Compression type and evaporation type combined refrigeration energy gradient utilization system and method

Abstract

The invention relates to the technical field of refrigeration equipment in the medical industry, in particular to a compression type and evaporation type combined refrigeration energy gradient utilization system and method. Through cooperation of the evaporative cooling water chilling unit, the water-cooled water chilling unit and the plate heat exchange unit, the characteristic of low wet bulb temperature in dry climate areas can be fully utilized, the energy-saving characteristic of the evaporative cooling water chilling unit and the stable water outlet characteristic of the water-cooled water chilling unit are integrated, and operation is stable and reliable; the use requirements of clean workshops in the medical industry can be met, and the energy consumption of the workshops is effectively saved; the high-temperature water cooled by the primary cooling water and the plate type heat exchange unit is used for non-important areas such as floor radiation cooling, a tail end dry type wind disc and an indirect evaporative cooling ventilation air conditioning unit; low-temperature water cooled by the secondary cooling water and the water-cooled water chilling unit is used for important areas needing stable and reliable cold sources, such as combined air conditioners and shady and cool warehouses in a clean plant purification area in the medical industry, so that gradient utilization of energy is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of pharmaceutical industry refrigeration equipment, and in particular to an energy cascade utilization system and method for combined compression and evaporation refrigeration. Background Art

[0002] The energy consumption of clean workshops in the pharmaceutical industry is high, and the production area can usually reach 300-500w / ㎡. For laboratories with high biosafety levels or more fume hoods, a new air system is required.

[0003] In hot and dry climates, the absolute amount of water vapor in the air is low, resulting in low relative humidity. When air comes into contact with liquid water, the water evaporates easily. During the humidification process, the evaporating water absorbs heat, lowering the air temperature. This characteristic has led to the development of evaporative cooling technology, which currently includes evaporative cooling air conditioners and indirect evaporative cooling chillers.

[0004] Existing relevant energy-saving and design standards stipulate that in areas with low outdoor calculated design dew point temperature for outdoor air conditioning in summer, and in dry areas with calculated outdoor air wet bulb temperature less than 23℃, it is advisable to use indirect evaporative cooling chillers as the cold source of the air-conditioning system or use evaporative cooling system air-conditioning system.

[0005] However, for pharmaceutical cleanrooms, the temperature in Class A, B, and C air cleanrooms should be between 20°C and 24°C, with a relative humidity of 45% to 60%. Class D air cleanrooms should be between 18°C and 26°C, with a relative humidity of 45% to 65%. Furthermore, pure steam should be used for humidification of clean area air. This places high demands on the stability and quality of the cooling source. Evaporative cooling chillers are limited by the temperature and humidity of the outdoor air, making them difficult to use in pharmaceutical cleanrooms.

[0006] Indirect-direct combined evaporative cooling chillers handle temperatures between the dew point and wet-bulb temperature of the inlet air and are categorized into large and small temperature differential types. When used alone, large temperature differential units are connected in series, resulting in high resistance at the end. Small temperature differential units are connected in parallel, simplifying the piping but providing low cooling capacity, requiring more units and requiring a high investment in the mainframe. Furthermore, evaporative cooling chillers are open systems, resulting in poor water quality.

[0007] At the same time, due to the large heat dissipation of equipment in some rooms of pharmaceutical factories and laminar flow areas, the existing technology often adopts increasing the ventilation frequency or adding surface cooling coils to solve the problem. However, surface cooling coils operate in wet conditions and are troubled by dripping and bacterial growth. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a system and method for cascade utilization of energy for combined compression and evaporative refrigeration, which can fully utilize the low wet-bulb temperature in dry climate areas, integrate the energy-saving characteristics of evaporative cooling chillers and the stable water output characteristics of water-cooled chillers, realize the cascade utilization of energy in the refrigeration process, operate stably and reliably, meet the use requirements of clean workshops in the pharmaceutical industry, and effectively save energy consumption in the workshops.

[0009] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0010] 1. An energy cascade utilization system for combined compression and evaporative refrigeration

[0011] The present invention provides an energy cascade utilization system for combined compression and evaporative refrigeration, comprising an evaporative cooling chiller 1, a water-cooled chiller 2, and a plate heat exchanger 3. The cold water circuit inlet of the plate heat exchanger 3 is connected to the water outlet of the evaporative cooling chiller 1 via a primary cooling water supply pipe 8, and the hot water circuit inlet and outlet of the plate heat exchanger 3 are connected to a high-temperature water inlet pipe 5 and a high-temperature water outlet pipe 4, respectively.

[0012] The cold water circuit outlet of the plate heat exchanger 3 is connected to the secondary cooling water supply pipe 10 through the primary cooling water outlet pipe 9, and the secondary cooling water supply pipe 10 is connected to the water inlet of the condenser 17 in the water-cooled chiller 2. The outlet of the condenser 17 is connected to the return water port of the evaporative cooling chiller 1 through the secondary cooling water outlet pipe 11. The water inlet and outlet of the evaporator 19 in the water-cooled chiller 2 are respectively connected to the low-temperature water inlet pipe 7 and the low-temperature water outlet pipe 6.

[0013] Furthermore, the high-temperature water outlet pipe 4 is connected to the non-stable cold source cooling equipment in the factory, and the low-temperature water outlet pipe 6 is connected to the stable cold source cooling equipment in the factory.

[0014] Furthermore, a high-temperature water circulation pump 12 is installed on the high-temperature water inlet pipe 5 , and a low-temperature water circulation pump 13 is installed on the low-temperature water inlet pipe 7 .

[0015] Furthermore, a cooling water circulation pump 14 is connected between the primary cooling water outlet pipe 9 and the secondary cooling water supply pipe 10 .

[0016] Furthermore, an electric three-way valve 15 is provided on the secondary cooling water outlet pipe 11 , and a middle interface of the electric three-way valve 15 is connected to the secondary cooling water supply pipe 10 through a bypass pipe 16 .

[0017] Furthermore, the evaporative cooling chiller 1 selects a large temperature difference evaporative cooling chiller, and the primary cooling water in the plate heat exchanger 3 exchanges heat with the water of the unstable cold source cooling equipment flowing into the high-temperature water inlet pipe 5, so that the heat in the water of the unstable cold source cooling equipment is absorbed and flows back to the unstable cold source cooling equipment from the high-temperature water outlet pipe 4.

[0018] Furthermore, a compressor 20 is further provided in the water-cooled chiller 2. The compressor 20 draws in the low-pressure and low-temperature refrigerant gas in the water-cooled chiller 2 and increases its temperature and pressure by compressing and boosting it, thereby turning it into a high-temperature and high-pressure refrigerant gas.

[0019] The secondary cooling water in the condenser 17 performs heat exchange with the high-temperature and high-pressure refrigerant gas, so that the heat in the refrigerant gas is absorbed, thereby cooling the refrigerant gas and condensing it into a high-pressure refrigerant liquid.

[0020] Furthermore, the water-cooled chiller 2 is further provided with an expansion valve 18, which releases the high-pressure refrigerant liquid into the evaporator at a constant rate, thereby turning it into a low-temperature and low-pressure refrigerant;

[0021] The evaporator 19 exchanges heat with the water of the stable cold source cooling equipment flowing into the low-temperature water inlet pipe 7 through the low-temperature and low-pressure refrigerant, so that the heat in the water of the stable cold source cooling equipment is absorbed and flows back to the stable cold source cooling equipment from the low-temperature water outlet pipe 6.

[0022] 2. A cascaded energy utilization method for combined compression and evaporative refrigeration

[0023] Based on the same inventive concept, the present invention also provides an energy cascade utilization method for combined compression and evaporative refrigeration, based on the above-mentioned energy cascade utilization system, specifically comprising the following steps:

[0024] S1, generates primary cooling water through evaporative cooling chiller and flows into plate heat exchanger;

[0025] S2, the plate heat exchanger unit exchanges heat with the liquid flowing into the high-temperature water inlet pipe through the primary cooling water to generate high-temperature water after primary cooling, and transports the high-temperature water to the non-stable cold source cooling equipment through the high-temperature water outlet pipe;

[0026] S3, the primary cooling water in the plate heat exchanger absorbs heat and heats up to form secondary cooling water and flows into the water-cooled chiller;

[0027] S4, the water-cooled chiller cools the liquid flowing into the low-temperature water inlet pipe with the secondary cooling water to generate secondary cooled low-temperature water, and delivers the low-temperature water to the stable cold source cooling device through the low-temperature water outlet pipe;

[0028] S5, according to the water consumption demand ratio of the unstable cold source cooling equipment and the stable cold source cooling equipment, adjust the opening of the middle interface of the electric three-way valve in real time to control the secondary cooling water flow returning to the water-cooled chiller and flowing into the evaporative cooling chiller.

[0029] The real-time adjustment of the opening of the intermediate interface of the electric three-way valve specifically includes:

[0030] 1) When the water demand ratio of the non-stable cold source cooling equipment decreases, the opening of the middle interface of the electric three-way valve is increased to allow more secondary cooling water flowing out of the secondary cooling water outlet pipe to flow into the secondary cooling water inlet pipe through the bypass pipe for secondary utilization;

[0031] 2) When the water demand ratio of the non-stable cold source cooling equipment increases, the opening of the middle interface of the electric three-way valve is reduced to allow more secondary cooling water flowing out of the secondary cooling water outlet pipe to flow into the evaporative cooling chiller for cooling.

[0032] Compared with the prior art, the present invention has the following main advantages:

[0033] 1. The present invention uses an evaporative cooling chiller, a water-cooled chiller and a plate heat exchanger to fully utilize the low wet-bulb temperature in dry climates. It combines the energy-saving characteristics of the evaporative cooling chiller with the stable water output characteristics of the water-cooled chiller. The operation is stable and reliable, which can meet the use requirements of clean workshops in the pharmaceutical industry and effectively save energy consumption in the workshop.

[0034] 2. The high-temperature water cooled by the primary cooling water and plate heat exchanger is used in non-critical areas such as floor radiant cooling, terminal dry-type fan coils, and indirect evaporative cooling ventilation and air-conditioning units. The low-temperature water cooled by the secondary cooling water and water-cooled chillers is used in critical areas requiring a stable and reliable cooling source, such as modular air conditioning in clean workshops and purification areas in the pharmaceutical industry, and cool storage, thereby achieving cascaded energy utilization.

[0035] 3. The present invention not only enables the application of evaporative cooling technology in clean workshops in the pharmaceutical industry, but also improves the energy efficiency level of water-cooled chillers due to the low condensation temperature of the cooling water after evaporative cooling. At the same time, the laminar flow at the end of the workshop, such as the filling room, can make the surface cooling coil run in a dry condition by using high-temperature water after a single cooling, thus solving the problems of dripping and bacterial growth. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Schematic diagram of the structure of the energy cascade utilization system of the compression and evaporation combined refrigeration in an embodiment of the present invention;

[0037] Figure 2 The figure is a flow chart of the energy cascade utilization method of the combined compression and evaporation refrigeration in an embodiment of the present invention.

[0038] In the figure: 1. Evaporative cooling chiller; 2. Water-cooled chiller; 3. Plate heat exchanger; 4. High-temperature water outlet pipe; 5. High-temperature water inlet pipe; 6. Low-temperature water outlet pipe; 7. Low-temperature water inlet pipe; 8. Primary cooling water supply pipe; 9. Primary cooling water outlet pipe; 10. Secondary cooling water supply pipe; 11. Secondary cooling water outlet pipe; 12. High-temperature water circulation pump; 13. Low-temperature water circulation pump; 14. Cooling water circulation pump; 15. Electric three-way valve; 16. Bypass pipe; 17. Condenser; 18. Expansion valve; 19. Evaporator; 20. Compressor. DETAILED DESCRIPTION

[0039] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0040] It should be pointed out that, according to the needs of implementation, the various steps / components described in this application can be split into more steps / components, or two or more steps / components or partial operations of steps / components can be combined into new steps / components to achieve the purpose of the present invention.

[0041] Example 1: This example provides a system for cascade utilization of energy using a combined compression and evaporation refrigeration system. Figure 1 As shown, it mainly includes: an evaporative cooling chiller 1, a water-cooled chiller 2 and a plate heat exchanger 3. The cold water circuit inlet of the plate heat exchanger 3 is connected to the water outlet of the evaporative cooling chiller 1 through a primary cooling water supply pipe 8, and the hot water circuit inlet and outlet of the plate heat exchanger 3 are connected to the high-temperature water inlet pipe 5 and the high-temperature water outlet pipe 4 respectively;

[0042] The cold water circuit outlet of the plate heat exchanger 3 is connected to the secondary cooling water supply pipe 10 through the primary cooling water outlet pipe 9, and the secondary cooling water supply pipe 10 is connected to the water inlet of the condenser 17 in the water-cooled chiller 2. The outlet of the condenser 17 is connected to the return water port of the evaporative cooling chiller 1 through the secondary cooling water outlet pipe 11. The water inlet and outlet of the evaporator 19 in the water-cooled chiller 2 are respectively connected to the low-temperature water inlet pipe 7 and the low-temperature water outlet pipe 6.

[0043] Furthermore, the high-temperature water outlet pipe 4 is connected to the non-stable cold source cooling equipment in the factory, and the low-temperature water outlet pipe 6 is connected to the stable cold source cooling equipment in the factory.

[0044] Furthermore, a high-temperature water circulation pump 12 is installed on the high-temperature water inlet pipe 5 , and a low-temperature water circulation pump 13 is installed on the low-temperature water inlet pipe 7 .

[0045] Furthermore, a cooling water circulation pump 14 is connected between the primary cooling water outlet pipe 9 and the secondary cooling water supply pipe 10 .

[0046] Furthermore, an electric three-way valve 15 is provided on the secondary cooling water outlet pipe 11 , and a middle interface of the electric three-way valve 15 is connected to the secondary cooling water supply pipe 10 through a bypass pipe 16 .

[0047] Furthermore, the evaporative cooling chiller 1 selects a large temperature difference evaporative cooling chiller, and the primary cooling water in the plate heat exchanger 3 exchanges heat with the water of the unstable cold source cooling equipment flowing into the high-temperature water inlet pipe 5, so that the heat in the water of the unstable cold source cooling equipment is absorbed and flows back to the unstable cold source cooling equipment from the high-temperature water outlet pipe 4.

[0048] Furthermore, a compressor 20 is further provided in the water-cooled chiller 2. The compressor 20 draws in the low-pressure and low-temperature refrigerant gas in the water-cooled chiller 2 and increases its temperature and pressure by compressing and boosting it, thereby turning it into a high-temperature and high-pressure refrigerant gas.

[0049] The secondary cooling water in the condenser 17 performs heat exchange with the high-temperature and high-pressure refrigerant gas, so that the heat in the refrigerant gas is absorbed, thereby cooling the refrigerant gas and condensing it into a high-pressure refrigerant liquid.

[0050] Furthermore, the water-cooled chiller 2 is further provided with an expansion valve 18, which releases the high-pressure refrigerant liquid into the evaporator at a constant rate, thereby turning it into a low-temperature and low-pressure refrigerant;

[0051] The evaporator 19 exchanges heat with the water of the stable cold source cooling equipment flowing into the low-temperature water inlet pipe 7 through the low-temperature and low-pressure refrigerant, so that the heat in the water of the stable cold source cooling equipment is absorbed and flows back to the stable cold source cooling equipment from the low-temperature water outlet pipe 6.

[0052] Example 2. This example provides an energy cascade utilization system for combined compression and evaporative refrigeration. The outlet water temperature of the evaporative cooling chiller is related to the local climate environment. Therefore, the high-temperature water after the system is cooled once is used for non-important areas such as floor radiation cooling, laminar surface cooling coils in filling rooms, terminal dry air discs, and indirect evaporative cooling ventilation and air-conditioning units; and the low-temperature water after the second cooling by the water-cooled chiller is used for important areas that require stable and reliable cold sources, such as combined air conditioning in the purification area of clean workshops in the pharmaceutical industry and cool storage, so as to achieve cascade utilization of energy.

[0053] Furthermore, the evaporative cooling chiller adopts a large temperature difference type. The primary cooling water provided first passes through a plate heat exchanger to exchange heat with high-temperature water in the plant. After the primary cooling water is heated, it forms secondary cooling water that flows into the water-cooled chiller for use as cooling water, and finally returns to the evaporative cooling chiller for evaporative cooling.

[0054] Furthermore, since the demand for high-temperature water and low-temperature water of the terminal equipment is not always in constant proportion, this may result in a phenomenon in which the demand for high-temperature water is small and the cooling water temperature entering the water-cooled chiller is too low, or a demand for high-temperature water is large and the cooling water temperature entering the water-cooled chiller is too high. There is even a phenomenon in which the comfort air-conditioning no longer needs cooling in the transition season, but the production area still needs cooling due to equipment heat dissipation. Therefore, the present application installs an electric three-way valve on the secondary cooling water outlet pipe of the water-cooled chiller, and the middle interface of the electric three-way valve is connected to the secondary cooling water supply pipe through a bypass pipe.

[0055] Furthermore, the energy consumption comparison between the energy cascade utilization system using the combined compression and evaporative refrigeration of the present application and the traditional water-cooled chiller is shown in the table below. The energy saving rate can reach 45%. After analysis, when the COP of the water-cooled chiller is between 4 and 7 and the total cooling capacity is above 3000kw, the energy saving rate can be guaranteed to be above 40%, and the energy saving effect is significant.

[0056]

[0057]

[0058] Furthermore, central air-conditioning systems are major energy consumers in today's commercial and industrial buildings, and the energy efficiency of most computer rooms is between 2.5 and 3.5. In recent years, with the development of high-efficiency computer rooms, the energy efficiency can reach above 5.0. However, for areas that adopt the energy cascade utilization system of the combined compression and evaporative cooling application, the energy efficiency of the computer room can even reach 8.0-10.0, which has huge energy-saving potential.

[0059] Example 3: Based on the same inventive concept, this embodiment also provides a method for energy cascade utilization of compression and evaporation combined refrigeration. Based on the energy cascade utilization system described above, as shown in FIG. Figure 2 As shown, the specific steps include:

[0060] S1, generates primary cooling water through evaporative cooling chiller and flows into plate heat exchanger;

[0061] S2, the plate heat exchanger unit exchanges heat with the liquid flowing into the high-temperature water inlet pipe through the primary cooling water to generate high-temperature water after primary cooling, and transports the high-temperature water to the non-stable cold source cooling equipment through the high-temperature water outlet pipe;

[0062] S3, the primary cooling water in the plate heat exchanger absorbs heat and heats up to form secondary cooling water and flows into the water-cooled chiller;

[0063] S4, the water-cooled chiller cools the liquid flowing into the low-temperature water inlet pipe with the secondary cooling water to generate secondary cooled low-temperature water, and delivers the low-temperature water to the stable cold source cooling device through the low-temperature water outlet pipe;

[0064] S5, according to the water consumption demand ratio of the unstable cold source cooling equipment and the stable cold source cooling equipment, adjust the opening of the middle interface of the electric three-way valve in real time to control the secondary cooling water flow returning to the water-cooled chiller and flowing into the evaporative cooling chiller.

[0065] The real-time adjustment of the opening of the intermediate interface of the electric three-way valve specifically includes:

[0066] 1) When the water demand ratio of the non-stable cold source cooling equipment decreases, the opening of the middle interface of the electric three-way valve is increased to allow more secondary cooling water flowing out of the secondary cooling water outlet pipe to flow into the secondary cooling water inlet pipe through the bypass pipe for secondary utilization;

[0067] 2) When the water demand ratio of the non-stable cold source cooling equipment increases, the opening of the middle interface of the electric three-way valve is reduced to allow more secondary cooling water flowing out of the secondary cooling water outlet pipe to flow into the evaporative cooling chiller for cooling.

[0068] Optionally, when the secondary cooling water temperature is low, the flow rate of the bypass pipe can be controlled by the condenser inlet water temperature or the high and low pressure differential. When the condenser inlet water temperature is lower than a set value or the high and low pressure differential is less than a set value, the opening of the middle interface of the electric three-way valve is increased to allow more secondary cooling water to flow directly back to the condenser water inlet. Conversely, the opening of the middle interface of the electric three-way valve is reduced to increase the water flow into the evaporative cooling chiller, ensuring the stable operation of the conventional chiller.

[0069] Furthermore, all parts of this application that are not described in detail are the same as the existing technology or are implemented using the existing technology.

[0070] In summary:

[0071] 1. The present invention uses an evaporative cooling chiller, a water-cooled chiller and a plate heat exchanger to fully utilize the low wet-bulb temperature in dry climates. It combines the energy-saving characteristics of the evaporative cooling chiller with the stable water output characteristics of the water-cooled chiller. The operation is stable and reliable, which can meet the use requirements of clean workshops in the pharmaceutical industry and effectively save energy consumption in the workshop.

[0072] 2. The high-temperature water cooled by the primary cooling water and plate heat exchanger is used in non-critical areas such as floor radiant cooling, terminal dry-type fan coils, and indirect evaporative cooling ventilation and air-conditioning units. The low-temperature water cooled by the secondary cooling water and water-cooled chillers is used in critical areas requiring a stable and reliable cooling source, such as modular air conditioning in clean workshops and purification areas in the pharmaceutical industry, and cool storage, thereby achieving cascaded energy utilization.

[0073] 3. The present invention not only enables the application of evaporative cooling technology in clean workshops in the pharmaceutical industry, but also improves the energy efficiency level of water-cooled chillers due to the low condensation temperature of the cooling water after evaporative cooling. At the same time, the laminar flow at the end of the workshop, such as the filling room, can make the surface cooling coil run in a dry condition by using high-temperature water after a single cooling, thus solving the problems of dripping and bacterial growth.

[0074] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An energy cascade utilization system for combined compression and evaporation refrigeration, characterized in that: The invention comprises an evaporative cooling chiller (1), a water-cooled chiller (2) and a plate heat exchanger (3), wherein the cold water circuit inlet of the plate heat exchanger (3) is connected to the water outlet of the evaporative cooling chiller (1) via a primary cooling water supply pipe (8), and the hot water circuit inlet and outlet of the plate heat exchanger (3) are connected to a high-temperature water inlet pipe (5) and a high-temperature water outlet pipe (4) respectively; The cold water circuit outlet of the plate heat exchange unit (3) is connected to the secondary cooling water supply pipe (10) through the primary cooling water outlet pipe (9), the secondary cooling water supply pipe (10) is connected to the water inlet of the condenser (17) in the water-cooled chiller (2), the water outlet of the condenser (17) is connected to the return water port of the evaporative cooling chiller (1) through the secondary cooling water outlet pipe (11), and the water inlet and outlet of the evaporator (19) in the water-cooled chiller (2) are connected to the low-temperature water inlet pipe (7) and the low-temperature water outlet pipe (6) respectively.

2. The energy cascade utilization system of the combined compression and evaporation refrigeration according to claim 1 is characterized in that: The high-temperature water outlet pipe (4) is connected to the non-stable cold source cooling equipment in the factory, and the low-temperature water outlet pipe (6) is connected to the stable cold source cooling equipment in the factory.

3. The energy cascade utilization system of the combined compression and evaporation refrigeration according to claim 1 is characterized in that: A high-temperature water circulation pump (12) is installed on the high-temperature water inlet pipe (5), and a low-temperature water circulation pump (13) is installed on the low-temperature water inlet pipe (7).

4. The energy cascade utilization system of the combined compression and evaporation refrigeration according to claim 1 is characterized in that: A cooling water circulation pump (14) is connected between the primary cooling water outlet pipe (9) and the secondary cooling water supply pipe (10).

5. The energy cascade utilization system of the combined compression and evaporation refrigeration according to claim 1 is characterized in that: An electric three-way valve (15) is provided on the secondary cooling water outlet pipe (11), and a middle interface of the electric three-way valve (15) is connected to the secondary cooling water supply pipe (10) via a bypass pipe (16).

6. The energy cascade utilization system of the combined compression and evaporation refrigeration according to claim 2 is characterized in that: The evaporative cooling chiller (1) uses a large temperature difference type evaporative cooling chiller, and the primary cooling water in the plate heat exchanger (3) exchanges heat with the water for the non-stable cold source cooling device flowing in through the high-temperature water inlet pipe (5), so that the heat in the water for the non-stable cold source cooling device is absorbed and flows back to the non-stable cold source cooling device from the high-temperature water outlet pipe (4).

7. The energy cascade utilization system of the combined compression and evaporation refrigeration according to claim 2 is characterized in that: The water-cooled chiller (2) is further provided with a compressor (20), which draws in the low-pressure and low-temperature refrigerant gas in the water-cooled chiller (2) and increases its temperature and pressure by compressing and pressurizing it, thereby turning it into a high-temperature and high-pressure refrigerant gas; The secondary cooling water in the condenser (17) performs heat exchange with the high-temperature and high-pressure refrigerant gas, so that the heat in the refrigerant gas is absorbed, thereby cooling the refrigerant gas and condensing it into a high-pressure refrigerant liquid.

8. The energy cascade utilization system of the combined compression and evaporation refrigeration according to claim 7 is characterized in that: The water-cooled chiller (2) is further provided with an expansion valve (18), and the expansion valve (18) releases the high-pressure refrigerant liquid into the evaporator at a constant speed, thereby converting it into a low-temperature and low-pressure refrigerant; The evaporator (19) exchanges heat with the water for the stable cold source cooling device flowing in from the low-temperature water inlet pipe (7) through the low-temperature low-pressure refrigerant, so that the heat in the water for the stable cold source cooling device is absorbed and flows back to the stable cold source cooling device from the low-temperature water outlet pipe (6).

9. A method for cascaded utilization of energy for combined compression and evaporation refrigeration, based on the cascaded utilization system for combined compression and evaporation refrigeration according to any one of claims 1 to 8, characterized in that: The steps include: S1, generates primary cooling water through evaporative cooling chiller and flows into plate heat exchanger; S2, the plate heat exchanger unit exchanges heat with the liquid flowing into the high-temperature water inlet pipe through the primary cooling water to generate high-temperature water after primary cooling, and transports the high-temperature water to the non-stable cold source cooling equipment through the high-temperature water outlet pipe; S3, the primary cooling water in the plate heat exchanger absorbs heat and heats up to form secondary cooling water and flows into the water-cooled chiller; S4, the water-cooled chiller cools the liquid flowing into the low-temperature water inlet pipe with the secondary cooling water to generate secondary cooled low-temperature water, and delivers the low-temperature water to the stable cold source cooling device through the low-temperature water outlet pipe; S5, according to the water consumption demand ratio of the unstable cold source cooling equipment and the stable cold source cooling equipment, adjust the opening of the middle interface of the electric three-way valve in real time to control the secondary cooling water flow returning to the water-cooled chiller and flowing into the evaporative cooling chiller.

10. The energy cascade utilization method of compression-evaporation combined refrigeration according to claim 9, characterized in that: The real-time adjustment of the opening of the intermediate interface of the electric three-way valve specifically includes: 1) When the water demand ratio of the non-stable cold source cooling equipment decreases, the opening of the middle interface of the electric three-way valve is increased to allow more secondary cooling water flowing out of the secondary cooling water outlet pipe to flow into the secondary cooling water inlet pipe through the bypass pipe for secondary utilization; 2) When the water demand ratio of the non-stable cold source cooling equipment increases, the opening of the middle interface of the electric three-way valve is reduced to allow more secondary cooling water flowing out of the secondary cooling water outlet pipe to flow into the evaporative cooling chiller for cooling.

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