A heat pump vapor system

Abstract

The application discloses a heat pump steam system, which comprises an economizer, a refrigerant compressor, a steam generator, a gas-liquid separator, a steam compressor, an oil cooler and a preheater; the cold side of the economizer is communicated with the refrigerant compressor and the steam generator, the hot side is communicated with the gas-liquid separator and the steam compressor, the heat of high-temperature condensed water is recovered through refrigerant throttling, on the one hand, the problem that the temperature of high-temperature condensed water at the bottom of the gas-liquid separator is much higher than the water spraying temperature of the steam compressor is solved, on the other hand, the heat of the high-temperature condensed water is recovered, and the heat utilization efficiency is high. The hot side of the oil cooler is communicated with the steam compressor, the cold side is communicated with the preheater and the steam generator, the heat of high-temperature lubricating oil is recovered through an oil-water heat exchanger, on the one hand, the problem that emulsification is invalid due to the excessively high temperature of the lubricating oil is solved, on the other hand, the heat of the high-temperature lubricating oil is recovered, and the heat utilization efficiency is improved again.

Description

Technical Field

[0001] This invention relates to the field of heat pump steam technology, and more specifically to a heat pump steam system. Background Technology

[0002] With the advancement of national energy consumption reform, air pollution prevention and control, and energy conservation, emission reduction, and low-carbon development strategies, the proportion of products powered by electricity in the energy consumption market will increase significantly. Currently, industrial park pipeline steam supply generally uses gas-fired boilers, which have low primary energy conversion rates and emit large amounts of CO2 and NO. X Furthermore, the initial installation cost is high. In contrast, advanced electric-driven high-temperature steam heat pump technology offers significant energy savings, achieving 50%-60% energy savings compared to gas-fired boilers and 2-3 times the energy efficiency ratio compared to electric boilers. Therefore, it is necessary to research electric-driven high-temperature steam heat pump technology.

[0003] Currently, high-temperature heat pumps are used internationally to produce high-temperature and high-pressure hot water. Low-pressure steam is produced by depressurizing and flashing high-pressure hot water. When higher-temperature steam is needed, a steam compressor unit is used to continue to increase the temperature and pressure. Overall, the thermal efficiency is relatively low. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a medium-temperature heat pump steam system that utilizes heat in a cascade coupling manner to improve the overall utilization efficiency.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A heat pump steam system includes an economizer, a refrigerant compressor, a steam generator, a gas-liquid separator, a steam compressor, an oil cooler, and a preheater;

[0007] One side of the economizer is connected to the refrigerant compressor and the steam generator, and the other side is connected to the gas-liquid separator and the steam compressor.

[0008] One side of the oil cooler is connected to the steam compressor, and the other side is connected to the preheater and the steam generator.

[0009] Furthermore, the heat pump steam system also includes an oil pump and an evaporator;

[0010] One side of the preheater is used to receive water for the first heating of the water. After the first heating, the water enters the oil cooler for a second heating. After the second heating, the water enters the steam compressor for heating and pressurization. The heated and pressurized water then enters the gas-liquid separator to separate steam and condensate. The separated steam is discharged, and the separated condensate enters the economizer for cooling. The cooled condensate then enters the steam compressor, completing the water-steam loop cycle.

[0011] The refrigerant compressor is used to receive refrigerant. After being processed by the refrigerant compressor, the refrigerant enters the steam generator and is then divided into two streams. One stream of refrigerant enters the economizer to complete the vaporization and heat absorption process before entering the refrigerant compressor to continue the cycle. The other stream of refrigerant enters the evaporator to complete the vaporization and heat absorption process before returning to the refrigerant compressor to continue the cycle.

[0012] The evaporator is used to connect to the heat source water. The evaporator cools the connected heat source water. The cooled heat source water enters the preheater, where it is cooled a second time before being discharged.

[0013] The lubricating oil outlet of the steam compressor passes through the oil pump and oil cooler in sequence before returning to the lubricating oil inlet of the steam compressor.

[0014] Furthermore, the oil cooler employs an oil-water heat exchanger.

[0015] Furthermore, the steam compressor adopts an independent oil lubrication circulation loop, and the compression process is cooled by water spray, with the water spray temperature being 70-90℃.

[0016] Furthermore, the refrigerant compressor is a semi-hermetic screw compressor.

[0017] Furthermore, the refrigerant enters the economizer through the first pressure reducing valve.

[0018] Furthermore, the other refrigerant enters the evaporator through the second pressure reducing valve.

[0019] Furthermore, a third pressure reducing valve is installed in the pipeline between the economizer and the steam compressor.

[0020] Furthermore, the refrigerant used is R245FA, R1336mzz(Z), or R1234ze(Z).

[0021] Furthermore, the steam generator employs a heat exchanger with dual-sided phase change.

[0022] Furthermore, the refrigerant compressor is a semi-hermetic screw compressor.

[0023] The beneficial effects of this invention are as follows:

[0024] The system described in this invention uses an economizer to recover heat from high-temperature condensate. This solves the problem that the temperature of the high-temperature condensate at the bottom of the gas-liquid separator is much higher than the spray temperature of the steam compressor, and also recovers the heat from the high-temperature condensate, resulting in high thermal efficiency.

[0025] The system described in this invention uses an oil-water cooler to recover heat from high-temperature lubricating oil. This solves the problem of emulsification failure caused by excessively high lubricating oil temperature, and further improves thermal utilization efficiency by recovering the heat from the high-temperature lubricating oil. Attached Figure Description

[0026] Figure 1 This is a diagram showing the main equipment of the heat pump steam system according to an embodiment of the present invention;

[0027] Figure 2 This is a flow chart of the working fluid in the heat pump steam system according to an embodiment of the present invention;

[0028] The diagram shows the following labels: 1. Refrigerant compressor; 2. Steam generator; 3. Economizer; 4. Evaporator; 5. Steam compressor; 6. Oil pump; 7. Oil cooler; 8. Gas-liquid separator; 9. Preheater; 10. Flange; 11. First pressure reducing valve; 12. Second pressure reducing valve; 13. Third pressure reducing valve; 101. Heat source water inlet pipe; 102. Preheater hot side inlet pipe; 103. Heat source water outlet pipe; 104. Refrigerant compressor inlet pipe; 105. Refrigerant compressor outlet pipe; 106. Condenser refrigerant side outlet pipe; 107. Economizer cold side inlet pipe; 108. Cold side outlet pipe. 109. Refrigerant compressor refrigerant inlet pipe; 110. Second expansion valve inlet pipe; 111. Evaporator refrigerant side inlet pipe; 112. Steam compressor inlet pipe; 113. Steam compressor outlet pipe; 114. Saturated steam outlet pipe; 115. Saturated condensate outlet pipe; 116. Economizer hot side outlet pipe; 117. Steam compressor liquid injection inlet pipe; 118. Steam compressor oil circulation outlet pipe; 119. Oil cooler lubricating oil inlet pipe; 120. Steam compressor oil circulation inlet pipe; 121. System water inlet pipe; 122. Oil cooler cold side inlet pipe; 123. Steam generator water inlet pipe. Detailed Implementation

[0029] The present invention will now be further described with reference to the accompanying drawings and specific embodiments:

[0030] See Figures 1 to 2The heat pump steam system provided in this embodiment mainly includes a water-steam circulation loop, a refrigerant circulation loop, a heat source water circulation loop, and a lubricating oil circulation loop. Specifically, it includes a refrigerant compressor 1, a steam compressor 5, a steam generator 2, an economizer 3, an evaporator 4, an oil cooler 7, a gas-liquid separator 8, an oil pump 6, a preheater 9, a water inlet pump 10, a first pressure reducing valve 11, a second pressure reducing valve 12, a third pressure reducing valve 13, and related connecting pipes and valves.

[0031] The economizer 3 is connected to the refrigerant compressor 1 and the steam generator 2 on one side, and to the gas-liquid separator 8 and the steam compressor 5 on the other side. The economizer recovers the heat of the high-temperature condensate, which solves the problem that the temperature of the high-temperature condensate at the bottom of the gas-liquid separator is much higher than the spray temperature of the steam compressor. On the other hand, it recovers the heat of the high-temperature condensate, resulting in high thermal efficiency.

[0032] The oil cooler 7 is connected to the steam compressor 2 on one side and to the preheater 9 and steam generator 2 on the other side. The oil cooler recovers the heat of the high-temperature lubricating oil, which solves the problem of emulsification failure caused by excessively high lubricating oil temperature, and recovers the heat of the high-temperature lubricating oil, thus improving the heat utilization efficiency.

[0033] In the water-steam circulation loop, room temperature softened water (around 20°C) enters the system water inlet pipe 120, is pumped by water pump 10, and enters the preheater 9 for the first heating (40-50°C). Then, it enters the oil cooler 7 through the cold side inlet pipe 121 for the second heating (70-80°C), and then enters the steam generator 2 through the steam generator inlet pipe 122 to complete the phase change vaporization process. The heated and vaporized steam (100-120°C) enters the steam compressor inlet pipe 111, is heated and pressurized by the steam compressor 5 (150-180°C), and then enters the gas-liquid separator 8 through the steam compressor outlet pipe 112. Finally, the saturated steam (150-180℃) is separated and discharged from the system through the saturated steam outlet pipe 113. The separated saturated condensate (150-180℃) enters the economizer 3 through the saturated condensate outlet pipe 114. After absorbing heat in the economizer 3, it is cooled to 70-90℃ and enters the steam compressor 5 through the hot side outlet pipe 115 of the economizer, the third pressure reducing valve 13, and the liquid injection inlet pipe 116 of the steam compressor. On the one hand, it eliminates the superheat during the steam compression process, and on the other hand, it is used as a sealing liquid film in the compression chamber. Its heat is recovered by the economizer 3 and then enters the refrigerant compressor 1, completing the water-steam loop cycle process. In other words, in this embodiment, the economizer 3 is a heat exchanger. Unlike the prior art, it absorbs heat through the throttling and evaporation of the refrigerant itself. Its heat source is the high-temperature condensate at the bottom of the gas-liquid separator. The heated and vaporized gaseous working fluid enters the refrigerant compressor, and the cooled condensate enters the steam compressor. By using the economizer 3 to recover the heat of the high-temperature condensate, the problem of the high temperature of the condensate at the bottom of the gas-liquid separator being much higher than the spray temperature of the steam compressor is solved on the one hand, and the heat of the high-temperature condensate is recovered on the other hand, resulting in high thermal efficiency.

[0034] In the refrigerant circulation loop, low-temperature, low-pressure refrigerant (around 50°C) enters refrigerant compressor 1 through refrigerant compressor inlet pipe 104, and then enters steam generator 2 through refrigerant compressor outlet pipe 105 (105-125°C). In steam generator 2, it completes the liquefaction and heat release process. After passing through condenser refrigerant side outlet pipe 106, it splits into two streams of refrigerant. One stream passes through first pressure reducing valve 11 and enters economizer 3. After completing the vaporization and heat absorption process, it enters refrigerant compressor 1 through refrigerant compressor make-up pipe 108 to continue circulating. By separating one stream of refrigerant, which is vaporized in economizer and then injected into refrigerant compressor, the superheat during compression is reduced, providing heating capacity for the unit. The other stream of refrigerant passes through second pressure reducing valve 12 and enters evaporator 4, completing the vaporization and heat absorption process. The low-temperature, low-pressure gaseous refrigerant then returns to refrigerant compressor 1 through refrigerant compressor inlet pipe 104 to continue circulating.

[0035] In the heat source water circulation loop, heat source water (around 60℃) enters the evaporator 4 through the heat source water inlet pipe 101. After cooling (to 50-55℃), it enters the preheater 9 through the preheater hot-side inlet pipe 102. After absorbing heat, the preheater 9 cools down again (to 25-30℃) and exits the system through the heat source water outlet pipe. The system removes some heat from the heat source water, and the mass flow rate of the heat source water remains unchanged. The heat removed by the preheater 9 can be used to heat the softened water at room temperature, improving the heat utilization rate. Simultaneously, combined with the above refrigerant circulation loop, it can be seen that the fluids on both sides of the evaporator are refrigerant and heat source water, respectively. The heat source water releases heat as it cools down, while the refrigerant absorbs heat, thus achieving thermal balance.

[0036] In the lubricating oil circulation loop, the lubricating oil outlet of the steam compressor passes through the oil pump 6 and the oil cooler 7 in sequence before returning to the lubricating oil inlet 119 of the steam compressor. The oil cooler is an oil-water heat exchanger. As can be seen from the above water-steam circulation loop, the room temperature softened water is heated for the first time by the preheater 9 and then enters the oil cooler for a second heating. That is to say, in this embodiment, the oil cooler 7 is a heat exchanger. The difference from the prior art is that it adopts a water cooling method, and the cooling energy comes from the system water inlet. On the one hand, it improves the quality of the water entering the steam generator, and on the other hand, it reduces the temperature of the circulating lubricating oil, which has a coupled and superimposed effect and high heat utilization rate.

[0037] In one specific embodiment, the aforementioned steam compressor is an open-type screw compressor, the bearing chamber uses an independent water-cooled oil-lubricated circulation loop, and the compression chamber is cooled by water spray at a temperature of 70-90°C. Further, the aforementioned refrigerant compressor is a semi-hermetic high-temperature oil-lubricated screw compressor, using working fluids such as R245FA, R1336mzz(Z), and R1234ze(Z); the steam generator 2 employs a double-sided phase-change heat exchanger to simultaneously realize the steam generation and separation process, with a pressure less than 1.0 MPa.

[0038] For those skilled in the art, various other corresponding changes and modifications can be made based on the technical solutions and concepts described above, and all such changes and modifications should fall within the protection scope of the claims of this invention.

Claims

1. A heat pump steam system, characterized in that, This includes economizers, refrigerant compressors, steam generators, gas-liquid separators, steam compressors, oil coolers, and preheaters; One side of the economizer is connected to the refrigerant compressor and the steam generator, and the other side is connected to the gas-liquid separator and the steam compressor. One side of the oil cooler is connected to the steam compressor, and the other side is connected to the preheater and the steam generator; It also includes oil pumps and evaporators; One side of the preheater is used to receive water for the first heating of the water. After the first heating, the water enters the oil cooler for a second heating. After the second heating, the water enters the steam compressor for heating and pressurization. The heated and pressurized water then enters the gas-liquid separator to separate steam and condensate. The separated steam is discharged, and the separated condensate enters the economizer for cooling. The cooled condensate then enters the steam compressor, completing the water-steam loop cycle. The refrigerant compressor is used to receive refrigerant. After being processed by the refrigerant compressor, the refrigerant enters the steam generator and is then divided into two streams. One stream of refrigerant enters the economizer to complete the vaporization and heat absorption process before entering the refrigerant compressor to continue the cycle. The other stream of refrigerant enters the evaporator to complete the vaporization and heat absorption process before returning to the refrigerant compressor to continue the cycle. The evaporator is used to connect to the heat source water. The evaporator cools the connected heat source water. The cooled heat source water enters the preheater, where it is cooled a second time before being discharged. The lubricating oil outlet of the steam compressor passes through the oil pump and oil cooler in sequence before returning to the lubricating oil inlet of the steam compressor.

2. The heat pump steam system as described in claim 1, characterized in that, The oil cooler uses an oil-water heat exchanger.

3. The heat pump steam system as described in claim 1, characterized in that, The steam compressor uses an independent oil-lubricated circulation loop, and the compression process is cooled by water spray, with the water spray temperature being 70-90℃.

4. The heat pump steam system as described in claim 1, characterized in that, The refrigerant compressor is a semi-hermetic screw compressor.

5. The heat pump steam system as described in claim 1, characterized in that, The refrigerant enters the economizer through the first pressure reducing valve.

6. The heat pump steam system as described in claim 1 or 4, characterized in that, The other refrigerant enters the evaporator through the second pressure reducing valve.

7. The heat pump steam system as described in claim 1, characterized in that, A third pressure reducing valve is installed in the pipeline between the economizer and the steam compressor.

8. The heat pump steam system as described in claim 1, characterized in that, The refrigerant used is R245FA, R1336mzz(Z), or R1234ze(Z).

9. The heat pump steam system as described in claim 1, characterized in that, The steam generator employs a double-sided phase change heat exchanger.

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