Gas-liquid separation system for coal gas and online dredging method for cooler

Abstract

The invention relates to a coal gas gas-liquid separation system which comprises a gas-liquid separator, a compressor for converting coal gas into high-temperature and high-pressure coal gas and two cooling flow paths for cooling the high-temperature and high-pressure coal gas, and the two cooling flow paths are both connected to the gas-liquid separator. The two cooling flow paths are alternately connected or disconnected, when one cooling flow path is blocked, the other cooling flow path is opened, and the two cooling flow paths are both provided with control assemblies used for controlling the flow of high-temperature and high-pressure coal gas. The invention further provides an online cooler dredging method which is used for the gas-liquid separation system. The two cooling flow paths are adopted, when one flow path is blocked, the other flow path can be opened to be supplied to a downstream user, gas using of the downstream user is not affected, meanwhile, the control assembly is adopted for controlling the flow of high-temperature and high-pressure coal gas, impurities of the blocked cooling flow path can be removed in an online blowing mode, and the compressor can be prevented from being damaged.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgy and chemical engineering, and in particular to a coal gas-liquid separation system and a cooler online dredging method. Background Art

[0002] Coal gas made from coal, biomass, petroleum, etc., as well as coke oven gas produced as a byproduct of the coking process, contain not only effective ingredients such as CO, H2 and CH4, but also impurities such as CO2, H2O, H2S, COS, NH3, HCN, tar, benzene, and naphthalene. Although the initial purification can remove most of the impurities, users often need to pressurize the gas during subsequent use, so that impurities will be enriched in the gas, especially tar, naphthalene, etc., which will clog the cooler after the compressor, causing the gas path to be blocked, and in severe cases, it will affect the normal operation of the compressor. Although deep purification methods can be used at the source of the gas, the investment cost is relatively high, and if the purification device is operated throughout the year, the operating costs are also high. Summary of the invention

[0003] The purpose of the present invention is to provide a coal gas-liquid separation system and a cooler online dredging method, which can at least solve some of the defects in the prior art.

[0004] To achieve the above-mentioned purpose, an embodiment of the present invention provides the following technical solution: a coal gas-liquid separation system, comprising a gas-liquid separator, a compressor for converting coal gas into high-temperature and high-pressure coal gas, and two cooling flow paths for cooling the high-temperature and high-pressure coal gas, both of which are connected to the gas-liquid separator, and the two cooling flow paths are alternately turned on or off, and when one of the cooling flow paths is blocked, the other cooling flow path is opened, and both cooling flow paths are provided with control components for controlling the flow rate of the high-temperature and high-pressure coal gas.

[0005] Furthermore, a cooler is provided on each cooling flow path, and the cooler is connected to a water return end and a water inlet end.

[0006] Furthermore, stop valves are provided on the flow paths before and after the cooler.

[0007] Furthermore, the control component includes a regulating valve arranged on the flow path before the cooler.

[0008] Furthermore, the blocked cooling flow path is also connected to a pipeline for power generation.

[0009] Furthermore, a flow meter is provided on the pipeline used for power generation.

[0010] Furthermore, stop valves are provided on the flow paths before and after the flow meter.

[0011] The embodiment of the present invention provides another technical solution: a cooler online dredging method, which is used in the above-mentioned gas-liquid separation system, wherein the cooling flow path adopts a cooler, and comprises the following steps:

[0012] S1, when the cooler of one of the cooling flow paths is blocked, opening another cooling flow path to ensure the gas supply to downstream users;

[0013] S2, in the blocked cooling flow path, a control component is used to control the high-temperature and high-pressure coal gas to enter the blocked cooling flow path, so as to online purge the cooler of the cooling flow path to remove impurities.

[0014] Furthermore, a compressor with a surplus of compressed gas capacity is selected.

[0015] Furthermore, the control component uses a regulating valve to adjust the flow path opening to match the surplus compressed gas volume of the compressor.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. Two cooling channels are used. When one channel is blocked, the other channel can be opened to supply gas to downstream users without affecting the gas use of downstream users. At the same time, control components are used to control the flow of high-temperature and high-pressure gas, which can not only online purge and remove impurities from the blocked cooling channel, but also avoid damage to the compressor.

[0018] 2. Solve the problem of compressor aftercooler clogging due to high impurity content in the gas, and the increased cost and operating cost are low. The alternating use of two sets of coolers does not affect the normal operation of the compressor.

[0019] 3. After the gas is compressed by the compressor, the temperature will rise to form high-temperature gas, which can be used as impurity purge gas without the need for a heater. There is no need to connect steam pipelines and nitrogen replacement purge on site, reducing energy medium consumption. After purging, the gas is sent to power generation and other users for treatment, without causing environmental pollution.

[0020] 4. During purging, the gas compressor is in working condition, and the valve may not be closed tightly, which may cause gas leakage. This method can complete the cooler blockage purging work by remote operation, avoid on-site operation, avoid safety hazards, and is more efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of a flow path of a gas-liquid separation system for coal gas provided in an embodiment of the present invention;

[0022] In the figure numbers: 1-gas-liquid separator; 2-compressor; 3-first cooler; 4-second cooler; 5-water inlet end; 6-water return end; 7-flow meter; A-coal gas; B-power generation; C-downstream user. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] See also Figure 1 The embodiment of the present invention provides a gas-liquid separation system, comprising a gas-liquid separator 1, a compressor 2 for converting gas A into high-temperature and high-pressure gas, and two cooling channels for cooling the high-temperature and high-pressure gas. The two cooling channels are connected to the gas-liquid separator 1, and the two cooling channels are alternately turned on or off. When one of the cooling channels is blocked, the other cooling channel is opened. The two cooling channels are provided with a control component for controlling the flow rate of high-temperature and high-pressure gas. In this embodiment, two cooling channels are used, and when one of the channels is blocked, the other channel can be opened to supply the downstream user C, without affecting the gas use of the downstream user C. At the same time, the control component is used to control the flow rate of high-temperature and high-pressure gas, which can not only purge the blocked cooling channel online to remove impurities, but also avoid damaging the compressor 2. Specifically, the gas A is first converted into high-temperature and high-pressure gas by the compressor 2, and then sent to the gas-liquid separator 1 for gas-water separation after cooling on the cooling channel, and then sent to the downstream user C. Since compressor 2 will pressurize gas A, impurities will be enriched in the gas. As the system runs longer and longer, the cooler will be blocked by these impurities, causing the gas path to be blocked, making compressor 2 unable to work normally, and damaging compressor 2 over time. Although the problem can be solved by using a deep purification method before the supply of gas A, the investment cost of this method is relatively high. Therefore, this embodiment adds a cooling flow path. On the one hand, when one of the cooling flow paths is blocked, another cooling flow path can be opened to ensure the gas demand of downstream user C, and the normal operation of compressor 2 is also ensured, extending the service life of compressor 2. On the other hand, the abundant compressed gas volume of compressor 2 can be used to adjust the flow rate of high-temperature and high-pressure gas through the control component, so that the abundant compressed gas volume of compressor 2 can be used to perform online impurity purge on the blocked cooling flow path, and the blocked cooling flow path can be unblocked without affecting the gas compression volume of compressor 2. After the blocked cooling flow path is unblocked, it can be used as a backup cooling flow path. If another cooling flow path is blocked again, the unblocked cooling flow path can be restored to use, thereby achieving uninterrupted gas demand of downstream user C.

[0025] See also Figure 1, a cooler is provided on each cooling flow path, and the cooler is connected to a return water end 6 and a water inlet end 5. In this embodiment, a cooler is used in the cooling flow path to realize the cooling of high-temperature and high-pressure coal gas. For the convenience of distinction, the coolers on the two cooling flow paths are defined as a first cooler 3 and a second cooler 4, respectively. Preferably, a stop valve is provided on the flow paths before and after the cooler. For example, a stop valve S1 and a stop valve S2 are provided on the front and rear flow paths of the first cooler 3, respectively, and a stop valve F1 and a stop valve F2 are provided on the front and rear flow paths of the second cooler 4, respectively. An inlet valve LS1 is provided on the pipeline connected to the water inlet end 5 of the first cooler 3, an outlet valve LS2 is provided on the pipeline connected to the return water end 6 of the first cooler 3, an inlet valve LF1 is provided on the pipeline connected to the water inlet end 5 of the second cooler 4, and an outlet valve LF2 is provided on the pipeline connected to the return water end 6 of the second cooler 4.

[0026] See also Figure 1 , the control component includes a regulating valve arranged on the flow path in front of the cooler. In this embodiment, the control method can adopt a regulating valve, and the flow path opening that matches the surplus compressed gas volume of the compressor 2 is adjusted by the regulating valve. For example, if the surplus compressed gas volume of the compressor 2 is 5%, the flow path opening is controlled to be 5%, and the other unblocked cooling flow path is opened to a normal 100% flow path opening. The regulating valve is provided on both cooling flow paths, such as a regulating valve TS is provided on the flow path in front of the first cooler 3, and a regulating valve TV is provided on the flow path in front of the second cooler 4.

[0027] See also Figure 1 , the blocked cooling flow path is also connected to a pipeline for power generation B. In this embodiment, the blown impurities can be sent to power generation B and other combustion users. Preferably, a stop valve and a flow meter 7 are also provided on the pipeline. The pipeline from the first cooler 3 to power generation B is provided with a stop valve S3, and the pipeline from the second cooler 4 to power generation B is provided with a stop valve F3. A flow meter 7 and a stop valve V3 are provided on the pipeline after the two pipelines merge, so that the high-temperature coal gas can be sent to users such as power generation B after the back-blowing cooler, avoiding gas venting and waste. The flow meter 7 can monitor the flow rate of high-temperature compressed coal gas used for purging. Preferably, a gas inlet electric stop valve V1 is provided in front of the compressor 2, an electric stop valve V2 is provided to the downstream user C, and the gas-liquid separator 1 is provided with high and low liquid level detection L1 and L2, and an interlocking drain valve PV.

[0028] See also Figure 1, an embodiment of the present invention provides an online unblocking method for a cooler, which is used in the above-mentioned gas-liquid separation system, and includes the following steps: S1, when one of the cooling channels is blocked, another cooling channel is opened to ensure the gas supply of the downstream user C; S2, on the blocked cooling channel, a control component is used to control the high-temperature and high-pressure coal gas to enter the blocked cooling channel, so as to purge and remove impurities from the cooling channel online. In this embodiment, two cooling channels are used, and when one channel is blocked, the other channel can be opened to supply the downstream user C, which does not affect the gas use of the downstream user C. At the same time, a control component is used to control the flow rate of the high-temperature and high-pressure coal gas, which can not only purge and remove impurities from the blocked cooling channel online, but also avoid damage to the compressor 2. Specifically, the coal gas A is first converted into high-temperature and high-pressure coal gas by the compressor 2, and then sent to the gas-liquid separator 1 for gas-water separation after cooling on the cooling channel, and then sent to the downstream user C. Since compressor 2 will pressurize gas A, impurities will be enriched in the gas. As the system runs longer and longer, the cooler will be blocked by these impurities, causing the gas path to be blocked, making compressor 2 unable to work normally, and damaging compressor 2 over time. Although the problem can be solved by using a deep purification method before the supply of gas A, the investment cost of this method is relatively high. Therefore, this embodiment adds a cooling flow path. On the one hand, when one of the cooling flow paths is blocked, another cooling flow path can be opened to ensure the gas demand of downstream user C, and the normal operation of compressor 2 is also ensured, extending the service life of compressor 2. On the other hand, the abundant compressed gas volume of compressor 2 can be used to adjust the flow rate of high-temperature and high-pressure gas through the control component, so that the abundant compressed gas volume of compressor 2 can be used to perform online impurity purge on the blocked cooling flow path, and the blocked cooling flow path can be unblocked without affecting the gas compression volume of compressor 2. After the blocked cooling flow path is unblocked, it can be used as a backup cooling flow path. If another cooling flow path is blocked again, the unblocked cooling flow path can be restored to use, thereby achieving uninterrupted gas demand of downstream user C.

[0029] The specific operation steps of this embodiment are:

[0030] When the compressor 2 is operating normally, under normal production conditions, the first cooler 3 is used, the stop valve S1, stop valve S2, and regulating valve TS are opened, the cooler inlet and return pipe valves are opened, the stop valve S3 is closed, the second cooler 4 is standby, the front and rear valves are closed, and the inlet and return pipe valves of the second cooler 4 are closed. The coal gas is compressed by the compressor 2 and becomes high-temperature coal gas, which is cooled by the first cooler 3 and then sent to the downstream user C through the gas-water separator.

[0031] When the first cooler 3 is blocked, the gas channel of the cooler becomes narrower, the gas outlet pressure gradually increases, and the exhaust volume becomes smaller, which cannot meet the needs of users. At this time, the second cooler 4 is put into use, and the stop valve F1, stop valve F2 and regulating valve TV are opened remotely, and the valve of the water inlet and return pipe of the second cooler 4 is opened, and then the pipeline from the first cooler 3 to the gas-liquid separator 1 and the downstream user C is cut off by closing the stop valve S2, and the water inlet valve LS1 of the first cooler 3 is closed, and the stop valve S3 is opened. Through the flow meter 7 interlocking regulating valve TS, a part of the high-temperature compressed coal gas is diverted to the first cooler 3 for online purge and impurity removal. The impurities condensed in the first cooler 3 will be completely taken out, and the blown high-temperature impurity-containing coal gas is sent to the power generation B and other combustion users through the stop valve V3 and its pipeline.

[0032] After the first cooler 3 is purged, the stop valve S1 and the stop valve S3 are closed. At this time, the first cooler 3 can be used as a backup, so that the first cooler 3 and the second cooler 4 are circulated.

[0033] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A gas-liquid separation system, comprising a gas-liquid separator, characterized in that: It also includes a compressor for converting coal gas into high-temperature and high-pressure coal gas and two cooling flow paths for cooling the high-temperature and high-pressure coal gas. The two cooling flow paths are connected to the gas-liquid separator, and the two cooling flow paths are alternately opened or closed. When one of the cooling flow paths is blocked, the other cooling flow path is opened. The two cooling flow paths are provided with control components for controlling the flow of high-temperature and high-pressure coal gas.

2. The gas-liquid separation system according to claim 1, characterized in that: The cooling flow path is provided with a cooler, and the cooler is connected to a water return end and a water inlet end.

3. The gas-liquid separation system according to claim 2, characterized in that: Stop valves are provided on the flow paths before and after the cooler.

4. The gas-liquid separation system according to claim 1, characterized in that: The control component includes a regulating valve arranged on the flow path before the cooler.

5. The gas-liquid separation system according to claim 1, characterized in that: The blocked cooling flow path is also connected to a pipeline for power generation.

6. The gas-liquid separation system according to claim 5, characterized in that: The pipeline used for power generation is provided with a flow meter.

7. The gas-liquid separation system according to claim 6, characterized in that: Stop valves are provided on the flow paths before and after the flow meter.

8. A cooler online dredging method, characterized in that: For use in the gas-liquid separation system according to any one of claims 1 to 7, the cooling flow path adopts a cooler, comprising the following steps: S1, when the cooler of one of the cooling flow paths is blocked, opening another cooling flow path to ensure the gas supply to downstream users; S2, in the blocked cooling flow path, a control component is used to control the high-temperature and high-pressure coal gas to enter the blocked cooling flow path, so as to online purge the cooler of the cooling flow path to remove impurities.

9. The cooler online dredging method according to claim 8, characterized in that: Select a compressor with ample compressed air capacity.

10. The cooler online dredging method according to claim 9, characterized in that: The control component uses a regulating valve to adjust the flow path opening that matches the surplus compressed gas volume of the compressor.

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