An energy-saving, ultra-low charge, three-condition refrigeration heat recovery device and its working method

Abstract

This invention provides an energy-saving, ultra-low refrigerant charge three-condition refrigeration and heat recovery device and its operating method. The device includes a refrigeration system and a heat recovery system. The refrigeration system comprises a refrigeration side, a cooling-carrying side, and a condensation-evaporation system. The cooling-carrying side includes a medium-temperature system, a high-temperature system, and a low-temperature system. The condensation-evaporation system is connected to both the refrigeration side and the cooling-carrying side for heat exchange between them. The heat recovery system is connected to the refrigeration side, the medium-temperature system, and the low-temperature system for recovering and storing heat for defrosting the medium-temperature and low-temperature evaporators. The three-condition combination provided by this invention achieves a cooling-carrying efficiency greater than cascade efficiency by more than 4%; the high-temperature stage, using a two-stage configuration, achieves an efficiency greater than a single-unit two-stage + single-stage efficiency by more than 2.5%, reducing refrigerant charge and making it more environmentally friendly.

Description

Technical Field

[0001] This invention relates to the field of industrial refrigeration technology, and in particular to an energy-saving, ultra-low charge, three-condition refrigeration heat recovery device and its working method. Background Technology

[0002] For refrigeration systems with multiple temperature requirements, it is expensive and inefficient to equip each operating condition with a separate system. During system operation, the evaporator will frost up. Traditional defrosting methods such as electro-defrosting are energy-intensive, water defrosting can easily cause food contamination, and CO2 heat medium defrosting has high pressure and requires an additional defrosting compressor. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides an energy-saving, ultra-low-charge, three-condition refrigeration and heat recovery device and its operating method. This invention primarily utilizes a refrigeration system and a heat recovery system to simultaneously meet three operating conditions: high temperature (3~10℃), medium temperature (0~4℃), and low temperature (-18~-25℃). The heat generated during system operation is recovered for evaporator defrosting; simultaneously, the ammonia charge in the high-temperature stage is controlled to be less than 5 tons; and a two-stage configuration in the high-temperature stage improves system energy efficiency.

[0004] The technical means employed in this invention are as follows: An energy-saving, ultra-low charge, three-condition refrigeration and heat recovery device includes: a refrigeration system and a heat recovery system; wherein: The refrigeration system includes a refrigeration side, a cooling side, and a condensation-evaporation system; the cooling side includes a medium-temperature system, a high-temperature system, and a low-temperature system; the condensation-evaporation system is connected to the refrigeration side and the cooling side respectively, and is used for heat exchange between the refrigeration side and the cooling side. The heat recovery system is connected to the refrigeration side, the medium-temperature system, and the low-temperature system respectively, and is used to recover and store heat for defrosting the medium-temperature evaporator and the low-temperature evaporator.

[0005] Further, the refrigeration side includes: a low-temperature gas separator, an ammonia / fluorine low-temperature stage compressor, an ammonia / fluorine high-temperature stage compressor, a condenser, a float valve, a first throttle valve, a high-temperature gas separator, and a fourth throttle valve, wherein: The low-temperature gas separator is connected to an ammonia / fluorine low-temperature compressor at its output end, which is used to separate low-temperature gas and liquid. The ammonia / fluorine cryogenic compressor has its input end connected to a cryogenic gas separator and its output end connected to a high-temperature gas separator, and is used to compress cryogenic and low-pressure gas into high-temperature and high-pressure gas. The ammonia / fluorine high-temperature compressor has a high-temperature gas separator connected to its input end and a condenser connected to its output end, and is used to compress low-temperature, low-pressure gas into high-temperature, high-pressure gas. The condenser has its input end connected to an ammonia / fluorine high-temperature compressor and its output end connected to a high-temperature gas separator, and is used to condense gas into liquid. The high-temperature gas separator is used to separate the throttled gas and liquid, and to deheat the gas in the ammonia / fluorine cryogenic compressor.

[0006] The float valve and the first throttle valve are installed in parallel between the condenser and the high-temperature gas separator. The float valve controls the opening and closing of the valve by the floating and sinking of the float ball, and is used for throttling. The first throttle valve serves as a backup for the float valve and is also used for throttling. The fourth throttle valve is installed on the pipeline between the low-temperature gas separator and the high-temperature gas separator, and is used for throttling and pressure reduction.

[0007] Furthermore, the intermediate-temperature system, used to maintain the temperature of the intermediate-temperature operating condition between 0 and 4°C, includes: a CO2 intermediate-temperature tank, a CO2 intermediate-temperature pump, and an intermediate-temperature evaporator; wherein: The CO2 medium-temperature tank has an inlet connected to a medium-temperature evaporator and an outlet connected to a CO2 medium-temperature pump, which is used to separate gas and liquid and store medium-temperature refrigerant. The CO2 medium-temperature pump has its input end connected to a CO2 medium-temperature tank and its output end connected to a medium-temperature evaporator. It is used to pressurize the liquid flowing out of the CO2 medium-temperature tank and supply liquid to the medium-temperature evaporator at multiple times the flow rate. The medium-temperature evaporator has an input end connected to a medium-temperature CO2 pump and an output end connected to a medium-temperature CO2 tank, used to evaporate the refrigerant and achieve refrigeration.

[0008] Furthermore, the high-temperature system, used to maintain the temperature under high-temperature conditions between 3 and 10°C, includes: a CO2 / ethylene glycol heat exchanger, a high-temperature evaporator, a third electric valve, and a high-temperature ethylene glycol pump, wherein: The CO2 / ethylene glycol heat exchanger is connected to a CO2 medium-temperature tank at one end and to a high-temperature evaporator at the other end for ethylene glycol heat exchange. The high-temperature evaporator is connected to a CO2 / ethylene glycol heat exchanger to cool the high-temperature ethylene glycol and achieve refrigeration.

[0009] The third electric valve is installed at the inlet of the high-temperature evaporator and is used to control the flow of liquid into the high-temperature evaporator. The high-temperature ethylene glycol pump is installed at the inlet of the heat exchanger to pressurize the liquid flowing into the heat exchanger and supply liquid to the heat exchanger at multiple times the flow rate.

[0010] Furthermore, the cryogenic system, used to maintain the temperature under cryogenic conditions between -18 and -25°C, includes a CO2 cryogenic pump, a cryogenic evaporator, and a CO2 cryogenic tank; wherein: The CO2 cryogenic pump has its input end connected to a CO2 cryogenic tank and its output end connected to a cryogenic evaporator. It is used to pressurize the liquid flowing out of the CO2 cryogenic tank and supply liquid to the cryogenic evaporator at multiple times the flow rate. The low-temperature evaporator has an input end connected to a CO2 low-temperature pump and an output end connected to a CO2 low-temperature tank, used to evaporate the refrigerant and achieve refrigeration.

[0011] The CO2 cryogenic tank has an inlet connected to a cryogenic evaporator and an outlet connected to a CO2 cryogenic pump, which is used to separate gas and liquid and store cryogenic refrigerant.

[0012] Furthermore, the condensation and evaporation system includes: a medium-temperature ammonia / fluorine / CO2 condenser and a low-temperature ammonia / fluorine / CO2 condenser, wherein: The medium-temperature ammonia / fluorine / CO2 condenser-evaporator has an input end connected to a high-temperature gas separator and an output end connected to a medium-temperature CO2 tank. It is used to condense medium-temperature steam into liquid to achieve heat exchange between the refrigeration side and the medium-temperature system. The low-temperature ammonia / fluorine / CO2 condenser-evaporator has an input end connected to a low-temperature gas separator and an output end connected to a low-temperature CO2 tank. It is used to condense low-temperature vapor into liquid to achieve heat exchange between the refrigeration side and the low-temperature system.

[0013] Further, the heat recovery system includes: a second electric valve, a fifth electric valve, a sixth electric valve, a seventh electric valve, a first ethylene glycol pump, a heat recovery ethylene glycol heat exchanger, a second ethylene glycol pump, a heat recovery water tank, and a third ethylene glycol pump, wherein: The first ethylene glycol pump is installed at the inlet of the heat recovery ethylene glycol plate heat exchanger and is used to recover heat; The heat recovery ethylene glycol plate heat exchanger is connected to the ammonia / fluorine high-temperature stage compressor via a sixth electric valve and to the ammonia / fluorine low-temperature stage compressor via a seventh electric valve. The second ethylene glycol pump is connected to the heat recovery ethylene glycol plate heat exchanger and the heat recovery water tank, respectively, and is used to supply liquid to the heat recovery ethylene glycol plate heat exchanger; The heat recovery water tank is connected to a low-temperature evaporator via a fifth electric valve and to a medium-temperature evaporator via a second electric valve. The third ethylene glycol pump is installed at the outlet of the heat recovery water tank and is used to store the recovered hot ethylene glycol.

[0014] Furthermore, the intermediate temperature system further includes: a first electric valve and a second throttle valve; wherein: The first electric valve is located between the CO2 medium-temperature pump and the second throttle valve, and is used to control the liquid outflow from the CO2 medium-temperature pump. The second throttle valve is located between the first electric valve and the medium-temperature evaporator and is used to regulate the liquid flow rate.

[0015] Furthermore, the cryogenic system also includes: a fourth electric valve and a third throttle valve, wherein: The fourth electric valve is installed between the CO2 cryogenic pump and the third throttle valve to control the flow of liquid into the cryogenic evaporator; The third throttle valve is installed between the fourth electric valve and the cryogenic evaporator to control the liquid flow rate.

[0016] This invention also provides a method for operating an energy-saving, ultra-low charge, three-condition refrigeration heat recovery device, specifically including the following steps: The exhaust gas from the ammonia / fluorine cryogenic compressor, after being superheated and cooled to saturated temperature, enters the ammonia / fluorine cryogenic compressor and is compressed into high-temperature and high-pressure gas. The two-phase mixture of the high-temperature and high-pressure exhaust gas from the ammonia / fluorine cryogenic compressor, after being condensed by the condenser, enters the high-temperature gas separator after being throttled by the float valve and the first throttle valve. After the high-temperature gas separator separates the gas and liquid, the liquid enters the cryogenic gas separator after being throttled by the fourth throttle valve. The liquid in the high-temperature gas separator and the gas in the medium-temperature CO2 tank exchange heat in a medium-temperature ammonia / fluorine / CO2 condenser-evaporator. The medium-temperature saturated liquid in the CO2 medium-temperature tank is pumped to the medium-temperature evaporator by the CO2 medium-temperature pump, and then vaporized into a two-phase mixture and enters the CO2 medium-temperature tank. The saturated liquid in the CO2 medium-temperature tank and the high-temperature ethylene glycol liquid in the high-temperature evaporator exchange heat in the CO2 / ethylene glycol heat exchanger. The liquid in the low-temperature gas separator exchanges heat with the gas in the low-temperature CO2 tank in a low-temperature ammonia / fluorine / CO2 condenser-evaporator. The saturated liquid under low-temperature operating conditions in the CO2 low-temperature tank is transported to the low-temperature evaporator by the CO2 low-temperature pump for heat exchange and vaporization into a two-phase mixture, which then enters the CO2 low-temperature tank. The oil-cooled high-temperature liquid in the ammonia / fluorine low-temperature stage compressor and the ammonia / fluorine high-temperature stage compressor is stored in the heat recovery water tank after heat exchange with the heat recovery ethylene glycol plate by the first ethylene glycol pump. It is used for defrosting of the medium-temperature evaporator and the low-temperature evaporator.

[0017] Compared with the prior art, the present invention has the following advantages: 1. The present invention provides an energy-saving, ultra-low charge three-condition refrigeration heat recovery device and its working method. Under the condition, the energy efficiency of the cooling load is greater than 4% or more of the cascade; the high-temperature stage adopts a two-stage combination energy efficiency greater than 2.5% or more of the single-unit two-stage + single-stage energy efficiency.

[0018] 2. The present invention provides an energy-saving, ultra-low charge three-condition refrigeration heat recovery device and its working method, which eliminates the high-temperature ammonia / fluorine storage tank in actual operation and reduces the refrigerant charge by ≥18%.

[0019] 3. The present invention provides an energy-saving, ultra-low charge three-condition refrigeration heat recovery device and its working method, in which the working oil cooler is replaced with ethylene glycol cooling in actual operation, reducing the refrigerant charge by about 5%.

[0020] 4. The present invention provides an energy-saving, ultra-low charge three-condition refrigeration heat recovery device and its working method. The system has a high degree of integration and simultaneously meets three conditions: high temperature 3~10℃, medium temperature 0~4℃, and low temperature -18~-25℃, saving about 6% of the machine room floor space.

[0021] 5. The present invention provides an energy-saving, ultra-low charge, three-condition refrigeration heat recovery device and its working method, which recovers the "waste heat" generated during unit operation and uses it for defrosting the terminal evaporator. It is more energy-efficient than capacitor defrosting; it causes less food contamination than water defrosting; and it has lower defrosting pressure and is safer than specific heat CO2 working fluid.

[0022] 6. The present invention provides an energy-saving, ultra-low charge three-condition refrigeration heat recovery device and its working method, which uses natural and environmentally friendly refrigerants ammonia (ODP=0, GWP=0) and CO2 (ODP=0, GWP=1) as refrigerants, making it more environmentally friendly and in line with the dual-carbon policy.

[0023] 7. The present invention provides an energy-saving ultra-low charge three-condition refrigeration heat recovery device and its working method. In this project, the low temperature 66,900 tons / medium temperature 6,400 tons storage tank has a total ammonia charge of <5 tons.

[0024] Based on the above reasons, this invention can be widely promoted in the field of industrial refrigeration. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the structure of an energy-saving, ultra-low charge, three-condition refrigeration heat recovery device provided by the present invention.

[0027] In the diagram: 101. Low-temperature gas separator; 102. Ammonia / Fluorine low-temperature stage compressor; 103. Ammonia / Fluorine high-temperature stage compressor; 104. Condenser; 105. Float valve; 106. First throttle valve; 107. High-temperature gas separator; 108. Medium-temperature ammonia / Fluorine / CO2 condenser / evaporator; 109. Medium-temperature CO2 tank; 110. Medium-temperature CO2 pump; 111. First electric valve; 112. Second throttle valve; 113. Medium-temperature evaporator; 114. Second electric valve; 115. CO2 / ethylene glycol heat exchanger; 116. Third electric valve; 117. CO2 low-temperature pump; 118. Fourth electric valve; 119. Third throttle valve; 120. Low-temperature evaporator; 121. Fifth electric valve; 122. CO2 low-temperature tank; 123. Low-temperature ammonia / Fluorine / CO2 condenser-evaporator; 124, sixth electric valve; 125, seventh electric valve; 126, first ethylene glycol pump; 127, heat recovery ethylene glycol plate heat exchanger; 128, second ethylene glycol pump; 129, heat recovery water tank; 130, third ethylene glycol pump; 131, high-temperature ethylene glycol pump; 132, high-temperature evaporator; 133, fourth throttle valve.

[0028] 1. First pipe; 2. Second pipe; 3. Third pipe; 4. Fourth pipe; 5. Fifth pipe; 6. Sixth pipe; 7. Seventh pipe; 8. Eighth pipe; 9. Ninth pipe; 10. Tenth pipe; 11. Eleventh pipe; 12. Twelfth pipe; 13. Thirteenth pipe; 14. Fourteenth pipe; 15. Fifteenth pipe; 16. Sixteenth pipe; 17. Seventeenth pipe; 18. Eighteenth pipe; 19. Nineteenth pipe; 20. Twentieth pipe; 21. Twenty-first pipe; 22. Twenty-second pipe; 23. Twenty-third pipe; 24. Twenty-fourth pipe; 25. Twenty-fifth pipe; 26. Twenty-sixth pipe; 27. Twenty-seventh pipe; 28. Twenty-eighth pipe; 29. ​​Twenty-ninth pipe; 30. Thirtyth pipe; 31. Thirty-first pipe; 32. Thirty-second pipe; 33. Thirty-third pipe; 34. Thirty-fourth pipe; 35. Thirty-fifth pipe; 36. Thirty-sixth pipe; 37. Thirty-seventh pipe. Detailed Implementation

[0029] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0032] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0033] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0034] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0035] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0036] like Figure 1 As shown, this invention provides an energy-saving, ultra-low charge, three-condition refrigeration and heat recovery device, comprising: a refrigeration system and a heat recovery system; wherein: The refrigeration system includes a refrigeration side, a cooling side, and a condensation-evaporation system; the cooling side includes a medium-temperature system, a high-temperature system, and a low-temperature system; the condensation-evaporation system is connected to the refrigeration side and the cooling side respectively, and is used for heat exchange between the refrigeration side and the cooling side. The heat recovery system is connected to the refrigeration side, the medium-temperature system and the low-temperature system respectively, and is used to recover and store heat for defrosting the medium-temperature evaporator 113 and the low-temperature evaporator 120.

[0037] In a specific implementation, as a preferred embodiment of the present invention, the refrigeration side includes: a low-temperature gas separator 101, an ammonia / fluorine low-temperature stage compressor 102, an ammonia / fluorine high-temperature stage compressor 103, a condenser 104, a float valve 105, a first throttle valve 106, a high-temperature gas separator 107, and a fourth throttle valve 133, wherein: The low-temperature gas separator 101 is connected to the ammonia / fluorine low-temperature compressor 102 at its output end, and is used to separate low-temperature gas and liquid. In this embodiment, the outlet of the low-temperature gas separator 101 is connected to the ammonia / fluorine low-temperature compressor 102 through the first pipe 1, and the inlet of the low-temperature gas separator 101 is connected to the outlet of the high-temperature gas separator 107 in sequence through the fourth throttle valve 133, the ninth pipe 9, and the eighth pipe 8.

[0038] The ammonia / fluorine cryogenic compressor 102 has its input end connected to a cryogenic gas separator 101 and its output end connected to a high-temperature gas separator 107, and is used to compress cryogenic and low-pressure gas into high-temperature and high-pressure gas. The ammonia / fluorine high-temperature compressor 103 has its input end connected to a high-temperature gas separator 107 and its output end connected to a condenser 104, and is used to compress low-temperature, low-pressure gas into high-temperature, high-pressure gas. In this embodiment, the inlet of the ammonia / fluorine high-temperature compressor 103 is connected to the high-temperature gas separator 107 through a third pipe 3, and the outlet is connected to the inlet of the condenser 104 through a fourth pipe 4. The condenser 104 has its input end connected to the ammonia / fluorine high-temperature compressor 103 and its output end connected to the high-temperature gas separator 107, and is used to condense gas into liquid. In this embodiment, the outlet of the condenser 104 is connected to the inlet of the high-temperature gas separator 107 through the fifth pipe 5 and the sixth pipe 6. The high-temperature gas separator 107 is used to separate high-temperature gas and liquid, and to deheat the gas supplied to the ammonia / fluorine cryogenic compressor 102. In this embodiment, the high-temperature gas separator 107 is connected to the inlet and outlet of the shell of the medium-temperature evaporator 113 through the seventh pipe 7 and the eighth pipe 8, respectively; the inlet of the high-temperature gas separator 107 is connected to the ammonia / fluorine cryogenic compressor 102 through the second pipe 2. The float valve 105 and the first throttle valve 106 are installed in parallel between the condenser 104 and the high-temperature gas separator 107. The float valve 105 controls the opening and closing of the valve by the floating and sinking of the float ball, and is used for throttling. The first throttle valve 106 serves as a backup for the float valve 105 and is also used for throttling. The fourth throttle valve 133 is installed on the pipeline between the low-temperature gas separator 101 and the high-temperature gas separator 107 for throttling and pressure reduction.

[0039] In a specific implementation, as a preferred embodiment of the present invention, the intermediate-temperature system is used to maintain the temperature of the intermediate-temperature operating condition between 0 and 4°C, and includes: a CO2 intermediate-temperature tank 109, a CO2 intermediate-temperature pump 110, and an intermediate-temperature evaporator 113; wherein: The CO2 intermediate temperature tank 109 has its inlet connected to the intermediate temperature evaporator 113 and its outlet connected to the CO2 intermediate temperature pump 110, used to separate gas and liquid and store intermediate temperature refrigerant. In this embodiment, the CO2 intermediate temperature tank 109 is connected to the inlet of the intermediate temperature evaporator 113 in sequence through the CO2 intermediate temperature pump 110, the first electric valve 111, and the second throttle valve 112 on the fourteenth pipe 14. The CO2 intermediate temperature tank 109 is connected to the inlet and outlet of the shell of the CO2 / ethylene glycol heat exchanger 115 through the sixteenth pipe 16 and the seventeenth pipe 17, respectively.

[0040] The CO2 medium-temperature pump 110 has its input end connected to the CO2 medium-temperature tank 109 and its output end connected to the medium-temperature evaporator 113. It is used to pressurize the liquid flowing out of the CO2 medium-temperature tank 109 and supply liquid to the medium-temperature evaporator 113 at multiple times the flow rate. The medium-temperature evaporator 113 has its input end connected to the medium-temperature CO2 pump 110 and its output end connected to the medium-temperature CO2 tank 109, which is used to evaporate the refrigerant to achieve refrigeration. In this embodiment, the outlet of the medium-temperature evaporator 113 is connected to the inlet of the medium-temperature CO2 tank 109 through the fifteenth pipe 15. In a specific implementation, as a preferred embodiment of the present invention, the high-temperature system is used to maintain the temperature of the high-temperature operating condition between 3 and 10°C, and includes: a CO2 / ethylene glycol heat exchanger 115, a high-temperature evaporator 132, a third electric valve 116, and a high-temperature ethylene glycol pump 131, wherein: The CO2 / ethylene glycol heat exchanger 115 is connected at one end to the CO2 medium-temperature tank 109 and at the other end to the high-temperature evaporator 132 for ethylene glycol heat exchange. In this embodiment, the outlet of the CO2 / ethylene glycol heat exchanger 115 tube layer is connected to the inlet of the high-temperature evaporator 132 through the thirty-sixth pipe 36 and the third electric valve 116, and is connected to the outlet of the high-temperature evaporator 132 through the thirty-seventh pipe 37 and the high-temperature ethylene glycol pump 131. The high-temperature evaporator 132 is connected to the CO2 / ethylene glycol heat exchanger 115, which is used to cool the high-temperature ethylene glycol to achieve refrigeration. The third electric valve 116 is installed at the inlet of the high-temperature evaporator 132 and is used to control the flow of liquid into the high-temperature evaporator 132. The high-temperature ethylene glycol pump 131 is installed at the inlet of the heat exchanger 115 to pressurize the liquid flowing into the heat exchanger 115 and supply liquid to the heat exchanger 115 at a flow rate multiple times.

[0041] In a specific implementation, as a preferred embodiment of the present invention, the cryogenic system is used to maintain the temperature of the cryogenic operating condition between -18 and -25°C, and includes a CO2 cryogenic pump 117, a cryogenic evaporator 120, and a CO2 cryogenic tank 122; wherein: The CO2 cryogenic pump 117 has its input end connected to the CO2 cryogenic tank 122 and its output end connected to the cryogenic evaporator 120. It is used to pressurize the liquid flowing out of the CO2 cryogenic tank 122 and supply liquid to the cryogenic evaporator 120 at a flow rate of more than 10 times. The low-temperature evaporator 120 has its input end connected to a CO2 low-temperature pump 117 and its output end connected to a CO2 low-temperature tank 122, and is used to evaporate the refrigerant to achieve refrigeration. In this embodiment, the outlet of the low-temperature evaporator 120 is connected to the inlet of the CO2 low-temperature tank 122 through the twenty-first pipe 21; The CO2 cryogenic tank 122 has its inlet connected to the cryogenic evaporator 120 and its outlet connected to the CO2 cryogenic pump 117, used to separate gas and liquid and store cryogenic refrigerant. In this embodiment, the CO2 cryogenic tank 122 is connected to the inlet of the cryogenic evaporator 120 in sequence through the CO2 cryogenic pump 117, the fourth electric valve 118, and the third throttle valve 119 on the twentieth pipe 20. In a specific implementation, as a preferred embodiment of the present invention, the condensation and evaporation system includes: a medium-temperature ammonia / fluorine / CO2 condenser and evaporator 108 and a low-temperature ammonia / fluorine / CO2 condenser and evaporator 123, wherein: The medium-temperature ammonia / fluorine / CO2 condenser-evaporator 108 has its input end connected to the high-temperature gas separator 107 and its output end connected to the medium-temperature CO2 tank 109. It is used to condense medium-temperature steam into liquid, realizing heat exchange between the refrigeration side and the medium-temperature system. In this embodiment, one end of the tube layer of the medium-temperature ammonia / fluorine / CO2 condenser-evaporator 108 is connected to the inlet and outlet of the high-temperature gas separator 107 through the eighth pipe 8 and the seventh pipe 7, respectively; the other end is connected to the inlet and outlet of the CO2 medium-temperature tank 109 through the twelfth pipe 12 and the thirteenth pipe 13, respectively. The low-temperature ammonia / fluorine / CO2 condenser-evaporator 123 has its input end connected to a low-temperature gas separator 101 and its output end connected to a low-temperature CO2 tank 122. It is used to condense low-temperature vapor into liquid, achieving heat exchange between the refrigeration side and the low-temperature system. In this embodiment, one end of the shell of the low-temperature ammonia / fluorine / CO2 condenser-evaporator 123 is connected to the inlet and outlet of the low-temperature gas separator 101 via tenth pipe 10 and eleventh pipe 11, respectively; the other end is connected to the inlet and outlet of the CO2 tank 122 via eighteenth pipe 18 and nineteenth pipe 19, respectively. In a preferred embodiment of the present invention, the heat recovery system includes: a second electric valve 114, a fifth electric valve 121, a sixth electric valve 124, a seventh electric valve 125, a first ethylene glycol pump 126, a heat recovery ethylene glycol heat exchanger 127, a second ethylene glycol pump 128, a heat recovery water tank 129, and a third ethylene glycol pump 130, wherein: The first ethylene glycol pump 126 is installed at the inlet of the heat recovery ethylene glycol plate heat exchanger 127 for recovering heat; The heat recovery glycol plate heat exchanger 127 is connected to the ammonia / fluorine high-temperature stage compressor 103 via the sixth electric valve 124 and to the ammonia / fluorine low-temperature stage compressor 102 via the seventh electric valve 125. In this embodiment, the left outlet of the heat recovery glycol plate heat exchanger 127 is connected to the oil cooling inlets of the ammonia / fluorine low-temperature stage compressor 102 and the ammonia / fluorine high-temperature stage compressor 103 via the twenty-second pipe 22, the twenty-fourth pipe 24, and the twenty-sixth pipe 26. The left inlet of the heat recovery glycol plate heat exchanger 127 is connected to the left outlet of the heat recovery glycol plate heat exchanger 127 via the twenty-third pipe 23, the twenty-fifth pipe 25, and the twenty-seventh pipe 27. The right outlet of the heat recovery glycol plate heat exchanger 127 is connected to the left inlet of the heat recovery water tank 129 via the twenty-ninth pipe 29, and the right inlet of the heat recovery glycol plate heat exchanger 127 is connected to the left outlet of the heat recovery water tank 129 via the twenty-eighth pipe 28 and the second glycol pump 128.

[0042] The second ethylene glycol pump 128 is connected to the heat recovery ethylene glycol plate heat exchanger 127 and the heat recovery water tank 129 respectively, and is used to supply liquid to the heat recovery ethylene glycol plate heat exchanger 127; The heat recovery water tank 129 is connected to the low-temperature evaporator 120 via a fifth electric valve 121 and to the medium-temperature evaporator 113 via a second electric valve 114. In this embodiment, the right outlet of the heat recovery water tank 129 is connected to the inlet of the low-temperature evaporator 120 via a third ethylene glycol pump 130, a thirtieth pipe 30, a thirty-third pipe 33, and the fifth electric valve 121. The left outlet of the heat recovery water tank 129 is connected to the inlet of the medium-temperature evaporator 113 via a third ethylene glycol pump 130, a thirtieth pipe 30, a thirty-fifth pipe 35, and the second electric valve 114. The right inlet of the heat recovery water tank 129 is connected to the outlet of the low-temperature evaporator 120 via a thirty-first pipe 31 and a thirty-second pipe 32. The left inlet of the heat recovery water tank 129 is connected to the outlet of the medium-temperature evaporator 113 via a thirty-first pipe 31 and a thirty-fourth pipe 34.

[0043] The third ethylene glycol pump 130 is installed at the outlet of the heat recovery water tank 129 and is used to store the recovered hot ethylene glycol.

[0044] In a specific implementation, as a preferred embodiment of the present invention, the intermediate temperature system further includes: a first electric valve 111 and a second throttle valve 112; wherein: The first electric valve 111 is disposed between the CO2 medium-temperature pump 110 and the second throttle valve 112, and is used to control the liquid outflow from the CO2 medium-temperature pump 110.

[0045] The second throttle valve 112 is located between the first electric valve 111 and the medium-temperature evaporator 113, and is used to regulate the liquid flow rate.

[0046] In a specific implementation, as a preferred embodiment of the present invention, the cryogenic system further includes: a fourth electric valve 118 and a third throttle valve 119, wherein: The fourth electric valve 118 is installed between the CO2 cryogenic pump 117 and the third throttle valve 119, and is used to control the flow of liquid into the cryogenic evaporator 120. The third throttle valve 119 is installed between the fourth electric valve 118 and the low-temperature evaporator 120 to control the liquid flow rate.

[0047] This invention also provides a method for operating an energy-saving, ultra-low charge, three-condition refrigeration heat recovery device, characterized by the following steps: The exhaust gas from the ammonia / fluorine cryogenic compressor 102, after being superheated and cooled to saturated temperature, enters the ammonia / fluorine cryogenic compressor 103 and is compressed into high-temperature and high-pressure gas. The two-phase mixture condensed by the condenser 104 from the high-temperature and high-pressure exhaust gas from the ammonia / fluorine cryogenic compressor 103 enters the high-temperature gas separator 107 after being throttled by the float valve 105 and the first throttle valve 106. After the high-temperature gas separator 107 separates the gas and liquid, the liquid enters the cryogenic gas separator 101 after being throttled by the fourth throttle valve 133. The liquid in the high-temperature gas separator 107 and the gas in the medium-temperature CO2 tank 109 exchange heat in the medium-temperature ammonia / fluorine / CO2 condenser-evaporator 108. The medium-temperature saturated liquid in the medium-temperature CO2 tank 109 is transported to the medium-temperature evaporator 113 by the medium-temperature CO2 pump 110, and then vaporized into a two-phase mixture and enters the medium-temperature CO2 tank 109. The saturated liquid in the medium-temperature CO2 tank 109 and the high-temperature ethylene glycol liquid in the high-temperature evaporator 132 exchange heat in the CO2 / ethylene glycol heat exchanger 115. The liquid in the low-temperature gas separator 101 and the gas in the low-temperature CO2 tank 122 exchange heat in the low-temperature ammonia / fluorine / CO2 condenser-evaporator 123; The low-temperature saturated liquid in the CO2 low-temperature tank 122 is transported to the low-temperature evaporator 120 by the CO2 low-temperature pump 117 for heat exchange and vaporization into a two-phase mixture, which then enters the CO2 low-temperature tank 122. The oil-cooled high-temperature liquid in the ammonia / fluorine low-temperature compressor 102 and the ammonia / fluorine high-temperature compressor 103 is stored in the heat recovery water tank 129 after heat exchange with the heat recovery ethylene glycol plate heat exchanger 127 via the first ethylene glycol pump 126. This liquid is used for defrosting the medium-temperature evaporator 113 and the low-temperature evaporator 120.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An energy-saving, ultra-low charge, three-condition refrigeration heat recovery device, characterized in that, include: Refrigeration system and heat recovery system; wherein: The refrigeration system includes a refrigeration side, a cooling side, and a condensation-evaporation system; the cooling side includes a medium-temperature system, a high-temperature system, and a low-temperature system; the condensation-evaporation system is connected to the refrigeration side and the cooling side respectively, and is used for heat exchange between the refrigeration side and the cooling side. The medium-temperature system includes: a CO2 medium-temperature tank (109), a CO2 medium-temperature pump (110), and a medium-temperature evaporator (113). The low-temperature system includes a CO2 low-temperature pump (117), a low-temperature evaporator (120), and a CO2 low-temperature tank (122). The refrigeration side includes: a low-temperature gas separator (101), an ammonia / fluorine low-temperature stage compressor (102), an ammonia / fluorine high-temperature stage compressor (103), a condenser (104), a float valve (105), a first throttle valve (106), a high-temperature gas separator (107), and a fourth throttle valve (133), wherein: The low-temperature gas separator (101) is connected to the ammonia / fluorine low-temperature compressor (102) at its output end, and is used to separate low-temperature gas and liquid. The outlet of the low-temperature gas separator (101) is connected to the ammonia / fluorine low-temperature compressor (102) through the first pipe (1), and the inlet of the low-temperature gas separator (101) is connected to the outlet of the high-temperature gas separator (107) in sequence through the fourth throttle valve (133), the ninth pipe (9), and the eighth pipe (8). The ammonia / fluorine cryogenic compressor (102) has its input end connected to a cryogenic gas separator (101) and its output end connected to a high-temperature gas separator (107), and is used to compress cryogenic and low-pressure gas into high-temperature and high-pressure gas. The ammonia / fluorine high-temperature compressor (103) has its input end connected to a high-temperature gas separator (107) and its output end connected to a condenser (104), used to compress low-temperature, low-pressure gas into high-temperature, high-pressure gas; the inlet of the ammonia / fluorine high-temperature compressor (103) is connected to the high-temperature gas separator (107) through a third pipe (3), and the outlet is connected to the inlet of the condenser (104) through a fourth pipe (4); The condenser (104) has its input end connected to an ammonia / fluorine high-temperature compressor (103) and its output end connected to a high-temperature gas separator (107) for condensing gas into liquid; the outlet of the condenser (104) is connected to the inlet of the high-temperature gas separator (107) through a fifth pipe (5) and a sixth pipe (6); The high-temperature gas separator (107) is used to separate the throttled gas and liquid and de-superheat the gas in the ammonia / fluorine cryogenic compressor (102); the high-temperature gas separator (107) is connected to the inlet and outlet of the shell of the medium-temperature evaporator (113) through the seventh pipe (7) and the eighth pipe (8); the inlet of the high-temperature gas separator (107) is connected to the ammonia / fluorine cryogenic compressor (102) through the second pipe (2); The float valve (105) and the first throttle valve (106) are connected in parallel between the condenser (104) and the high-temperature gas separator (107). The float valve (105) controls the opening and closing of the valve by the floating and sinking of the float ball and is used for throttling. The first throttle valve (106) serves as a backup for the float valve (105) and is also used for throttling. The fourth throttle valve (133) is installed on the pipeline between the low-temperature gas separator (101) and the high-temperature gas separator (107) for throttling and pressure reduction; The heat recovery system is connected to the refrigeration side, the medium-temperature system and the low-temperature system respectively, and is used to recover and store heat for defrosting the medium-temperature evaporator (113) and the low-temperature evaporator (120).

2. The energy-saving, ultra-low charge, three-condition refrigeration heat recovery device according to claim 1, characterized in that, The intermediate temperature system is used to maintain the temperature in intermediate temperature operating conditions between 0 and 4°C, wherein: The CO2 medium-temperature tank (109) has an inlet connected to a medium-temperature evaporator (113) and an outlet connected to a CO2 medium-temperature pump (110), which is used to separate gas and liquid and store medium-temperature refrigerant. The CO2 medium-temperature pump (110) has its input end connected to the CO2 medium-temperature tank (109) and its output end connected to the medium-temperature evaporator (113). It is used to pressurize the liquid flowing out of the CO2 medium-temperature tank (109) and supply liquid to the medium-temperature evaporator (113) at multiple times the flow rate. The medium-temperature evaporator (113) has its input end connected to a medium-temperature CO2 pump (110) and its output end connected to a medium-temperature CO2 tank (109), which is used to evaporate the refrigerant and achieve refrigeration.

3. The energy-saving, ultra-low charge, three-condition refrigeration heat recovery device according to claim 2, characterized in that, The high-temperature system, used to maintain the temperature under high-temperature conditions between 3 and 10°C, includes: a CO2 / ethylene glycol heat exchanger (115), a high-temperature evaporator (132), a third electric valve (116), and a high-temperature ethylene glycol pump (131), wherein: The CO2 / ethylene glycol heat exchanger (115) is connected at one end to a CO2 medium-temperature tank (109) and at the other end to a high-temperature evaporator (132) for ethylene glycol heat exchange. The high-temperature evaporator (132) is connected to a CO2 / ethylene glycol heat exchanger (115) for cooling high-temperature ethylene glycol to achieve refrigeration. The third electric valve (116) is located at the inlet of the high-temperature evaporator (132) and is used to control the flow of liquid into the high-temperature evaporator (132). The high-temperature ethylene glycol pump (131) is installed at the inlet of the CO2 / ethylene glycol heat exchanger (115) to pressurize the liquid flowing into the CO2 / ethylene glycol heat exchanger (115) and supply liquid to the CO2 / ethylene glycol heat exchanger (115) at multiple times the flow rate.

4. The energy-saving, ultra-low charge, three-condition refrigeration heat recovery device according to claim 3, characterized in that, The cryogenic system is used to maintain the temperature in cryogenic operating conditions between -18 and -25°C, wherein: The CO2 cryogenic pump (117) has its input end connected to the CO2 cryogenic tank (122) and its output end connected to the cryogenic evaporator (120). It is used to pressurize the liquid flowing out of the CO2 cryogenic tank (122) and supply liquid to the cryogenic evaporator (120) at multiple times the flow rate. The low-temperature evaporator (120) has its input end connected to a CO2 low-temperature pump (117) and its output end connected to a CO2 low-temperature tank (122), which is used to evaporate the refrigerant to achieve refrigeration. The CO2 cryogenic tank (122) has an inlet connected to a cryogenic evaporator (120) and an outlet connected to a CO2 cryogenic pump (117), which is used to separate gas and liquid and store cryogenic refrigerant.

5. The energy-saving, ultra-low charge, three-condition refrigeration and heat recovery device according to claim 4, characterized in that, The condensation and evaporation system includes: a medium-temperature ammonia / fluorine / CO2 condenser and evaporator (108) and a low-temperature ammonia / fluorine / CO2 condenser and evaporator (123), wherein: The medium-temperature ammonia / fluorine / CO2 condenser-evaporator (108) is connected to a high-temperature gas separator (107) at its input end and to a medium-temperature CO2 tank (109) at its output end. It is used to condense medium-temperature steam into liquid and realize heat exchange between the refrigeration side and the medium-temperature system. The low-temperature ammonia / fluorine / CO2 condenser-evaporator (123) is connected to a low-temperature gas separator (101) at its input end and to a low-temperature CO2 tank (122) at its output end. It is used to condense low-temperature vapor into liquid and realize heat exchange between the refrigeration side and the low-temperature system.

6. The energy-saving, ultra-low charge, three-condition refrigeration heat recovery device according to claim 5, characterized in that, The heat recovery system includes: a second electric valve (114), a fifth electric valve (121), a sixth electric valve (124), a seventh electric valve (125), a first ethylene glycol pump (126), a heat recovery ethylene glycol plate heat exchanger (127), a second ethylene glycol pump (128), a heat recovery water tank (129), and a third ethylene glycol pump (130), wherein: The first ethylene glycol pump (126) is installed at the inlet of the heat recovery ethylene glycol plate heat exchanger (127) for recovering heat; The heat recovery ethylene glycol plate heat exchanger (127) is connected to the ammonia / fluorine high-temperature stage compressor (103) via the sixth electric valve (124) and to the ammonia / fluorine low-temperature stage compressor (102) via the seventh electric valve (125). The second ethylene glycol pump (128) is connected to the heat recovery ethylene glycol plate heat exchanger (127) and the heat recovery water tank (129) respectively, and is used to supply liquid to the heat recovery ethylene glycol plate heat exchanger (127); The heat recovery water tank (129) is connected to the low-temperature evaporator (120) via the fifth electric valve (121) and to the medium-temperature evaporator (113) via the second electric valve (114). The third ethylene glycol pump (130) is installed at the outlet of the heat recovery water tank (129) for storing the recovered hot ethylene glycol.

7. The energy-saving, ultra-low charge, three-condition refrigeration heat recovery device according to claim 6, characterized in that, The intermediate temperature system further includes: a first electric valve (111) and a second throttle valve (112); wherein: The first electric valve (111) is disposed between the CO2 medium-temperature pump (110) and the second throttle valve (112) to control the liquid outflow from the CO2 medium-temperature pump (110); The second throttle valve (112) is located between the first electric valve (111) and the medium-temperature evaporator (113) and is used to regulate the liquid flow rate.

8. The energy-saving, ultra-low charge, three-condition refrigeration heat recovery device according to claim 7, characterized in that, The cryogenic system further includes: a fourth electric valve (118) and a third throttle valve (119), wherein: The fourth electric valve (118) is installed between the CO2 cryogenic pump (117) and the third throttle valve (119) to control the flow of liquid into the cryogenic evaporator (120). The third throttle valve (119) is installed between the fourth electric valve (118) and the cryogenic evaporator (120) to control the liquid flow rate.

9. A method for operating the energy-saving, ultra-low charge, three-condition refrigeration heat recovery device as described in claim 8, characterized in that, Specifically, the following steps are included: The exhaust gas from the ammonia / fluorine cryogenic compressor (102) is saturated gas after being deheated by the high-temperature gas separator (107) and then compressed into high-temperature and high-pressure gas in the ammonia / fluorine high-temperature compressor (103). The two-phase mixture of the high-temperature and high-pressure exhaust gas from the ammonia / fluorine high-temperature compressor (103) after being condensed by the condenser (104) is throttled by the float valve (105) and the first throttle valve (106) and then enters the high-temperature gas separator (107). After the high-temperature gas separator (107) separates the gas and liquid, the liquid enters the cryogenic gas separator (101) after being throttled by the fourth throttle valve (133). The liquid in the high-temperature gas separator (107) and the gas in the medium-temperature CO2 tank (109) exchange heat in the medium-temperature ammonia / fluorine / CO2 condenser-evaporator (108); The medium-temperature saturated liquid in the medium-temperature CO2 tank (109) is transported to the medium-temperature evaporator (113) by the medium-temperature CO2 pump (110), and then vaporized into a two-phase mixture and enters the medium-temperature CO2 tank (109); the saturated liquid in the medium-temperature CO2 tank (109) and the high-temperature ethylene glycol liquid in the high-temperature evaporator (132) exchange heat in the CO2 / ethylene glycol heat exchanger (115); The liquid in the low-temperature gas separator (101) and the gas in the low-temperature CO2 tank (122) exchange heat in the low-temperature ammonia / fluorine / CO2 condenser-evaporator (123); The saturated liquid under low-temperature conditions in the CO2 low-temperature tank (122) is transported to the low-temperature evaporator (120) by the CO2 low-temperature pump (117) for heat exchange and vaporization into a two-phase mixture, which then enters the CO2 low-temperature tank (122). The oil-cooled high-temperature liquid in the ammonia / fluorine low-temperature compressor (102) and the ammonia / fluorine high-temperature compressor (103) is stored in the heat recovery water tank (129) after heat exchange with the heat recovery ethylene glycol plate heat exchanger (127) via the first ethylene glycol pump (126) for defrosting of the medium-temperature evaporator (113) and the low-temperature evaporator (120).

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