Crystallization tower type heat exchanger device coupled with heat pump

Abstract

The utility model discloses a tower type heat exchanger device coupled with a heat pump and used for crystallization. The tower type heat exchanger device comprises an energy recovery assembly and an energy exchange assembly communicated with the energy recovery assembly. Wherein the energy recovery assembly comprises a high-pressure heat exchange medium storage tank, a throttling pressure reducing valve and a low-pressure heat exchange medium storage tank which are connected with the high-pressure heat exchange medium storage tank through pipelines, a refrigerant cooler connected with the low-pressure heat exchange medium storage tank through a pipeline, and a motorized part connected with the refrigerant cooler through a pipeline; the high-pressure heat exchange medium storage tank and the low-pressure heat exchange medium storage tank are both connected with a heating medium heater through pipelines, a flow regulating valve is installed on the pipeline connecting the high-pressure heat exchange medium storage tank and the heating medium heater, and a first throttling pressure reducing valve is installed on the pipeline connecting the low-pressure heat exchange medium storage tank and the heating medium heater. According to the tower type heat exchanger, a single tower type heat exchanger can operate, and a plurality of tower type heat exchangers can operate at the same time, so that the operation flexibility is high, the market requirements are better met, one-time investment and occupied area are saved, and the product quality and yield are ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of refined acrylic acid crystallization, in particular to a tower heat exchanger device for crystallization coupled with a heat pump. Background Art

[0002] The existing tower heat exchanger has too large a capacity per unit, and the tower heat exchanger manufacturing requirements are very high. With the large-scale single crystallization equipment and the increase in tower diameter, higher requirements are put forward for the tower's verticality, horizontality, curvature of the internal heat exchange tube, diameter deviation, and wall thickness deviation. It is very easy to have bias flow, and the investment cost also increases. Since the product needs to control the aldehyde content at the ppm level, as the tower diameter increases, it brings great challenges to the uniform distribution of liquid in each heat exchange tube. The existing tower heat exchanger usually uses a single tower heat exchanger that can only be operated intermittently, which makes the production efficiency significantly low. Utility Model Content

[0003] In view of the shortcomings of the prior art, the purpose of the utility model is to provide a tower heat exchanger device for crystallization coupled with a heat pump, which can be operated by a single tower heat exchanger or multiple tower heat exchangers can be operated simultaneously, with great operational flexibility, better adapting to market demand, saving one-time investment and land occupation, and ensuring product quality and yield. In order to achieve the above-mentioned purpose and other advantages according to the utility model, a tower heat exchanger device for crystallization coupled with a heat pump is provided, comprising:

[0004] An energy exchange component in communication with the energy recovery component;

[0005] The energy recovery component includes a high-pressure heat exchange medium storage tank, a throttling pressure reducing valve connected to the high-pressure heat exchange medium storage tank through a pipeline and a low-pressure heat exchange medium storage tank, a refrigerant cooler connected to the low-pressure heat exchange medium storage tank through a pipeline, and a motor connected to the refrigerant cooler through a pipeline, the high-pressure heat exchange medium storage tank and the low-pressure heat exchange medium storage tank are both connected to a heat medium heater through a pipeline, a flow regulating valve is installed on the pipeline connecting the high-pressure heat exchange medium storage tank and the heat medium heater, and a first throttling pressure reducing valve is installed on the pipeline connecting the low-pressure heat exchange medium storage tank and the heat medium heater;

[0006] The energy exchange component includes a refrigerant tank and a heat medium tank arranged in parallel with the refrigerant tank. The refrigerant tank and the refrigerant cooler are connected by a refrigerant circulation pipeline, and a refrigerant auxiliary cooler is installed on the refrigerant circulation pipeline between the refrigerant tank and the refrigerant cooler. A circulation structure is formed between the refrigerant tank, the refrigerant cooler and the refrigerant auxiliary cooler. The heat medium tank and the heat medium heater are connected by a heat medium ring pipeline, and a heat medium auxiliary cooler is installed on the heat medium ring pipeline between the heat medium tank and the heat medium heater. A circulation structure is formed between the heat medium tank, the heat medium heater and the heat medium auxiliary cooler.

[0007] Preferably, the heat medium tank is connected to at least one tower heat exchanger through a pipeline, a tower bottom liquid collecting tank is fixedly connected to one end of the tower heat exchanger, the heat medium tank is connected to the tower bottom liquid collecting tank through a pipeline, and the refrigerant tank is connected to one end of the tower heat exchanger away from the tower bottom liquid collecting tank.

[0008] Preferably, one end of the tower bottom liquid collecting tank away from the tower heat exchanger is connected to the acrylic acid raw material feed tank, the residual liquid tank and the product tank through a pipeline.

[0009] Preferably, the motorized part comprises a compressor.

[0010] Compared with the prior art, the utility model has the following beneficial effects: a single tower heat exchanger can be operated or multiple tower heat exchangers can be operated simultaneously, the operation flexibility is large, and it is more adaptable to market demand. Multiple tower heat exchangers are connected in parallel to share a set of energy exchange and recovery system and storage tank system, saving one-time investment and land occupation. It avoids the problem of uneven film distribution on each heat exchange tube caused by the excessive diameter of a single tower heat exchanger due to the increase in single-set production capacity, resulting in poor crystallization effect, and the inability to guarantee product quality and yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural schematic diagram of an energy recovery component of a tower heat exchanger device for crystallization coupled with a heat pump according to the utility model;

[0012] Figure 2 A schematic diagram of the piping structure of a tower heat exchanger of a tower heat exchanger device for crystallization coupled with a heat pump according to the utility model;

[0013] Figure 3 It is a schematic diagram of the pipe connection structure of a tower heat exchanger and an energy recovery component of a tower heat exchanger device for crystallization coupled with a heat pump according to the utility model;

[0014] Figure 4 The utility model is a schematic diagram of the pipeline structure of an acrylic acid raw material feed tank, a residual liquid tank and a product tank of a tower heat exchanger device for crystallization coupled with a heat pump according to the utility model. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0016] Reference Figure 1-4, a tower heat exchanger device for crystallization coupled to a heat pump, comprising: an energy recovery component communicating with an energy exchange component;

[0017] The energy recovery component includes a high-pressure heat exchange medium storage tank 1, a throttling pressure reducing valve connected to the high-pressure heat exchange medium storage tank 1 through a pipeline, a low-pressure heat exchange medium storage tank 2, a refrigerant cooler 5 connected to the low-pressure heat exchange medium storage tank 2 through a pipeline, and a motor 4 connected to the refrigerant cooler 5 through a pipeline, and the motor 4 includes a compressor. The high-pressure heat exchange medium storage tank 1 and the low-pressure heat exchange medium storage tank 2 are both connected to a heat medium heater 6 through a pipeline, a flow regulating valve 7 is installed on the pipeline connecting the high-pressure heat exchange medium storage tank 1 and the heat medium heater 6, and a first throttling pressure reducing valve 8 is installed on the pipeline connecting the low-pressure heat exchange medium storage tank 2 and the heat medium heater 6; when the energy recovery component is working, the energy recovery component exchanges heat with the energy exchange component through a specific heat exchange medium such as ammonia, freon and other substances, and the heat exchange medium can be turned into liquid through high pressure, and can be turned into low-temperature gas through decompression, and heat absorption and release are completed through gas-liquid phase change, thereby completing the heating and cooling of the cold and hot media.

[0018] When heating the heat medium: the high-temperature and high-pressure gas (1.0-2.0 MPaG, temperature 40-50°C) from the outlet of the compressor 4 passes through the outlet pipe of the compressor 4 and enters the refrigerant cooler 5. The heat exchange medium of the energy recovery component exchanges heat with the heat medium from the heat medium tank 10 in the refrigerant cooler 5. The heat medium is heated, and the high-pressure gas is cooled to liquid and discharged from the bottom of the refrigerant cooler 5. After the flow rate is adjusted by the flow control valve 7, it enters the high-pressure heat exchange medium storage tank 1. Its pressure is 1.0-2.0 MPaG and the temperature is 40-50°C. After the heat exchange medium storage tank 1 is stored, the gas phase at the top passes through the throttling pressure reducing valve 3, the pressure is reduced to 0.1~0.2MPaG, the temperature is reduced to -10℃~-30℃, and then enters the low-pressure heat exchange medium storage tank 2 for storage, with a pressure of 0.1~0.2MPaG and a temperature of -10℃~-30℃; the other way directly passes through the throttling pressure reducing valve 3, the pressure is reduced to 0.1~0.2MPaG, the temperature is reduced to -10℃~-30℃, and then enters the low-pressure heat exchange medium storage tank 2 (0.1~0.2MPaG, temperature -10~-30℃) for storage. In the low-pressure heat exchange medium storage tank 2, the gas phase is discharged from the top and enters the inlet of the compressor 4 together with the gas phase from the refrigerant cooler 5, and is compressed into high-temperature and high-pressure gas by the compressor 4 to complete a cycle.

[0019] When cooling the refrigerant: the liquid low-temperature and low-pressure heat exchange medium from the low-pressure heat exchange medium storage tank 2 is discharged from the bottom of the storage tank, pumped into the top of the refrigerant cooler 5, and exchanges heat with the material refrigerant outside the heat exchange tube. The refrigerant outside the tube is cooled to -10~-20℃, and the low-pressure heat exchange medium is heated and undergoes a phase change into a gas-liquid mixture. After passing through the gas-liquid separation device at the bottom of the refrigerant cooler 5, the gas enters the outlet of the compressor 4 together with the low-pressure gas from the low-pressure heat exchange medium storage tank 2. The liquid that has not undergone a phase change into a gas-liquid enters the low-pressure heat exchange medium storage tank 2 again by gravity to complete the cooling of the refrigerant.

[0020] Through the above steps, the energy absorbed from the refrigerant is compressed by the compressor 4 and supplied to the heat medium to heat the heat medium, thereby realizing the transmission of energy from low temperature to high temperature, thereby realizing the reuse of heat. The heat exchange medium in the high-pressure heat exchange medium storage tank 1 is pumped through the discharge pipeline at the bottom of the tank and enters the jacket of the acrylic acid raw material feed tank 15, the product tank 17 and the residual liquid tank 16 as the jacket heating medium to make full use of the energy. The high-pressure heat exchange medium storage tank 1 is equipped with a hot water heating pipeline, which is used to supplement heat to the system when the heat is unbalanced.

[0021] The energy exchange component includes a refrigerant tank 9 and a heat medium tank 10 arranged in parallel with the refrigerant tank 9. The refrigerant tank 9 is connected to the refrigerant cooler 5 through a refrigerant circulation pipeline, and a refrigerant auxiliary cooler 11 is installed on the refrigerant circulation pipeline between the refrigerant tank 9 and the refrigerant cooler 5. A circulation structure is formed between the refrigerant tank 9, the refrigerant cooler 5 and the refrigerant auxiliary cooler. The heat medium tank 10 is connected to the heat medium heater 6 through a heat medium loop pipeline, and a heat medium auxiliary cooler 12 is installed on the heat medium loop pipeline between the heat medium tank 10 and the heat medium heater 6. A circulation structure is formed between the heat medium tank 10, the heat medium heater 6 and the heat medium auxiliary cooler 12. The heat medium auxiliary heat exchanger 12 and the refrigerant auxiliary heat exchanger 11 play the role of auxiliary heating and auxiliary cooling, so that the device can be smoothly operated in the start-up phase and balance the energy balance in normal operation.

[0022] Furthermore, the heat medium tank 10 is connected to at least one tower heat exchanger 13 through a pipeline. When the heat medium tank 10 is connected to two tower heat exchangers 13, the two tower heat exchangers 13 are in parallel relationship, or the heat medium tank 10 can be connected to more than two tower heat exchangers 13 as needed. A tower bottom liquid collecting tank 14 is fixedly connected to one end of the tower heat exchanger 13. The tower bottom liquid collecting tank 14 and the tower heat exchanger 13 are connected through a pipeline. A heat exchanger is installed in the pipeline. The heat medium tank 10 is connected to the tower bottom liquid collecting tank 14 through a pipeline, and the refrigerant tank 9 is connected to one end of the tower heat exchanger 13 away from the tower bottom liquid collecting tank 14.

[0023] Furthermore, one end of the tower bottom liquid collecting tank 14 away from the tower heat exchanger 13 is connected to the acrylic acid raw material feed tank 15, the residual liquid tank 16 and the product tank 17 through a pipeline. When crystallization is performed, precooling, crystallization, partial melting and complete melting are first performed.

[0024] When precooling, energy recovery is turned on to cool the refrigerant in the refrigerant tank 9. The refrigerant comes out of the refrigerant storage tank 9 and forms a cycle through the refrigerant circulation pipeline-refrigerant cooler 5-refrigerant auxiliary cooler 11-refrigerant tank 9. After circulating and cooling with the energy recovery component, the refrigerant in the refrigerant tank 9 is maintained at -10℃~-30℃; then the material side refrigerant system is precooled. The cooled refrigerant enters from the top of the tower heat exchanger 13 through the refrigerant material side main circulation pipeline-cold / hot medium main circulation pipeline, and drops from the top of the tower to the lower part of the tower heat exchanger 13. From the lower part, it returns to the refrigerant tank 9 through the refrigerant reflux pipeline, completing a cooling cycle of the refrigerant to the tower heat exchanger 13. Precool the tower heat exchanger 13 to maintain the refrigerant temperature on the material side at -10~-30℃.

[0025] When crystallization is performed, the raw material of crude acrylic acid is transported from the crude acrylic acid feed pipeline to the acrylic acid raw material feed tank 15, and then transported to the tower bottom liquid collecting tank 14 through the liquid collecting tank raw material feed pipeline. After the tower bottom liquid collecting tank 14 reaches the specified liquid level, the acrylic acid raw material in the tower bottom liquid collecting tank 14 is pumped from the tower bottom liquid collecting tank 14 to the top of the tower heat exchanger 13 through the product circulation pipeline, so that the material circulates in the tower heat exchanger 13. At the same time, the refrigerant cools the material in the form of a film outside the heat exchange tube, and crystals begin to form. When the liquid level in the tower bottom liquid collecting tank 14 drops to a preset value, the crystallization step ends. In this process, two tower heat exchangers 13 can be opened at the same time, or one tower heat exchanger 13 can be opened according to the production demand.

[0026] When partial melting is performed, after the crystallization step is completed, the energy recovery component is turned on to heat the heat medium in the heat medium tank 10. The heat medium comes out of the heat medium tank 10 and forms a cycle through the heat medium circulation pipeline-heat medium heater 6-heat medium auxiliary heater 12-heat medium tank 10. After circulating and heating with the energy recovery component, the heat medium is heated from 20-32°C to 25-37°C; then the material side heat medium system is heated. The heated heat medium enters from the top of the tower heat exchanger 13 through the heat medium material side main circulation pipeline-cold / hot medium main circulation pipeline, descends from the top of the tower to the lower part of the tower heat exchanger 13, and returns to the refrigerant tank 9 from the lower part through the refrigerant reflux pipeline, completing a cooling cycle of the refrigerant to the tower heat exchanger 13. The tower heat exchanger 13 is heated to maintain the material side heat medium temperature at 25--37°C. The heat medium flows through the outside of the tube wall in the form of a film, the crystals partially melt, and the molten material flows along the tube into the bottom liquid collecting tank 14 until the liquid level of the bottom liquid collecting tank 14 reaches a preset value, the valve of the pipeline from the bottom liquid collecting tank 14 to the residual liquid tank 16 is opened, and the residual liquid flows into the residual liquid tank 16 due to potential energy, and the material in the residual liquid tank 16 is sent from the residual liquid tank 16 to the esterification acid tank through the residual liquid delivery pump as the esterification unit production raw material.

[0027] When all the melting is done, after partial melting is completed, the heat medium is slowly and continuously heated up through the energy recovery component at a heating rate of 0.1-1°C / h to increase the temperature of the heat medium, and the crystals on the inner wall of the tower heat exchanger 13 are heated through the material side circulation pipeline to completely melt the remaining crystals. The molten material flows along the pipe into the bottom liquid collecting tank 14 at the lower part of the tower heat exchanger 13, and the molten refined acrylic acid in the bottom liquid collecting tank 14 is discharged to the product tank 17 through the lower material outlet, and is sent to the product daily production tank through the product tank 17 delivery pump, thus completing the primary crystallization process.

[0028] In order to further obtain a product of higher purity according to specific requirements, the above crystallization process is repeated once or multiple times to achieve the desired product.

[0029] In summary, the present application solves the problem that the production capacity of a single device is too large and the diameter of the tower heat exchanger 13 used for crystallization cannot be increased indefinitely. Moreover, in the present application, two sets of parallel tower heat exchanger crystallization systems share a set of cold and hot medium heat exchange system, a set of heat pump energy recovery system, and a set of tank area system, thereby saving investment and land occupation. The two sets of tower heat exchanger crystallization systems are connected in parallel, combined with computer automatic control, and the flexibility of device operation is greatly improved. The device load can be adjusted according to market demand. It is only necessary to make the cold and hot medium system, the heat pump system and the tank area size meet the needs of the two sets of tower heat exchangers. Since the operation is intermittent operation, for the cold and hot medium system and the heat pump system, the heat exchange with the tower heat exchanger is achieved by adjusting the temperature and flow, thereby meeting the needs of crystallization, sweating, and melting; for the tank area system, it is necessary to control the liquid level of the tank within a reasonable range during operation. Moreover, in the present application, it is only necessary to make the sizes of the cold and hot medium system, the heat pump system and the tank area meet the requirements of the two sets of tower heat exchangers. Since the operation is an intermittent operation, for the cold and hot medium system and the heat pump system, heat exchange with the tower heat exchanger 13 is achieved by adjusting the temperature and flow rate, thereby meeting the requirements of crystallization, sweating and melting; for the tank area system, it is necessary to control the liquid level of the tank within a reasonable range during operation.

[0030] The number of devices and processing scale described here are used to simplify the description of the utility model. The application, modification and variation of the utility model are obvious to those skilled in the art.

[0031] Although the implementation scheme of the utility model has been disclosed as above, it is not limited to the applications listed in the specification and implementation scheme. It can be fully applied to various fields suitable for the utility model. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the utility model is not limited to the specific details and the illustrations shown and described here.

Claims

1. A tower heat exchanger device for crystallization coupled with a heat pump, characterized in that: include: An energy exchange component in communication with the energy recovery component; The energy recovery component comprises a high-pressure heat exchange medium storage tank (1), a throttling pressure reducing valve (3) connected to the high-pressure heat exchange medium storage tank (1) through a pipeline and a low-pressure heat exchange medium storage tank (2), a refrigerant cooler (5) connected to the low-pressure heat exchange medium storage tank (2) through a pipeline, and a motor (4) connected to the refrigerant cooler (5) through a pipeline, the high-pressure heat exchange medium storage tank (1) and the low-pressure heat exchange medium storage tank (2) are both connected to a heat medium heater (6) through a pipeline, a flow regulating valve (7) is installed on the pipeline connecting the high-pressure heat exchange medium storage tank (1) and the heat medium heater (6), and a first throttling pressure reducing valve (8) is installed on the pipeline connecting the low-pressure heat exchange medium storage tank (2) and the heat medium heater (6); The energy exchange component comprises a refrigerant tank (9) and a heat medium tank (10) arranged in parallel with the refrigerant tank (9); the refrigerant tank (9) and the refrigerant cooler (5) are connected via a refrigerant circulation pipeline, and a refrigerant auxiliary cooler (11) is installed on the refrigerant circulation pipeline between the refrigerant tank (9) and the refrigerant cooler (5); a circulation structure is formed between the refrigerant tank (9), the refrigerant cooler (5) and the refrigerant auxiliary cooler (11); the heat medium tank (10) and the heat medium heater (6) are connected via a heat medium loop pipeline, and a heat medium auxiliary cooler (12) is installed on the heat medium loop pipeline between the heat medium tank (10) and the heat medium heater (6); and a circulation structure is formed between the heat medium tank (10), the heat medium heater (6) and the heat medium auxiliary cooler (12).

2. A tower heat exchanger device for crystallization coupled with a heat pump as claimed in claim 1, characterized in that: The heat medium tank (10) is connected to at least one tower heat exchanger (13) via a pipeline, and a tower bottom liquid collecting tank (14) is fixedly connected to one end of the tower heat exchanger (13). The heat medium tank (10) and the tower bottom liquid collecting tank (14) are connected via a pipeline, and the refrigerant tank (9) is connected to one end of the tower heat exchanger (13) away from the tower bottom liquid collecting tank (14).

3. A tower heat exchanger device for crystallization coupled with a heat pump as claimed in claim 2, characterized in that: One end of the tower bottom liquid collecting tank (14) away from the tower heat exchanger (13) is connected to the acrylic acid raw material feed tank (15), the residual liquid tank (16) and the product tank (17) through a pipeline.

4. A tower heat exchanger device for crystallization coupled with a heat pump as claimed in claim 1, characterized in that: The motor (4) includes a compressor.

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