Cigarette factory waste heat recovery system and method

Abstract

The invention relates to the technical field of waste heat recovery, and discloses a cigarette factory waste heat recovery system and method.The cigarette factory waste heat recovery system comprises a cold supply loop, and the cold supply loop comprises a refrigerating machine group, a heat pump energy storage unit, a plurality of heat exchangers and a plurality of cold using equipment groups; all the cooling equipment groups are circularly communicated with the refrigerating machine group through pipelines in a parallel connection manner; the heat exchanger is used for transferring waste heat generated by the production system into a heat-conducting medium of the cold supply loop, and the heat pump energy storage unit is arranged at the outlet end of the cold supply loop and can recycle and store heat in the heat-conducting medium of the heat pump energy storage unit. According to the waste heat recovery system for the cigarette factory, the cold supply loops spread all over the production system are utilized, waste heat is recovered into the heat-conducting medium which is heated after heat exchange is completed through the multiple heat exchangers, heat in the heat-conducting medium is transferred and stored through the heat pump energy storage unit, and comprehensive recovery of the production waste heat of the cigarette factory is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of waste heat recovery, and in particular to a waste heat recovery system and method for a cigarette factory. Background Art

[0002] During the cigarette production process, a large amount of waste heat is generated in various production areas, including the tobacco-making workshop, the cigarette-rolling and packaging workshop, and the alcoholization warehouse. This waste heat is directly discharged and dissipated into the environment, resulting in energy waste and increasing production energy costs.

[0003] Therefore, it is very necessary to develop a comprehensive waste heat recovery and utilization system for the entire area of a cigarette factory to achieve efficient utilization of energy in cigarette production. Summary of the Invention

[0004] The purpose of the present invention is to develop a comprehensive waste heat recovery and utilization system for the entire area of a cigarette factory.

[0005] In order to achieve the above-mentioned purpose, the present invention provides a waste heat recovery system for a cigarette factory, which includes a cooling circuit, which includes a refrigeration group, a heat pump energy storage unit, multiple heat exchangers and multiple cooling equipment groups; all cooling equipment groups are circulated and connected with the refrigeration group through pipelines and in parallel; the heat exchanger is used to transfer the waste heat generated by the production system to the heat transfer medium of the cooling circuit, and the heat pump energy storage unit is arranged at the outlet end of the cooling circuit and can recover and store the heat in its heat transfer medium.

[0006] In some embodiments, the cooling circuit also includes a refrigeration system water distributor, which is arranged at the inlet end of the cooling circuit and is connected to the outlet of the evaporation end of the refrigeration group. The refrigeration system water distributor can adjust the flow rate of the heat transfer medium flowing to each cooling equipment group.

[0007] In some embodiments, the cooling circuit also includes a refrigeration system water collector, which is arranged at the outlet end of the cooling circuit and its heat transfer medium outlet is connected to the inlet of the evaporation end of the refrigeration group. All cooling equipment groups are connected to the heat transfer medium inlet of the refrigeration system water collector through pipes. The refrigeration system water collector can collect the heat transfer medium flowing through all cooling equipment groups.

[0008] In some embodiments, the heat pump energy storage unit includes a heat pump unit and a hot water storage tank. The evaporation end of the heat pump unit is in circulation communication with the refrigeration system water collector, and the condensation end of the heat pump unit is in circulation communication with the hot water storage tank.

[0009] In some embodiments, the inlet of the evaporation end of the heat pump unit is connected to the opening on the side of the refrigeration system collector where the heat transfer medium is provided. The outlet of the evaporation end of the heat pump unit is connected to the opening on the side of the refrigeration system collector where the heat transfer medium is provided.

[0010] In some embodiments, the inlet of the evaporation end of the heat pump unit is connected to the outlet of the condensation end of the refrigeration group, and the outlet of the evaporation end of the heat pump unit is connected to the inlet of the condensation end of the refrigeration group.

[0011] In some embodiments, the production system includes multiple production units, the multiple production units include a silk production unit, and the multiple cooling equipment groups include a silk cooling equipment group located in the silk production unit; the silk production unit includes a silk water collector, and the silk cooling equipment group includes multiple silk cooling equipment, and all silk cooling equipment are circulated and connected to the refrigeration group through the silk water collector; the silk production unit is equipped with odor removal equipment, dust removal equipment and vacuum equipment, and the three transfer the waste heat generated by them to the heat transfer medium of the cooling circuit through heat exchangers; the silk production unit is equipped with a silk heat pump energy storage unit, and the silk heat pump energy storage unit is circulated and connected to the silk water collector to recover the heat stored in its heat transfer medium.

[0012] In some embodiments, the production system includes multiple production units, including an alcoholization production unit, and the multiple cooling equipment groups include an alcoholization air conditioner installed in the alcoholization production unit, and the alcoholization air conditioner is cyclically connected to the refrigeration group; the alcoholization production unit transfers the waste heat generated by it to the heat transfer medium of the cooling circuit through a heat exchanger, and the heat storage tank is cyclically connected to the alcoholization air conditioner.

[0013] In some embodiments, the hot water storage tank is connected to an auxiliary heating device, which is used to heat the water in the hot water storage tank.

[0014] On the other hand, the present invention provides a method for recovering waste heat from a cigarette factory. The method utilizes the chilled water circulation of a refrigeration group to recover the waste heat generated in each production area into chilled water that has been heated after heat exchange with the cooling equipment through multiple heat exchangers. A heat pump system is set at the end of the chilled water circulation returning to the refrigeration group to recover the heat carried by the heated chilled water and store it in the heat pump system.

[0015] The above technical solution of the present invention has the following beneficial effects: The refrigeration group can transport the low-temperature heat-conducting medium to each cold-using equipment group through the cold supply circuit to meet the cold demand of the cold-using equipment group. The heat-conducting medium is heated after heat exchange in the cold-using equipment group. At the same time, the waste heat generated in the production system is transferred to the heated heat-conducting medium flowing in the cold supply circuit through multiple heat exchangers. The heated heat-conducting medium continues to be transmitted along the cold supply pipeline to the heat pump energy storage unit. The heat pump energy storage unit transfers and stores the heat in the heat-conducting medium. At the same time, the heat-conducting medium is initially cooled, and then the heat-conducting medium enters the refrigeration group again for cooling treatment. The waste heat recovery system of the cigarette factory of the present invention utilizes the cold supply circuit distributed throughout the production system, recovers the waste heat to the heat-conducting medium that has been heated after the heat exchange through multiple heat exchangers, and transfers and stores the heat in the heat-conducting medium through the heat pump energy storage unit, thereby realizing the comprehensive recovery of waste heat from the cigarette factory production. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 FIG. 1 is a schematic diagram of a waste heat recovery system according to an embodiment of the present invention.

[0017] Description of Reference Numerals 1. Refrigeration unit; 2. Refrigeration system water distributor; 3. Heat pump energy storage unit; 4. Production unit; 5. Coil production unit; 8. Coil cooling equipment group; 10. Coil water collector; 7. Silk-making cooling equipment group; 9. Silk-making water collector; 11. Silk-making heat pump unit; 12. Silk-making heat storage tank; 13. Odor removal equipment; 14. Dust removal equipment; 15. Vacuum equipment; 16. Heat exchanger; 17. Air compressor equipment; 18. Boiler equipment; 19. Alcohol production unit; 6. Alcohol air conditioning; 20. Heat storage tank; 21. Heat pump unit; 22. Refrigeration system water collector. DETAILED DESCRIPTION

[0018] The following is a detailed description of the specific embodiments of the present invention. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0019] In the present invention, unless otherwise specified, directional terms such as "upper" and "lower" generally refer to directions in the assembled state. "Inside" and "outside" refer to inside and outside relative to the outline of each component itself.

[0020] It should be noted that the terms "first," "second," and the like in the specification and claims of the present invention and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate for the embodiments of the present invention described herein. In addition, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to these processes, methods, products, or apparatuses.

[0021] like Figure 1 As shown, the present invention provides a waste heat recovery system for a cigarette factory, which includes a cooling circuit, which includes a refrigeration group 1, a heat pump energy storage unit 3, multiple heat exchangers 16 and multiple cooling equipment groups; all cooling equipment groups are circulated and connected with the refrigeration group 1 through pipelines and in parallel; the heat exchanger 16 is used to transfer the waste heat generated by the production system to the heat transfer medium of the cooling circuit, and the heat pump energy storage unit 3 is arranged at the outlet end of the cooling circuit and can recover and store heat in its heat transfer medium.

[0022] Specifically, the refrigeration group 1 can transport the low-temperature heat-conducting medium to each cold-using equipment group through the cold supply circuit to meet the cold demand of the cold-using equipment group. The heat-conducting medium is heated after heat exchange in the cold-using equipment group. At the same time, the waste heat generated in the production system is transferred to the heated heat-conducting medium flowing in the cold supply circuit through multiple heat exchangers 16. The heated heat-conducting medium continues to be transmitted along the cold supply pipeline to the heat pump energy storage unit 3. The heat pump energy storage unit 3 transfers and stores the heat in the heat-conducting medium. At the same time, the heat-conducting medium is initially cooled, and then the heat-conducting medium enters the refrigeration group 1 again for cooling treatment. The waste heat recovery system of the cigarette factory of the present invention utilizes the cold supply circuit distributed throughout the production system, recovers the waste heat to the heat-conducting medium that has been heated after the heat exchange through multiple heat exchangers 16, and transfers and stores the heat in the heat-conducting medium through the heat pump energy storage unit 3, thereby realizing the comprehensive recovery of waste heat from the cigarette factory production.

[0023] It should be noted that, along the flow direction of the heat transfer medium in the cooling circuit, the heat exchanger 16 is arranged behind the cooling equipment group to transfer the residual heat to the heated heat transfer medium.

[0024] In some embodiments of the present invention, the cooling circuit also includes a refrigeration system water distributor 2, which is arranged at the inlet end of the cooling circuit and is connected to the outlet of the evaporation end of the refrigeration group 1. The refrigeration system water distributor 2 can adjust the flow rate of the heat transfer medium flowing to each cooling equipment group.

[0025] Specifically, all the cooling equipment groups are connected in parallel through the cooling circuit, and the refrigeration system water distributor 2 can reasonably control the flow of the cooling circuit where each cooling equipment group is located according to demand.

[0026] In some embodiments of the present invention, the cooling circuit also includes a refrigeration system water collector 22, which is arranged at the outlet end of the cooling circuit and its heat transfer medium outlet is connected to the inlet of the evaporation end of the refrigeration group 1. All cooling equipment groups are connected to the heat transfer medium inlet of the refrigeration system water collector 22 through pipelines. The refrigeration system water collector 22 can collect the heat transfer medium flowing through all cooling equipment groups.

[0027] Specifically, the heated heat transfer medium after heat exchange with the cooling equipment group is collected into the refrigeration system collector 22 through the cooling circuit.

[0028] In some embodiments of the present invention, the heat pump energy storage unit 3 includes a heat pump unit 21 and a hot water storage tank 20, the evaporation end of the heat pump unit 21 is in circulation communication with the refrigeration system water collector 22, and the condensation end of the heat pump unit 21 is in circulation communication with the hot water storage tank 20.

[0029] Specifically, the heat transfer medium in the refrigeration system water collector 22 enters the evaporation end of the heat pump unit 21 for heat exchange. The evaporation end of the heat pump unit 21 absorbs the heat in the heat transfer medium and transfers it to the hot water storage tank 20 for storage through the condensation end of the heat pump unit 21. At the same time, the heat transfer medium after preliminary cooling returns to the refrigeration system water collector 22 from the evaporation end of the heat pump unit 21 and continues to flow to the refrigeration group 1.

[0030] In some embodiments of the present invention, the inlet of the evaporation end of the heat pump unit 21 is connected to the opening of the refrigeration system collector 22 on the side where the heat transfer medium is provided. The outlet of the evaporation end of the heat pump unit 21 is connected to the opening of the refrigeration system collector 22 on the side where the heat transfer medium is provided.

[0031] Specifically, the evaporation end of the heat pump unit 21 introduces heat transfer medium into its internal pipes from the side of the refrigeration system manifold 22 where the heat transfer medium enters for heat exchange. The initially cooled heat transfer medium is then transported back to the side of the refrigeration system manifold 22 that is connected to the refrigeration cluster 1. This arrangement prevents the cooled heat transfer medium from re-entering the evaporation end of the heat pump unit 21.

[0032] In some embodiments of the present invention, the inlet of the evaporation end of the heat pump unit 21 is connected to the outlet of the condensation end of the refrigeration group 1, and the outlet of the evaporation end of the heat pump unit 21 is connected to the inlet of the condensation end of the refrigeration group 1.

[0033] Specifically, the heat pump unit 21 can transfer the heat in the cooling medium used to cool the heat transfer medium of the refrigeration group 1 to the hot water storage tank 20 through the heat pump unit 21. Figure 1 As shown, the cooling medium flows out of the condensing end of refrigeration cluster 1, merges with the heat transfer medium through a pipeline, and enters the evaporation end of heat pump unit 21 for heat exchange. After cooling, it and the heat transfer medium return through two branches to the condensing end of refrigeration cluster 1 and the refrigeration system water collector 22, respectively. Of course, this configuration is based on the premise that the heat transfer medium and the cooling medium are the same medium, for example, water is used for both the heat transfer medium and the cooling medium.

[0034] In some embodiments of the present invention, the production system includes multiple production units 4, the multiple production units 4 include a silk production unit, and the multiple cooling equipment groups include a silk cooling equipment group 7 located in the silk production unit; the silk production unit includes a silk collecting water tank 9, and the silk cooling equipment group 7 includes multiple silk cooling equipment, all of which are circulated and connected to the refrigeration group 1 through the silk collecting water tank 9; the silk production unit is provided with odor removal equipment 13, dust removal equipment 14 and vacuum equipment 15, and the three respectively transfer the waste heat generated by them to the heat transfer medium of the cooling circuit through the heat exchanger 16; the silk production unit is equipped with a silk heat pump energy storage unit, and the silk heat pump energy storage unit is circulated and connected to the silk collecting water tank 9 to recover the heat stored in its heat transfer medium.

[0035] Specifically, in order to quickly meet the higher heat demands of some production units 4, a heat recovery device is separately installed in the area of these production units 4 to supply heat to these production units 4. For example, in the silk-making cold workshop, the heated heat-conducting medium, after undergoing heat exchange with the silk-making cold equipment group 7, is first extracted heat by the silk-making heat pump energy storage unit in this workshop, and then collected in the refrigeration system water collector 22 for further extraction by the heat pump energy storage unit 3. Before the silk-making heat pump energy storage unit extracts heat, the odor removal equipment 13, dust removal equipment 14, and vacuum equipment 15 respectively transfer the waste heat generated by them to the heat-conducting medium through the heat exchanger 16 for heat extraction by the silk-making heat pump energy storage unit. After the silk-making heat pump energy storage unit extracts heat, other waste heat in the production system (such as heat generated by the air compressor equipment 17 and boiler equipment 18) is also transferred to the heat-conducting medium through the heat exchanger 16 for heat extraction by the heat pump energy storage unit 3.

[0036] In addition, the silk-making heat pump energy storage unit is similar to the heat pump energy storage unit 3 of the overall waste heat recovery system of the cigarette factory. It has a silk-making heat pump unit 11 and a silk-making hot water storage tank 12. The silk-making heat pump unit 11 is circulated with the silk-making water collector 9 to extract heat from the heat-conducting medium in the silk-making water collector 9. The silk-making hot water storage tank 12 exchanges heat with the silk-making water collector 9 to store the heat and realizes heat supply when the silk-making production unit needs it.

[0037] In some embodiments, the roll production unit 5 is similar to the silk production unit, and has a roll cooling equipment group 8 and a roll water collector 10. The roll water collector 10 is equipped with a roll heat pump energy storage unit 3 to absorb the heat of the heat-conducting medium in the roll water collector 10 and supply heat to the roll production unit 5.

[0038] In some embodiments of the present invention, the production system includes multiple production units 4, including an alcoholization production unit 19, and multiple cooling equipment groups include an alcoholization air conditioner 6 arranged in the alcoholization production unit 19, and the alcoholization air conditioner 6 is circulated with the refrigeration group 1; the alcoholization production unit 19 transfers the waste heat generated by it to the heat transfer medium of the cooling circuit through the heat exchanger 16, and the heat storage tank 20 is circulated with the alcoholization air conditioner 6.

[0039] Specifically, the alcoholization workshop has repeated cooling and heating requirements, so the alcoholization workshop is equipped with a heat exchanger 16 to collect waste heat to meet the heating requirements of the alcoholization air conditioner 6, and the heat storage tank 20 can continuously provide heat for other equipment in the alcoholization production unit 19.

[0040] In some embodiments of the present invention, the hot water storage tank 20 is connected to an auxiliary heating device, and the auxiliary heating device is used to heat the water in the hot water storage tank 20 .

[0041] Specifically, in order to fill the heat supply gap of the cigarette factory, an auxiliary heating device can be used to heat the water in the heat storage tank 20 to increase the temperature.

[0042] In some embodiments, the auxiliary heating device can be used as an electric heater and can utilize low-price peak and valley electricity at night to heat the hot water storage tank 20, thereby saving overall production costs.

[0043] On the other hand, the present invention provides a method for recovering waste heat from a cigarette factory. The method utilizes the chilled water circulation of the refrigeration group 1 to recover the waste heat generated in each production area into the chilled water that has been heated after heat exchange with the cooling equipment through multiple heat exchangers 16, and a heat pump system is set at the end of the chilled water circulation returning to the refrigeration group 1 to recover the heat carried by the heated chilled water and store it in the heat pump system.

[0044] refer to Figure 1 , the overall operation process of the cigarette factory waste heat recovery system of the present invention is described again below.

[0045] The low-temperature heat-conducting medium produced by the refrigeration group 1 enters the cooling circuit and, through the diversion effect of the refrigeration system water distributor 2, flows to the branches of the cooling circuit where different production units 4 are located according to the cooling needs of each production unit 4, thereby providing cooling for the cooling equipment group in the production unit 4. The low-temperature heat-conducting medium is heated after heat exchange with the cooling equipment group, returns to the cooling circuit, and continues to be transported downward. On the journey of the heated heat-conducting medium returning to the refrigeration group 1, multiple heat exchangers 16 are provided to recover the waste heat of the production system into the heated heat-conducting medium. At the end of the cooling circuit, the heat-conducting medium converges into the refrigeration system water collector 22, and the heat pump unit 21 can extract the heat-conducting medium from the refrigeration system water collector 22 to its evaporation end for heat exchange, so as to transfer the heat in the heat-conducting medium and store it in the hot water storage tank 20. The heat transfer medium cooled at the evaporation end of the heat pump unit 21 returns to the refrigeration system water collector 22 and finally enters the refrigeration group 1 for further cooling, so as to enter the circulation of the cooling circuit again.

[0046] Because the silk production unit has a high heat demand, a silk production heat pump energy storage unit and a heat exchanger 16 for recovering excess heat from the odor removal equipment 13, dust removal equipment 14, and vacuum equipment 15 are installed on the branch of the cooling circuit where the silk production unit is located. This heat exchanger 16 stores the excess heat in the heated heat transfer medium after being used by the silk production cooling equipment group 7. The heat in the heat transfer medium is then extracted by the silk production heat pump energy storage unit for use by the silk production unit. The heat transfer medium, after being dehumidified, returns to the cooling circuit and continues to flow downward.

[0047] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0048] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. To avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0049] In addition, the various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A waste heat recovery system for a cigarette factory, characterized in that: It comprises a cooling circuit, wherein the cooling circuit comprises a refrigeration group (1), a heat pump energy storage unit (3), a plurality of heat exchangers (16) and a plurality of cooling equipment groups; All the cooling equipment groups are connected in a cyclic manner with the refrigeration group (1) through pipelines and in parallel; The heat exchanger (16) is used to transfer the waste heat generated by the production system to the heat transfer medium of the cooling circuit. The heat pump energy storage unit (3) is arranged at the outlet end of the cooling circuit and is capable of recovering and storing heat in the heat-conducting medium.

2. The waste heat recovery system for a cigarette factory according to claim 1, characterized in that: The cooling circuit also includes a cooling system water distributor (2), The refrigeration system water distributor (2) is provided at the inlet end of the cooling circuit and is connected to the outlet of the evaporation end of the refrigeration group (1). The refrigeration system water distributor (2) is capable of regulating the flow of the heat transfer medium flowing to each of the cooling equipment groups.

3. The waste heat recovery system for a cigarette factory according to claim 2, characterized in that: The cooling circuit also includes a cooling system water collector (22), The refrigeration system water collector (22) is arranged at the outlet end of the cooling circuit and its heat transfer medium outlet is connected to the inlet of the evaporation end of the refrigeration group (1). All the cooling equipment groups are connected to the heat transfer medium inlet of the refrigeration system water collector (22) through pipelines. The refrigeration system water collector (22) can collect the heat transfer medium flowing through all the cooling equipment groups.

4. The waste heat recovery system for a cigarette factory according to claim 3, characterized in that: The heat pump energy storage unit (3) comprises a heat pump unit (21) and a hot water storage tank (20); the evaporation end of the heat pump unit (21) is in circulation communication with the refrigeration system water collector (22); and the condensation end of the heat pump unit (21) is in circulation communication with the hot water storage tank (20).

5. The waste heat recovery system for a cigarette factory according to claim 4, characterized in that: The inlet of the evaporation end of the heat pump unit (21) is communicated with the opening of the refrigeration system water collector (22) on the side provided with the heat transfer medium inlet, and the outlet of the evaporation end of the heat pump unit (21) is communicated with the opening of the refrigeration system water collector (22) on the side provided with the heat transfer medium outlet.

6. The waste heat recovery system for a cigarette factory according to claim 4, characterized in that: The inlet of the evaporation end of the heat pump unit (21) is communicated with the outlet of the condensation end of the refrigeration group (1), and the outlet of the evaporation end of the heat pump unit (21) is communicated with the inlet of the condensation end of the refrigeration group (1).

7. The waste heat recovery system for a cigarette factory according to claim 4, characterized in that: The production system comprises a plurality of production units (4), wherein the plurality of production units (4) include a silk production unit, and the plurality of cooling equipment groups include a silk production cooling equipment group (7) provided in the silk production unit; The silk production unit includes a silk water collector (9), and the silk cooling equipment group (7) includes a plurality of silk cooling equipment, and all of the silk cooling equipment are circulated and connected through the silk water collector (9) and the refrigeration group (1); The silk production unit is provided with an odor removal device (13), a dust removal device (14) and a vacuum device (15), which respectively transfer the waste heat generated by the three to the heat transfer medium of the cooling circuit through the heat exchanger (16); The silk production unit is equipped with a silk heat pump energy storage unit, and the silk heat pump energy storage unit is cyclically connected to the silk water collector (9) to recover and store heat in its heat transfer medium.

8. The waste heat recovery system for a cigarette factory according to claim 4, characterized in that: The production system comprises a plurality of production units (4), wherein the plurality of production units (4) include an alcoholization production unit (19), and the plurality of cooling equipment groups include an alcoholization air conditioner (6) provided in the alcoholization production unit (19), wherein the alcoholization air conditioner (6) is in cyclic communication with the refrigeration unit group (1); The alcohol production unit (19) transfers the waste heat generated by it to the heat transfer medium of the cooling circuit through the heat exchanger (16), and the heat storage tank (20) is cyclically connected to the alcohol air conditioner (6).

9. The waste heat recovery system for a cigarette factory according to claim 4, characterized in that: The hot water storage tank (20) is connected to an auxiliary heating device, and the auxiliary heating device is used to heat the water in the hot water storage tank (20).

10. A method for recovering waste heat from a cigarette factory, characterized in that: By utilizing the chilled water circulation of the refrigeration group (1), the waste heat generated in each production area is recovered into the chilled water heated after heat exchange with the refrigeration equipment through multiple heat exchangers (16), and a heat pump system is set at the end of the chilled water circulation returning to the refrigeration group (1) to recover the heat carried by the heated chilled water and store it in the heat pump system.

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