Heat pump device for recycling waste heat of compressor for heating

Abstract

The invention discloses a heat pump device for waste heat recovery and heating of a compressor, which comprises a circulating hot water unit, the circulating hot water unit is connected with a heat pump circulating unit through a pipeline, and the heat pump circulating unit is connected with a useful heat equipment unit through a pipeline. By means of the arrangement, the heat pump device for recycling and heating the waste heat of the compressor solves the problems that in the prior art, the heat of the waste heat of the compressor is limited, and stable operation of a heat utilization equipment unit cannot be guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of waste heat recovery devices for compressors in natural gas processing plants, and relates to a heat pump device for recovering waste heat from compressors for heating. Background Art

[0002] During the production and processing of natural gas processing plants, some process gases generate a lot of waste heat after being pressurized. Take centrifugal compressors as an example. Centrifugal compressors transmit the energy of the prime mover to the gas through the high-speed rotating impeller, so that the gas pressure and speed are increased. The gas converts the speed energy into pressure energy in the fixed components inside the compressor. It is mainly used to compress and transport gas. However, centrifugal air compressors generate heat when compressing and transporting gas. If this heat is directly discharged into the atmosphere, it will cause thermal pollution.

[0003] The quality of compressor waste heat is low and it is difficult to recycle. At present, most compressor waste heat is recycled by prefabricating hot water. To make hot water with waste heat, that is, to recover the compression heat generated by traditional compressors and use the energy in it to obtain hot water, the key is the heat exchange effect between waste heat and hot air through the pipe wall. For example, most of the compressor waste heat hot water is made by direct heat exchange. The air compressor uses a water cooling unit to recover waste heat. However, in the context of compressor waste heat recovery in large-scale treatment plants, the above recovery methods have the following problems: First, when the unit is running, the supply and demand of heat are unbalanced. In the capacity ramp-up stage, or when other compressors are running at low load, the waste heat recovery heat is limited and the heat supply is insufficient. It is necessary to remind heat professionals to consider other heat sources. At certain times, such as in summer when the heat demand is small, the heat supply exceeds the demand, and the cooling tower is required to supply circulating cooling water to cool the compressor. Second, the temperature provided by the compressor waste heat does not reach the rated temperature of the heat-using equipment. Summary of the invention

[0004] The purpose of the present invention is to provide a heat pump device for recovering waste heat from a compressor for heating, which solves the problem in the prior art that the heat of the waste heat from the compressor is limited and cannot ensure the stable operation of the heat-using equipment unit.

[0005] The technical solution adopted by the present invention is a heat pump device for recovering waste heat from a compressor for heating, comprising a circulating hot water unit, the circulating hot water unit is connected to a heat pump circulating unit via a pipeline, and the heat pump circulating unit is connected to a heat-use equipment unit via a pipeline.

[0006] The present invention is also characterized in that:

[0007] The circulating hot water unit includes a hot water buffer tank, which is provided with two inlets and two outlets. The first inlet of the hot water buffer tank is connected to the circulating hot water network through a pipeline, and the first outlet of the hot water buffer tank is connected to a hot water circulation pump, a compressor outlet heat exchange unit and a hot water heat medium heat exchanger in sequence through a pipeline. The hot water heat medium heat exchanger is connected to the second inlet of the hot water buffer tank through a pipeline.

[0008] The compressor outlet heat exchange unit includes a plurality of compressor outlet heat exchangers, and the plurality of compressor outlet heat exchangers are connected in series or in parallel.

[0009] The heat pump circulation unit includes a heat pump compressor inlet buffer tank, the outlet of the heat pump compressor inlet buffer tank is connected to the heat pump first-stage compressor, the heat pump second-stage compressor, the first heat medium separator and the heat medium air cooler through a pipeline, the heat medium air cooler is connected to the hot water heat medium heat exchanger through a pipeline, and also includes a heat pump compressor interstage heat exchanger, the heat pump compressor interstage heat exchanger is provided with two inlets and two outlets, the first inlet and the first outlet of the heat pump compressor interstage heat exchanger are connected to the circulating heat transfer oil pipeline network through a pipeline, the second outlet of the heat pump compressor interstage heat exchanger is respectively connected to the inlets of the heat pump first-stage compressor and the heat pump second-stage compressor through a pipeline, the inlet of the heat medium separator is connected to a throttle valve through a pipeline, and the throttle valve is connected to the circulating heat medium pipeline network through a pipeline.

[0010] The heat-using equipment unit includes a deethanizer reboiler and a regeneration tower reboiler. The deethanizer reboiler is connected to a second heat medium separator through a pipeline, and the regeneration tower reboiler is connected to a third heat medium separator through a pipeline. Liquid inlets of the second heat medium separator and the third heat medium separator are respectively connected to a throttle valve through pipelines, and inlets of the deethanizer reboiler and the regeneration tower reboiler are connected to an inlet of a heat pump secondary compressor through a pipeline.

[0011] The gas inlet ports of the second heat medium separator and the third heat medium separator are connected to the inlet ports of the deethanizer reboiler and the regeneration tower reboiler respectively.

[0012] A valve is connected to the pipeline between the hot water buffer tank and the hot water circulation pump, and a valve is connected to the pipeline between the heat medium separator and the heat medium air cooler.

[0013] The beneficial effects of the present invention are:

[0014] The heat pump device for recovering waste heat from the compressor adopts heat medium, which can effectively utilize the waste heat of the compressor and greatly increase the temperature. The heat pump compressor adopts a two-stage pressurization method, and the pressure ratio of the gaseous heat medium is more than 15 times. Compared with heating with thermal oil, it does not produce pollution, has zero carbon emissions, and is a clean and green process. The heat pump system has fewer devices, lower investment, and good economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the heat pump device used for heating by recovering waste heat from a compressor according to the present invention.

[0016] In the figure: 1. hot water buffer tank, 2. hot water circulation pump, 3. compressor outlet heat exchanger, 4. hot water heat medium heat exchanger, 5. heat pump compressor inlet buffer tank, 6. heat pump first-stage compressor, 7. heat pump second-stage compressor, 8. heat pump compressor interstage heat exchanger, 9. first heat medium separator, 10. heat medium air cooler, 11. deethanizer reboiler, 12. second heat medium separator, 13. third heat medium separator, 14, regeneration tower reboiler, 15. throttle valve, 16. circulating heat transfer oil pipeline network, 17. circulating hot water pipeline network, 18. circulating heat medium pipeline network. DETAILED DESCRIPTION

[0017] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] like Figure 1 As shown, it includes a circulating hot water unit, the circulating hot water unit is connected to a heat pump circulating unit through a pipeline, and the heat pump circulating unit is connected to a useful heat equipment unit through a pipeline.

[0019] The circulating hot water unit includes a hot water buffer tank 1, which is provided with two inlets and two outlets. The first inlet of the hot water buffer tank 1 is connected to the circulating hot water network 17 through a pipeline. The first outlet of the hot water buffer tank 1 is connected to the hot water circulation pump 2, the compressor outlet heat exchange unit and the hot water heat medium heat exchanger 4 in sequence through a pipeline. The hot water heat medium heat exchanger 4 is connected to the second inlet of the hot water buffer tank 1 through a pipeline. The compressor outlet heat exchange unit includes a plurality of compressor outlet heat exchangers 3, and the plurality of compressor outlet heat exchangers 3 are connected in series or in parallel. The compressor outlet air temperature of the whole plant, which is not fully utilized, is 99-154°C, and the value of individual utilization is low. Therefore, these waste heats are comprehensively utilized by circulating hot water. The hot water from the circulating hot water network 17 is 55°C. The compressor outlet heat exchanger 3 is used for heat exchange, and the circulating hot water temperature is increased to 85°C, and then enters the heat pump circulation unit. After heat exchange, the circulating water enters the hot water buffer tank 1 and is pumped into the network by the hot water circulation pump 2.

[0020] The heat pump circulation unit includes a heat pump compressor inlet buffer tank 5, the outlet of the heat pump compressor inlet buffer tank 5 is connected to the heat pump primary compressor 6, the heat pump secondary compressor 7, the first heat medium separator 9 and the heat medium air cooler 10 through a pipeline, the heat medium air cooler 10 is connected to the hot water heat medium heat exchanger 4 through a pipeline, and also includes a heat pump compressor interstage heat exchanger 8, the heat pump compressor interstage heat exchanger 8 is provided with two inlets and two outlets, the first inlet and the first outlet of the heat pump compressor interstage heat exchanger 8 are connected to the circulating heat transfer oil pipeline network 16 through a pipeline, the second outlet of the heat pump compressor interstage heat exchanger 8 is respectively connected to the inlets of the heat pump primary compressor 6 and the heat pump secondary compressor 7 through a pipeline, the inlet of the heat medium separator 9 is connected to the throttle valve 15 through a pipeline, and the throttle valve 15 is connected to the circulating heat medium pipeline network 18 through a pipeline. The heat medium is highly volatile. To avoid gas-liquid two-phase flow in the system pipeline, the heat medium in the circulating heat medium network is firstly reduced in pressure and temperature through the throttle valve 15, and then enters the first heat medium separator 9 to be divided into gas-liquid two-phase. The liquid phase is further cooled by air through the heat medium air cooler 10, and then heats up through the hot water of the heating circulating hot water network 17 and the hot water heat medium heat exchanger 4. After one heat exchange, the heat medium is heated up and becomes gas phase, and enters the heat pump compressor inlet buffer tank 5. The air flow enters the heat pump primary compressor 6 smoothly, and enters the heat pump secondary compressor 7 after one pressurization. After two-stage pressurization, a 133°C high-temperature and high-pressure heat medium is obtained. The gas phase heat medium is heated up through the heat pump compressor interstage superheater 8 and the heat oil of the circulating heat oil network 16, and enters the heat pump primary compressor 6 and the heat pump secondary compressor 7.

[0021] The heat-using equipment unit includes a deethanizer reboiler 11 and a regeneration tower reboiler 14. The deethanizer reboiler 11 is connected to a second heat medium separator 12 through a pipeline, and the regeneration tower reboiler 14 is connected to a third heat medium separator 13 through a pipeline. The liquid inlets of the second heat medium separator 12 and the third heat medium separator 13 are respectively connected to a throttle valve 15 through pipelines, and the inlets of the deethanizer reboiler 11 and the regeneration tower reboiler 14 are connected to the inlet of the heat pump secondary compressor 7 through a pipeline.

[0022] The gas inlet ports of the second heat medium separator 12 and the third heat medium separator 13 are respectively connected to the inlet ports of the deethanizer reboiler 11 and the regeneration tower reboiler 14. The heat medium compressed by the heat pump primary compressor 6 and the heat pump secondary compressor 7 enters the deethanizer reboiler 11. The design temperature of the deethanizer reboiler 11 is 108°C. The high-temperature heat medium meets the heating load at the bottom of the tower. The two streams exchange heat in the deethanizer bottom reboiler. The light components at the bottom of the tower return to the top of the deethanizer reboiler 11. After the heat medium is cooled, it enters the second heat medium separator 12. The gas phase continues to exchange heat as a heat exchange medium. The liquid phase returns to the first heat medium separator 9 and enters the heat pump circulation system. The same applies to the regeneration tower reboiler.

[0023] A valve is connected to the pipeline between the hot water buffer tank 1 and the hot water circulation pump 2 , and a valve is connected to the pipeline between the heat medium separator 9 and the heat medium air cooler 10 .

[0024] The heat pump device for compressor waste heat recovery and heating provided by the present invention has the following working principle: the heat of the compressor waste heat gas is 99-154°C, and the circulating hot water from the pipe network is 55°C. The compressor outlet heat exchanger 3 is used to exchange heat with the high-temperature gas at the compressor outlet. The circulating hot water temperature of the circulating hot water pipe network 17 is increased to 85°C, and then enters the heat pump circulation unit. The heat of the high-temperature gas at each compressor outlet is released after heat exchange, and the low-temperature gas and liquid flow to the air cooler. After heat exchange, the circulating hot water of the circulating hot water pipe network 17 enters the hot water buffer tank 1 and is pumped into the pipe network by the hot water circulation pump 2. The low-temperature heat exchange medium of the heat pump circulation unit is obtained through the circulating hot water unit. The temperature of the heat medium in the circulating heat medium network is reduced to 86°C through the throttle valve 15, and it is divided into gas and liquid phases when entering the storage tank. The temperature of the liquid phase is 50°C after passing through the heat medium air cooler 10, and it flows to the hot water heat medium heat exchanger 4 to exchange heat with the hot water passing through the heating circulating hot water network 17. After one heat exchange, the heat medium rises to 64.2°C, and the pressure is 175kPa at this time, and enters the heat pump compressor inlet buffer tank 5. The airflow enters the heat pump primary compressor 6 smoothly. After one compression, the heat medium is 115.9°C and 930kPa. After one pressurization, it enters the heat pump secondary compressor 7. The gas phase of the heat medium separator is heated by high-temperature heat transfer oil and the temperature rises from 86°C to 91°C. It merges with the outlet logistics of the heat pump primary compressor 6 to generate heat medium to the inlet of the heat pump secondary compressor 7, with a temperature of 102.1°C and a pressure of 890kPa. After two-stage pressurization, a high-temperature and high-pressure heat medium of 133°C and 2880kPa is obtained. The heat medium compressed by the heat pump circulation unit enters the deethanizer reboiler 11. The design temperature of the deethanizer reboiler 11 is 108°C. The high-temperature heat medium meets the heating load of the deethanizer reboiler 11. The two streams exchange heat in the deethanizer reboiler 11. The light components at the bottom of the deethanizer reboiler 11 return to the top of the deethanizer reboiler 11. The heat medium enters the second heat medium separator 12 after cooling down. The gas phase continues to exchange heat as a heat exchange medium. The liquid phase returns to the heat medium storage tank and enters the first heat medium separator 9. The principle of the regeneration tower reboiler is the same.

[0025] Example 1

[0026] like Figure 1 As shown, the heat pump device for compressor waste heat recovery and heating proposed in this embodiment includes a circulating hot water unit, the circulating hot water unit is connected to a heat pump circulating unit through a pipeline, and the heat pump circulating unit is connected to a heat-using equipment unit through a pipeline.

[0027] Example 2

[0028] like Figure 1As shown, the heat pump device for compressor waste heat recovery and heating proposed in this embodiment includes a circulating hot water unit, the circulating hot water unit is connected to a heat pump circulation unit through a pipeline, and the heat pump circulation unit is connected to a heat-using equipment unit through a pipeline; the circulating hot water unit includes a hot water buffer tank 1, the hot water buffer tank 1 is provided with two inlets and two outlets, the first inlet of the hot water buffer tank 1 is connected to a circulating hot water network 17 through a pipeline, the first outlet of the hot water buffer tank 1 is connected to a hot water circulation pump 2, a compressor outlet heat exchange unit and a hot water heat medium heat exchanger 4 in sequence through a pipeline, and the hot water heat medium heat exchanger 4 is connected to the second inlet of the hot water buffer tank 1 through a pipeline; the compressor outlet heat exchange unit includes a plurality of compressor outlet heat exchangers 3, and the plurality of compressor outlet heat exchangers 3 are connected in series or in parallel.

[0029] Example 3

[0030] like Figure 1As shown, the heat pump device for compressor waste heat recovery and heating proposed in this embodiment includes a circulating hot water unit, the circulating hot water unit is connected to a heat pump circulation unit through a pipeline, and the heat pump circulation unit is connected to a heat-using equipment unit through a pipeline; the circulating hot water unit includes a hot water buffer tank 1, the hot water buffer tank 1 is provided with two inlets and two outlets, the first inlet of the hot water buffer tank 1 is connected to a circulating hot water network 17 through a pipeline, the first outlet of the hot water buffer tank 1 is connected to a hot water circulation pump 2, a compressor outlet heat exchange unit and a hot water heat medium heat exchanger 4 in sequence through a pipeline, and the hot water heat medium heat exchanger 4 is connected to the second inlet of the hot water buffer tank 1 through a pipeline; the compressor outlet heat exchange unit includes a plurality of compressor outlet heat exchangers 3, and the plurality of compressor outlet heat exchangers 3 are connected in series or in parallel. The heat pump circulation unit includes a heat pump compressor inlet buffer tank 5, the outlet of the heat pump compressor inlet buffer tank 5 is connected to the heat pump primary compressor 6, the heat pump secondary compressor 7, the first heat medium separator 9 and the heat medium air cooler 10 through a pipeline, the heat medium air cooler 10 is connected to the hot water heat medium heat exchanger 4 through a pipeline, and also includes a heat pump compressor interstage heat exchanger 8, the heat pump compressor interstage heat exchanger 8 is provided with two inlets and two outlets, the first inlet and the first outlet of the heat pump compressor interstage heat exchanger 8 are connected to the circulating heat transfer oil pipeline network 16 through a pipeline, the second outlet of the heat pump compressor interstage heat exchanger 8 is respectively connected to the inlets of the heat pump primary compressor 6 and the heat pump secondary compressor 7 through a pipeline, and the inlet of the heat medium separator 9 is connected to the heat pump compressor interstage heat exchanger 8 through a pipeline. The pipeline is connected with a throttle valve 15, and the throttle valve 15 is connected with the circulating heat medium network 18 through the pipeline; the heat-using equipment unit includes a deethanizer reboiler 11 and a regeneration tower reboiler 14, the deethanizer reboiler 11 is connected with the second heat medium separator 12 through the pipeline, the regeneration tower reboiler 14 is connected with the third heat medium separator 13 through the pipeline, the liquid inlet of the second heat medium separator 12 and the third heat medium separator 13 are respectively connected with the throttle valve 15 through the pipeline, and the inlet of the deethanizer reboiler 11 and the regeneration tower reboiler 14 is connected with the inlet of the heat pump secondary compressor 7 through the pipeline; the gas inlet of the second heat medium separator 12 and the third heat medium separator 13 is respectively connected with the inlet of the deethanizer reboiler 11 and the regeneration tower reboiler 14.

[0031] Example 4

[0032] like Figure 1As shown, the heat pump device for compressor waste heat recovery and heating proposed in this embodiment includes a circulating hot water unit, the circulating hot water unit is connected to a heat pump circulation unit through a pipeline, and the heat pump circulation unit is connected to a heat-using equipment unit through a pipeline; the circulating hot water unit includes a hot water buffer tank 1, the hot water buffer tank 1 is provided with two inlets and two outlets, the first inlet of the hot water buffer tank 1 is connected to a circulating hot water network 17 through a pipeline, the first outlet of the hot water buffer tank 1 is connected to a hot water circulation pump 2, a compressor outlet heat exchange unit and a hot water heat medium heat exchanger 4 in sequence through a pipeline, and the hot water heat medium heat exchanger 4 is connected to the second inlet of the hot water buffer tank 1 through a pipeline; the compressor outlet heat exchange unit includes a plurality of compressor outlet heat exchangers 3, and the plurality of compressor outlet heat exchangers 3 are connected in series or in parallel. The heat pump circulation unit includes a heat pump compressor inlet buffer tank 5, the outlet of the heat pump compressor inlet buffer tank 5 is connected to the heat pump primary compressor 6, the heat pump secondary compressor 7, the first heat medium separator 9 and the heat medium air cooler 10 through a pipeline, the heat medium air cooler 10 is connected to the hot water heat medium heat exchanger 4 through a pipeline, and also includes a heat pump compressor interstage heat exchanger 8, the heat pump compressor interstage heat exchanger 8 is provided with two inlets and two outlets, the first inlet and the first outlet of the heat pump compressor interstage heat exchanger 8 are connected to the circulating heat transfer oil pipeline network 16 through a pipeline, the second outlet of the heat pump compressor interstage heat exchanger 8 is respectively connected to the inlets of the heat pump primary compressor 6 and the heat pump secondary compressor 7 through a pipeline, the inlet of the heat medium separator 9 is connected to the throttle valve 15 through a pipeline, and the throttle valve 15 is connected to the circulating heat medium pipeline network 16 through a pipeline. The heat-using equipment unit includes a deethanizer reboiler 11 and a regeneration tower reboiler 14, the deethanizer reboiler 11 is connected to the second heat medium separator 12 through a pipeline, the regeneration tower reboiler 14 is connected to the third heat medium separator 13 through a pipeline, the liquid inlets of the second heat medium separator 12 and the third heat medium separator 13 are respectively connected to the throttle valve 15 through pipelines, and the inlets of the deethanizer reboiler 11 and the regeneration tower reboiler 14 are connected to the inlet of the heat pump secondary compressor 7 through a pipeline; the gas inlets of the second heat medium separator 12 and the third heat medium separator 13 are respectively connected to the inlets of the deethanizer reboiler 11 and the regeneration tower reboiler 14; a valve is connected to the pipeline between the hot water buffer tank 1 and the hot water circulation pump 2, and a valve is connected to the pipeline between the heat medium separator 9 and the heat medium air cooler 10.

Claims

1. A heat pump device for recovering waste heat from a compressor, characterized in that: It comprises a circulating hot water unit, wherein the circulating hot water unit is connected with a heat pump circulating unit through a pipeline, and the heat pump circulating unit is connected with a heat-use equipment unit through a pipeline.

2. The heat pump device for recovering waste heat from a compressor for heating according to claim 1, characterized in that: The circulating hot water unit comprises a hot water buffer tank (1), the hot water buffer tank (1) being provided with two inlets and two outlets, the first inlet of the hot water buffer tank (1) being connected to a circulating hot water pipe network (17) via a pipeline, the first outlet of the hot water buffer tank (1) being connected in sequence to a hot water circulation pump (2), a compressor outlet heat exchange unit and a hot water heat medium heat exchanger (4) via a pipeline, and the hot water heat medium heat exchanger (4) being connected to the second inlet of the hot water buffer tank (1) via a pipeline.

3. The heat pump device for recovering waste heat from a compressor for heating according to claim 2, characterized in that: The compressor outlet heat exchange unit comprises a plurality of compressor outlet heat exchangers (3), and the plurality of compressor outlet heat exchangers (3) are connected in series or in parallel.

4. The heat pump device for recovering waste heat from a compressor for heating according to claim 2, characterized in that: The heat pump circulation unit comprises a heat pump compressor inlet buffer tank (5), the outlet of the heat pump compressor inlet buffer tank (5) is connected to a heat pump primary compressor (6), a heat pump secondary compressor (7), a first heat medium separator (9) and a heat medium air cooler (10) through a pipeline, the heat medium air cooler (10) is connected to the hot water heat medium heat exchanger (4) through a pipeline, and also comprises a heat pump compressor interstage heat exchanger (8), the heat pump compressor interstage heat exchanger (8) is provided with two inlets and two outlets, the first inlet and the first outlet of the heat pump compressor interstage heat exchanger (8) are connected to a circulating heat transfer oil pipeline network (16) through a pipeline, the second outlet of the heat pump compressor interstage heat exchanger (8) is respectively connected to the inlets of the heat pump primary compressor (6) and the heat pump secondary compressor (7) through a pipeline, the inlet of the heat medium separator (9) is connected to a throttle valve (15) through a pipeline, and the throttle valve (15) is connected to the circulating heat medium pipeline network (18) through a pipeline.

5. The heat pump device for recovering waste heat from a compressor for heating according to claim 4, characterized in that: The heat-using equipment unit comprises a deethanizer reboiler (11) and a regeneration tower reboiler (14); the deethanizer reboiler (11) is connected to a second heat medium separator (12) via a pipeline; the regeneration tower reboiler (14) is connected to a third heat medium separator (13) via a pipeline; the liquid inlet ports of the second heat medium separator (12) and the third heat medium separator (13) are respectively connected to a throttle valve (15) via pipelines; and the inlet ports of the deethanizer reboiler (11) and the regeneration tower reboiler (14) are connected to the inlet port of a heat pump secondary compressor (7) via pipelines.

6. The heat pump device for recovering waste heat from a compressor for heating according to claim 5, characterized in that: The gas inlet ports of the second heat medium separator (12) and the third heat medium separator (13) are respectively connected to the inlet ports of the deethanizer reboiler (11) and the regeneration tower reboiler (14).

7. The heat pump device for recovering waste heat from a compressor for heating according to claim 6, characterized in that: A valve is connected to the pipeline between the hot water buffer tank (1) and the hot water circulation pump (2), and a valve is connected to the pipeline between the heat medium separator (9) and the heat medium air cooler (10).

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