Phase-change self-circulation waste heat heat pump uncoupled rectification system

Abstract

The utility model discloses an uncoupled rectification system of a phase-change self-circulation waste heat heat pump. The uncoupled rectification system comprises an evaporator, according to the phase change self-circulation waste heat heat pump uncoupled rectification system, an evaporator is installed in a first pipeline and connected with a compressor suction tank through a second pipeline, the compressor suction tank is connected with a compressor through a third pipeline, the compressor is connected with a working medium condenser through a fourth pipeline, and the working medium condenser is connected with a throttling valve through a thirteenth pipeline; the throttling valve is connected with the evaporator through a fifth pipeline, the working medium condenser is connected with a cold material input pipeline and a hot material return pipeline, and the phase change self-circulation waste heat heat pump non-coupling rectification system achieves efficient energy conversion in a compression circulation mode. Through compression of a working medium, the system can absorb heat from a low-temperature heat source and then release heat in the requirement of a high-temperature heat source, so that conversion and transmission of heat energy are achieved, the compression type closed heat pump has higher energy utilization efficiency, and energy consumption can be remarkably reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of petrochemical industry, in particular to a phase change self-circulation waste heat heat pump non-coupled distillation system. Background Technique

[0002] During the operation of the fractionating towers of each process unit in refineries, a top condensation system is usually set up. The gas-phase material at the top of the tower is cooled by air-cooling, circulating water or other media. During the cooling process, a large amount of heat is directly carried away by air-cooling, circulating water or other media, and a large amount of waste heat is not recovered and utilized, resulting in a large amount of energy waste. At the same time, there are many materials that need to be heated in each process unit of refineries. These materials are usually heated by high-temperature heat sources such as steam, with a large heating load and relatively high operating costs of the unit. If the quality of the heat of the gas-phase material at the top of the fractionating tower can be improved and then transferred to the materials that need to be heated for use, the operating cost of the unit will be greatly reduced and the efficiency will be greatly increased.

[0003] At present, the main waste heat recovery technologies widely used in industry are low-temperature waste heat power generation, low-temperature waste heat refrigeration, and circulating water / air cooler cooling. Low-temperature waste heat power generation consists of four major components: a waste heat boiler heat exchanger, a turbine, a condenser, and a working fluid pump. The waste heat flow releases heat to the organic working fluid in the heat exchanger, and the working fluid becomes steam due to heat absorption. This steam expands and does work through the turbine, thereby driving a generator to generate electricity or driving other rotating machinery. The steam discharged from the turbine releases heat to the cooling water in the condenser and condenses into a liquid, and then is sent back to the heat exchanger with the help of the working fluid pump, and continuous circulation can generate electricity or produce power. Due to the characteristics of simple system technology and no wet steam zone, etc., it is especially suitable for low-temperature and medium- and small-capacity energy recovery. However, the total thermoelectric efficiency of this technology is only about 5%, the heat energy recovery rate is low, and the investment cost of the unit is high. Low-temperature waste heat refrigeration is a high-tech that uses industrial waste (waste) heat as a heat source to produce chilled water above 7°C for air conditioning or industrial cooling, which can greatly improve the energy utilization rate of enterprises, achieve the goals of energy conservation, water conservation, reduction of greenhouse gas emissions, and reduction of heat emissions. The power consumption of the waste heat refrigeration system only accounts for 2-3% of the output power of the refrigerating machine, saving 70-80% of electricity compared with electric refrigeration, and a large amount of primary energy can be saved. The utilization rate of primary energy is greatly improved, with an improvement of about 10%. Reducing the use of coal and oil can reduce the emissions of harmful gases such as CO2 and NOX and greenhouse gases, and improve the environmental conditions. The refrigerating machine uses lithium bromide-water as the working fluid, is non-toxic and odorless, operates safely and reliably, and does not pollute the environment. Low-temperature waste heat refrigeration can be widely applied to petrochemical enterprises, and is a high-tech for recovering heat energy above 65°C and effectively utilizing it. However, restricted by the settings of the whole-plant process units, the total consumption of chilled water is limited. Although circulating water / air cooler cooling is a commonly used method in refining enterprises, it uses circulating water / air coolers to cool the low-temperature process medium to the temperature required by the process. This method not only consumes a large amount of circulating water or electric energy, but also causes a huge waste of low-temperature heat energy.

[0004] Therefore, a phase change self-circulating waste heat heat pump non-coupled distillation system is proposed to facilitate the recovery and utilization of the waste heat of the fractionating tower condensation system. Summary of the Invention

[0005] The purpose of the present invention is to provide a phase change self-circulating waste heat heat pump non-coupled distillation system to solve the problems raised in the above background technology.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] A phase change self-circulating waste heat heat pump non-coupled distillation system includes an evaporator installed on the fractionating tower condensation system. The fractionating tower condensation system includes a fractionating tower, a fractionating tower bottom reboiler, a fractionating tower top air cooler, a fractionating tower top water cooler, a fractionating tower top reflux drum, and a fractionating tower top reflux pump. The fractionating tower is connected to the fractionating tower top air cooler through a first pipeline. The evaporator is installed on the first pipeline. The evaporator is connected to a compressor suction tank through a second pipeline. The compressor suction tank is connected to a compressor through a third pipeline. The compressor is connected to a working medium condenser through a fourth pipeline. The working medium condenser is connected to a throttle valve through a thirteenth pipeline. The throttle valve is connected to the evaporator through a fifth pipeline. A cold material input pipeline and a hot material return pipeline are connected to the working medium condenser.

[0008] As a further scheme of the present invention: The feed inlet of the fractionating tower is a fractionating tower feed pipeline.

[0009] As a further scheme of the present invention: The fractionating tower top air cooler is connected to the fractionating tower top water cooler through a sixth pipeline. The fractionating tower top water cooler is connected to the fractionating tower top reflux drum through a seventh pipeline. The fractionating tower top reflux drum is connected to the fractionating tower top reflux pump through an eighth pipeline. The fractionating tower top reflux pump is connected to the fractionating tower through a ninth pipeline.

[0010] As a further scheme of the present invention: A product output pipeline is also connected to the fractionating tower top reflux pump.

[0011] As a further scheme of the present invention: A tenth pipeline is also connected to the fractionating tower top reflux drum, and the tenth pipeline is connected to the fuel gas network.

[0012] As a further scheme of the present invention: The bottom discharge port of the fractionating tower is connected to the fractionating tower bottom reboiler through an eleventh pipeline. The fractionating tower bottom reboiler is connected to the bottom reflux port of the fractionating tower through a twelfth pipeline. The bottom discharge port of the fractionating tower is also connected to an external delivery pipeline.

[0013] As a further scheme of the present invention: A low-pressure steam inlet pipeline and a condensate discharge pipeline are also connected to the fractionating tower bottom reboiler, and the condensate discharge pipeline is connected to the condensate network.

[0014] As a further solution of the present utility model: both the reflux pump at the top of the fractionating column and the compressor are externally connected with a power supply and a switch.

[0015] Compared with the prior art, the beneficial effects of the present utility model are:

[0016] Compression cycle: The phase change self-circulating waste heat heat pump non-coupled distillation system adopts the compression cycle principle. By compressing the working medium, its temperature and pressure are increased to achieve heat transfer. This cycle process includes several key steps such as evaporation, compression, condensation, and expansion to achieve the extraction and transfer of thermal energy.

[0017] Closed system: The phase change self-circulating waste heat heat pump non-coupled distillation system is a closed system. The working medium does not directly contact the external environment during the circulation process, thus avoiding the pollution and loss of the working medium. The working medium in the system can be recycled, reducing energy consumption and costs, and reducing environmental impact.

[0018] Efficient energy conversion: The phase change self-circulating waste heat heat pump non-coupled distillation system realizes efficient energy conversion through the compression cycle. By compressing the working medium, the system can absorb heat from the low-temperature heat source and then release heat in the high-temperature heat source demand, thus realizing the conversion and transfer of thermal energy. Compared with other traditional heating methods, the compression-type closed heat pump has higher energy utilization efficiency and can significantly save energy consumption. Description of the drawings

[0019] Figure 1 It is a condensation system diagram of the fractionating column in a phase change self-circulating waste heat heat pump non-coupled distillation system.

[0020] Figure 2 It is a structural connection diagram of a phase change self-circulating waste heat heat pump non-coupled distillation system.

[0021] In the figure: 1. Fractionating column; 2. Reboiler at the bottom of the fractionating column; 3. Air cooler at the top of the fractionating column; 4. Water cooler at the top of the fractionating column; 5. Reflux drum at the top of the fractionating column; 6. Reflux pump at the top of the fractionating column; 7. Feed pipeline of the fractionating column; 8. Eleventh pipeline; 9. Twelfth pipeline; 10. First pipeline; 11. Sixth pipeline; 12. Seventh pipeline; 13. Eighth pipeline; 14. Ninth pipeline; 15. Product output pipeline; 16. Tenth pipeline; 17. Low-pressure steam inlet pipeline; 18. Condensate discharge pipeline; 19. Evaporator; 20. Compressor suction tank; 21. Compressor; 22. Working medium condenser; 23. Throttle valve; 24. Fifth pipeline; 25. Second pipeline; 26. Third pipeline; 27. Fourth pipeline; 28. Thirteenth pipeline; 29. Cold material input pipeline; 30. Hot material return pipeline; 31. External delivery pipeline. Detailed implementation manners

[0022] Next, in combination with the accompanying drawings in the embodiments of the present utility model, the technical solutions in the embodiments of the present utility model will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0023] Please refer to Figures 1 to 2 , in the embodiments of the present utility model, a phase change self-circulating waste heat heat pump non-coupled distillation system includes an evaporator 19 installed on the fractionation tower condensation system. The fractionation tower condensation system includes a fractionation tower 1, a fractionation tower bottom reboiler 2, a fractionation tower top air cooler 3, a fractionation tower top water cooler 4, a fractionation tower top reflux drum 5, and a fractionation tower top reflux pump 6. The fractionation tower 1 is connected to the fractionation tower top air cooler 3 through a first pipeline 10. The evaporator 19 is installed on the first pipeline 10. The evaporator 19 is connected to a compressor suction drum 20 through a second pipeline 25. The compressor suction drum 20 is connected to a compressor 21 through a third pipeline 26. The compressor 21 is connected to a working medium condenser 22 through a fourth pipeline 27. The working medium condenser 22 is connected to a throttle valve 23 through a thirteenth pipeline 28. The throttle valve 23 is connected to the evaporator 19 through a fifth pipeline 24. A cold material input pipeline 29 and a hot material return pipeline 30 are connected to the working medium condenser 22.

[0024] The gas-phase material at the top of the fractionation tower 1 enters the evaporator 19 of the newly added phase change self-circulating waste heat heat pump non-coupled distillation system to evaporate the circulating special working medium. The evaporated circulating special working medium enters the compressor suction drum 20 and then enters the compressor 21 for compression. The partially condensed gas-phase material at the top of the tower enters the original fractionation tower top air cooler 3 for further cooling. The special working medium heated and pressurized by the compressor 21 enters the newly added special working medium condenser 22 for condensation and heat release to provide heat for the heat sink. The condensed special working medium then passes through the throttle valve 23 to reduce the pressure and re-enters the evaporator 19 at the top of the tower to complete the cycle of heat recovery.

[0025] The feed port of the fractionation tower 1 is a fractionation tower feed pipeline 7.

[0026] The fractionation tower top air cooler 3 is connected to the fractionation tower top water cooler 4 through a sixth pipeline 11. The fractionation tower top water cooler 4 is connected to the fractionation tower top reflux drum 5 through a seventh pipeline 12. The fractionation tower top reflux drum 5 is connected to the fractionation tower top reflux pump 6 through an eighth pipeline 13. The fractionation tower top reflux pump 6 is connected to the fractionation tower 1 through a ninth pipeline 14.

[0027] A product output pipeline 15 is also connected to the fractionation tower top reflux pump 6.

[0028] A tenth pipeline 16 is also connected to the fractionation tower top reflux drum 5, and the tenth pipeline 16 is connected to the fuel gas network.

[0029] The bottom discharge port of the fractionating tower 1 is connected to the reboiler 2 at the bottom of the fractionating tower through the eleventh pipeline 8. The reboiler 2 at the bottom of the fractionating tower is connected to the bottom reflux port of the fractionating tower 1 through the twelfth pipeline 9. An external delivery pipeline 31 is also connected to the bottom discharge port of the fractionating tower 1.

[0030] A low-pressure steam inlet pipeline 17 and a condensate discharge pipeline 18 are also connected to the reboiler 2 at the bottom of the fractionating tower. The condensate discharge pipeline 18 is connected to the condensate water network.

[0031] The material from the upstream device enters the fractionating tower 1 for separation. The bottom of the tower is heated by the reboiler 2 at the bottom of the fractionating tower, and the heat source is provided by low-pressure steam. The gas-phase material at the top of the fractionating tower enters the reflux drum 5 at the top of the fractionating tower for gas-liquid separation after being cooled by the air cooler 3 at the top of the fractionating tower and the water cooler 4 at the top of the fractionating tower. The non-condensable gas is sent to the fuel gas network.

[0032] After the condensed material in the reflux drum 5 at the top of the fractionating tower is boosted by the reflux pump 6 at the top of the fractionating tower, part of it returns to the upper part of the fractionating tower 1 as reflux, and part of it is sent out as a product or sent to the downstream device.

[0033] Both the reflux pump 6 at the top of the fractionating tower and the compressor 21 are externally connected to a power source and a switch.

[0034] The phase change self-circulating waste heat heat pump non-coupled distillation system can be applicable to different temperature ranges, including low-temperature, medium-temperature, and high-temperature environments. By adjusting the type of working fluid and working parameters in the compression cycle, the heat energy conversion that adapts to different temperature requirements can be achieved. The phase change self-circulating waste heat heat pump non-coupled distillation system can achieve precise control of the system operation by adjusting the operating parameters (such as pressure and flow rate) of the compressor, the design of the heat exchanger, and the control system, etc. This enables the system to be adjusted according to actual needs to meet different process requirements or heat supply demands.

[0035] The working principle of the present utility model is:

[0036] The material from the upstream device enters the fractionating tower 1 through the fractionating tower feed pipeline 7. The vaporous material resolved is sent from the top of the fractionating tower 1 to the overhead air cooler 3 of the fractionating tower through the first pipeline 10 for cooling. The non-condensable gas is sent to the water cooler 4 at the top of the fractionating tower through the sixth pipeline 11 for further cooling. The cooled material enters the reflux drum 5 at the top of the fractionating tower through the seventh pipeline 12. The non-condensable gas is sent to the non-condensable gas pipe network through the tenth pipeline 16. The condensed material is drawn out from the bottom of the reflux drum 5 at the top of the fractionating tower, pressurized by the reflux pump 6 at the top of the fractionating tower through the eighth pipeline 13. Part of it returns to the upper part of the fractionating tower 1 through the ninth pipeline 14 as reflux, and part is sent out as a product or to the downstream device through the product output pipeline 15. The material at the bottom of the fractionating tower enters the reboiler 2 at the bottom of the fractionating tower through the eleventh pipeline 8 for heating, and the heated material returns to the fractionating tower 1 through the twelfth pipeline 9. The low-pressure steam enters the reboiler 2 at the bottom of the fractionating tower through the low-pressure steam inlet pipeline 17 and serves as the heat source of the reboiler 2 at the bottom of the fractionating tower. The condensed water after heat exchange returns to the condensate pipe network through the condensate discharge pipeline. The vaporous material at the top of the fractionating tower 1 enters the evaporator 19 through the first pipeline 10, transfers the latent heat during the cooling process to the proprietary working fluid in the phase change self-circulating waste heat heat pump distillation system, and the proprietary working fluid evaporates and absorbs heat and gasifies in the evaporator 19. The gasified proprietary working fluid enters the compressor suction tank 20 through the second pipeline 25, and the gaseous proprietary working fluid is sent to the compressor 21 for compression through the third pipeline 26 at the top of the suction tank 20. The proprietary working fluid heated and pressurized by the compressor 21 is sent to the newly added working fluid condenser 22 through the fourth pipeline 27 for condensation and heat release to provide heat for the heat sink.

[0037] The cold process material enters the newly added working fluid condenser 22 through the cold material input pipeline 29 to extract heat, and the hot material after heat extraction returns to the original process device through the hot material return pipeline 30. The condensed proprietary working fluid is sent to the throttle valve 23 through the thirteenth pipeline 28, and after depressurization through the throttle valve 23, it re-enters the evaporator 19 at the top of the tower through the fifth pipeline 24 to complete the cycle of heat recovery.

[0038] Actual application case: In the maleic anhydride hydrogenation device, the methanol feed temperature is 40°C, and steam heating is required to fully gasify the methanol. The methanol vaporizer consumes about 19 t / h of low-pressure steam. The temperature at the top of the methanol distillation tower in the device is about 72.4°C, and the temperature after condensation is about 64°C. The condensation load is about 26413 KW. Due to the relatively low temperature level, a large amount of gaseous latent heat cannot be directly recovered and utilized, and now it is directly cooled by circulating water, consuming a large amount of circulating water.

[0039] After adding the phase change self-circulating waste heat heat pump non-coupled distillation system, the circulating proprietary working fluid recovers the gaseous heat at the top of the methanol distillation tower. After gasification, the proprietary working fluid is compressed, pressurized, and heated by the compressor and provided for use in the methanol vaporizer, completely replacing the steam consumption of the methanol vaporizer.

[0040] The gas phase at the top of the methanol rectification column enters the evaporator of the newly added phase-change self-circulating waste heat heat pump non-coupled rectification system to evaporate the circulating working fluid. After evaporation, the circulating working fluid enters the compressor for compression. The partially condensed gas phase at the top of the column enters the original cooler for further cooling. The working fluid heated and pressurized by the compressor enters the newly added methanol vaporizer to release heat by condensation, replacing all the steam to provide heat for the methanol vaporizer. The condensed working fluid then passes through a throttle valve to reduce the pressure and re-enters the evaporator at the top of the column to complete the cycle of heat recovery.

[0041] After the implementation of the phase-change self-circulating waste heat heat pump non-coupled rectification system, 19 t / h of low-pressure steam can be saved, and the consumption of circulating water at the top of the column can be reduced by 740 t / h. Calculated based on an annual operating duration of 8400 hours, the annual energy-saving benefit is 21 million yuan, and the CO2 emission reduction is approximately 40,000 tons per year. The patented technology has good economic and social benefits.

[0042] Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A phase-change self-circulating waste heat heat pump uncoupled distillation system, comprising an evaporator (19) installed on a fractionation tower condensation system, characterized in that: The fractionation tower condensation system comprises a fractionation tower (1), a fractionation tower bottom reboiler (2), a fractionation tower top air cooler (3), a fractionation tower top water cooler (4), a fractionation tower top reflux tank (5) and a fractionation tower top reflux pump (6), the fractionation tower (1) is connected to the fractionation tower top air cooler (3) via a first pipeline (10), an evaporator (19) is installed on the first pipeline (10), the evaporator (19) is connected to a compressor suction tank (20) via a second pipeline (25), and the compressor (20) is connected to the compressor (21) via a second pipeline (25). The compressor suction tank (20) is connected to the compressor (21) via a third pipeline (26); the compressor (21) is connected to the working medium condenser (22) via a fourth pipeline (27); the working medium condenser (22) is connected to the throttle valve (23) via a thirteenth pipeline (28); the throttle valve (23) is connected to the evaporator (19) via a fifth pipeline (24); and the working medium condenser (22) is connected to a cold material input pipeline (29) and a hot material return pipeline (30).

2. According to claim 1, a phase change self-circulating waste heat heat pump uncoupled distillation system is characterized by: The feed inlet of the fractionation tower (1) is a fractionation tower feed pipeline (7).

3. According to claim 1, a phase-change self-circulating waste heat heat pump uncoupled distillation system is characterized in that: The air cooler (3) at the top of the fractionation tower is connected to the water cooler (4) at the top of the fractionation tower via a sixth pipeline (11); the water cooler (4) at the top of the fractionation tower is connected to the reflux tank (5) at the top of the fractionation tower via a seventh pipeline (12); the reflux tank (5) at the top of the fractionation tower is connected to the reflux pump (6) at the top of the fractionation tower via an eighth pipeline (13); and the reflux pump (6) at the top of the fractionation tower is connected to the fractionation tower (1) via a ninth pipeline (14).

4. The phase-change self-circulating waste heat heat pump uncoupled distillation system according to claim 1, characterized in that: The fractionation tower top reflux pump (6) is also connected to a product output pipeline (15).

5. The phase-change self-circulating waste heat heat pump uncoupled distillation system according to claim 1, characterized in that: The fractionation tower top reflux tank (5) is also connected to a tenth pipeline (16), and the tenth pipeline (16) is connected to the fuel gas pipeline network.

6. The phase-change self-circulating waste heat heat pump uncoupled distillation system according to claim 1, characterized in that: The bottom discharge port of the distillation tower (1) is connected to the bottom reboiler (2) of the distillation tower via an eleventh pipeline (8), the bottom reboiler (2) of the distillation tower is connected to the bottom reflux port of the distillation tower (1) via a twelfth pipeline (9), and the bottom discharge port of the distillation tower (1) is also connected to an external delivery pipeline (31).

7. The phase-change self-circulating waste heat heat pump uncoupled distillation system according to claim 1, characterized in that: The reboiler (2) at the bottom of the fractionation tower is also connected to a low-pressure steam inlet pipeline (17) and a condensate discharge pipeline (18), and the condensate discharge pipeline (18) is connected to the condensate pipeline network.

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