A heat exchanger leakage safety pressure relief device

Abstract

The utility model discloses a heat exchanger leakage safety pressure relief device, including methanol cooler, separator and liquid separation tank, and the outlet gas is connected with the import of methanol cooler through pipeline L1, and the export of methanol cooler is connected with the import of separator through pipeline L2, the water inlet and the water outlet of methanol cooler are connected through pipeline L3 and pipeline L4 respectively, and the pipeline L4 is connected with pipeline L5, and the pipeline L5 is provided with safety valve F1, the pipeline L5 downstream of safety valve F1 is connected with pipeline L6, and the pipeline L6 is connected with the import of liquid separation tank, and the liquid outlet of liquid separation tank is connected with methanol underground tank through pipeline L7, and the gas outlet of liquid separation tank is connected with torch pipe network through pipeline L8, the advantage is: avoid the leakage of pipe course toxic gas emission to the atmosphere and cause environmental pollution, personnel poisoning and the risk of explosion.

Description

Technical Field

[0001] This utility model relates to the field of high-pressure series low-pressure heat exchanger leakage safety pressure relief technology, and in particular to a heat exchanger leakage safety pressure relief device. Background Technology

[0002] Fresh syngas (CO, CO2, and H2) from the upstream process is mixed with recycle gas (CO, CO2, and H2) in a buffer tank and then enters the inlet gas preheater (shell side) for countercurrent heat exchange with the outlet gas (tube side) from the synthesis tower. After being heated to about 200°C, it enters the synthesis tower from the top. At 4.5–5.3 MPa and 220–260°C, some CO, CO2, and H2 react to produce methanol (gas phase). The outlet gas enters the inlet gas preheater (tube side) for countercurrent heat exchange with the inlet gas (shell side) and is cooled to about 95°C. The outlet gas is then further condensed to about 40°C by a methanol cooler and enters a methanol separator to separate methanol. The unreacted gas is returned to the system as recycle gas after being pressurized to continue participating in the reaction.

[0003] like Figure 1 As shown, the gas exiting the tower (pressure 4.5–5.3 MPa, temperature approximately 95°C; composition: CO, CO2, H2, methanol gaseous phase, etc.) enters the methanol cooler through the L1 tube. The cooled gas (pressure 4.5–5.3 MPa, temperature approximately 40°C; composition: CO, CO2, H2, methanol liquid phase, etc.) enters the middle of the methanol separator through the L2 tangent. Methanol is separated by the principle of cyclone separation. The lower methanol is sent to the methanol expansion tank through pipeline L10, and the liquid level LT1 is remotely controlled by valve F5. The unreacted gas at the top is returned to the system as circulating gas through pipeline L11 after being pressurized to continue participating in the reaction.

[0004] The circulating water from the circulating water network (pressure approximately 0.4 MPa, temperature 25–34 °C) enters the shell side of the methanol cooler via L3, and after counter-current heat exchange, it goes to the circulating return water network via L4.

[0005] The methanol cooler is a shell-and-tube heat exchanger, and there is a possibility of leakage during operation. However, the high-pressure medium (CO, CO2, H2, methanol) in the tube side is a high-pressure, flammable, and toxic gas. In the event of a leak, the high-pressure medium (4.5–5.3 MPa) will enter the low-pressure circulating water side of the shell side (approximately 0.4 MPa), causing the safety valve F1 in the circulating water return line to trip. After safety valve F1 trips, the gas-liquid mixture containing the tube-side medium and the shell-side circulating water is depressurized to the air through pipeline L5. This will cause the following problems:

[0006] 1. Methanol in the pipeline medium is easily soluble in water, so the gas-liquid mixture in the emissions contains methanol, which is discharged into the plant area in a disorderly manner, causing pollution;

[0007] 2. The toxic CO gas in the pipeline medium will be released into the atmosphere, causing environmental pollution and personnel poisoning;

[0008] 3. Combustible gases such as CO and H2 in the pipeline medium may be released into the atmosphere, posing a risk of explosion. Utility Model Content

[0009] The purpose of this invention is to provide a heat exchanger leakage safety pressure relief device, thereby solving the aforementioned problems existing in the prior art.

[0010] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0011] A heat exchanger leakage safety pressure relief device includes a methanol cooler, a separator, and a liquid separator. Gas exiting the tower is connected to the inlet of the methanol cooler via pipeline L1, and the outlet of the methanol cooler is connected to the inlet of the separator via pipeline L2. The inlet and outlet of the methanol cooler are connected via pipelines L3 and L4, respectively. Pipeline L4 is connected to pipeline L5, on which a safety valve F1 is installed. Pipeline L6 is connected downstream of safety valve F1 on pipeline L5. Pipeline L6 is connected to the inlet of the liquid separator. The outlet of the liquid separator is connected to a methanol underground tank via pipeline L7, and the gas outlet of the liquid separator is connected to a flare network via pipeline L8.

[0012] Preferably, an automatic switching valve F2 is installed on the pipeline L7; the automatic switching valve F2 is connected to the liquid separator via a level transmitter LT2.

[0013] Preferably, a one-way valve F3 is provided on the pipeline L8.

[0014] Preferably, the nitrogen storage device is connected to the separator via pipeline L9; a switch valve F4 is installed on the pipeline L9.

[0015] Preferably, the outlet of the separator is connected to the methanol expansion tank via pipeline L10.

[0016] Preferably, an automatic switching valve F5 is installed on the pipeline L10; the automatic switching valve F5 is connected to the separator via a level transmitter LT1.

[0017] Preferably, the outlet of the separator is connected to a pipeline L11.

[0018] The beneficial effects of this invention are: 1. Alcohol-containing waste liquid is discharged into an underground methanol tank and sent to a distillation system for refining, avoiding the problem of environmental pollution caused by discharge into the factory area. Simultaneously, methanol is recovered and reused, creating corporate benefits. 2. Toxic CO gas in the tubular medium is sent to the flare network for combustion treatment, avoiding environmental pollution and personnel poisoning. 3. Combustible gases CO and H2 in the tubular medium are sent to the flare network for combustion treatment, avoiding the possibility of explosion upon release into the atmosphere. Attached Figure Description

[0019] Figure 1 This is a structural diagram of the original pressure relief process in an embodiment of this utility model;

[0020] Figure 2 This is a structural diagram of the safety pressure relief device in an embodiment of this utility model. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the utility model and are not intended to limit the scope of the utility model.

[0022] This embodiment provides a heat exchanger leakage safety pressure relief device, such as... Figure 2 As shown, the system includes a methanol cooler, a separator, and a liquid separator. Gas exiting the tower is connected to the inlet of the methanol cooler via pipeline L1. The outlet of the methanol cooler is connected to the inlet of the separator via pipeline L2. The inlet and outlet of the methanol cooler are connected via pipelines L3 and L4, respectively. Pipeline L4 is connected to pipeline L5, which is equipped with a safety valve F1. Downstream of safety valve F1, pipeline L5 is connected to pipeline L6, which is connected to the inlet of the liquid separator. The outlet of the liquid separator is connected to the underground methanol tank via pipeline L7, and the gas outlet of the liquid separator is connected to the flare network via pipeline L8. An automatic switching valve F2 is installed on pipeline L7, which is connected to the liquid separator via a level transmitter LT2. A one-way valve F3 is installed on pipeline L8.

[0023] When a leak occurs in the tubing, the high-pressure media CO, CO2, H2, and methanol from the tubing will enter the shell-side circulating water side, causing the safety valve F1 in the circulating water return line to trip. After safety valve F1 trips, the mixed gas and liquid containing the tubing media and shell-side circulating water is discharged to the separator tank via pipeline L6. The solution that has absorbed methanol is separated in the separator tank. The level transmitter LT2 controls the automatic switching valve F2 to open based on the liquid level in the separator tank, sending the solution in pipeline L7 to the methanol underground tank for recovery treatment. The unabsorbed gas is then sent to the flare network for combustion treatment via check valve F3 and pipeline L8.

[0024] In this embodiment, the nitrogen storage device is connected to the separator via pipeline L9; a switch valve F4 is installed on pipeline L9. The nitrogen supplied to the separator via pipeline L9 is mainly used for routine pipeline cleaning and inspection, and for replenishing nitrogen for fire extinguishing in case of abnormalities.

[0025] In this embodiment, the liquid outlet of the separator is connected to the methanol expansion tank via pipeline L10. An automatic switching valve F5 is installed on pipeline L10; the automatic switching valve F5 is connected to the separator via a level transmitter LT1. The gas outlet of the separator is connected to pipeline L11. The separator separates methanol using the principle of cyclone separation. The level transmitter LT1 controls the automatic switching valve F5 to open based on the liquid level in the separator, sending the separated methanol from the lower part of the separator to the methanol expansion tank via pipeline L10 for recovery. Unreacted gas from the upper part of the separator is returned to the system as circulating gas via pipeline L11 after pressurization to continue participating in the reaction.

[0026] By adopting the above-disclosed technical solution of this utility model, the following beneficial effects are obtained:

[0027] This invention provides a heat exchanger leakage safety pressure relief device. Alcohol-containing waste liquid is discharged into an underground methanol tank and then sent to a distillation system for purification, avoiding environmental pollution from discharge into the plant area. Simultaneously, methanol is recycled, creating business benefits. Toxic CO gas in the tube-side medium is sent to a flare network for combustion, preventing environmental pollution and personnel poisoning. Combustible gases CO and H2 in the tube-side medium are also sent to a flare network for combustion, preventing the possibility of explosion upon atmospheric release.

[0028] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A heat exchanger leakage safety pressure relief device, characterized in that: The system includes a methanol cooler, a separator, and a liquid separator. The outlet gas is connected to the inlet of the methanol cooler via pipeline L1, and the outlet of the methanol cooler is connected to the inlet of the separator via pipeline L2. The inlet and outlet of the methanol cooler are connected via pipelines L3 and L4, respectively. Pipeline L4 is connected to pipeline L5, which is equipped with a safety valve F1. Pipeline L6 is connected downstream of safety valve F1 on pipeline L5. Pipeline L6 is connected to the inlet of the liquid separator. The outlet of the liquid separator is connected to the underground methanol tank via pipeline L7, and the outlet of the liquid separator is connected to the flare network via pipeline L8.

2. The heat exchanger leakage safety pressure relief device according to claim 1, characterized in that: An automatic switching valve F2 is installed on the pipeline L7; the automatic switching valve F2 is connected to the liquid separator via the liquid level transmitter LT2.

3. The heat exchanger leakage safety pressure relief device according to claim 1, characterized in that: A one-way valve F3 is installed on the pipeline L8.

4. The heat exchanger leakage safety pressure relief device according to any one of claims 1 to 3, characterized in that: The nitrogen storage device is connected to the separator via pipeline L9; a switch valve F4 is installed on pipeline L9.

5. The heat exchanger leakage safety pressure relief device according to claim 4, characterized in that: The outlet of the separator is connected to the methanol expansion tank via pipeline L10.

6. The heat exchanger leakage safety pressure relief device according to claim 5, characterized in that: An automatic switching valve F5 is installed on the pipeline L10; the automatic switching valve F5 is connected to the separator via a level transmitter LT1.

7. The heat exchanger leakage safety pressure relief device according to claim 6, characterized in that: The air outlet of the separator is connected to pipeline L11.

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