The flow rate measurement display and control device includes a flow indicator, a flow transmitter, and a flow control valve; In the nitrogen supply system, the oxygen supply system, and the hydrogen-containing waste gas inlet system, a ball valve is provided between the pressure reducing valve and the regulating valve, and the ball valve is used to open and close the gas pipeline connecting the pressure reducing valve and the regulating valve; a temperature sensor is also provided on the gas pipeline after the regulating valve; in the hydrogen-containing waste gas inlet system, a flow control alarm is also provided on the gas pipeline after the regulating valve. The pressure sensing device provided on the gas buffer tank includes a pressure sensor, a pressure indicator, and a pressure transmitter; the pressure sensor is used to obtain the actual pressure in the gas buffer tank; The pressure indicator is used to display the actual pressure in the gas buffer tank; the pressure transmitter is used to upload the actual pressure obtained by the pressure sensor to the central control system.

5. The hydrogen catalytic oxidation removal device for radioactive waste gas in a nuclear power plant with controllable gas concentration according to claim 1, characterized in that: There are multiple analytical transmitters and air-insulated switches installed on the gas pipeline after the pipeline mixer. The analytical transmitters are electrically connected to the central control system and are also electrically connected to the air-insulated switches; there are also multiple analytical transmitters installed on the gas pipeline after the fan; the analytical transmitters are used to obtain the hydrogen content at different positions of the gas pipeline and upload the values to the central control system; the air-insulated switches are used to protect the electrical circuits of the analytical transmitters from overload or short-circuit phenomena; there is also a pressure controller installed on the gas pipeline after the fan, and the pressure controller is electrically connected to the central control system and is used to control the pressure in the gas pipeline after the fan according to the instructions of the central control system; there is also an orifice plate installed on the main exhaust pipe connected to the outlet of the fan; the multiple analytical transmitters installed on the gas pipeline after the fan are also electrically connected to the analog relay unit; there is a heating cable corresponding to the fan; there is also a liquid level control valve installed on the tail gas circulation pipeline connected to the fan.

6. The catalytic oxidation hydrogen removal device for radioactive waste gas in a nuclear power plant with controllable gas concentration according to claim 1, characterized in that: Temperature indicators and temperature detectors are installed on the gas pipeline after the catalytic bed, after the preheater, after the electric heater, on the chilled water inlet pipeline of the cooler and on the chilled water outlet pipeline of the cooler; both the temperature indicators and the temperature detectors are electrically connected to the central control system and are used to display and upload the temperature values at the corresponding positions; There is also a temperature control alarm installed on the gas pipeline after the electric heater, and the temperature control alarm is electrically connected to the central control system and is used to perform temperature alarm according to the alarm instructions issued by the central control system; both the electric heater and the temperature control alarm are electrically connected to the control transformer; On the gas pipeline between the catalytic bed and the preheater, there is a pneumatic diaphragm control valve, and the pneumatic diaphragm control valve is electrically connected to the central control system and is used to control the pressure and flow rate of the gas in the gas pipeline according to the instructions of the central control system.

7. The catalytic oxidation hydrogen removal device for radioactive waste gas in a nuclear power plant with controllable gas concentration according to claim 1, characterized in that: Two-position control valves are installed on both the gas outlet pipeline and the condensate water outlet pipeline of the gas buffer tank; two-position control valves are also installed on the condensate water outlet pipeline of the trap; there is also a liquid level signal converter installed on the condensate water outlet pipeline of the trap; Both the two-position control valves and the air-insulated switches are electrically connected to the potentiometer isolator, and the potentiometer isolator is also electrically connected to the frequency converter.

8. A working method of a catalytic oxidation hydrogen removal device for radioactive waste gas in a nuclear power plant with controllable gas concentration as described in any one of claims 1 to 7, characterized in that, Specifically, it includes the following steps: When the oxygen concentration in the oxygen supply system is within the set range, the central control system interlocks and controls the regulating valve and the flow measurement display and control device in the oxygen supply system to control the oxygen flow supplied by the oxygen cylinder in the oxygen supply system within the set value; when the oxygen concentration in the oxygen supply system exceeds the set range, the ball valve and the regulating valve in the oxygen supply system are interlocked and controlled by the central control system to control the oxygen concentration in the whole device within the set value; When the nitrogen concentration in the nitrogen replenishment system is within the set range, the central control system interlock controls the regulating valve and the flow measurement display and control device in the nitrogen replenishment system to control the oxygen flow supplied by the oxygen cylinder in the nitrogen replenishment system within the set value; when the nitrogen concentration in the nitrogen replenishment system exceeds the set range, the ball valve and the regulating valve in the nitrogen replenishment system are interlock controlled by the central control system to control the nitrogen concentration in the entire device within the set value; The central control obtains the hydrogen content at different positions on the gas pipeline after the pipeline mixer, and controls the hydrogen concentration in the entire device to be lower than the set value by regulating the intake air volumes of the oxygen replenishment system, the nitrogen replenishment system, and the hydrogen-containing waste gas intake system.

9. The working method of the catalytic oxidation hydrogen removal device for radioactive waste gas in a nuclear power plant with controllable gas concentration according to claim 8, characterized in that: When the oxygen concentration in the oxygen replenishment system exceeds the set range, the ball valve and the regulating valve in the oxygen replenishment system are interlock controlled by the central control system to control the oxygen concentration in the entire device within 2%.

10. The working method of the catalytic oxidation hydrogen removal device for radioactive waste gas in a nuclear power plant with controllable gas concentration according to claim 8, characterized in that: The hydrogen concentration in the hydrogen-containing waste gas does not exceed 4%.

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