Heating system for desalted water spraying system in coke-oven gas screw compressor unit

Abstract

The utility model belongs to the technical field of desalted water spraying systems of screw compressor units, and discloses a heating system for a desalted water spraying system in a coke-oven gas screw compressor unit. According to the heating system, after heat exchange is conducted through the gas-liquid cooler, water with waste heat conducts primary heating on circulating desalted water through the heat exchanger, and meanwhile an electric heating belt is arranged on a pipeline before the water enters the filter to conduct secondary heating on the circulating desalted water. Therefore, according to the improved desalted water spraying system, the cooling phenomenon of the sprayed saline water is reduced through circulating desalted water heated twice, it is guaranteed that the sprayed saline water cannot enter the filter due to cold to cause coalescence in a filter element, the replacement frequency of the filter element is reduced, the service life of the filter is prolonged, and the operation stability of a coke-oven gas screw compressor unit is improved. Meanwhile, the heat exchanger is introduced into the improvement, so that the heat energy of the gas-liquid cooler can be recycled, the electric energy loss of the electric heating belt is reduced, and the production cost of an enterprise is further reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of desalted water spraying systems of screw compressor units, and in particular relates to a heating system for a desalted water spraying system in a coke oven gas screw compressor unit. Background Art

[0002] In the process of producing LNG from coke oven gas, the coke oven gas compressor is the key to transporting gas to the subsequent process. At present, our factory uses screw compressors for coke oven gas compression. In order to avoid the blockage of the unit by tar, naphthalene and other impurities generated during the compression of coke oven gas, we use the desalted water spraying process to effectively cool and clean the unit rotor to extend the service life of the unit. The desalted water spraying system is a recycling method, which mainly returns the desalted water in the gas-liquid separator to the unit inlet through the filter.

[0003] In order to ensure the stable operation of the desalted water spray system, the filter is usually set to a "one-on, one-off" mode, that is, when one filter is in operation, the other is in standby mode in case of emergency. However, after more than two years of actual operation, it was found that the frequency of replacement of the spray filter element in winter is much greater than in summer. This phenomenon attracted the attention of our factory technicians. After in-depth analysis, it was found that the factory building adopts an open design. The circulating desalted water is cooled when it is transported to the filter through a long process, causing the heavy components such as tar and naphthalene in the circulating desalted water to agglomerate inside the filter element of the filter due to reduced solubility. As the agglomerates continue to increase, the amount of sprayed salt water gradually decreases, and thus cannot meet the needs of production. At this time, it is necessary to switch online and replace the new filter element to ensure the normal operation of the spray system.

[0004] In view of the above problems, how to take simple and effective measures to reduce the cooling phenomenon of the spray water, and then ensure that the spray water will not enter the filter due to cooling and cause internal agglomeration of the filter element, is crucial to improving the operating stability and efficiency of the coke oven gas screw compressor unit. Compared with other transformation measures, this is also the most effective way to reduce the replacement frequency of the filter element and reduce production costs. Utility Model Content

[0005] Aiming at the problem in the background technology that the circulating desalination causes the heavy components such as tar and naphthalene to agglomerate inside the filter element due to the reduction of solubility due to the cooling. In this regard, through on-site investigation, we use the water with residual temperature after the heat exchange of the gas-liquid cooler to heat the circulating desalted water for the first time through the heat exchanger, and at the same time, set an electric heating belt on the pipeline before entering the filter to heat the circulating desalted water for the second time, so as to ensure that the circulating desalted water entering the filter will not cause the recombinant components such as tar and naphthalene to be analyzed on the filter element due to the too low temperature. Based on the above-mentioned transformation plan, the utility model provides a heating system for the desalted water spray system in the coke oven gas screw compressor unit.

[0006] To achieve the above-mentioned purpose, the utility model adopts the following technical scheme: a heating system for a desalted water spray system in a coke oven gas screw compressor unit, comprising a screw compressor, a coke oven gas pipeline connected to the inlet of the screw compressor through an inlet silencer, a first section of a medium pipeline connected to the outlet of the screw compressor through an outlet silencer, the first section of a medium pipeline connected to the air inlet of a gas-liquid cooler, the air outlet of the gas-liquid cooler connected to the inlet of a gas-liquid separator through a second section of a medium pipeline, the water inlet of the gas-liquid cooler connected to an industrial water main pipe through a cooling water branch pipe, the water outlet of the gas-liquid cooler connected to the water inlet of a heat exchanger through a heat exchange pipeline, the water outlet of the heat exchanger connected to the return pipeline through a return water branch pipe, the liquid phase outlet of the gas-liquid separator connected to the medium inlet of the heat exchanger through the first section of a circulation pipeline, and the medium outlet of the heat exchanger connected to the heat exchanger through the second section of a circulation pipeline. The second-section circulation pipeline is connected to the inlet of the first filter, and the outlet of the first filter is connected to the inlet of the screw compressor through the third-section circulation pipeline. The second filter is installed on the inlet and outlet of the first filter through a bypass pipeline. The first electromagnetic control valve is respectively provided on the inlet and outlet of the first filter, and a first differential pressure transmitter is installed between the inlet and outlet thereof. The second electromagnetic control valve is respectively provided on the inlet and outlet of the second filter, and a second differential pressure transmitter is installed between the inlet and outlet thereof. The first differential pressure transmitter and the second differential pressure transmitter are interlocked with the two first electromagnetic control valves and the two second electromagnetic control valves through a DCS control system. An electric heating tape and a first temperature detector are respectively provided on the second-section circulation pipeline, and the two are interlocked through a DCS control system. The electric heating tape is used to heat the enriched desalted water to a predetermined temperature.

[0007] As a further supplement to the above technical solution, a pneumatic control valve is arranged on the third section of the circulation pipeline, and the third section of the circulation pipeline on the left side of the pneumatic control valve is connected to the desalted water tank through a desalted water pipeline. A desalted water pump is arranged on the desalted water pipeline for regularly renewing the circulating desalted water to maintain the cleanliness of the desalted water, and a second check valve is installed on the outlet side of the desalted water pump to prevent the circulating desalted water from entering the desalted water pump and damaging the equipment.

[0008] As a further supplement to the above technical solution, a first check valve and a manual control valve are respectively installed on the first section of the circulation pipeline, and a sewage pipeline is arranged on the first section of the circulation pipeline between the first check valve and the manual control valve. A manual shut-off valve is arranged on the sewage pipeline. When the manual shut-off valve is opened and the desalted water pump is started, the circulating desalted water is renewed by opening the pneumatic control valve, or the first filter and the second filter are reversely cleaned by opening the manual control valve.

[0009] As a further supplement to the above technical solution, a second temperature monitor and a pressure transmitter are respectively installed on the first section of the medium pipeline. The second temperature monitor forms an interlocking control with the pneumatic control valve through the DCS control system, and ensures the stability of the exhaust temperature by controlling the opening and closing degree of the pneumatic control valve.

[0010] As a further supplement to the above technical solution, a flow transmitter is installed on the third section of the circulation pipeline on the right side of the pneumatic control valve. The flow transmitter forms a flow signal interlocking control with the desalted water pump through the DCS control system, and the desalted water pump is started regularly to replenish the circulating desalted water.

[0011] Compared with the prior art, the utility model has the following advantages:

[0012] 1. The utility model heats the circulating desalted water twice through the heat exchanger and the electric heating belt, which reduces the cooling phenomenon of the original circulating desalted water and effectively avoids the problem of agglomeration inside the filter element due to the cold entering the filter. The modified desalted water spray system not only ensures the normal operation of the spray system, but also significantly reduces the replacement frequency of the filter element, thereby reducing the overall maintenance cost.

[0013] 2. The utility model makes full use of the heat energy after the heat exchange of the gas-liquid cooler to heat the circulating desalted water for the first time, thus realizing the recycling of heat energy. This transformation not only improves the energy utilization efficiency, but also reduces the power loss of the electric heating belt, further reducing the production cost for the enterprise.

[0014] 3. The utility model sets a first check valve and a manual control valve, connects a sewage pipeline between the two valves, and manually shuts off the valve in the sewage pipeline. Through the above valve and sewage pipeline design, the utility model can effectively clean the gas-liquid cooler, gas-liquid separator and filter. This not only extends the service life of these equipment, but also improves the operating stability of the coke oven gas screw compressor unit.

[0015] 4. The utility model realizes precise control of exhaust gas temperature by installing a second temperature monitor and a pressure transmitter on the first section of the medium pipeline and combining them with the DCS control system, thereby ensuring the stable operation of the coke oven gas to LNG process.

[0016] 5. The second check valve installed on the outlet side of the desalted water pump of the utility model effectively prevents the circulating desalted water from flowing back into the desalted water pump, thereby avoiding the risk of equipment damage and enhancing the safety of the equipment.

[0017] 6. Through the above-mentioned innovative design and technical application, the utility model not only improves the operating stability and service life of the equipment, but also realizes the recovery and utilization of heat energy and energy saving and consumption reduction, bringing significant economic benefits to the enterprise. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural diagram of the heating system of the desalted water spray system in the utility model.

[0019] In the figure: the screw compressor is 1, the inlet silencer is 2, the outlet silencer is 3, the coke oven gas pipeline is 4, the first section of the medium pipeline is 5, the gas-liquid cooler is 6, the second section of the medium pipeline is 7, the gas-liquid separator is 8, the cooling water branch is 9, the heat exchange pipeline is 10, the heat exchanger is 11, the return water branch is 12, the first section of the circulation pipeline is 13, the second section of the circulation pipeline is 14, the third section of the circulation pipeline is 15, the first filter is 16, the bypass pipeline is 17, the second filter is 18, the desalted water pipe is 19, the cooling water pipe is 20, the heat exchanger is 21, the heat exchanger is 22, the return water pipe is 23, the heat exchanger is 24, the return water pipe is 25, the first section of the circulation pipeline is 26, the second section of the circulation pipeline is 27, the third section of the circulation pipeline is 28, the first filter is 29, the bypass pipeline is 30, the second filter is 31, the desalted water pipe is 32, the desalted water pipe is 33, the heat exchanger is 34, the heat exchanger is 35, the return water pipe is 36, the first section of the circulation pipeline is 37, the second section of the circulation pipeline is 38, the desalted water pipe is 39, the heat exchanger is 30, the heat exchanger is 31, the return water pipe is 32, the heat exchanger is 33, the heat exchanger is 35, the return water pipe is 36, the heat exchanger is 37, the return water pipe is 38, the heat exchanger is 39, the heat exchanger is 30, the return water pipe is 39, the heat exchanger is 31, the return water pipe is 31, the heat exchanger is 3 Line is 19, desalted water tank is 20, desalted water pump is 21, pneumatic control valve is 22, flow transmitter is 23, first check valve is 24, electric heating tape is 25, first temperature detector is 26, first differential pressure transmitter is 27, second differential pressure transmitter is 28, first solenoid control valve is 29, second solenoid control valve is 30, second temperature monitor is 31, pressure transmitter is 32, second check valve is 33, sewage pipeline is 34, manual shut-off valve is 35, manual control valve is 36. DETAILED DESCRIPTION

[0020] In order to further illustrate the technical solution of the utility model, the following Figure 1 ,According to the transformation implementation process of this project, we further illustrate the utility model through four embodiments.

[0021] The desalted water spraying system in the original coke oven gas screw compressor unit includes a screw compressor 1, a coke oven gas pipeline 4 is connected to the inlet of the screw compressor 1 through an inlet silencer 2, a first section medium pipeline 5 is connected to the outlet of the screw compressor 1 through an outlet silencer 3, the first section medium pipeline 5 is connected to the air inlet of the gas-liquid cooler 6, the air outlet of the gas-liquid cooler 6 is connected to the inlet of the gas-liquid separator 8 through a second section medium pipeline 7, the water inlet of the gas-liquid cooler 6 is connected to the industrial water main pipe through a cooling water branch pipe 9, the water outlet of the heat exchanger 11 is directly connected to the return water pipeline through a return water branch pipe 12, and the liquid phase outlet of the gas-liquid separator 8 is connected to the first filter 1 through a first section circulation pipeline 13 6, the outlet of the first filter 16 is connected to the inlet of the screw compressor 1 through the third-section circulation pipeline 15, a second filter 18 is installed on the inlet and outlet of the first filter 16 through a bypass pipeline 17, a pneumatic control valve 22 is arranged on the third-section circulation pipeline 15, and the third-section circulation pipeline 15 on the left side of the pneumatic control valve 22 is connected to the desalted water tank 20 through a desalted water pipeline 19, a desalted water pump 21 is arranged on the desalted water pipeline 19, which is used to regularly update the circulating desalted water to maintain the cleanliness of the desalted water, and a second check valve 33 is installed on the outlet side of the desalted water pump 21 to prevent the circulating desalted water from entering the desalted water pump 21 and damaging the equipment. Embodiment 1

[0022] As attached Figure 1 As shown, a heating system for a desalted water injection system in a coke oven gas screw compressor unit mainly includes a heat exchanger 11 and an electric heating belt 25, wherein the water outlet of a gas-liquid cooler 6 is connected to the water inlet of the heat exchanger 11 through a heat exchange pipeline 10, the water outlet of the heat exchanger 11 is connected to the return pipeline through a return branch pipe 12, the liquid phase outlet of a gas-liquid separator 8 is connected to the medium inlet of the heat exchanger 11 through a first section circulation pipeline 13, the medium outlet of the heat exchanger 11 is connected to the inlet of a first filter 16 through a second section circulation pipeline 14, the outlet of the first filter 16 is connected to the inlet of the screw compressor 1 through a third section circulation pipeline 15, and a third section circulation pipeline 17 is installed on the inlet and outlet of the first filter 16 through a bypass pipeline 17. Two filters 18, first electromagnetic control valves 29 are respectively provided on the inlet and outlet of the first filter 16, and a first differential pressure transmitter 27 is installed between the inlet and outlet thereof; second electromagnetic control valves 30 are respectively provided on the inlet and outlet of the second filter 18, and a second differential pressure transmitter 28 is installed between the inlet and outlet thereof; the first differential pressure transmitter 27 and the second differential pressure transmitter 28 are interlocked with the two first electromagnetic control valves 29 and the two second electromagnetic control valves 30 through a DCS control system; an electric heating tape 25 and a first temperature detector 26 are respectively provided on the second section circulation pipeline 14, and the two are interlockedly controlled through a DCS control system, and the electric heating tape 25 is used to heat the enriched desalted water to a predetermined temperature. Embodiment 2

[0023] In order to achieve effective cleaning of the gas-liquid cooler, gas-liquid separator and filter, the service life of these equipment is extended to further improve the operating stability of the coke oven gas screw compressor unit.

[0024] As attached Figure 1 As shown, a first check valve 24 and a manual control valve 36 are respectively installed on the first section of the circulation pipeline 13, and a sewage pipeline 34 is arranged on the first section of the circulation pipeline 13 between the first check valve 24 and the manual control valve 36. A manual shut-off valve 35 is arranged on the sewage pipeline 34. When the manual shut-off valve 35 is opened and the desalted water pump 21 is started, the circulating desalted water is renewed by opening the pneumatic control valve 22, or the first filter 16 and the second filter 18 are reversely cleaned by opening the manual control valve 36. Embodiment 3

[0025] In order to achieve accurate control of the exhaust temperature of the screw compressor, the stable operation of the coke oven gas to LNG process is guaranteed. Figure 1 As shown, we install a second temperature monitor 31 and a pressure transmitter 32 on the first section of the medium pipeline 5. The second temperature monitor 31 forms a chain control with the pneumatic control valve 22 through the DCS control system, and controls the opening and closing degree of the pneumatic control valve 22 to ensure the stability of the exhaust temperature. Embodiment 4

[0026] In order to ensure the stable operation of the desalted water spray system. Figure 1 As shown, we install a flow transmitter 23 on the third section of the circulation pipeline 15 on the right side of the pneumatic control valve 22. The flow transmitter 23 forms a flow signal interlocking control with the desalted water pump 21 through the DCS control system, and regularly starts the desalted water pump 21 to replenish the circulating desalted water.

[0027] 1. Normal operation: The manual control valve 36 and the pneumatic control valve 22 are both open, and the manual shut-off valve 35 is closed. The DCS control system controls the opening and closing degree of the pneumatic control valve 22 in real time according to the exhaust gas temperature detected by the second temperature monitor 31, and can ensure the stability of the exhaust temperature during the regular cleaning of the screw compressor 1 unit coking and decoking process. The liquid medium gas passes through the gas-liquid cooler 6 to reduce the exhaust temperature from 85°C to about 40°C. After the liquid medium gas is cooled, it enters the gas-liquid separator 8 for gas-liquid separation. The circulating desalted water enriched with impurities such as tar and naphthalene coming out of the liquid phase outlet is first heated by the heat exchanger 11 and then second heated by the electric heating belt 25, and then enters the first filter 16 or the second filter 18 for filtration, and finally enters the inlet of the screw compressor 1 for reuse.

[0028] 2. Regularly replace the circulating desalted water: (1) Keep the pneumatic control valve 22 open, open the manual shut-off valve 35 and close the manual control valve 36, start the desalted water pump 21, and pump the desalted water tank 20 through the screw compressor 1 and the gas-liquid cooler 6 in sequence, and discharge it from the sewage pipeline 34 to the wastewater pool; (2) Continue to open the manual shut-off valve 35 and start the desalted water pump 21, close the pneumatic control valve 22 and open the manual control valve 36, and pump the desalted water tank 20 through the first filter 16 or the second filter 18 and the heat exchanger 11 in sequence, and discharge it from the sewage pipeline 34 to the wastewater pool; (3) Open the pneumatic control valve 22 and the manual control valve 36 again, close the manual shut-off valve 35, start the desalted water pump 21, and continue to inject desalted water until the indicator detected by the flow transmitter 23 meets the preset value, and the DCS control system automatically shuts down the desalted water pump 21, completing the replacement of the circulating desalted water.

[0029] The above shows and describes the main features and advantages of the utility model. For those skilled in the art, it is obvious that the specific implementation of the utility model is not limited to the details of the above exemplary embodiments, and the creative ideas and design ideas of the utility model can be realized in other specific forms without departing from the spirit or basic features of the utility model, which should be equivalent to the protection scope disclosed in the technical solution of the utility model. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the utility model is limited by the attached claims rather than the above description, so it is intended to include all changes that fall within the meaning and scope of the equivalent elements of the claims in the utility model.

[0030] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A heating system for a desalted water spraying system in a coke oven gas screw compressor unit, comprising a screw compressor (1), a coke oven gas pipeline (4) connected to the inlet of the screw compressor (1) through an inlet silencer (2), a first section of a medium pipeline (5) connected to the outlet of the screw compressor (1) through an outlet silencer (3), the first section of the medium pipeline (5) connected to the air inlet of a gas-liquid cooler (6), the air outlet of the gas-liquid cooler (6) connected to the inlet of a gas-liquid separator (8) through a second section of the medium pipeline (7), the water inlet of the gas-liquid cooler (6) connected to an industrial water main pipe through a cooling water branch pipe (9), characterized in that: The water outlet of the gas-liquid cooler (6) is connected to the water inlet of the heat exchanger (11) through a heat exchange pipeline (10), the water outlet of the heat exchanger (11) is connected to the return pipeline through a return branch pipe (12), the liquid phase outlet of the gas-liquid separator (8) is connected to the medium inlet of the heat exchanger (11) through a first section of the circulation pipeline (13), the medium outlet of the heat exchanger (11) is connected to the inlet of the first filter (16) through a second section of the circulation pipeline (14), the outlet of the first filter (16) is connected to the inlet of the screw compressor (1) through a third section of the circulation pipeline (15), a second filter (18) is installed at the inlet and outlet of the first filter (16) through a bypass pipeline (17), and a second filter (18) is installed at the inlet and outlet of the first filter (16) through a bypass pipeline (17). A first electromagnetic control valve (29) is provided respectively and a first differential pressure transmitter (27) is installed between the inlet and outlet thereof; a second electromagnetic control valve (30) is provided at the inlet and outlet of the second filter (18) and a second differential pressure transmitter (28) is installed between the inlet and outlet thereof; the first differential pressure transmitter (27) and the second differential pressure transmitter (28) are interlocked with the two first electromagnetic control valves (29) and the two second electromagnetic control valves (30) through a DCS control system; an electric heating tape (25) and a first temperature detector (26) are provided respectively on the second section circulation pipeline (14), and the two are interlocked with each other through a DCS control system; the electric heating tape (25) is used to heat the enriched desalted water to a predetermined temperature.

2. A heating system for a desalted water spraying system in a coke oven gas screw compressor unit according to claim 1, characterized in that: A pneumatic control valve (22) is provided on the third section of the circulation pipeline (15). The third section of the circulation pipeline (15) on the left side of the pneumatic control valve (22) is connected to a desalted water tank (20) via a desalted water pipeline (19). A desalted water pump (21) is provided on the desalted water pipeline (19) for regularly renewing the circulating desalted water so as to maintain the cleanliness of the desalted water. A second check valve (33) is installed on the outlet side of the desalted water pump (21) to prevent the circulating desalted water from entering the desalted water pump (21) and damaging the equipment.

3. A heating system for a desalted water spraying system in a coke oven gas screw compressor unit according to claim 2, characterized in that: A first check valve (24) and a manual control valve (36) are respectively installed on the first section of the circulation pipeline (13); a sewage pipeline (34) is provided on the first section of the circulation pipeline (13) between the first check valve (24) and the manual control valve (36); a manual shut-off valve (35) is provided on the sewage pipeline (34); when the manual shut-off valve (35) is opened and the desalted water pump (21) is started, the pneumatic control valve (22) is opened to update the circulating desalted water, or the manual control valve (36) is opened to reversely clean the first filter (16) and the second filter (18).

4. A heating system for a desalted water spraying system in a coke oven gas screw compressor unit according to claim 2 or 3, characterized in that: A second temperature monitor (31) and a pressure transmitter (32) are respectively installed on the first section of the medium pipeline (5); the second temperature monitor (31) forms a chain control with the pneumatic control valve (22) through a DCS control system, and controls the opening and closing degree of the pneumatic control valve (22) to ensure the stability of the exhaust gas temperature.

5. A heating system for a desalted water spraying system in a coke oven gas screw compressor unit according to claim 4, characterized in that: A flow transmitter (23) is installed on the third section of the circulation pipeline (15) on the right side of the pneumatic control valve (22). The flow transmitter (23) forms a flow signal interlocking control with the desalted water pump (21) through a DCS control system, and regularly starts the desalted water pump (21) to replenish the circulating desalted water.

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