Conduction oil supply system of polycarbonate device using waste heat of steam condensate

Abstract

The utility model provides a conduction oil supply system of a polycarbonate device utilizing waste heat of steam condensate, which comprises a conduction oil furnace connected with a secondary conduction oil circulation pipeline through an oil supplement pipe, and the secondary conduction oil circulation pipeline is provided with a secondary conduction oil pump. The second-stage heat-conducting oil circulating pipeline is used for circularly supplying oil to a second-stage heat-conducting oil user, the oil supplementing pipe is provided with an oil supplementing valve, the oil return pipe is connected with the second-stage heat-conducting oil circulating pipeline, the oil return pipe is provided with an oil return valve, and the other end of the oil return pipe is connected with a liquid inlet of the heat exchanger; a liquid outlet of the heat exchanger is sequentially connected with a primary heat-conducting oil pump and a heat-conducting oil furnace through pipelines, a steam condensate pipeline is connected with a heating liquid inlet of the heat exchanger, and a heating liquid outlet of the heat exchanger is connected with a steam condensate header pipe of the polycarbonate device. According to the oil supply system, the steam condensate and the low-temperature heat conduction oil are used for heat exchange, the temperature and pressure of the steam condensate are reduced, the low-grade steam flash evaporation amount is reduced, the return oil temperature of the heat conduction oil is increased, and fuel consumption of the heat conduction oil furnace is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of polycarbonate synthesis, in particular to a heat-conducting oil supply system for a polycarbonate device utilizing the residual heat of steam condensate. Background Art

[0002] The polycarbonate synthesis process is to synthesize polycarbonate by melt ester exchange of bisphenol A and diphenyl carbonate. In the polycarbonate synthesis unit, since the polymerization reaction requires a higher temperature, a heat transfer oil system is often used to heat and insulate the polymerization reaction and related pipelines. Due to different temperature requirements in different places, the temperature control temperature of each secondary heat transfer oil is also different. For example, the melting point of bisphenol A is 156°C, the heating temperature of the heat transfer oil is 170-175°C, and the secondary heat transfer oil return temperature is 155-160°C, which is relatively low. The diphenyl carbonate synthesis unit uses a large amount of high-grade steam for heating, the pressure is generally above 2.5MPa, the steam condensate temperature is generally 180-200°C, and the high-temperature and high-pressure steam condensate is generally used for flashing low-grade steam for system use. Since most of the diphenyl carbonate synthesis unit is high-boiling point materials such as phenol and diphenyl carbonate, the amount of low-grade steam for flashing is relatively abundant and has been in a state of venting loss. Summary of the invention

[0003] The technical problem to be solved by the utility model is to provide a heat transfer oil supply system for a polycarbonate device using the waste heat of steam condensate, using high-pressure and high-temperature steam condensate to exchange heat with low-temperature heat transfer oil, thereby reducing the temperature and pressure of the steam condensate, reducing the flash evaporation amount of low-grade steam, increasing the temperature of the heat transfer oil return, and reducing the fuel consumption of the heat transfer oil furnace.

[0004] In order to solve the above technical problems, the technical solution adopted by the utility model is: a heat transfer oil supply system for a polycarbonate device utilizing the waste heat of steam condensate, comprising a heat transfer oil furnace, a heat transfer oil high-level tank supplies oil to the heat transfer oil furnace through a pipeline, the heat transfer oil furnace is connected to a secondary heat transfer oil circulation pipeline through an oil replenishing pipe, the secondary heat transfer oil circulation pipeline is provided with a secondary heat transfer oil pump, the secondary heat transfer oil circulation pipeline is used to circulate oil supply to secondary heat transfer oil users, the oil replenishing pipe is provided with an oil replenishing valve, one end of the return oil pipe is connected to the secondary heat transfer oil circulation pipeline, the return oil pipe is provided with an oil return valve, the other end of the return oil pipe is connected to the liquid inlet of the heat exchanger, the discharge port of the heat exchanger is connected to the primary heat transfer oil pump and the heat transfer oil furnace in sequence through a pipeline, the steam condensate pipeline is connected to the heating liquid inlet of the heat exchanger, and the heating liquid outlet of the heat exchanger is connected to the steam condensate main pipe of the polycarbonate device.

[0005] In a preferred solution, the steam condensate pipeline is connected to the steam condensate main pipe through a branch pipe, and valves are provided on the heating liquid inlet and the branch pipe of the heat exchanger.

[0006] In a preferred embodiment, the steam condensate in the steam condensate pipeline comes from the high-grade steam user condensate main pipe of the polycarbonate device.

[0007] In a preferred solution, the steam condensate pipeline is provided with a first thermometer, and the oil return pipe is provided with a second thermometer.

[0008] In a preferred embodiment, the fuel of the thermal oil furnace is methanol or purge gas.

[0009] The utility model provides a heat transfer oil supply system for a polycarbonate device using residual heat of steam condensate, which has the following beneficial effects:

[0010] 1. Use high-pressure and high-temperature steam condensate to exchange heat with low-temperature heat transfer oil to reduce the temperature and pressure of steam condensate, reduce the flash volume of low-grade steam, and reduce the venting loss of excess low-grade steam.

[0011] 2. Increase the temperature of the first-stage heat transfer oil return oil and reduce the fuel consumption of the heat transfer oil furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The utility model is further described below in conjunction with the accompanying drawings and embodiments:

[0013] Figure 1 It is a structural schematic diagram of the utility model;

[0014] In the figure: thermal oil furnace 1, oil supply pipe 2, secondary thermal oil circulation pipeline 3, secondary thermal oil pump 4, oil supply valve 5, oil return pipe 6, oil return valve 7, heat exchanger 8, primary thermal oil pump 9, steam condensate pipeline 10, steam condensate main pipe 11, branch pipe 12, valve 13, first thermometer 14, second thermometer 15, thermal oil high level tank 16. DETAILED DESCRIPTION

[0015] like Figure 1 As shown, a thermal oil supply system for a polycarbonate device utilizing waste heat of steam condensate includes a thermal oil furnace 1, wherein the fuel of the thermal oil furnace 1 is methanol or purge gas, and a thermal oil high-level tank 16 supplies oil to the thermal oil furnace 1 through a pipeline. Specifically, the thermal oil high-level tank 16 is connected to the liquid inlet of a primary thermal oil pump 9 through a pipeline to realize the oil supply to the thermal oil furnace 1.

[0016] The thermal oil furnace 1 is connected to the secondary thermal oil circulation pipeline 3 through the oil replenishing pipe 2. The secondary thermal oil circulation pipeline 3 is replenished with oil through the oil replenishing pipe 2. The secondary thermal oil circulation pipeline 3 is provided with a secondary thermal oil pump 4. The secondary thermal oil circulation pipeline 3 is used to circulate oil to the secondary thermal oil users. The oil replenishing pipe 2 is provided with an oil replenishing valve 5. The oil replenishing of the secondary thermal oil circulation pipeline 3 is controlled by opening and closing the oil replenishing valve 5.

[0017] One end of the return oil pipe 6 is connected to the secondary heat transfer oil circulation pipeline 3, and an oil return valve 7 is provided on the return oil pipe 6. The other end of the return oil pipe 6 is connected to the liquid inlet of the heat exchanger 8. The discharge port of the heat exchanger 8 is connected to the primary heat transfer oil pump 9 and the heat transfer oil furnace 1 in sequence through pipelines. The steam condensate pipeline 10 is connected to the heating liquid inlet of the heat exchanger 8, and the heating liquid outlet of the heat exchanger 8 is connected to the steam condensate main pipe 11 of the polycarbonate device.

[0018] The steam condensate in the steam condensate pipeline 10 comes from the high-grade steam user condensate main pipe of the polycarbonate device.

[0019] By opening the oil replenishing valve 5 and the oil return valve 7, the heat-conducting oil heated in the heat-conducting oil furnace 1 enters the secondary heat-conducting oil circulation pipeline 3, and the temperature of the heat-conducting oil in the secondary heat-conducting oil circulation pipeline 3 is adjusted. At the same time, the heat-conducting oil in the secondary heat-conducting oil circulation pipeline 3 flows out through the return oil pipe 6, is heated by the heat exchanger 8, and then flows into the heat-conducting oil furnace 1, thereby increasing the temperature of the heat-conducting oil return oil and reducing the fuel consumption of the heat-conducting oil furnace.

[0020] Preferably, the steam condensate pipeline 10 is connected to the steam condensate main pipe 11 through a branch pipe 12 , and valves 13 are provided on the heating liquid inlet of the heat exchanger 8 and the branch pipe 12 .

[0021] When the steam condensate temperature of the steam condensate pipeline 10 is low, the valve 13 on the heating liquid inlet of the heat exchanger 8 is closed, and the valve 13 on the branch pipe 12 is opened, and the steam condensate is directly discharged from the branch pipe 12 to the steam condensate main pipe 11 without passing through the heat exchanger 8.

[0022] The steam condensate pipeline 10 is provided with a first thermometer 14, and the return oil pipe 6 is provided with a second thermometer 15. The steam condensate temperature of the steam condensate pipeline 10 and the heat transfer oil temperature of the return oil pipe 6 are respectively monitored by the first thermometer 14 and the second thermometer 15. When the temperature difference between the first thermometer 14 and the second thermometer 15 is less than 15°C, the valve 13 on the heating liquid inlet of the heat exchanger 8 is closed, and the valve 13 on the branch pipe 12 is opened, and the steam condensate is directly discharged from the branch pipe 12 to the steam condensate main pipe 11 without passing through the heat exchanger 8.

[0023] The working process of the utility model is as follows:

[0024] The high-level thermal oil tank 16 supplies oil to the thermal oil furnace 1 through a pipeline, injects thermal oil into the oil supply system, opens the oil replenishment valve 5 and the oil return valve 7, and the thermal oil heated in the thermal oil furnace 1 enters the secondary thermal oil circulation pipeline 3. The secondary thermal oil pump 4 is turned on to establish a secondary thermal oil circulation. The thermal oil flows in the secondary thermal oil circulation pipeline 3 to supply oil and heat the secondary thermal oil users. The primary thermal oil pump 9 is turned on to establish a primary thermal oil circulation through the oil replenishment pipe 2 and the oil return pipe 6. The thermal oil flowing out of the oil return pipe 6 is heated by the heat exchanger 8 and then flows into the thermal oil furnace 1, thereby increasing the temperature of the thermal oil return and reducing the fuel consumption of the thermal oil furnace.

[0025] At the initial stage of the steam condensate pipeline 10 being put into operation, the valve 13 on the heating liquid inlet of the heat exchanger 8 is closed, and the valve 13 on the branch pipe 12 is opened, and the steam condensate is directly discharged from the branch pipe 12 to the steam condensate main pipe 11 without passing through the heat exchanger 8. When the pressure of the steam condensate pipeline 10 is stable, the temperature display value of the first thermometer 14 is higher than the temperature display value of the second thermometer 15, and the temperature difference is greater than 15°C, the valve 13 on the heating liquid inlet of the heat exchanger 8 is opened, and the valve 13 on the branch pipe 12 is closed, and the steam condensate exchanges heat with the secondary heat transfer oil return oil through the heat exchanger 8.

[0026] When the pressure of the steam condensate pipeline 10 is unstable or the steam condensate temperature is low, the temperature displayed on the first thermometer 14 is lower than the temperature displayed on the second thermometer 15 or the first thermometer 14 is higher than the temperature displayed on the second thermometer 15 but the temperature difference is less than 15°C, close the valve 13 on the heating liquid inlet of the heat exchanger 8, open the valve 13 on the branch pipe 12, and the steam condensate is directly discharged from the branch pipe 12 to the steam condensate main pipe 11 without passing through the heat exchanger 8.

[0027] The above embodiments are only preferred technical solutions of the present invention and should not be regarded as limitations of the present invention. The embodiments and features in the embodiments of the present application can be arbitrarily combined with each other without conflict. The protection scope of the present invention shall be the technical solutions recorded in the claims, including equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A heat transfer oil supply system for a polycarbonate device utilizing waste heat of steam condensate, comprising a heat transfer oil furnace (1), a heat transfer oil high-level tank (16) supplying oil to the heat transfer oil furnace (1) through a pipeline, the heat transfer oil furnace (1) being connected to a secondary heat transfer oil circulation pipeline (3) through an oil replenishment pipe (2), the secondary heat transfer oil circulation pipeline (3) being provided with a secondary heat transfer oil pump (4), the secondary heat transfer oil circulation pipeline (3) being used for circulating oil supply to secondary heat transfer oil users, the oil replenishment pipe (2) being provided with an oil replenishment valve (5), one end of an oil return pipe (6) being connected to the secondary heat transfer oil circulation pipeline (3), the oil return pipe (6) being provided with an oil return valve (7), characterized in that: The other end of the oil return pipe (6) is connected to the liquid inlet of the heat exchanger (8), the liquid discharge port of the heat exchanger (8) is connected to the first-stage heat transfer oil pump (9) and the heat transfer oil furnace (1) in sequence through pipelines, the steam condensate pipeline (10) is connected to the heating liquid inlet of the heat exchanger (8), and the heating liquid outlet of the heat exchanger (8) is connected to the steam condensate main pipe (11) of the polycarbonate device.

2. The thermal oil supply system for a polycarbonate device utilizing residual heat of steam condensate according to claim 1, characterized in that: The steam condensate pipeline (10) is connected to the steam condensate main pipe (11) via a branch pipe (12), and valves (13) are provided on the heating liquid inlet of the heat exchanger (8) and the branch pipe (12).

3. The thermal oil supply system for a polycarbonate device utilizing residual heat of steam condensate according to claim 1, characterized in that: The steam condensate in the steam condensate pipeline (10) comes from the high-grade steam user condensate main pipe of the polycarbonate device.

4. The thermal oil supply system for a polycarbonate device utilizing residual heat of steam condensate according to claim 2, characterized in that: The steam condensate pipeline (10) is provided with a first thermometer (14), and the oil return pipe (6) is provided with a second thermometer (15).

5. The thermal oil supply system for a polycarbonate device utilizing residual heat of steam condensate according to claim 1, characterized in that: The fuel of the thermal oil furnace (1) is methanol or purge gas.

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