CN113007915A

CN113007915A - Thermodynamic method and device for changing state by utilizing steam pressure

Info

Publication number: CN113007915A
Application number: CN202110199302.6A
Authority: CN
Inventors: 郑成勋
Original assignee: Zheng Xixun
Current assignee: Zheng Xixun
Priority date: 2021-02-23
Filing date: 2021-02-23
Publication date: 2021-06-22

Abstract

The invention relates to the field of refrigerators, and particularly discloses a thermodynamic method and a thermodynamic device for changing a state by utilizing steam pressure, wherein the thermodynamic method and the thermodynamic device comprise a compressor, a liquefaction mechanism, a precooler and an evaporator which are sequentially connected; the liquefaction mechanism is one of a condenser, a cooler and a throttle valve or an expansion machine, the precooler comprises a cooling part and a cooling cavity, the cooling part is an assembly for cooling working media flowing through the cooling cavity, the cooling part is one of an external cold source or a system self-cooling assembly, and the cooling cavity is provided with a first inlet and a first outlet; the first inlet is connected to the condenser outlet and the first outlet is connected to the evaporator inlet. The invention adds the precooler to make the liquid working medium with the temperature lower than the required temperature enter the evaporator, thereby improving the heat conversion efficiency of the evaporator and the condenser and further improving the refrigerating speed of the refrigerator; by adding the vapor compression device, the vapor in the evaporator or the evaporation cavity can be self-pressurized, the burden of the compressor is reduced, and the purpose of energy conservation is achieved.

Description

Thermodynamic method and device for changing state by utilizing steam pressure

Technical Field

The invention relates to the field of refrigerators, in particular to a thermodynamic method and a thermodynamic device for changing a state by utilizing steam pressure.

Background

Air conditioners and refrigerators are the most common refrigerators in modern life and almost become necessary electrical appliances in people's life. In a traditional refrigerator, a liquid working medium enters an evaporator after passing through a throttler, the pressure in the evaporator is reduced as a compressor extracts working medium steam in the evaporator, the liquid working medium evaporates and absorbs heat under low pressure to form working medium steam, the compressor pressurizes and discharges the extracted working medium steam into a condenser, the pressure in the condenser is high, and the working medium steam is liquefied into working medium liquid under high pressure and releases heat, so that heat exchange is completed. The refrigerating mode is direct and efficient, and can quickly obtain the refrigerating or heating effect.

In addition, the conventional refrigerator needs the compressor to continuously operate to pump away the steam in the evaporator and maintain the low pressure in the evaporator for the evaporation of the liquid working medium, even if the saturated vapor pressure at the required temperature is very high, the energy consumption is high.

Disclosure of Invention

To overcome the deficiencies of the prior art, the present invention provides a thermodynamic method and apparatus that utilizes vapor pressure to change states.

The technical scheme adopted by the invention is as follows: the system comprises a working medium, a working medium pipeline, a compressor, an evaporator, a precooler and a liquefaction mechanism, wherein the liquefaction mechanism is one of a condenser, a cooler and a throttle valve or an expander; the compressor, the liquefaction mechanism, the precooler and the evaporator are connected in sequence; the precooler comprises a cooling part and a cooling cavity, wherein the cooling part is an assembly for cooling a liquid working medium flowing through the cooling cavity, the cooling part is one of an external cold source or a system self-cooling assembly, and the cooling cavity is provided with a first inlet and a first outlet; the first inlet is connected with the outlet of the liquefying mechanism, and the first outlet is connected with the inlet of the evaporator.

Preferably, the system self-cooling assembly comprises a throttling device and an evaporation cavity, the evaporation cavity is provided with a second inlet and a second outlet, the outlet of the liquefaction mechanism, the throttling device and the second inlet are sequentially connected, and the second outlet is connected with the suction end of the compressor.

Preferably, when the cooling part is an external cold source, the liquefaction mechanism and the precooler can be combined into one component; after the steam working medium is condensed, the liquid working medium is supercooled to be lower than the required refrigeration temperature.

Preferably, a thermodynamic device utilizing vapor pressure to change states as claimed in claim 1, wherein: the steam self-pressurizing device comprises a steam self-pressurizing device, a steam self-pressurizing device and a steam jet pump, wherein the steam self-pressurizing device is one or a combination of a plurality of mechanical pressurizers, steam self-pressurizing devices or steam jet pumps, and comprises a compressing part, an acting part and a transmission mechanism; the compression part comprises a pressure cylinder, and a third inlet and a third outlet are arranged on one side of the pressure cylinder; the work applying part comprises a driving cylinder, and a fourth inlet and a fourth outlet are arranged on one side of the driving cylinder; the transmission mechanism is used for transmitting the pressure generated by the acting part to the compression part, and the pressure cylinder is connected with the driving cylinder through the transmission mechanism.

Preferably, there are a plurality of vapor compression devices, and the operation mode of the plurality of vapor compression devices is one of series-cascade operation, parallel operation, and series-parallel switching operation.

Preferably, a flash evaporation device is arranged between the outlet of the liquefaction mechanism and the throttling device, and a steam outlet of the flash evaporation device is connected with the steam compression device or is connected with a steam outlet of the evaporation cavity through the steam compression device and is used for driving the steam compression device to do work; the working medium pipeline entering the first inlet is arranged below the liquid level of the liquid working medium in the flash evaporation device.

Preferably, the number of the evaporators is at least one, the number of the condensers is at least one, the steam outlet of at least one evaporator is connected with the steam compression device, and the steam outlets of the other evaporators are respectively connected with the suction end of the compressor or the steam compression device at the outlet of the evaporator; the inlet of at least one condenser is connected with a vapor compression device; the condensers are communicated with each other to enable the working medium to flow among the condensers.

Preferably, the energy storage device also comprises an energy storage device used for absorbing or providing heat energy and exchanging heat with the environment space, and the energy storage device comprises at least one of a high-temperature energy storage device or a low-temperature energy storage device; the high-temperature energy accumulator comprises a high-temperature energy storage working medium and a high-temperature heat exchanger, an inlet of the high-temperature heat exchanger is connected with a steam outlet of the steam compression device at an outlet of the evaporator or a liquid working medium outlet of the condenser, and an outlet of the high-temperature heat exchanger is connected with a steam inlet of the condenser or a liquid working medium outlet of the condenser; the low-temperature energy accumulator comprises a low-temperature energy storage working medium and a low-temperature heat exchanger, the low-temperature heat exchanger is connected with a certain evaporator, an inlet of the certain evaporator is connected with a first outlet and a fourth outlet of a steam compression device arranged at an outlet of the evaporator, and an outlet of the certain evaporator is connected with the steam compression device arranged at an outlet of the evaporator.

Preferably, the energy accumulator can be detached and moved to other places to be used as a heat source or a cold source.

Preferably, the thermodynamic device is overlapped with a refrigeration system and an acting system of other working media.

A thermodynamic method for changing a state by utilizing vapor pressure is adopted, and the thermodynamic device for changing the state by utilizing the vapor pressure comprises the following steps:

a1, cooling the liquid working medium in the precooler by the cooling part, and reducing the temperature of the liquid working medium to be lower than the required refrigeration temperature;

a2, feeding the cooled liquid working medium into an evaporator;

a3, in the evaporator, evaporating the low-temperature liquid working medium by heating to make the temperature of the working medium close to the required temperature, and condensing the evaporated working medium after being compressed by the compressor;

a4, when the precooler is not cooled by an external cold source but is cooled by a system self-cooling assembly, an evaporation cavity for evaporating the liquid working medium of the system is arranged in the precooler, the liquid working medium is evaporated in the evaporation cavity to absorb heat, and simultaneously exchanges heat with the liquid working medium in the cooling cavity, so that the temperature of the liquid working medium in the cooling cavity is reduced;

a5, the vapor evaporated in the evaporator or mixed with the vapor in the evaporation cavity of the precooler enters the suction end of the compressor or respectively enters the suction ends with corresponding pressures.

Preferably, the device further comprises a vapor compression device, wherein the vapor compression device comprises a compression part, a work-doing part and a transmission mechanism; the compression part comprises a pressure cylinder, and a third inlet and a third outlet are arranged on one side of the pressure cylinder; the work applying part comprises a driving cylinder, and a fourth inlet and a fourth outlet are arranged on one side of the driving cylinder; the thermodynamic method for changing state by vapor pressure is realized by the vapor compression device, and the realization method is as follows:

b1, the vapor compression device is a self-compression device, the vapor working medium in the evaporator is compressed by utilizing the vapor pressure in the evaporator and the pressure difference between the air suction end of the compressor or between other low-pressure areas such as the environment, the vapor in the evaporator is compressed and then is led into a liquefaction mechanism for condensation;

b2, taking a steam working medium in the evaporator as driving steam, and leading the steam pressure in the evaporation cavity into a suction end of the compressor after the steam pressure is lifted by the steam compression device; after the driving steam does work, the driving steam is mixed with a steam working medium in the evaporation cavity and then enters the air suction ends of the compressors or respectively enters the air suction ends of the compressors corresponding to the respective steam pressure;

b3, according to the pressure to be achieved by compression, on the premise of meeting the pressure after compression, a communicating hole is also arranged between the pressure cylinder and the driving cylinder, the part of the working medium which is driven in the driving cylinder enters a cavity generated by the pressure cylinder through the communicating hole, so as to reduce the amount of the steam which is not used any more, and the rest of the working medium in the pressure cylinder directly enters the compressor.

The invention has the beneficial effects that:

(1) by adding the precooler, the temperature of the liquid working medium entering the evaporator is reduced, so that the heat conversion efficiency of the evaporator and the condenser is improved, and the refrigerating efficiency of the refrigerator is further improved.

(2) By adding the vapor compression device, the vapor in the evaporator or the evaporation cavity can be self-pressurized, the burden of the compressor is reduced, and the purpose of energy conservation is achieved.

Drawings

FIG. 1 is a schematic diagram of a refrigerator incorporating a precooler according to the present invention.

Fig. 2 is a schematic diagram of a refrigerator incorporating a self-cooling precooler of the present invention.

Fig. 3 is a schematic view of a vapor compression device according to an embodiment of the present invention.

Fig. 4 is a schematic view of a turbo type vapor compression device of the present invention.

Fig. 5 is a schematic view of another embodiment of the vapor compression apparatus of the present invention.

Fig. 6 is a schematic view of another embodiment of the present invention.

FIG. 7 is a schematic view of an embodiment of the present invention with an evaporative condenser.

FIG. 8 is a schematic diagram of a high and low temperature dual system according to the present invention.

Fig. 9 is a schematic view of an embodiment of the cascade refrigeration of the present invention. .

Fig. 10 is a schematic view of another cascade refrigeration embodiment of the present invention.

Fig. 11 is a schematic view of another embodiment of the present invention.

Fig. 12 is a schematic view of an eighth embodiment of the present invention.

In the figure: 1. a precooler; 11. a cooling section; 111. a throttling device; 112. an evaporation chamber; 113. a second inlet; 114. a second outlet; 12. a cooling chamber; 121. a first inlet; 122. a first outlet; 13. a high-temperature stage precooler; 2. a vapor compression device; 21. a high temperature stage vapor compression device; 22. a drive cylinder; 221. a third inlet; 222. a third outlet; 23. a pressure cylinder; 231. a fourth inlet; 232. a fourth outlet; 24. a transmission mechanism; 241. a piston; 242. a connecting rod; 243. a crankshaft; 244. a blade; 3. an evaporator; 4. a condenser; 41. a low temperature stage condenser; 5. a compressor; 51. a high temperature stage compressor; 52. a low temperature stage compressor; 6. a liquid working medium pump; 7. an evaporative condenser; 71. a second evaporative condenser; 8. a gas-liquid separator; 9. a steam generator; 10. a work-doing device.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and the detailed description, and it should be noted that any combination of the embodiments or technical features described below can be used to form a new embodiment without conflict.

The names of liquid working medium, working medium liquid, working medium steam, steam and the like in the scheme are all state changes caused by common evaporation and liquefaction when the working medium runs in a thermodynamic device, and belong to the conventional names in the field.

Referring to fig. 1 to 12, the invention is a thermodynamic device changing state by vapor pressure, comprising a working medium, a working medium pipeline, a compressor 5, an evaporator 3, a precooler 1 and a liquefaction mechanism, wherein the liquefaction mechanism is one of a condenser 4, a cooler and a throttle valve or an expander; the compressor 5, the liquefaction mechanism, the precooler 1 and the evaporator 3 are connected in sequence; the precooler 1 comprises a cooling part 11 and a cooling cavity 12, wherein the cooling part 11 is a component for cooling a liquid working medium flowing through the cooling cavity 12, the cooling part 11 is one of an external cold source or a system self-cooling component, and the cooling cavity 12 is provided with a first inlet 121 and a first outlet 122; the first inlet 121 is connected to the liquefaction mechanism outlet and the first outlet 122 is connected to the evaporator 3 inlet.

Preferably, the system self-cooling assembly comprises a throttling device 111 and an evaporation cavity 112, the evaporation cavity 112 is provided with a second inlet 113 and a second outlet 114, the outlet of the liquefaction mechanism, the throttling device 111 and the second inlet 113 are connected in sequence, and the second outlet 114 is connected with the suction end of the compressor 5.

Preferably, when the cooling part 11 is an external cold source, the liquefaction mechanism and the precooler 1 may be combined into one component; after the steam working medium is condensed, the liquid working medium is supercooled to be lower than the required refrigeration temperature.

Preferably, a thermodynamic device utilizing vapor pressure to change states, as claimed in claim 1, wherein: the steam compression device 2 is one or a combination of a plurality of mechanical superchargers, steam self-superchargers or steam jet pumps, and the steam self-superchargers comprise compression parts, power-applying parts and transmission mechanisms 24; the compression part comprises a pressure cylinder 23, and one side of the pressure cylinder 23 is provided with a third inlet 221 and a third outlet 222; the acting part comprises a driving cylinder 22, and a fourth inlet 231 and a fourth outlet 232 are arranged on one side of the driving cylinder 22; the transmission mechanism 24 is used for transmitting the pressure generated by the work doing part to the compression part, and the pressure cylinder 23 and the driving cylinder 22 are connected through the transmission mechanism 24.

Preferably, there are a plurality of vapor compression devices 2, and the operation manner of the plurality of vapor compression devices 2 is one of a series cascade operation, a parallel operation, and a series-parallel switching operation in sequence.

Preferably, a flash evaporation device is arranged between the outlet of the liquefaction mechanism and the throttling device 111, and a steam outlet of the flash evaporation device is connected with the steam compression device 2 or connected with a steam outlet of the evaporation cavity 112 through the steam compression device 2 and used for driving the steam compression device 2 to do work; the working medium pipeline entering the first inlet 121 is arranged below the liquid level of the liquid working medium in the flash evaporation device.

Preferably, at least one evaporator 3 is provided, at least one condenser 4 is provided, the vapor outlet of at least one evaporator 3 is connected with the vapor compression device 2, and the vapor outlets of the other evaporators 3 are respectively connected with the suction end of the compressor 5 or the vapor compression device 2 at the outlet of the evaporator 3; the inlet of the at least one condenser 4 is connected to the vapour compression device 2; the plurality of condensers 4 are communicated with each other so that the working medium flows between the condensers 4.

Preferably, the energy storage device also comprises an energy storage device which is used for absorbing or providing heat energy and exchanging heat with the environment space, and the energy storage device comprises at least one of a high-temperature energy storage device or a low-temperature energy storage device; the high-temperature energy accumulator comprises a high-temperature energy storage working medium and a high-temperature heat exchanger, an inlet of the high-temperature heat exchanger is connected with a steam outlet of the steam compression device 2 at an outlet of the evaporator 3 or a liquid working medium outlet of the condenser 4, and an outlet of the high-temperature heat exchanger is connected with a steam inlet of the condenser 4 or a liquid working medium outlet of the condenser 4; the low temperature energy storage ware includes low temperature energy storage working medium and low temperature heat exchanger, and low temperature heat exchanger is connected with a certain evaporimeter 3, and the entry of a certain evaporimeter 3 links to each other with first export 122 and the fourth export 232 of the vapor compression device 2 that the export of evaporimeter 3 was equipped with, and the export of a certain evaporimeter 3 links to each other with the vapor compression device 2 that the export of evaporimeter 3 was equipped with.

Preferably, the accumulator can be removed and moved elsewhere for use as a heat source or heat sink.

a1, cooling the liquid working medium in the precooler 1 by the cooling part 11, and reducing the temperature of the liquid working medium to be lower than the required refrigeration temperature;

a2, feeding the cooled liquid working medium into an evaporator 3;

a3, in the evaporator 3, the low-temperature liquid working medium is heated and evaporated, so that the temperature of the working medium is close to the required temperature, and the evaporated working medium is condensed after being compressed by the compressor 5;

a4, when the precooler 1 is not cooled by an external cold source but is cooled by a system self-cooling component, an evaporation cavity 112 for evaporating the liquid working medium of the system is arranged in the precooler 1, the liquid working medium evaporates and absorbs heat in the evaporation cavity 112 and exchanges heat with the liquid working medium in the cooling cavity 12 at the same time, so as to reduce the temperature of the liquid working medium in the cooling cavity 12;

the vapor evaporated in the A5 and the evaporator 3 or the vapor mixed with the vapor in the evaporation cavity 112 of the precooler 1 enters the suction end of the compressor 5 or respectively enters the suction ends with corresponding pressures.

Preferably, the device also comprises a vapor compression device 2, wherein the vapor compression device 2 comprises a compression part, a work-doing part and a transmission mechanism 24; the compression part comprises a pressure cylinder 23, and one side of the pressure cylinder 23 is provided with a third inlet 221 and a third outlet 222; the acting part comprises a driving cylinder 22, and a fourth inlet 231 and a fourth outlet 232 are arranged on one side of the driving cylinder 22; the thermodynamic method of changing state by means of vapor pressure is implemented by means of a vapor compression device 2, which is implemented as follows:

b1, the vapor compression device 2 is a self-compression device, the vapor working medium in the evaporator 3 is compressed by utilizing the vapor pressure in the evaporator 3 and the pressure difference between the suction end of the compressor 5 or between other low-pressure areas such as the environment, the vapor in the evaporator 3 is compressed and then is led into a liquefaction mechanism for condensation;

b2, taking the steam working medium in the evaporator 3 as driving steam, and leading the steam pressure in the evaporation cavity 112 into the air suction end of the compressor 5 after the steam pressure is lifted by the steam compression device 2; after the driving steam does work, the driving steam is mixed with a steam working medium in the evaporation cavity 112 and then enters the air suction end of the compressor 5, or respectively enters the air suction ends of the compressors 5 corresponding to respective steam pressure;

b3, according to the pressure to be achieved by compression, on the premise of meeting the pressure after compression, a communication hole is further formed between the pressure cylinder 23 and the driving cylinder 22, the part of the working medium after the driving in the driving cylinder 22 enters a cavity generated by the pressure cylinder 23 through the communication hole to reduce the amount of the steam which is not used any more, and the rest working medium in the pressure cylinder 23 directly enters the compressor 5.

The components of the invention are connected by working medium pipelines, for example, a copper tube is used as a liquid working medium pipeline, and liquid working medium or working medium steam circulates in a thermodynamic device through the working medium pipeline.

Referring to fig. 1 to 6, a household air conditioner is taken as an example of the first embodiment of the present invention, and the required indoor temperature is generally about 20 degrees. The precooler 1 of the embodiment adopts a system self-cooling mode, and the working medium adopts R404/R410/R134 a.

The liquid working medium flowing out of the outlet of the condenser 4 enters the precooler 1 in two paths. One path of liquid working medium enters the cooling cavity 12, and the other path of liquid working medium enters the evaporation cavity 112 after passing through the throttling device 111. In the evaporation cavity 112, the liquid working medium evaporates, so that the temperature of the liquid working medium in the cooling cavity 12 is reduced to be lower than the required refrigeration temperature. The working medium steam enters the air suction end of the compressor 5, is compressed by the compressor 5 and then enters the condenser 4 to be condensed into liquid working medium. The liquid working medium with reduced temperature enters the evaporator 3 to evaporate and absorb heat.

The present embodiment is further provided with a vapor compression device 2, and the vapor compression device 2 of the present embodiment adopts a self-compression principle, and the outlet of the evaporator 3 is connected with the fourth inlet 231 of the pressure cylinder 23 and the third inlet 221 of the driving cylinder 22 of the vapor compression device 2, respectively. The steam working medium in the evaporator 3 enters the driving cylinder 22 and is compressed into the steam working medium in the pressure cylinder 23. The compressed steam working medium enters the condenser 4 or the inlet of the compressor 5; a part of steam working medium of the driving cylinder 22 enters the pressure cylinder 23 and then is compressed, and the rest of the steam working medium enters the air suction end of the compressor 5; a part of the steam working medium which does work in the driving cylinder 22 enters the air suction end of the compressor 5, and the rest of the steam working medium enters the pressure cylinder 23. The steam working medium flows into the air suction end of the compressor 5 from the driving cylinder 22 of the steam compression device 2, and the steam flowing out of the evaporation cavity 112 is compressed by the steam compression device 2.

The liquid working medium is evaporated in the evaporation cavity 112, so that the liquid working medium in the cooling cavity 12 reaches 0 ℃. The liquid working medium with the temperature of 0 ℃ enters the evaporator 3, exchanges heat with indoor air and evaporates. The compressor 5 firstly pumps away the working medium steam in the evaporator 3, so that the liquid working medium can enter conveniently, and the liquid working medium can form higher steam pressure again after being continuously evaporated in the evaporator 3. Taking R404a as an example, the saturated vapor pressure at 20 degrees is about 12 bar. According to the temperature of the outdoor unit, after the steam of which the pressure is close to 12bar is compressed by the steam compression device 2, the compressed steam is sent to the condenser 4 for condensation and heat release; and carrying out thermodynamic cycle again on the condensed liquid working medium.

Preferably, there are at least two vapor compression devices 2, and the vapor working medium compressed by one vapor compression device 2 enters another vapor compression device 2 for further compression, so that the vapor compression devices 2 operate in a cascade manner to form two-stage or even multi-stage series compression, thereby achieving higher pressure; it is also possible to connect two or more inlets of the vapor compression device 2 to the outlet of the evaporator 3, so that several vapor compression devices 2 are connected in parallel to form one stage. Thus, the compression ratio of the steam compression device 2 can be adjusted according to different working conditions, and the required working medium steam pressure can be obtained. The vapor compression device 2 can also adopt an isentropic expansion work-doing mode, namely, a turbocharging mode and the like to realize self-pressurization.

Preferably, the second inlet 113 of the evaporation cavity 112 is provided with a pressure booster, such as a steam jet pump or a turbocharger, and the working medium steam in the evaporation cavity 112 can be pumped out and pressurized by the pressure booster, and then enters the air suction end of the compressor 5 after being mixed with the steam working medium at the outlet of the evaporator 3, so that the evaporation pressure in the evaporation cavity 112 is further reduced, and the steam pressure entering the air suction end of the compressor 5 is not reduced. The lower the evaporation pressure is, the larger the latent heat is, the better the refrigeration effect is, and the purpose of energy conservation is achieved. When the compressor 5 has a multi-stage pressure suction end, the vapor working media at the outlet of the evaporator 3 and the second outlet 114 of the evaporation cavity 112 may not be mixed and respectively enter the suction ends of the compressor 5 with different pressures.

Preferably, a flash evaporation device is arranged between the throttling device 111 and the outlet of the condenser 4. The liquid working medium entering the cooling chamber 12 passes through the position below the liquid level of the liquid in the flash evaporation device, exchanges heat with the liquid, and then flows out of the flash evaporation device. The steam outlet of the flash evaporation device can be communicated with the steam in the evaporator 3, and a steam compression device 2 at the outlet of the evaporator 3 is utilized; or an independent steam compression device 2 is arranged between steam outlets of the evaporation cavity 112, steam of the flash evaporation device enters the working device to work, and the steam compression device 2 compresses working medium steam and enters the evaporation cavity 112 to enter the compressor 5 together.

Preferably, the vapor compression device 2 is one of a mechanical supercharger and a vapor jet pump for supercharging. By compressing the vapor in the evaporation cavity 112, a lower evaporation pressure can be obtained, and further a lower temperature liquid working medium can be obtained.

Preferably, in order to reduce the hardware quantity for realizing the above scheme, the flash evaporation pressure of the flash evaporation device is selected to be the same as the steam pressure in the evaporator 3, and the steam working medium discharged by the flash evaporation device is mixed with the steam working medium in the evaporator 3 and then flows into the driving cylinder 22 to compress the steam working medium flowing out of the evaporation cavity 112.

The steam working medium evaporated in the evaporator 3 is not compressed by the compressor 5, and part of the steam is compressed by the steam compression device 2, so that the energy can be saved.

When the heat pump is used as a heat pump, the condenser 4 and the evaporator 3 are exchanged by using a valve, and the heat pump belongs to the conventional application of the prior art.

The working principle of the embodiment is as follows:

first, the evaporation pressure in the evaporation chamber 112 is reduced. For example, when the saturated vapor pressure of R404a is 1bar (absolute pressure), the corresponding temperature is about-45 ℃; the temperature corresponding to 4bar is-12 ℃.

When the outdoor temperature is about 0 ℃ in winter, the evaporation pressure in the evaporation cavity 112 is 1-2 bar, and the temperature of the liquid working medium in the cooling cavity 12 is as low as possible. Then the low-temperature liquid working medium enters an evaporator 3 of the outdoor unit and exchanges heat with outdoor air at 0 ℃. The saturated vapor pressure at 0 ℃ is 6bar, and the connection sequence of the vapor compression device 2 can be adjusted, so that the vapor compression device 2 can be operated in a cascade mode of multi-stage series compression. The compressed steam enters a condenser 4 of the indoor unit for condensation; or the compressor 5 intermittently switches the vapor in the evaporation chamber 112 and the vapor in the evaporator 3. When the steam in the evaporation cavity 112 is pumped, the liquid working medium is evaporated in the evaporator 3 of the outdoor unit; when the liquid working medium in the evaporator 3 reaches a certain amount, the steam in the evaporation cavity 112 is stopped being pumped, and the steam in the outdoor unit is pumped. Compared with refrigeration in summer, the heat pump in winter is influenced by physical properties of the working medium due to low temperature, the evaporation pressure is low, and especially when the pressure of the air suction end of the compressor 5 is 1-2 bar, the efficiency of the compressor 5 is low. However, since part of the vapor is not compressed by the compressor 5 by the vapor compression device 2, the overall efficiency is still higher than that of the conventional heat pump. Compared with the existing refrigeration method, the low-temperature liquid working medium can be evaporated by using the steam with the same pressure and unit mass, and more working medium steam can be generated.

Even in extreme weather of-20 ℃, the pressure of the R404a working medium in the evaporation cavity 112 is 1-2 bar, so that the temperature of the liquid working medium can be reduced to-30 ℃ to-40 ℃. The liquid working medium is evaporated after entering the evaporator 3, and the saturated vapor pressure at-20 ℃ is 3bar (absolute pressure). At the moment, the steam compression device 2 cannot play an obvious role in compressing steam, at the moment, the air suction end of the compressor 5 is directly connected with the outlet of the evaporator 3, working medium steam in the evaporator 3 is directly pumped for compression, or partial steam enters the indoor condenser 4 for condensation after being compressed by the multi-stage overlapped steam compression device 2; meanwhile, the steam in the flash evaporation device can not compress the steam in the evaporator 3, and directly enters the other air suction end of the compressor 5 to play a role in enhanced vapor injection compression.

The basic principle of the embodiment for realizing the beneficial effects is as follows:

the device can work by isentropic expansion and can work continuously at a certain pressure by the expansion energy generated by the evaporation of the working medium.

High pressure steam enters the driving cylinder 22 through the third inlet 221, and pushes the piston 241 to move, so that the working medium in the pressure cylinder 23 is compressed. The compressed working fluid is discharged from the fourth outlet 232 at a set pressure. After the piston 241 has moved to the leftmost dead center, the functions of the drive cylinder 22 and the pressure cylinder 23 are reversed. That is, the original cylinder 23 becomes the drive cylinder 22, and the original drive cylinder 22 becomes the cylinder 23. The high-pressure working medium pushes the piston 241 to move rightwards; working fluid in the cylinder is discharged from the third outlet 222 at a predetermined pressure. The discharged working fluid is used to drive other compression systems, such as compressing vapor in a vapor chamber. After the discharged working medium completes compression and work, the working medium is condensed in the system, then next circulation is carried out, the working medium discharged from the fourth outlet 232 or the third outlet 222 can be directly condensed, and the transmission mechanism 24 directly drives other compression devices.

Further, the vapor compression device 2 which does work by non-isentropic expansion is operated in a cascade manner.

Referring to fig. 5, taking the example that two vapor compression devices 2 are overlapped in series, the working medium discharged from the third outlet 222 of the vapor compression device 2 of the previous stage is used as the driving working medium to enter the vapor compression device 2 of the next stage which expands in non-isentropic manner, or enter a region with lower pressure, such as the suction end of the compressor 5; the working fluid discharged from the fourth outlet 232 of the previous stage vapor compression device 2 enters the pressure cylinder 23 of the previous stage vapor compression device 2 either as a driving working fluid or a working fluid to be compressed into the condenser 4. The pressure after the pressurization of the vapor compression device 2 of the next stage is lower than the pressure after the pressurization of the previous stage.

Further, the transmission mechanisms 24 of the plurality of vapor compression devices 2 are connected by a crankshaft 243.

Referring to fig. 4, the vapor compression device 2 may employ not only a linear reciprocating motion but also a circular motion, a circular motion to linear reciprocating motion, and the like. If a vane 244 pump is used, the pressure of the inlet working fluid is higher than the pressure of the outlet working fluid, and the working fluid pushes the vanes 244 and the crankshaft 243 to rotate and then flows out at the outlet. In the rotating process, along with the change of the length of the blades 244, the volume enclosed by the blades 244 is changed, so that the volume is gradually reduced, and the purpose of compressing the working medium is achieved.

The compression may be achieved by using only the rotation of the shaft as power without changing the length of the blades 244.

Furthermore, the discharged working medium can be discharged to an inlet of the compression system, so that self-pressurization is realized. Or to a region of lower pressure. If no area with lower pressure exists, the discharged working medium can be directly pressurized by a compression method such as mechanical compression, jet compression and the like and stored in a high-pressure area.

The compression may be powered by the vapor compression device 2, or the following compression method may be employed.

Referring to fig. 5, symmetrical pressure cylinders 23 are respectively arranged on the left side and the right side of a driving cylinder 22, a third inlet 221 and a third outlet 222 are respectively arranged on the left side and the right side of the driving cylinder 22, the sectional area of the pressure cylinder 23 is smaller than that of the driving cylinder 22, when a high-pressure working medium enters from the third inlet 221 on the left side of the driving cylinder 22, the third outlet 222 on the left side is closed, the third outlet 222 on the right side is opened, and the working medium on the right side of a piston 241 of the driving cylinder 22 is discharged from the third outlet 222 on the right side and cooled in the system. The piston 241 is pushed by the high-pressure working medium to move from left to right, and the piston 241 of the pressure cylinder 23 is driven by the connecting rod 242 to move from left to right. At this time, the fourth inlet 231 of the left pressure cylinder 23 is opened, the fourth outlet 232 of the left pressure cylinder 23 is closed, the working medium to be compressed is sucked from the fourth inlet 231 of the left pressure cylinder 23, the working medium can be from the evaporator 3, or from the steam which is exhausted by the acting part and used for doing work, and the ratio of the pressure after compression to the self-compression steam is comprehensively considered; the fourth inlet 231 of the right pressure cylinder 23 is closed and the fourth outlet 232 of the right pressure cylinder 23 is open, and the compressed working medium flows out of the fourth outlet 232 of the right pressure cylinder 23.

When the piston 241 of the driving cylinder 22 moves to the right dead point, the right third outlet 222 is closed and the left third outlet 222 is opened. High pressure working fluid enters from third inlet 221 on the right, pushing piston 241 to move to the left. At the same time, the fourth inlet 231 of the left pressure cylinder 23 is closed, and the fourth outlet 232 of the left pressure cylinder 23 is opened; the fourth inlet 231 of the right side cylinder 23 is open and the fourth outlet 232 of the right side cylinder 23 is closed. So that the piston 241 of the driving cylinder 22 reciprocates under the push of the high-pressure working medium.

Assuming that the sectional area of the drive cylinder 22 is 2 times the sectional area of the pressure cylinder 23 and the strokes are the same, the volume of one drive cylinder 22 can be roughly considered to be the volume of 2 pressure cylinders 23.

Further, the discharged working fluid can be discharged to a region of lower pressure. If no area with lower pressure exists, the discharged working medium can be directly pressurized by a compression method such as mechanical compression, jet compression and the like and stored in a high-pressure area.

Further, a combination of a plurality of vapor compression devices 2 may be utilized to achieve a higher compression ratio.

In the refrigeration and heat pump system, the working mode of heating, evaporating and expanding is utilized for compression, and the steam working medium can be compressed without a compressor 5 or other energy-consuming modes. By heating the liquid working medium, the working medium is compressed by utilizing the expansion work of the liquid working medium which is heated, evaporated and expanded.

In other systems requiring working medium pressurization, the vapor compression device can be used, and work is done by expansion energy to realize the pressurization effect.

Referring to fig. 1 to 6, as a second embodiment of the present invention, the refrigerant water system is used, the refrigerant water generally requires a temperature of 5 degrees, and R404a is used as the working medium.

In the first embodiment, the evaporation pressure of the evaporation cavity 112 is maintained at 1-2 bar, the vapor pressure in the evaporator 3 is maintained at about 6bar, and the evaporation temperature is maintained at about 0 ℃. The flash pressure is maintained at 6bar and enters the vapor compression device 2 together with the vapor in the evaporator 3.

The steam passes through the cascade type steam compression device 2, one part of the steam directly enters the condenser 4 for condensation, the rest steam passes through the steam compression device 2, the steam pressure in the evaporation cavity 112 is improved, and the steam are mixed and then enter the air suction end of the compressor 5; or not mixed, into the suction side of the compressor 5 for which the respective vapor pressures correspond. The evaporator 3 absorbs the heat in the water to obtain the required chilled water.

As a third embodiment of the invention, working media such as CO2/R23 are adopted for preparing cooling water of 5 degrees.

The compressor 5 is a compressor 5 capable of transcritical/supercritical cycle, and takes CO2 working medium as an example.

First, the compressor 5 is operated to obtain high-temperature and high-pressure gas. Condensation takes place in the condenser 4, depending on the ambient temperature; or cooled in a cooler (all conventional devices of a refrigeration system using a working fluid such as CO 2) and then throttled by a throttle valve, or a liquid working fluid is obtained by an expansion machine. The existing CO2 refrigeration has a supercritical refrigeration cycle, and because the technical characteristics of the invention utilize liquid working medium for refrigeration, most of CO2 is condensed and liquefied through the supercritical refrigeration cycle even if the supercritical refrigeration is adopted.

Therefore, the embodiment only aims at the cooling water system, and can completely liquefy the CO2 working medium; or the supercritical refrigeration cycle does not adopt a complete steam circulation mode, but the refrigerating capacity generated by the supercritical refrigeration cycle is used for condensing and liquefying the CO2 working medium per se, and the liquefied CO2 working medium circulates according to the following process. That is, the supercritical refrigeration cycle is not included in the technical description of the present invention, and even if this method is adopted, it is only used as a working fluid in the present invention to provide the condensation liquefaction function.

The liquid working medium enters the evaporation cavity 112 through the throttling device 111, and the evaporation cavity 112 is connected with the inlet of the compressor 5. And selecting proper evaporation pressure to reduce the temperature of the liquid working medium to be below 0 ℃.

The cooled liquid working medium enters an evaporator 3 to be evaporated, the evaporated steam enters a steam compression device 2, a part of steam enters a condenser 4 to be condensed after being compressed, and the rest steam enters the air suction end of a compressor 5 to be compressed by the compressor 5 and then enters the condenser 4 to be condensed.

Further, a flash evaporation device is arranged in front of the throttling device 111 at the front end of the evaporation cavity 112. The liquid working medium entering the cooling chamber 12 passes below the liquid level of the liquid in the flash evaporation device, exchanges heat with the liquid and then flows out of the flash evaporation device. The steam outlet of the flash evaporation device and the steam outlet of the evaporation cavity 112 are connected with the steam compression device 2, the steam compression device 2 compresses the steam in the evaporation cavity 112, and the compressed steam and the steam from the flash evaporation device for driving the steam compression device 2 enter the compressor 5 together. The pressure-increasing vapor compression device 2 may be a mechanical type or a vapor jet pump. The steam in the evaporation cavity 112 is injected by the flash steam, so that lower evaporation pressure can be obtained, and further the liquid working medium with lower temperature can be obtained.

Further, for winter heat pumps, the vapor in the evaporation chamber 112 is first pumped by the compressor 5, for example CO2, at 10bar for-40 degrees. Assuming that the outdoor temperature is-20 degrees,

the liquid is cooled to approximately-40 degrees and then introduced into the outdoor evaporator 3. The saturated vapour pressure at-20 degrees is 20bar at which the liquid CO2 evaporates in the evaporator 3. The vapor in the evaporator 3 drives the vapor compression device 2 to compress the vapor in the evaporation cavity 112, and the compressed vapor enters the compressor 5 together with the vapor driving the vapor compression device 2. The steam in the evaporator 3 can also be self-compressed by the steam compression device 2, and the compressed steam directly enters the indoor condenser 4 for condensation without passing through the compressor 5.

Further, the compressor 5 may be a two-stage compressor cascade, which may lower the temperature of the liquid working medium.

The principle and method are basically the same as the first and second embodiments, except that the working medium is changed, so that even if the low temperature below-20 is met, the vapor pressure of the CO2/R23 working medium is still high enough, enough heat can be generated when the chilled water generating low temperature in summer and the working medium serving as a heat pump in winter are used.

Because the critical temperature of the working medium is only about 30 ℃, the critical pressure is also higher. At least one high-pressure compressor 5 is therefore necessary to enable subcritical/transcritical and even supercritical circulation of such a working fluid.

If the temperature in summer is particularly high, the critical temperature is exceeded. Firstly, compressing steam by a compressor 5, then pumping the compressed steam into a cooler for cooling, and obtaining part of liquid working medium by a throttle valve or an expander; after enough liquid working media are obtained, the refrigeration cycle is started.

The suction pressure of the compressor 5, which is a high pressure of the transcritical compressor, cannot be too low, or the evaporation pressure of the evaporation chamber 112 may be affected. However, only the high-pressure compressor 5 is adopted, the temperature cannot be reduced to a lower temperature, and in order to obtain the lower temperature, a second compressor is required to be introduced, the second compressor belongs to a low-pressure compressor, the suction pressure and the discharge pressure are lower than those of the high-pressure compressor 5, and the compressor overlapping effect is achieved.

Referring to fig. 7, as a fourth embodiment of the present invention, the present invention can be applied to a self-cascade multi-stage system, and the present embodiment is described only in terms of two-stage cascade.

The working medium is divided into a high-temperature working medium and a low-temperature working medium, the high-temperature working medium adopts a high-temperature refrigerant R134a/R404a/R410, and the low-temperature working medium adopts a low-temperature refrigerant R23/R508/CO 2.

The present embodiment includes a compressor 5, a condenser 4, a gas-liquid separator 8, an evaporative condenser 7, and an evaporator 3. The compressor 5 compresses the mixed steam working medium, most of the high-temperature working medium is condensed in the condenser 4, and most of the liquid of the high-temperature working medium and the gas of the low-temperature working medium are separated by the gas-liquid separator 8. The liquid high-temperature working medium enters the evaporative condenser 7 to be evaporated, the low-temperature gas working medium enters the evaporative condenser 7 to be condensed into liquid, the liquid low-temperature working medium enters the evaporator 3 to be evaporated after throttling, and then the low-temperature working medium steam and the high-temperature working medium steam enter the compressor 5 together.

After being compressed by the compressor 5, the high-temperature and high-pressure steam enters the condenser 4. The high temperature stage working fluid is condensed in the condenser 4, while the low temperature stage working fluid is still in a steam state. After vapor-liquid separation, the low-temperature-level working medium flows to the condensation end of the evaporative condenser 7, and the liquid-state high-temperature-level working medium flows to the evaporation end of the evaporative condenser 7. In the evaporative condenser 7, the liquid high-temperature-level working medium is vaporized, and the low-temperature-level working medium gas is condensed into liquid. The liquid low-temperature working medium flows to the low-temperature evaporator 3, the low-temperature working medium is vaporized in the low-temperature evaporator 3, the vaporized low-temperature working medium and the high-temperature working medium steam flowing out of the evaporative condenser 7 flow to the compressor 5 together, and the low-temperature working medium and the high-temperature working medium steam are compressed by the compressor 5 and then circulate again.

The invention adopts the mode of reducing the temperature of the liquid working medium, then entering the evaporator 3 for evaporation, and the evaporated steam is self-compressed by the steam compression device 2, so that part of the steam directly enters the condenser 4 without passing through the compressor 5.

Referring to fig. 8, the low-temperature working medium is divided into two paths after flowing out from the evaporative condenser 7. One path enters an evaporation cavity 112 of the precooler 1 after passing through a throttling device 111; the other enters the cooling chamber 12 of the precooler 1. The vapor in the evaporation cavity 112 is pumped away by the compressor 5, so that the temperature of the liquid working medium in the cooling cavity 12 is reduced. The liquid with reduced temperature enters the evaporator 3 and is heated and evaporated in the evaporator 3. Taking R23 as an example, the saturated vapor pressure at 5 degrees is 30bar, and the vapor pressure in the evaporator 3 is kept at 25bar corresponding to 0 degrees.

At this time, the vapor in the evaporator 3 of the low temperature stage does not need to be compressed by the compressor 5. The pipeline from the evaporator 3 to the compressor 5 is closed, and the refrigerant can directly enter the evaporative condenser 7 and be condensed by high-temperature working medium.

In order to further save energy, a low-temperature-stage condenser 41 can be added, steam in the evaporator 3 enters the steam compression device 2, part of the steam entering the driving cylinder 22 enters the evaporative condenser 7 after work is done, and the rest of the steam enters the pressure cylinder 23 to be compressed; the steam directly entering the pressure cylinder 23 and the steam entering the pressure cylinder 23 from the driving cylinder 22 are compressed and then enter the low-temperature-stage condenser 41 to be condensed. At the moment, the compressed low-temperature working medium can be directly cooled by external cooling water to be condensed according to the pressure of the compressed low-temperature working medium and the condition of the external cooling water, and can also be condensed by a high-temperature refrigeration system. The refrigeration load of the high-temperature stage refrigeration system can also be reduced if the condensation is carried out by outside cooling water.

Depending on the ambient temperature, the condensation may be subcritical or transcritical.

Furthermore, before entering the throttling device 111 of the evaporation cavity 112, a flash evaporation device is arranged, so that the temperature of the liquid working medium entering the precooler 1 is reduced.

Further, the vapor pressure of the flash evaporation or throttling raises the vapor pressure in the evaporation cavity 112; the vapor flowing out of the driving cylinder 22 of the vapor compression device 2 raises the vapor pressure in the evaporation cavity 112 and then enters the suction end of the compressor 5.

Further, if the required refrigeration temperature is higher than the condensation temperature of the low-temperature-level refrigerant, the evaporative condenser 7 is used as a working medium cooling mode and integrates the condenser 4 and the precooler 1 into a whole. The low-temperature refrigerant liquid working medium flowing out of the evaporative condenser 7 enters the evaporator 3 for evaporation. The subsequent steps of evaporation are the same as the previous steps.

The technical scheme of the invention can also be adopted by a high-temperature-level refrigeration system.

The above is the case when the refrigeration temperature is relatively high and then the required temperature is relatively low, for example-50 c, when the saturated vapour pressure of R23 is 5 bar. At the moment, the evaporation pressure of the evaporation cavity 112 is kept at 1-2 bar, and liquid working medium at about-60 ℃ is obtained. The liquid working medium enters an evaporator 3 to be evaporated, then a part of steam is compressed to about 15bar by a steam compression device 2, then the compressed steam is sent to a precooler 1 to be condensed, and the rest R23 steam enters a compressor 5.

If a lower temperature is desired, the vapor pressure in the vaporization chamber 112 can no longer be reduced. If the temperature is reduced to-70 ℃, the pressure of R23 in the evaporator 3 is only 2bar, and the pressure difference between the evaporator 3 and the evaporation cavity 112 by R23 cannot play a role of compression. At this time, the vapor of the high-temperature-level working medium flowing out of the precooler 1 drives the vapor compression device 2 to compress the vapor of R23, and the efficiency of the compressor 5 is improved by increasing the pressure of R23.

Referring to fig. 9 to 11, as a fifth embodiment of the present invention, a cascade refrigeration method is adopted in the present embodiment, and a multi-stage system may be cascaded, which is only described in two stages.

Referring to fig. 9, the high-temperature stage includes a high-temperature stage compressor 51, a condenser 4, and an evaporative condenser 7. The low-temperature stage refrigeration system comprises a low-temperature stage compressor 52, an evaporative condenser 7, a precooler 1, an evaporator 3 and a vapor compression unit 2.

Similarly to the fourth embodiment, the vapor pressure of the low-temperature stage working fluid in the evaporator 3 is determined according to the desired temperature. According to the pressure after the compression of the vapor compression system, if the temperature of the high-temperature stage refrigeration system can be used for condensation, the vapor compressed by the vapor compression device 2 is selected and sent to the evaporative condenser 7 for condensation, then the pressure in the evaporator 3 is too low, such as 2-3 bar in the above example, at this time, the high-temperature stage and the low-temperature stage are independent from each other, and the high-temperature stage vapor cannot be used for compression, so the high-temperature stage vapor can only be compressed by the low-temperature stage compressor 52.

The high-temperature-level refrigeration system and the low-temperature-level refrigeration system adopt a method that low-temperature liquid working medium is heated and evaporated in an evaporator 3, and the evaporated steam is compressed by a steam compression device 2.

If the pressure of the low-temperature stage refrigeration system after vapor compression is high enough, a second evaporative condenser 71 can be additionally arranged, and condensation can be carried out by depending on the high-temperature stage refrigeration system or by utilizing external cooling water.

For example, various thermodynamic cycles of refrigeration or heat pump can be designed.

Referring to fig. 10, as a particular example, even the low temperature stage compressor 52 may be eliminated if only a higher temperature is required, such as 5 degrees of chilled water.

First, the equilibrium pressure of the entire system is as high as possible. The R23 working medium steam is condensed by the high-temperature stage refrigeration system, and is firstly condensed in the second evaporative condenser 71 to the saturated pressure of 25bar or below, and at the moment, the pressure of the whole system is the same because the pipelines of the whole system are communicated. The second evaporative condenser 71 is shut off from the entire system and this temperature and pressure are maintained. Then the pressure of the R23 working medium in the condenser 4 is reduced as much as possible to 7-15 bar corresponding to-20 to-40 degrees, and the pressure of the whole system is reduced at the moment. This pressure is the same except for the second evaporative condenser 71, and the condensed liquid working medium is present only in the evaporative condenser 7 and the second evaporative condenser 71. Then, a pipeline from the evaporator 3 to the evaporative condenser 7 is closed, a pipeline from the second evaporative condenser 71 to the evaporator 3 is opened, as the vapor pressure in the second evaporative condenser 71 is 25bar and is larger than 7-15 bar in the evaporator 3, the liquid working medium in the second evaporative condenser 71 enters the evaporator 3 through the precooler 1, and then the pipeline between the evaporator 3 and the two condensers 4 is closed, so that the vapor generated by evaporation in the evaporator 3 does not flow back to the condensers 4 any more. If 5 degrees of chilled water is to be obtained, the vapor pressure of the low-temperature refrigerant in the evaporator 3 needs to be 25bar, about 0 degrees. This is the case when condenser 4 is integrated with precooler 1, and it is also possible to add an evaporation chamber 112 in precooler 1 to further lower the temperature of the liquid working medium before entering evaporator 3.

The temperature of the evaporative condenser 7 is kept at about-20 ℃, so that the steam pressure of the low-temperature working medium reaches 15bar, the low-temperature working medium steam in the evaporator 3 is sent into the second evaporative condenser 71 through the steam compression device 2, and the part of steam is condensed at about 35-40 bar corresponding to 15-20 ℃. The working vapor flows out of the drive cylinder 22 of the vapor compression device 2 and enters the evaporative condenser 7 to be condensed. The liquid working medium in the second evaporative condenser 71 flows into the evaporative condenser 7 under the drive of the vapor pressure of 20bar, and then enters the evaporator 3 for evaporation through the precooler 1. The outlet of the second evaporative condenser 71 is provided with a high-temperature stage vapor compression device 21, and the outlet of the high-temperature stage vapor compression device 21 is connected with the condenser 4.

When the liquid working medium in the second evaporative condenser 71 is reduced to a certain degree, or the condensing temperature of the whole second evaporative condenser 71 is reduced to be lower than the temperature of the evaporative condenser 7, such as-40 ℃; alternatively, the second evaporative condenser 71 may be controlled to provide a temperature control in zones, with the two zones being separated, one zone being controlled as before and the other zone being controlled to reduce the condensing temperature, for example to-40 degrees. And then, the saturated vapor pressure corresponding to-40 ℃ is 7bar, a passage between the evaporative condenser 7 and the second evaporative condenser 71 is opened, the liquid working medium is pressed into the second evaporative condenser 71 from the evaporative condenser 7 to reach a certain liquid level, then the channels of the evaporative condenser 7 and the second evaporative condenser 71 are closed, and the subareas of the second evaporative condenser 71 are opened to synthesize a subarea. And introducing the steam compressed by the steam compression device 2 again, and condensing the steam according to about 35-40 bar corresponding to 15-20 ℃.

In this way, the low-temperature stage compressor 52 can be driven without using electricity, and the energy-saving effect is achieved.

The invention can also be added with a liquid working medium pump 6 or a low-power compressor for emptying the steam in the evaporator 3 when the compressor starts to operate, thereby reducing the steam pressure in the evaporator 3 and leading the liquid working medium to enter.

Further, a high-temperature stage pre-cooler 13 is added to the pipeline from the evaporative condenser 7 to the evaporator 3. The vapor in the evaporator 3 drives the vapor compression device 2, compresses the vapor in the evaporation cavity 112 of the high-temperature-stage precooler 13, and sends the compressed vapor to the evaporative condenser 7 for condensation.

The unpowered compressor system is suitable for refrigerating in summer, and the efficiency of the unpowered compressor system as a heat pump in winter is not as high as that of refrigerating.

As a sixth embodiment of the present invention, the present embodiment adopts a cascade of a refrigeration system and a work system.

At present, electric vehicles are more and more popular, but at present, batteries are afraid of low temperature, particularly one to-20 ℃, cannot be used normally basically, and do not talk about heat preservation in the vehicle. In summer, not only the air conditioner is needed in the vehicle, but also the battery is cooled. Temperature management of the electric vehicle is particularly important.

The working system is divided into a high-temperature-level system and a low-temperature-level system, and the working system is the same as the low-temperature-level refrigerating system in working medium. Taking CO2/R23 as the high-temperature working medium and R14 as the low-temperature working medium as an example.

The critical temperature of R14 was-46 degrees and the high temperature stage was started first, in the same way as in the third embodiment. In summer, the cooling is carried out firstly and then throttling condensation is carried out, wherein the cooling is carried out directly or firstly and then throttling condensation is carried out according to the temperature. The refrigeration method of the R14 refrigeration system is also the same as that of the cascade refrigeration system of the fifth embodiment.

Referring to fig. 11, after the system is operating normally, the liquid working medium pump 6 pumps part of the liquid R14 into the steam generator 9. The steam generator 9 is connected with the evaporative condenser 7, the environment and the condenser 4 of the high-temperature-level system in sequence according to the temperature. The generated steam enters the working device 10, and the working device 10 exchanges heat with the evaporator 3 of the low-temperature system. The steam working medium after the acting system acts is condensed and then returns to the liquid working medium pump 6 to do work again for circulation. The liquid working medium in the evaporator 3 is heated and evaporated, then flows to the evaporative condenser 7 through the vapor compression device 2 to be condensed, and then is subjected to refrigeration cycle again.

As a seventh embodiment of the present invention, this embodiment discloses a home centralized temperature control center. The temperature of the liquid working medium is reduced by a conventional refrigeration method, and then the low-temperature liquid working medium is evaporated in different evaporators 3 according to different evaporation pressures, so that different temperature control is realized. The temperature control includes not only indoor air temperature control but also control of freezing and various cold storage in a refrigerator, and even generation of hot water and steam. The refrigerator or the air conditioner is taken as a temperature control center, and if the refrigerator is taken as the center, an outdoor unit and an outdoor compressor are required to be added to provide enough power. With a home temperature control center, the whole home needs an outdoor unit, and each room is connected by a pipeline and used for each indoor air conditioner. The household temperature control center not only is a central air conditioner, but also can store heat and cold. The evaporator 3 is reserved to generate cold energy with required temperature, and the cold energy is used for providing cold energy for the movable air conditioning fan. By means of steam compression, a demand for hot water for dishwashers and the like is generated. Further, by overlapping the R245fa system, water vapor above 100 degrees can be generated.

As an eighth embodiment of the present invention, the present embodiment is applied to central heating using industrial waste heat. At present, the country is developing towards heating with 120/20 degrees, 120 degrees of hot water supply, 20 degrees of backwater and high temperature difference.

The current advanced technology is that an absorption heat pump is arranged in a power plant, and the steam of the power plant is utilized to transfer the low-temperature heat of cooling water to a heating primary pipe network, so that the temperature of the return water of the primary pipe network is raised to 80-90 ℃. And then, the return water of the primary net is heated to 120 ℃ from 80-90 ℃ by using the extracted steam of the steam turbine. In this process, two steam heats are required.

The invention provides a technical scheme for heating hot water only by cooling water without additional steam. By the scheme, 120/20 degrees can be achieved, and even 150 degrees and 180 degrees can be achieved; the return water temperature is reduced to 5-10 ℃.

Referring to fig. 12, the present embodiment includes a compressor 5, an evaporator 3 and a condenser 4, and the working medium is R134 a. The evaporator 3 exchanges heat in cooling water of a power plant, and the condenser 4 exchanges heat with a heating primary network.

Firstly, liquid R134a flows into the condenser 4 to exchange heat with heating return water, and the temperature of the return water is assumed to be 5-10 ℃. Then the low-temperature liquid working medium enters the evaporator 3 to exchange heat with the cooling water of the power plant. Assuming a plant cooling water temperature of 25 degrees, the liquid R134a is thermally evaporated in the evaporator 3, producing about 7bar of steam. The compressor 5 is a steam self-compression system, and a steam working medium in the evaporator 3 is subjected to pressure increase through the steam compression device 2, and then finally compressed steam is condensed in the condenser 4.

Referring to fig. 5, the vapor compression apparatus 2 shown in the figure is taken as an example, and the vapor in the evaporator 3 performs work to enter the left side pressure cylinder 23 and the left side driving cylinder 22, and pushes the piston 241 to move to the right side. The steam on the right side of the piston 241 of the driving cylinder 22 is discharged from the discharge port, flows to the condenser 4, exchanges heat with the heating return water and is condensed. The steam in the right side cylinder 23 is exhausted from the exhaust port of the cylinder 23. When the heating backwater is 5-10 ℃, the steam pressure is about 3.5-4 bar.

Further, the vapor compression device 2 is multi-stage stacked. The compressed vapor discharged from the right pressure cylinder 23 enters the drive cylinder 22 and the pressure cylinder 23 of the upper stage vapor compression device 2. When the piston 241 of the upper stage vapor compression device 2 moves, the vapor discharged from the driving cylinder 22 can be selectively discharged to the condenser 4 to increase the compression ratio; alternatively, the vapor flowing into the cylinder 23 of the next-stage vapor compression device 2 may flow into the left-side cylinder 23 and the vapor flowing into the evaporator 3 flows into the drive cylinder 22 when the piston 241 of the next-stage vapor compression device 2 moves rightward. This allows more compressed vapor to be obtained, increasing the heating capacity.

By adopting a multi-stage compression mode, the heating water can be heated to more than 80-90 degrees.

The condenser 4 adopts a multi-stage condensation mode, directly exchanges heat with a liquid R134a working medium during initial operation, then exchanges heat with a steam working medium discharged by a driving cylinder 22 of the steam compression device 2 in the steam compression process in sequence, and exchanges heat with a compressed R134a steam working medium discharged by the steam compression device 2.

Further, if the ambient temperature is lower than the heating return water temperature, the liquid working medium can exchange heat with the environment again. Namely, the finally compressed steam and the heating return water exchange heat and condense. The condensed high-temperature liquid R134a continues to exchange heat with return water, and then joins with the liquid working medium condensed by the heat exchange of the heating return water and the steam discharged from the driving cylinder 22 in the previous steam compression process. And then after heat exchange with return water is finished, heat exchange with the environment is carried out. And assuming that the ambient temperature is-10 ℃, the temperature of the liquid R134a after heat exchange with heating return water is 10 ℃, and then the temperature of the liquid working medium is reduced to-5 ℃ after heat exchange with the environment. Meanwhile, in the compression process of the driving cylinder 22, the discharged steam does not exchange heat with heating return water and exchanges heat with the environment for condensation, and the condensed steam pressure is lower.

This further reduces the temperature of the plant cooling water and also allows the steam exiting the drive cylinder 22 to condense at a lower temperature, which results in a lower steam pressure and a better compression effect.

If a liquid working medium pump 6 is needed, the liquid working medium pump is used for conveying liquid working medium.

Further, a water vapor heat pump system, or R245fa heat pump system, is stacked. The R245fa working medium can heat the water for heating the primary net to nearly 150 ℃, and the water vapor can heat the water to 180 ℃ or even higher.

Further, the water vapor heat pump system may employ the above multistage self-compression system, or may employ a compression system having a power input.

The power can be transmitted by adopting an electric transmission mode or provided by depending on a work doing system.

Further, the exhaust end of the compressor 5 is not only connected with the condenser 4, but also connected with the acting device 10 in parallel, the acting device 10 drives the steam compressor to compress secondary steam generated after water is heated to higher pressure, and then the secondary steam exchanges heat with return water of heating to heat the return water of heating to required temperature. The steam after acting is connected with the condenser 4 for heat exchange and condensation. The water vapor compressor can also be driven by the pressure difference between the vapor pressure of the R134a working medium in the evaporator 3 and the return water temperature of the primary network and the ambient temperature.

By adopting the method, the steam extraction of the steam turbine is not needed, and the normal power generation is not influenced. The 25 degrees of cooling water in the power plant is only an example temperature and is adjusted according to the ambient temperature and the amount of steam discharged in the compression process.

So that the thermal power plant can also function as a thermal power plant.

The prior art has no good method for heating water at about 60 ℃, the temperature is not suitable for heating a secondary network, the heating temperature of the electric steam compression type heat pump is not high enough, and the energy consumption is high; with absorption heat pumps, additional steam is required.

By adopting the technical scheme of the invention, the problem can be solved relatively simply.

In this embodiment a liquid working medium pump 6 is added. The liquid working medium pump 6 sends the liquid R134a to the evaporator 3, the evaporator 3 exchanges heat with the heating water with the temperature of 60 ℃, and the liquid R134a is heated and evaporated in the evaporator 3. The outlet of the evaporator 3 is connected with a vapor compression device 2, and the vapor in the evaporator 3 enters the pressure cylinder 23 on the left side, drives the left inlet of the piston 241 of the cylinder 22 and pushes the piston 241 to move rightwards. The steam on the right side of the piston 241 flows into the condenser 4 through a steam outlet to exchange heat with the return water of the secondary pipe network for condensation, and the steam of the right pressure cylinder 23 enters the condenser 4 after being compressed to exchange heat with the return water of the secondary pipe network which is heated by the steam exhausted by the driving cylinder 22 for condensation. Then the condensed liquid working medium is pumped into the evaporator 3 by a liquid working medium pump 6 together with the previous condensed liquid working medium.

The compression stage number can be single stage or multi-stage compression according to the heating requirement.

The backwater of the secondary network is sequentially heated by the steam of R134a, and then enters the secondary network for recycling.

Along with the continuous reduction of the heating water of the primary net, an electric vapor compression heat pump is needed, the water of the primary net is cooled to 5-10 degrees, the water of the secondary net is heated to more than 60 degrees, and the current technology can achieve the purpose.

And then the heating water of the primary network is returned to the power plant as return water to be heated again.

In the non-heating season, the compressor 5 can generate low-temperature liquid R134a, and then the low-temperature liquid working medium is introduced into the evaporator 3. The evaporator 3 is connected with cooling water of a power plant for heat exchange, the generated steam is gradually pressurized by the steam compression device 2, and high-temperature and high-pressure steam is generated according to the process. Thus, the thermal power plant can generate steam like a thermal power plant to meet different requirements.

The above embodiments are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited thereby, and any insubstantial changes and substitutions made by those skilled in the art based on the present invention are within the protection scope of the present invention.

Claims

1. The utility model provides an utilize pressure to change thermodynamic device of state, includes working medium, working medium pipeline, compressor and evaporimeter, characterized by: the system also comprises a precooler and a liquefaction mechanism, wherein the liquefaction mechanism is one of a condenser, a cooler and a throttle valve or an expansion machine; the compressor, the liquefaction mechanism, the precooler and the evaporator are connected in sequence; the precooler comprises a cooling part and a cooling cavity, wherein the cooling part is an assembly for cooling a liquid working medium flowing through the cooling cavity, the cooling part is one of an external cold source or a system self-cooling assembly, and the cooling cavity is provided with a first inlet and a first outlet; the first inlet is connected with the outlet of the liquefying mechanism, and the first outlet is connected with the inlet of the evaporator.

2. A thermodynamic device as claimed in claim 1, wherein the thermodynamic device changes state by vapour pressure, characterized by: the system self-cooling assembly comprises a throttling device and an evaporation cavity, the evaporation cavity is provided with a second inlet and a second outlet, the outlet of the liquefaction mechanism, the throttling device and the second inlet are sequentially connected, and the second outlet is connected with the air suction end of the compressor.

3. A thermodynamic device as claimed in claim 1, wherein the thermodynamic device changes state by vapour pressure, characterized by: the steam self-pressurizing device comprises a steam self-pressurizing device, a steam self-pressurizing device and a steam jet pump, wherein the steam self-pressurizing device is one or a combination of a plurality of mechanical pressurizers, steam self-pressurizing devices or steam jet pumps, and comprises a compressing part, an acting part and a transmission mechanism;

the compression part comprises a pressure cylinder, and a third inlet and a third outlet are arranged on one side of the pressure cylinder;

the work applying part comprises a driving cylinder, and a fourth inlet and a fourth outlet are arranged on one side of the driving cylinder;

the transmission mechanism is used for transmitting the pressure generated by the acting part to the compression part, and the pressure cylinder is connected with the driving cylinder through the transmission mechanism.

4. A thermodynamic device as claimed in claim 3, wherein the thermodynamic device changes state by vapour pressure, characterized by: the vapor compression device is provided with a plurality of vapor compression devices, and the operation mode of the plurality of vapor compression devices is one of serial cascade operation, parallel operation and serial and parallel switching operation in sequence.

5. A thermodynamic device as claimed in claim 3, wherein the thermodynamic device changes state by vapour pressure, characterized by: a flash evaporation device is arranged between the outlet of the liquefaction mechanism and the throttling device, and a steam outlet of the flash evaporation device is connected with the steam compression device or is connected with a steam outlet of the evaporation cavity through the steam compression device and is used for driving the steam compression device to do work; the working medium pipeline entering the first inlet is arranged below the liquid level of the liquid working medium in the flash evaporation device.

6. A thermodynamic device as claimed in claim 3, wherein the thermodynamic device changes state by vapour pressure, characterized by: the evaporator is provided with at least one evaporator, the condenser is provided with at least one evaporator, the steam outlet of at least one evaporator is connected with the steam compression device, and the steam outlets of the other evaporators are respectively connected with the suction end of the compressor or the steam compression device at the outlet of the evaporator; the inlet of at least one condenser is connected with a vapor compression device; the condensers are communicated with each other to enable the working medium to flow among the condensers.

7. A thermodynamic device as claimed in claim 6, wherein the thermodynamic device utilizes vapor pressure to change states, and the device further comprises: the energy storage device also comprises an energy storage device which is used for absorbing or providing heat energy and exchanging heat with the environment space, and the energy storage device comprises at least one of a high-temperature energy storage device or a low-temperature energy storage device;

the high-temperature energy accumulator comprises a high-temperature energy storage working medium and a high-temperature heat exchanger, an inlet of the high-temperature heat exchanger is connected with a steam outlet of the steam compression device at an outlet of the evaporator or a liquid working medium outlet of the condenser, and an outlet of the high-temperature heat exchanger is connected with a steam inlet of the condenser or a liquid working medium outlet of the condenser;

the low-temperature energy accumulator comprises a low-temperature energy storage working medium and a low-temperature heat exchanger, the low-temperature heat exchanger is connected with a certain evaporator, an inlet of the certain evaporator is connected with a first outlet and a fourth outlet of a steam compression device arranged at an outlet of the evaporator, and an outlet of the certain evaporator is connected with the steam compression device arranged at an outlet of the evaporator.

8. A thermodynamic device as claimed in claim 1, wherein the thermodynamic device utilizes vapor pressure to change states, and the device further comprises: the thermodynamic device is overlapped with a refrigeration system and an acting system of other working media.

9. A thermodynamic method of changing state using vapor pressure, characterized by: the method is carried out by using the thermodynamic device utilizing vapor pressure to change state as claimed in any one of claims 1 to 8, and comprises the following steps:

a2, feeding the cooled liquid working medium into an evaporator;

10. A thermodynamic method of changing state using vapor pressure as claimed in claim 9, wherein: the steam compression device comprises a compression part, a work application part and a transmission mechanism; the compression part comprises a pressure cylinder, and a third inlet and a third outlet are arranged on one side of the pressure cylinder; the work applying part comprises a driving cylinder, and a fourth inlet and a fourth outlet are arranged on one side of the driving cylinder;

the thermodynamic method for changing state by vapor pressure is realized by the vapor compression device, and the realization method is as follows: