An optimization method of a heat conducting oil closed circulation heating system

Abstract

The application discloses an optimization method of a heat-conducting oil closed circulation heating system, which comprises a heating module and an expansion tank module, the expansion tank of the expansion tank module is connected with the heating module through double expansion pipes, the heating module and the expansion tank module form a closed circulation loop, and the expansion tank module comprises an oil supplementing unit, a light component automatic discharging and recycling unit and a nitrogen supply unit; the heating module is sealed, supplemented with oil and discharged and recycled with light components through the expansion tank module. The application realizes automatic discharging and recycling of light components, guarantees safe and stable operation of the heat-conducting oil closed circulation system and oil quality, has high automation level and reduces the working intensity of operation personnel. The cooling medium adopts low-temperature heat-conducting oil in a low-position oil storage tank, and the purpose of cooling can be achieved by using the heat-conducting oil supplementing unit, so that a new cooling system is not needed, equipment investment is reduced, the light components after cooling are uniformly collected and are not directly discharged to the outside, and environmental pollution is reduced.

Description

Technical Field

[0001] This invention relates to the field of heat transfer oil heating technology, specifically to an optimization method for a closed-loop heat transfer oil heating system. Background Technology

[0002] A closed-loop thermal oil heating system refers to a thermal oil heating system isolated from the atmosphere, typically achieved using an inert gas. This type of closed-loop system is a pressure system. The expansion tank unit plays a crucial role in the thermal oil heating system. Usually, the expansion tank is installed at the highest point of the system. Besides accommodating the thermal oil that expands upon heating, it also replenishes thermal oil lost through evaporation or operation, provides nitrogen sealing, and removes light components from the thermal oil.

[0003] During operation, heat transfer oil may experience pressure drops and temperature increases in localized areas, leading to the precipitation of light components. These light components need to be discharged. Furthermore, the accumulation of light components at the inlet of the circulating pump during the circulation process can cause pump cavitation. Excessive light component content can lower the flash point of the heat transfer oil. If the flash point continues to decrease, a leak in the system could lead to a fire if it comes into contact with an open flame, posing a significant safety hazard.

[0004] Currently, the expansion tank unit in the closed-loop heat transfer oil system has a low level of automation. It is usually operated manually by operators according to the production operation conditions. It cannot automatically discharge the light components in the heat transfer oil. This not only results in high labor intensity for workers, slow response speed, and inaccurate adjustment, but also the lack of a cooling and recovery mechanism for light components in the current closed-loop heat transfer oil system. The light components are directly discharged into the air, which is not conducive to environmental protection. Summary of the Invention

[0005] In view of the above-mentioned shortcomings and deficiencies, the present invention provides an optimization method for a closed-loop heating system for thermal oil, which can realize the automatic discharge and recovery of light components, ensure the safe and stable operation of the closed-loop thermal oil system and the quality of the oil, and has a high level of automation, reducing the workload of operators.

[0006] To achieve the above objectives, the main technical solution adopted by the present invention includes: a heating module and an expansion tank module. The expansion tank of the expansion tank module is connected to the heating module through a double expansion pipe. The heating module and the expansion tank module form a closed loop. The heating module performs sealing, oil replenishment, and discharge and recovery of light components through the expansion tank module.

[0007] The heating module includes an organic heat carrier furnace, a circulating pump, process heat equipment, and an oil-gas separator. The organic heat carrier furnace, circulating pump, process heat equipment, and oil-gas separator are connected in sequence, and a first pressure detection device is installed at the outlet of the circulating pump.

[0008] The dual expansion pipe consists of a main expansion pipe and an auxiliary expansion pipe. The lower end of the expansion tank is connected to the oil-gas separator through the main expansion pipe, and the upper end of the expansion tank is connected to the inlet operating pipeline of the oil-gas separator through the auxiliary expansion pipe. A third PIC valve is provided on the auxiliary expansion pipe.

[0009] The expansion tank module also includes a light component discharge and recovery unit, which includes an oil-gas cooler and a condensate storage tank. The expansion tank is connected to the condensate storage tank via the oil-gas cooler. A second PIC valve is provided between the expansion tank and the oil-gas cooler. The second to third PIC valves are controlled by a first pressure detection device.

[0010] The expansion tank module also includes an oil replenishment unit, which includes a low-level oil storage tank and an oil replenishment pump. The low-level oil storage tank is located below the expansion tank. The oil outlet pipeline after the low-level oil storage tank and the oil replenishment pump are divided into two paths. One path is connected to the upper end of the expansion tank through a first valve, and the other path is connected to the oil-gas cooler through a second valve. After exchanging heat with the light components inside the oil-gas cooler, the oil flows back to the low-level oil storage tank.

[0011] The expansion tank module also includes a nitrogen supply unit, which includes a nitrogen cylinder and a second pressure detection device. The nitrogen cylinder is connected to the expansion tank. A third valve, a self-regulating pressure regulating valve, and a first PIC valve are sequentially installed on the pipeline connecting the nitrogen cylinder and the expansion tank. The first PIC valve is controlled by the second pressure detection device.

[0012] The expansion tank is equipped with a liquid level detection device and overflow pipes, drain pipes, and safety protection pipes, all connected to a low-level oil storage tank. The overflow pipe is located at the normal operating liquid level of the expansion tank and is equipped with an oil seal. The drain pipe is located at the lower end of the expansion tank and is equipped with a quick-release valve, which is controlled by the liquid level detection device. The safety protection pipe is located at the upper end of the expansion tank and is equipped with a safety valve.

[0013] The present invention has the following beneficial effects and advantages:

[0014] 1. The light component discharge and recovery unit of the present invention can realize automatic discharge and recovery of light components, ensuring the safe and stable operation of the heat transfer oil closed circulation system and the oil quality, and has a high level of automation, reducing the workload of operators.

[0015] 2. The present invention features an overflow pipe on the expansion tank, which effectively prevents overpressure discharge from the expansion tank and enhances the stability of the system. The overflow pipe is equipped with an oil seal to prevent nitrogen leakage and effectively reduce nitrogen consumption.

[0016] 3. The present invention has a light component cooling and recovery mechanism. The cooling medium is low-temperature heat transfer oil in a low-level oil storage tank. The cooling purpose can be achieved by using the heat transfer oil replenishment unit. There is no need to add a new cooling system, reducing equipment investment. The cooled light components are collected in a unified manner and are not directly discharged into the outside world, reducing environmental pollution. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention.

[0018] The components include: 1. Organic heat carrier furnace; 2. Circulating pump; 3. Process heat equipment; 4. Low-level oil storage tank; 5. Make-up oil pump; 6. Expansion tank; 7. Oil-gas separator; 8. Oil-gas cooler; 9. Condensate storage tank; 10. Nitrogen cylinder; 11. Oil seal; 12. Self-regulating pressure regulating valve; 13.1. First PIC valve; 13.2. Second PIC valve; 13.3. Third PIC valve; 14. Quick relief valve; 15. Safety valve; 16. Main expansion pipe; 17. Auxiliary expansion pipe; 18. Overflow pipe; 19. Relief pipe; 20. Safety protection pipe; V1. First valve; V2. Second valve; V3. Third valve. Detailed Implementation

[0019] The invention will now be further described with reference to the accompanying drawings. Figure 1 As shown, the present invention is an optimization method for a closed-loop heating system for heat transfer oil, characterized in that it includes a heating module and an expansion tank module. The expansion tank 6 of the expansion tank module is connected to the heating module through a double expansion pipe. The heating module and the expansion tank module form a closed-loop circulation circuit. The heating module performs sealing, oil replenishment, and discharge and recovery of light components through the expansion tank module.

[0020] The heating module includes an organic heat carrier furnace 1, a circulating pump 2, a process heat equipment 3, and an oil-gas separator 7. The organic heat carrier furnace 1, the circulating pump 2, the process heat equipment 3, and the oil-gas separator 7 are connected in sequence. A first pressure detection device is installed at the outlet of the circulating pump 2.

[0021] Because the heat transfer oil flow rate of the closed-loop heating system is relatively large, a dual expansion pipe is set up. The dual expansion pipe consists of a main expansion pipe 16 and an auxiliary expansion pipe 17. The lower end of the expansion tank 6 is connected to the oil-gas separator 7 through the main expansion pipe 16, and the upper end of the expansion tank 6 is connected to the inlet pipeline of the oil-gas separator 7 through the auxiliary expansion pipe 17. A third PIC valve 13.3 is provided on the auxiliary expansion pipe 17.

[0022] Specifically, the main expansion pipe 16 is a bidirectional flow pipe. When the heating module needs oil replenishment, the expansion tank 6 replenishes the heating module through the main expansion pipe 16. When replenishing the heating module, the third PIC valve 13.3 on the auxiliary expansion pipe 17 is closed, and the auxiliary expansion pipe 17 does not participate in oil replenishment. When the content of light components is too high in the early stage of system operation or during operation, and the pump cavitation occurs, the third PIC valve 13.3 opens to accelerate the discharge of light components from the heat transfer oil.

[0023] The expansion tank module also includes a light component discharge and recovery unit, which includes an oil-gas cooler 8 and a condensate storage tank 9. The expansion tank 6 is connected to the condensate storage tank 9 via the oil-gas cooler 8. A second PIC valve 13.2 is provided between the expansion tank 6 and the oil-gas cooler 8. The second to third PIC valves are controlled by a first pressure detection device.

[0024] The expansion tank module also includes an oil replenishment unit, which includes a low-level oil storage tank 4 and an oil replenishment pump 5. The low-level oil storage tank 4 is located below the expansion tank 6. The oil outlet pipeline after the low-level oil storage tank 4 and the oil replenishment pump 5 are divided into two paths. One path is connected to the upper end of the expansion tank 6 via the first valve V1, and the other path is connected to the oil-gas cooler 8 via the second valve V2. After exchanging heat with the light components inside the oil-gas cooler 8, the oil flows back to the low-level oil storage tank 4.

[0025] Specifically, when the closed-loop heating system for thermal oil is running, the outlet pressure of the circulating pump 2 fluctuates drastically, and cavitation occurs in the pump, i.e., light components are produced. The first pressure detection device is interlocked with the third PIC valve 13.3. When the pressure in the upper gas phase space of the expansion tank 6 increases to the first set value, the third PIC valve 13.3 is opened for adjustment. As the closed-loop heating system for thermal oil continues to run, the pressure continues to fluctuate drastically. The first pressure detection device is interlocked with the second PIC valve 13.2. When the pressure in the upper gas phase space of the expansion tank 6 increases to the second set value, the second PIC valve 13.2 is opened. The generated light components flow to the oil-gas cooler 8 through the light component release pipeline in the upper part of the expansion tank. The replenishment pump 5 and the second valve V2 are opened, and the low-temperature thermal oil in the low-level oil storage tank 4 flows back to the low-level oil storage tank 4 after passing through the pipeline of the oil-gas cooler 8, serving as the cooling medium for the light components. The cooling medium flows through the tube side, and the light components flow through the shell side.

[0026] Open the oil replenishment pump 5 and the second valve V1, and the heat transfer oil in the low-level oil storage tank 4 enters the expansion tank 6 to complete the oil replenishment.

[0027] The expansion tank module also includes a nitrogen supply unit, which includes a nitrogen cylinder 10 and a second pressure detection device. The nitrogen cylinder 10 is connected to the expansion tank 6. A third valve V3, a self-regulating pressure regulating valve 12, and a first PIC valve 13.1 are sequentially installed on the pipeline connecting the nitrogen cylinder 10 and the expansion tank 6. The first PIC valve 13.1 is controlled by the second pressure detection device.

[0028] Specifically, the first PIC valve 13.1 is interlocked with the second pressure detection device. When nitrogen needs to be added to the expansion tank 6, the first PIC valve 13.1 is opened. The self-regulating pressure regulating valve 12 is a pressure regulating valve. When nitrogen cylinder 10 needs to be disassembled, V3 is closed before operation.

[0029] The expansion tank 6 is equipped with a liquid level detection device and an overflow pipe 18, a discharge pipe 19, and a safety protection pipe 20, all connected to the low-level oil storage tank 4. The overflow pipe 18 is located slightly above the normal operating liquid level of the expansion tank 6 and is equipped with an oil seal 11. The discharge pipe 19 is located at the lower end of the expansion tank 6 and is equipped with a quick discharge valve 14, which is controlled by the liquid level detection device. The safety protection pipe 20 is located at the upper end of the expansion tank 6 and is equipped with a safety valve 15.

[0030] Specifically, when the level of heat transfer oil in expansion tank 6 is higher than the normal operating level, the heat transfer oil flows to the low-level oil storage tank 4 through overflow pipe 18. In order to prevent nitrogen from entering the low-level oil storage tank 4 through overflow pipe 18 and causing unnecessary waste of nitrogen, an oil seal 11 is installed on overflow pipe 18.

[0031] The quick release valve 14 is interlocked with the liquid level detection device. When the liquid level in the liquid phase space of the expansion tank 6 rises, the pressure in the upper gas phase space continues to rise. When the liquid level in the expansion tank 6 exceeds the overflow port, the quick release valve 14 opens and the overpressure protection safety valve 15 opens, allowing the heat transfer oil to flow to the low-level oil storage tank 4, ensuring the safe operation of the system.

Claims

1. An optimization method for a closed-loop heating system for thermal oil, characterized in that, include: The system comprises a heating module and an expansion tank module. The expansion tank of the expansion tank module is connected to the heating module via dual expansion pipes, forming a closed-loop circulation circuit. The heating module uses the expansion tank module for sealing, oil replenishment, and the discharge and recovery of light components. The heating module includes an organic heat carrier furnace, a circulating pump, process heat equipment, and an oil-gas separator, which are connected sequentially. A first pressure detection device is installed at the outlet of the circulating pump. The dual expansion pipes consist of a main expansion pipe and an auxiliary expansion pipe. The lower end of the expansion tank is connected to the oil-gas separator via the main expansion pipe, and the upper end of the expansion tank is connected to the inlet operating pipeline of the oil-gas separator via the auxiliary expansion pipe. A third PIC valve is installed on the auxiliary expansion pipe. The expansion tank module also includes a light component discharge and recovery unit, which includes an oil-gas cooler and a condensate storage tank. The expansion tank is connected to the condensate storage tank via the oil-gas cooler. A second PIC valve is provided between the expansion tank and the oil-gas cooler. The second PIC valve and the third PIC valve are controlled by a first pressure detection device. The expansion tank module also includes an oil replenishment unit, which includes a low-level oil storage tank and an oil replenishment pump. The low-level oil storage tank is located below the expansion tank. The oil outlet pipeline after the low-level oil storage tank and the oil replenishment pump are divided into two paths. One path is connected to the upper end of the expansion tank via a first valve, and the other path is connected to the oil-gas cooler via a second valve. After exchanging heat with the light components inside the oil-gas cooler, the oil flows back to the low-level oil storage tank.

2. The optimization method for the closed-loop circulation heating system of heat transfer oil according to claim 1, characterized in that: The expansion tank module also includes a nitrogen supply unit, which includes a nitrogen cylinder and a second pressure detection device. The nitrogen cylinder is connected to the expansion tank. A third valve, a self-regulating pressure regulating valve, and a first PIC valve are sequentially installed on the pipeline connecting the nitrogen cylinder and the expansion tank. The first PIC valve is controlled by the second pressure detection device.

3. The optimization method for the closed-loop circulation heating system of heat transfer oil according to claim 1, characterized in that: The expansion tank is equipped with a liquid level detection device and overflow pipes, drain pipes, and safety protection pipes, all connected to a low-level oil storage tank. The overflow pipe is located at the normal operating liquid level of the expansion tank and is equipped with an oil seal. The drain pipe is located at the lower end of the expansion tank and is equipped with a quick-release valve, which is controlled by the liquid level detection device. The safety protection pipe is located at the upper end of the expansion tank and is equipped with a safety valve.

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