CN-122015568-A - Skid-mounted plate heat exchanger automatic back flushing system and method based on oil-gas scene

CN122015568ACN 122015568 ACN122015568 ACN 122015568ACN-122015568-A

Abstract

The invention provides an automatic back flushing system and method of a skid-mounted plate heat exchanger based on an oil-gas scene, the automatic back flushing system of the skid-mounted plate heat exchanger based on the oil-gas scene comprises a controller, a power back flushing device, a natural circulation back flushing electric gate valve and a back flushing valve, the natural circulation back flushing electric gate valve is connected with the plate heat exchanger, the back flush valve is respectively connected with the plate heat exchanger and the power back flush device, and the controller controls the opening and closing of the natural circulation back flush electric gate valve and the back flush valve according to the pressure and temperature information of each pipeline of the plate heat exchanger, so that natural circulation back flush and power circulation back flush are performed. According to the skid-mounted plate heat exchanger automatic back flushing system and method based on the oil gas scene, the cleaning effect can be improved, the risks of all links are reduced, and the service life of equipment is prolonged while the manpower and material resources are saved.

Inventors

LI FENGMING
GAO ZHONGXIAN
WEI ZHENGNAN
JIAO BIN
LIU YOUHENG
LIN XUEZENG
LIU JINLIANG
ZHUANG XINFENG

Assignees

中国石油化工集团有限公司
中国石化集团胜利石油管理局有限公司

Dates

Publication Date: 20260512
Application Date: 20241112

Claims (19)

1. The automatic back flushing system of the skid-mounted plate heat exchanger based on the oil-gas scene is characterized by comprising a controller, a power back flushing device, a natural circulation back flushing electric gate valve and a back flushing valve, wherein the natural circulation back flushing electric gate valve is connected to the plate heat exchanger, the back flushing valve is respectively connected to the plate heat exchanger and the power back flushing device, and the controller controls the opening and closing of the natural circulation back flushing electric gate valve and the back flushing valve according to the pressure and temperature information of each pipeline of the plate heat exchanger, so that natural circulation back flushing and power circulation back flushing are carried out.
2. The automatic back flushing system of the skid-mounted plate heat exchanger based on the oil-gas scene as claimed in claim 1, wherein the number of the natural circulation back flushing electric gate valves and the number of the back flushing valves are two, the two natural circulation back flushing electric gate valves are positioned between a liquid inlet pipeline and a liquid return pipeline of the plate heat exchanger, one end of a first back flushing valve of the two back flushing valves is connected with the liquid return pipeline of the plate heat exchanger, the other end of the first back flushing valve is connected with a water inlet end of the power back flushing device, one end of a second back flushing valve is connected with the liquid inlet pipeline of the plate heat exchanger, and the other end of the second back flushing valve is connected with the water return end of the power back flushing device.
3. The automatic back flushing system of the skid-mounted plate heat exchanger based on the oil and gas scene as set forth in claim 2, further comprising four electric gate valves, four pressure transmitters, four temperature transmitters, wherein the four electric gate valves, the four pressure transmitters, the four temperature transmitters are respectively located on a liquid inlet line, a liquid return line, a water return line and a water inlet line of the plate heat exchanger.
4. The oil and gas scene based skid-mounted plate heat exchanger automatic backwash system of claim 3 further comprising an ultrasonic flow meter, wherein a first one of the four electrically powered gate valves, a first one of the four pressure transmitters, a first one of the four temperature transmitters are connected to a liquid return line of the plate heat exchanger, a second one of the four electrically powered gate valves, a second one of the four pressure transmitters, a second one of the four temperature transmitters are connected to a liquid return line of the plate heat exchanger, a third one of the four electrically powered gate valves, a third one of the four pressure transmitters, a third one of the four temperature transmitters are connected to a liquid return line of the plate heat exchanger, a fourth one of the four electrically powered gate valves, a fourth one of the four pressure transmitters, a fourth one of the four temperature transmitters are connected to the ultrasonic flow meter.
5. The automatic backwash system of skid-mounted plate heat exchangers based on oil and gas scenes according to claim 4, wherein the controller calculates and detects that the pressure difference value transmitted by the first pressure transmitter and the second pressure transmitter reaches more than 0.05Mpa, calculates the heat transfer coefficient of the plate heat exchangers to be lower than 85% of the normal average value according to the temperature value and the flow value transmitted by the first temperature transmitter, the second temperature transmitter, the third temperature transmitter, the fourth temperature transmitter and the ultrasonic flowmeter, and controls the two natural circulation backwash electric gate valves to be opened, wherein the first electric gate valve and the second electric gate valve are closed, the inlet is an outlet, and the outlet is an inlet, so that natural circulation backwash is performed.
6. The automatic back flushing system of the skid-mounted plate heat exchanger based on the oil-gas scene as set forth in claim 5, wherein the controller calculates that the pressure difference value transmitted by the first pressure transmitter and the second pressure transmitter is recovered to below 0.02Mpa, calculates that the heat transfer coefficient of the plate heat exchanger is recovered to more than 95% of the normal average value according to the temperature value and the flow value transmitted by the first temperature transmitter, the second temperature transmitter, the third temperature transmitter, the fourth temperature transmitter and the ultrasonic flowmeter, or controls the first electric gate valve and the second electric gate valve to be opened when the natural circulation back flushing duration time reaches 24 hours, and controls the first electric gate valve and the second electric gate valve to be closed, namely, the natural circulation back flushing system to be closed, and controls the natural circulation back flushing switching to be stopped within 48 hours.
7. The oil and gas scene based skid-mounted plate heat exchanger automatic backwash system of claim 4 further comprising a first medicine tank electric gate valve and a second medicine tank electric gate valve, the first medicine tank electric gate valve being located between the first chemical tank and the power backwash device, the second medicine tank electric gate valve being located between the second chemical tank and the power backwash device.
8. The automatic back flushing system of the skid-mounted plate heat exchanger based on the oil-gas scene as set forth in claim 7, wherein the power back flushing device comprises a heating module, a circulating water pump and a water tank, wherein the first medicine tank electric gate valve or the second medicine tank electric gate valve is opened according to the crude oil characteristics or the produced water characteristics, corresponding chemical agents are added into the water tank, the heating module heats the substances in the water tank, the circulating water pump pumps the heated agent mixed solution or clean water into the plate heat exchanger for soaking and back flushing, and the heating module can adopt diesel oil, a motor or electric heating.
9. The automatic backwash system of skid-mounted plate heat exchangers based on oil and gas scenes according to claim 8, wherein the controller calculates that the pressure difference value transmitted by the first pressure transmitter and the second pressure transmitter reaches more than 0.10Mpa, and calculates that the heat transfer coefficient of the plate heat exchangers is reduced to below 70% of the normal average value according to the temperature values and the flow values transmitted by the first temperature transmitter, the second temperature transmitter, the third temperature transmitter, the fourth temperature transmitter and the ultrasonic flowmeter, and then the backwash process of power cycle is started.
10. The automatic backwash system of a skid-mounted plate heat exchanger based on an oil-gas scene as claimed in claim 9, wherein when a power cycle backwash process is started, the first medicine tank electric gate valve or the second medicine tank electric gate valve is opened according to the medium type of the plate heat exchanger, corresponding chemical agents are added to the water tank, and after a certain time, the first medicine tank electric gate valve or the second medicine tank electric gate valve is closed; After the first medicine chest electric gate valve or the second medicine chest electric gate valve is closed, the power back flushing device is started, the first back flushing valve and the second back flushing valve are opened, the first electric gate valve and the second electric gate valve are closed, the medicine mixed liquid enters the plate heat exchanger through the first back flushing valve, and returns to the water tank through the second back flushing valve, so that the power circulation back flushing is carried out on the plate heat exchanger.
11. The automatic back flushing system of a skid-mounted plate heat exchanger based on an oil-gas scene as set forth in claim 10, wherein the controller calculates that the pressure difference value transmitted by the first pressure transmitter and the second pressure transmitter is recovered to below 0.02Mpa, calculates that the heat transfer coefficient of the plate heat exchanger is recovered to 95% of the normal average value according to the temperature values and the flow values transmitted by the first temperature transmitter, the second temperature transmitter, the third temperature transmitter, the fourth temperature transmitter and the ultrasonic flowmeter, or the first electric gate valve and the second electric gate valve are opened after the power back flushing duration reaches a predetermined value, the first back flushing valve and the second back flushing valve are closed, and the power back flushing device is stopped to recover the normal operation state.
12. The automatic backwash system of oil and gas scene based skid-mounted plate heat exchangers according to claim 11, further comprising a water tank drain valve connected to a drain line of the power backwash device, a water tank water replenishing valve connected to a water replenishing line of the power backwash device, wherein after the power backwash device is stopped, the water tank drain valve is opened, the water tank water replenishing valve is closed when the water level of the water tank is detected to be reduced to 0CM, the water tank water replenishing valve is opened, the water level of a water level gauge in the water tank is detected to be closed when the water level of the water tank is detected to be 100CM, and the power cycle backwash switching is not controlled any more within a predetermined time.
13. The oil and gas scene based skid-mounted plate heat exchanger automatic back flushing system of claim 2, further comprising a check valve connected between the power back flushing device and the first back flushing valve to prevent media, i.e., oil or produced water, from flowing into the power back flushing device.
14. The automatic back flushing method of the skid-mounted plate heat exchanger based on the oil gas scene is characterized in that the automatic back flushing method of the skid-mounted plate heat exchanger based on the oil gas scene adopts the automatic back flushing system of the skid-mounted plate heat exchanger based on the oil gas scene as set forth in claim 1, and the automatic back flushing method comprises the following steps: Step 1, when the controller calculates and detects that the pressure difference value transmitted by the first pressure transmitter and the second pressure transmitter reaches more than 0.05Mpa, according to the temperature value and the flow value transmitted by the first temperature transmitter, the second temperature transmitter, the third temperature transmitter, the fourth temperature transmitter and the ultrasonic flowmeter, the heat transfer coefficient of the plate heat exchanger is calculated to be reduced to be lower than 85% of the normal average value, and natural circulation back flushing is carried out; Step 2, when the controller calculates that the pressure difference value transmitted by the first pressure transmitter and the second pressure transmitter is recovered to be below 0.02Mpa, and according to the temperature value and the flow value transmitted by the first temperature transmitter, the second temperature transmitter, the third temperature transmitter, the fourth temperature transmitter and the ultrasonic flowmeter, the heat transfer coefficient of the plate heat exchanger is recovered to be more than 95% of the normal average value, or the natural circulation back flushing duration time is up to 24 hours, the natural circulation back flushing flow is closed; Step 3, when the controller calculates that the pressure difference value transmitted by the first pressure transmitter and the second pressure transmitter reaches more than 0.10Mpa, and according to the temperature value and the flow value transmitted by the first temperature transmitter, the second temperature transmitter, the third temperature transmitter, the fourth temperature transmitter and the ultrasonic flowmeter, the heat transfer coefficient of the plate heat exchanger is calculated to be reduced to be lower than 70% of the normal average value, and then a power cycle back flushing flow is started; And 4, when the controller calculates and detects that the pressure difference value transmitted by the first pressure transmitter and the second pressure transmitter is recovered to be below 0.02Mpa, and according to the temperature values and the flow values transmitted by the first temperature transmitter, the second temperature transmitter, the third temperature transmitter, the fourth temperature transmitter and the ultrasonic flowmeter, the heat transfer coefficient of the plate heat exchanger is recovered to be more than 95% of the normal average value, or after the power back flushing duration reaches a preset value, the power cycle back flushing flow is stopped, and the normal running state is recovered.
15. The automatic back flushing method of a skid-mounted plate heat exchanger based on an oil-gas scene as set forth in claim 14, wherein in step 1, two natural circulation back flushing electric gate valves are opened, the first electric gate valve and the second electric gate valve are closed, the inlet is an outlet, the outlet is an inlet, and natural circulation back flushing is performed.
16. The automatic back flushing method of a skid-mounted plate heat exchanger based on an oil-gas scene as set forth in claim 14, wherein in step 2, the first electric gate valve and the second electric gate valve are opened, the two natural circulation back flushing electric gate valves are closed, namely the natural circulation back flushing is closed, the normal operation state is restored, and the natural circulation back flushing switching is not controlled any more within 48 hours.
17. The automatic back flushing method of the skid-mounted plate heat exchanger based on the oil-gas scene as claimed in claim 14, wherein when the power cycle back flushing process is started in the step 3, the first medicine chest electric gate valve or the second medicine chest electric gate valve is opened according to the medium type of the plate heat exchanger, corresponding chemical agents are added to the water tank, and after a certain time, the first medicine chest electric gate valve or the second medicine chest electric gate valve is closed; After the electric gate valve of the first medicine chest or the electric gate valve of the second medicine chest is closed, the power back flushing device is started, the first back flushing valve and the second back flushing valve are opened, the first electric gate valve and the second electric gate valve are closed, the medicine mixed liquid enters the plate heat exchanger through the first back flushing valve, and the medicine mixed liquid returns to the water tank through the second back flushing valve, so that the power circulation back flushing is carried out on the plate heat exchanger.
18. The automatic back flushing method of the skid-mounted plate heat exchanger based on the oil-gas scene as set forth in claim 14, wherein in step 4, the first electric gate valve and the second electric gate valve are opened, the first back flushing valve and the second back flushing valve are closed, and the power back flushing device is stopped and the normal operation state is restored.
19. The automatic back flushing method of a skid-mounted plate heat exchanger based on an oil and gas scene as set forth in claim 18, wherein after the power back flushing device is stopped in step 4, a water tank drain valve is opened, a water tank water level is detected to be reduced to 0CM, a water tank water replenishing valve is opened, a water level gauge in the water tank is detected to be closed to be 100CM, and power cycle back flushing switching is not controlled any more in a predetermined time.

Description

Skid-mounted plate heat exchanger automatic back flushing system and method based on oil-gas scene Technical Field The invention relates to the technical field of petrochemical machinery, in particular to an automatic backwashing system and method for a skid-mounted plate heat exchanger based on an oil-gas scene. Background The pure titanium plate type heat exchanger has the characteristics of high heat transfer coefficient, small occupied area, capacity expansion, corrosion resistance and the like, and is widely applied as core heat exchange equipment in an oilfield waste heat utilization system. The plate heat exchanger runs stably and efficiently, the heat exchange efficiency of the whole waste heat system is directly affected, meanwhile, the crude oil output temperature raising requirement and the produced water recycling energy efficiency can be ensured, the crude oil output cost is effectively reduced, and the purposes of energy conservation and emission reduction are achieved. In the operation process of the plate heat exchanger, heat pump softened water and a medium exchange heat by flowing reversely in the heat exchanger, and heat is transferred from a high temperature side to a low temperature side. The different medium sides have the specificity problems that the crude oil side has the influence factors of mechanical impurities, floccules, associated gas and the like, and the produced water side has the influence factors of sediment, impurities, wax precipitation, scaling, oil sludge wall hanging and the like. The heat exchange coefficient of the heat exchanger is reduced, the economy is reduced, the flow passage is blocked, the piezoresistance is increased, and the reliability and the safety of medium output are directly affected. In order to ensure the efficient and stable operation of the plate heat exchanger, the plate heat exchanger needs to be cleaned in time. The method comprises the steps of firstly stopping the heat exchanger on site by operators, isolating softened water and media by closing a manual gate valve on a flow pipeline, secondly discharging softened water and media remained in the plate heat exchanger by a drain valve at the bottom of an inlet pipeline and an outlet pipeline of the heat exchanger, manually disassembling the plate heat exchanger, conveying the plates to a professional cleaning place, cleaning two sides of the plates piece by means of chemical agent soaking, high-pressure water flushing and the like, 4 conveying the cleaned plates back to the site, mounting the plates into a heat exchanger frame piece by piece, and finally opening the manual gate valve for the flow inlet and outlet of the original softened water and media after the water pressure test is qualified, and recovering the operation of the plate heat exchanger. The cleaning method is complex in cleaning process, long in time consumption, high in manpower and material resource consumption and accompanied with environmental protection risks due to the fact that the process nodes such as manpower, hazardous waste treatment, disassembly, transportation, hydraulic test and the like are involved in the disassembly and cleaning. According to different project medium characteristics, the disassembly cleaning frequency is different. And with the accumulation of disassemble washing times, irreversible damage can be caused to the heat exchanger plate and the sealing rubber strip, so that the heat exchange area is reduced, the heat exchange efficiency is reduced, the sealing rubber strip is replaced frequently and the like, the disassembly and washing cost is further increased, and the heat exchange energy efficiency and the economy of the whole waste heat utilization system are reduced. In the chinese patent application of application number CN202220700953.9, an automatic back flushing system for heat exchangers is involved. The system comprises a heat exchanger, an electric four-way valve and a filter valve, wherein one side of the electric four-way valve is respectively connected with a water inlet pipeline of the heat exchanger and a water outlet pipeline of the heat exchanger, the other side of the electric four-way valve is respectively connected with one end of the filter valve and the water inlet pipeline of the filter valve, the other end of the filter valve is connected with the water outlet pipeline, an electric blow-down valve is arranged at the bottom of the filter valve, the bottom of the electric blow-down valve is connected with a blow-down pipeline, a differential pressure transmitter A is arranged between the water inlet pipeline of the heat exchanger and the water outlet pipeline of the heat exchanger, the filter valve is connected with a differential pressure transmission B in parallel, the system is also provided with a control cabinet, and the electric four-way valve, the filter valve, the electric blow-down valve, the differential pressure transmitter A and the differential pressure transm