Centralized cooling station cooling system based on sewage treatment plant and control method thereof
By setting up first-stage and second-stage heat exchange units in the wastewater treatment plant, and using raw water and reclaimed water to exchange heat with the cooling water of the chiller station, the stability and efficiency problems of the cooling water system are solved, and efficient cooling of the chiller station is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUANGZHOU MUNICIPAL ENG DESIGN & RES INST CO LTD
- Filing Date
- 2025-12-22
- Publication Date
- 2026-04-14
AI Technical Summary
Centralized cooling plant cooling water systems have difficulty providing a stable cooling water source and have low heat exchange efficiency during operation.
By setting up first-stage and second-stage heat exchange units in the wastewater treatment plant, heat exchange is carried out between raw water and reclaimed water and cooling water in the chiller station, constructing closed-loop and open-loop heat exchange circuits, and optimizing the heat exchange process by combining dynamic control methods.
It effectively alleviated the cooling water source problem, improved the heat exchange efficiency of the cooling station, and provided a stable cooling water source through the water resources of the sewage treatment plant, thus promoting regional economic and environmental development.
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Figure CN121855151A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of heat exchange technology, and in particular to a centralized cooling station cooling system and its control method based on a sewage treatment plant. Background Technology
[0002] The cooling water system of a centralized cooling plant is a crucial component for ensuring the efficient operation of the refrigeration units. Its core function is to transfer the heat generated during the refrigeration process to the outside environment (usually the atmosphere) via cooling water. The heat generated by the refrigeration units is absorbed by the cooling water, and the high-temperature water (typically 35-37°C) is pumped to a cooling tower. Through the packing layer inside the tower, it comes into direct contact with the air, releasing heat into the atmosphere through evaporative and contact heat dissipation. The cooled water (typically 30-32°C) then flows back to the refrigeration units for reuse. In related technologies, centralized cooling plants require a large amount of cooling water during operation, often struggle to provide a stable cooling water source, and suffer from relatively low heat exchange efficiency.
[0003] In summary, the technical problems existing in the relevant technologies need to be improved. Summary of the Invention
[0004] The main objective of this application is to propose a centralized cooling station cooling system and its control method based on a sewage treatment plant, which can effectively alleviate the cooling water source problem of the centralized cooling station and effectively improve the heat exchange efficiency of the cooling station.
[0005] To achieve the above objectives, one aspect of this application proposes a centralized cooling station system based on a wastewater treatment plant, the system comprising: A centralized cooling station, used for centralized cooling supply; The first-stage heat exchange unit is located between the raw water inlet side of the pre-designed wastewater treatment plant and the centralized cooling station. The first-stage heat exchange unit is used to exchange heat between the raw water at the raw water inlet side and the cooling water of the centralized cooling station. The second-stage heat exchange unit is located between the reclaimed water side of the pre-designated wastewater treatment plant and the centralized cooling station. The second-stage heat exchange unit is used to exchange heat between the reclaimed water on the reclaimed water side and the cooling water of the cooling station. The centralized cooling station and the pre-designated wastewater treatment plant are planned and constructed in a coordinated manner as a whole.
[0006] In some embodiments, the first-stage heat exchange unit includes: The first heat exchanger is buried in the raw water ditch on the side of the raw water inlet and is used for indirect heat exchange with the raw water. The second heat exchanger is installed in the centralized cooling station and is used to exchange heat with the cooling water of the cooling station. The first cooling water pump is located between the first heat exchanger and the second heat exchanger. The first heat exchanger, the second heat exchanger, and the first cooling water pump are connected by a raw water side water pipe to form a first closed-loop heat exchange circuit. The first cooling water pump is used to transport raw water side cooling water in the first closed-loop heat exchange circuit.
[0007] In some embodiments, the second-stage heat exchange unit includes: The third heat exchanger has its input end connected to the reclaimed water intake pool on the reclaimed water side and its output end connected to the reclaimed water discharge pool on the reclaimed water side. The third heat exchanger is used to exchange heat with the cooling water of the cold station. The second cooling water pump is located between the third heat exchanger and the reclaimed water intake pool. The reclaimed water intake pool, the second cooling water pump, the third heat exchanger, and the reclaimed water discharge pool are connected by a reclaimed water side water pipe to form a first open direct current heat exchange pipeline. The second cooling water pump is used to transport reclaimed water side cooling water in the first open direct current heat exchange pipeline.
[0008] In some embodiments, the second-stage heat exchange unit further includes: A plate heat exchanger includes a first fluid channel and a second fluid channel. The input end of the first fluid channel is connected to the reclaimed water intake tank, and the output end of the first fluid channel is connected to the reclaimed water discharge tank. The reclaimed water intake tank, the first fluid channel, and the reclaimed water discharge tank constitute a second open-loop direct-flow heat exchange pipeline. The input end of the second fluid channel is connected to the output end of a third heat exchanger, and the output end of the second fluid channel is connected to the input end of the third heat exchanger via a second cooling water pump. The second fluid channel, the second cooling water pump, and the third heat exchanger constitute a second closed-loop circulation heat exchange circuit. The third cooling water pump is located between the input end of the first fluid flow channel and the regenerated water intake pool. The third cooling water pump is used to transport regenerated water in the second open DC heat exchange pipeline.
[0009] In some embodiments, both the reclaimed water intake pool and the reclaimed water discharge pool are located on the reclaimed water channel on the reclaimed water side, and the reclaimed water intake pool is located upstream of the reclaimed water discharge pool.
[0010] In some embodiments, the desired water channel parameters of the raw water channel are determined by preset wiping conditions of the first heat exchanger.
[0011] To achieve the above objectives, another aspect of this application proposes a control method for a centralized cooling system of a wastewater treatment plant, the method comprising the following steps: Obtain the load data of the chiller units in the centralized cooling plant; Dynamically collect preset temperature data; wherein, the preset temperature data includes raw water temperature data at the raw water inlet side and reclaimed water temperature data at the reclaimed water side; The target operating mode is determined based on the chiller unit load data, the raw water temperature data, and the reclaimed water temperature data, and then the first-stage heat exchange unit and the second-stage heat exchange unit are controlled according to the target operating mode.
[0012] In some embodiments, determining a target operating mode based on the chiller unit load data, the raw water temperature data, and the reclaimed water temperature data, and then controlling the first-stage heat exchange unit and the second-stage heat exchange unit according to the target operating mode, includes: When the chiller unit load data is determined to be greater than or equal to the preset load threshold, the target operating mode is determined to be the full-load operation mode, and then the first-stage heat exchange unit and the second-stage heat exchange unit are controlled to exchange heat according to the full-load operation mode. Alternatively, when it is determined that the chiller unit load data is less than the preset load threshold, the target operating mode is determined to be a partial load operation mode. Then, a target heat exchange unit is determined based on the raw water temperature data and the reclaimed water temperature data, so as to control the target heat exchange unit to perform heat exchange according to the partial load operation mode; wherein, the target heat exchange unit includes one of the first-stage heat exchange unit and the second-stage heat exchange unit.
[0013] In some embodiments, determining the target heat exchange unit based on the raw water temperature data and the reclaimed water temperature data, and controlling the target heat exchange unit to perform heat exchange according to the partial load operation mode, includes: The raw water temperature data and the reclaimed water temperature data are analyzed according to a preset priority principle to determine the target heat exchange unit; wherein, the preset priority principle includes a priority principle for condensation heat exchange efficiency; The target heat exchange unit is controlled to perform heat exchange according to the partial load operation mode.
[0014] In some embodiments, the step of analyzing the raw water temperature data and the reclaimed water temperature data according to a preset priority principle to determine the target heat exchange unit includes: When it is determined that the raw water temperature data is less than the reclaimed water temperature data, it is determined that the first-stage heat exchange unit meets the priority principle of condensation heat exchange efficiency, and the first-stage heat exchange unit is then used as the target heat exchange unit. Alternatively, if it is determined that the raw water temperature data is greater than the reclaimed water temperature data, and the second-stage heat exchange unit meets the priority principle of condensation heat exchange efficiency, then the second-stage heat exchange unit is selected as the target heat exchange unit.
[0015] The embodiments of this application include at least the following beneficial effects: This application provides a centralized cooling station cooling system and its control method based on a wastewater treatment plant. The system includes a centralized cooling station, a first-stage heat exchange unit, and a second-stage heat exchange unit. The first-stage heat exchange unit is located between the raw water inlet side of the wastewater treatment plant and the centralized cooling station, and is used for heat exchange between the raw water on the raw water side and the cooling water of the centralized cooling station. Simultaneously, the second-stage heat exchange unit is located between the reclaimed water side of the wastewater treatment plant and the centralized cooling station, and is used for heat exchange between the reclaimed water on the reclaimed water side and the cooling water of the cooling station. The centralized cooling station and the wastewater treatment plant are planned and constructed collaboratively as a whole. It is easy to understand that the embodiments of the present invention provide the necessary water source for the centralized cooling station by coordinating the overall planning and construction of the centralized cooling station with the pre-set sewage treatment plant, and then constructing the first-stage heat exchange unit and the second-stage heat exchange unit based on the pre-set sewage treatment plant. This effectively alleviates the cooling water source problem of the centralized cooling station. At the same time, by using the first-stage heat exchange unit and the second-stage heat exchange unit to exchange heat with the centralized cooling station, and then using the centralized cooling station for centralized cooling, the heat exchange efficiency of the cooling station is effectively improved. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of a centralized cooling station system based on a sewage treatment plant, provided by an embodiment of the present invention. Figure 2 This is a schematic diagram of another centralized cooling station cooling system based on a sewage treatment plant provided in an embodiment of the present invention; Figure 3 This is a flowchart of the steps of the control method for a centralized cooling station cooling system based on a sewage treatment plant provided in an embodiment of the present invention. Detailed Implementation
[0017] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit it. In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with those of this application; they are merely examples of apparatuses and methods consistent with some aspects of the embodiments of this application as detailed in the appended claims.
[0018] It is understood that the terms “first,” “second,” etc., used in this application may be used herein to describe various concepts, but unless otherwise stated, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another. For example, without departing from the scope of the embodiments of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the words “if,” “when,” or “in response to a determination” as used herein may be interpreted as “when…” or “when…” or “in response to a determination.”
[0019] As used in this application, the terms "at least one", "multiple", "each", "any", etc., "at least one" includes one, two or more, "multiple" includes two or more, "each" refers to each of the corresponding multiples, and "any" refers to any one of the multiples.
[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.
[0021] Before providing a detailed description of the embodiments of this application, some of the nouns and terms involved in the embodiments of this application will be explained first. The nouns and terms involved in the embodiments of this application are subject to the following interpretations.
[0022] Raw water refers to the wastewater awaiting treatment at the wastewater treatment plant. It is the core water resource source for wastewater treatment plants and mainly includes: domestic sewage (sewage generated from daily life of residents, such as drainage from washing, kitchens, and toilets), industrial wastewater (sewage discharged during industrial production processes, such as manufacturing, chemical, and food processing), and initial rainwater (highly polluted rainwater runoff generated in the initial stage of rainfall).
[0023] Reclaimed water is the core product of wastewater treatment plants in "turning waste into treasure". Its utilization not only saves fresh water resources, but also reduces the pollution of the environment caused by direct discharge of sewage. Its main application scenarios include industrial reuse (as industrial cooling water and process water), agricultural irrigation (for irrigation of farmland, orchards and nurseries), miscellaneous uses (as watering for urban greening, road cleaning, public toilet flushing, landscape water replenishment, etc.), ecological water replenishment (replenishing rivers, lakes, wetlands and other water bodies to improve the ecological environment), and groundwater recharge (injecting into underground aquifers to replenish groundwater).
[0024] The cooling water system of a centralized cooling plant is a crucial component for ensuring the efficient operation of the refrigeration units. Its core function is to transfer the heat generated during the refrigeration process to the outside environment (usually the atmosphere) via cooling water. The heat generated by the refrigeration units is absorbed by the cooling water, and the high-temperature water (typically 35-37°C) is pumped to a cooling tower. Through the packing layer inside the tower, it comes into direct contact with the air, releasing heat into the atmosphere through evaporative and contact heat dissipation. The cooled water (typically 30-32°C) then flows back to the refrigeration units for reuse. In related technologies, centralized cooling plants require a large amount of cooling water during operation, often struggle to provide a stable cooling water source, and suffer from relatively low heat exchange efficiency.
[0025] For example, a traditional centralized cooling plant typically includes cooling towers, cooling water pumps, pipes, valves, filters, a water replenishment system (to add fresh water due to evaporation / sewage losses), and water treatment equipment (such as chemical dosing devices to prevent scaling, corrosion, and microbial growth). The footprint required for the cooling tower in a centralized cooling plant varies depending on the plant's size, cooling capacity, refrigeration process, and site conditions. Generally, a small centralized cooling plant's cooling tower may occupy several hundred square meters, while a large one can reach several thousand square meters. Furthermore, during operation, cooling towers may experience problems such as Legionella growth, white mist (smoke), water drift, and noise. These issues not only concern public health and safety but may also affect the surrounding environment and operational efficiency. Simultaneously, the heat exchange capacity of a cooling tower is the result of the combined effects of environmental conditions, equipment design, and operational management. Its core function is to achieve efficient cooling of circulating water by enhancing the heat and moisture exchange between water and air. The cooling limit of a cooling tower is close to the local wet-bulb temperature (water cannot be cooled below the wet-bulb temperature). The lower the wet-bulb temperature, the greater the heat exchange potential; conversely, the higher the wet-bulb temperature, the smaller the heat exchange potential.
[0026] In view of this, this application provides a centralized cooling station cooling system and its control method based on a wastewater treatment plant. The system includes a centralized cooling station, a first-stage heat exchange unit, and a second-stage heat exchange unit. The first-stage heat exchange unit is located between the raw water inlet side of the wastewater treatment plant and the centralized cooling station, and is used for heat exchange between the raw water and the cooling water of the centralized cooling station. Simultaneously, the second-stage heat exchange unit is located between the reclaimed water side of the wastewater treatment plant and the centralized cooling station, and is used for heat exchange between the reclaimed water and the cooling water of the centralized cooling station. This invention, by constructing the first and second-stage heat exchange units based on a wastewater treatment plant, can provide the necessary water source for the centralized cooling station, effectively alleviating the cooling water source problem. Furthermore, by using the first and second-stage heat exchange units to exchange heat with the centralized cooling station, and then using the centralized cooling station for centralized cooling, the heat exchange efficiency of the cooling station is effectively improved.
[0027] Reference Figure 1The centralized cooling system based on a wastewater treatment plant provided in this embodiment of the invention includes a centralized cooling station 113, a first-stage heat exchange unit, and a second-stage heat exchange unit. Specifically, in this embodiment, the centralized cooling station 113 is used for centralized cooling. For example, chilled water from the centralized cooling station's chilled water circuit is pumped through a centralized cooling station chilled water pump to provide centralized cooling to target users. Correspondingly, in this embodiment, the first-stage heat exchange unit is located between the raw water inlet side of the pre-designated wastewater treatment plant 104 and the centralized cooling station, and is used to achieve heat exchange between the raw water at the raw water inlet side and the cooling water of the centralized cooling station, providing a first-stage heat source for the centralized cooling station. In addition, in this embodiment, the second-stage heat exchange unit is located between the reclaimed water side of the pre-designated wastewater treatment plant 104 and the centralized cooling station, and is used to achieve heat exchange between the reclaimed water on the reclaimed water side and the cooling water of the cooling station, providing a second-stage heat source for the centralized cooling station. In this embodiment, the wastewater treatment plant 104 receives raw water from the raw water inlet via the raw water pipe 103. After purification treatment, reclaimed water is generated and discharged from the reclaimed water channel 105 on the reclaimed water side of the wastewater treatment plant 104. Correspondingly, this embodiment of the invention utilizes the water resources of the wastewater treatment plant 104 to provide cooling water to the centralized cooling station 113 via a cooling water treatment device (cooling tower). By setting a first-stage heat exchange unit on the raw water inlet side of the wastewater treatment plant 104, the raw water exchanges heat with the centralized cooling station through the first-stage heat exchange unit. Simultaneously, a second-stage heat exchange unit is set on the reclaimed water side of the wastewater treatment plant 104, and the reclaimed water exchanges heat with the centralized cooling station through the second-stage heat exchange unit. This effectively improves the heat exchange efficiency of the cooling station. Furthermore, by using the raw water and reclaimed water from the wastewater treatment plant 104 as the cooling water source for the centralized cooling station, a stable cooling water source can be provided, effectively alleviating the cooling water source problem of the centralized cooling station. Accordingly, in this embodiment of the invention, the wastewater treatment plant and the centralized cooling station are planned and constructed in a coordinated manner, thereby alleviating the cooling water source problem of the centralized cooling station through the water resources of the wastewater treatment plant, effectively improving the heat exchange efficiency of the centralized cooling station cooling system, and promoting the regional economic, environmental protection and low-carbon development.
[0028] Reference Figure 1In some embodiments of the present invention, the first-stage heat exchange unit includes a first heat exchanger 102, a second heat exchanger 111, and a first cooling water pump 109. Specifically, in this embodiment, the first heat exchanger 102 is a raw water-side heat exchange pipe buried in a raw water ditch 101 at the raw water inlet side of a pre-designated wastewater treatment plant 104. In this embodiment, the first heat exchanger 102 indirectly exchanges heat with the raw water flowing through the raw water ditch 101. Furthermore, in this embodiment, the second heat exchanger 111 is a raw water-side condensing heat exchanger installed in a centralized cooling station 113, through which heat is exchanged with the cooling water in the centralized cooling station 113. Meanwhile, in this embodiment, the first cooling water pump 109 is located between the first heat exchanger 102 and the second heat exchanger 111. In this embodiment of the invention, the output end of the first heat exchanger 102 is connected to the input end of the second heat exchanger 111 through the raw water side cooling water inlet pipe 108, and the output end of the second heat exchanger 111 is connected to the input end of the first heat exchanger 102 through the raw water side cooling water outlet pipe 110. The first cooling water pump 109 is installed on the raw water side cooling water outlet pipe 110, thereby forming a first closed-loop heat exchange circuit between the first heat exchanger 102, the second heat exchanger 111 and the first cooling water pump 109, and providing power to the raw water side cooling water in the circuit through the first cooling water pump 109. For example, the first cooling water pump 109 draws the high-temperature cooling water (the fluid in the raw water side cooling water outlet pipe 110) from the second heat exchanger 111 installed in the centralized cooling station 113 to the raw water side heat exchange pipe (first heat exchanger 102) buried in the raw water ditch. After indirect heat exchange with the raw water, it forms low-temperature cooling water (i.e., the fluid in the raw water side cooling water inlet pipe 108), which is then transported back to the second heat exchanger 111 in the centralized cooling station for heat exchange, and so on.
[0029] Reference Figure 1In some embodiments of the present invention, the second-stage heat exchange unit includes a third heat exchanger 112 (a reclaimed water-side condensing heat exchanger) and a second cooling water pump 114. Specifically, in this embodiment, the input end of the third heat exchanger 112 is connected to the reclaimed water intake pool 106 on the reclaimed water side of the pre-designated wastewater treatment plant 104, while the output end of the third heat exchanger 112 is connected to the reclaimed water discharge pool 107 on the reclaimed water side of the pre-designated wastewater treatment plant 104, which is used for heat exchange with the cooling water of the centralized cooling station 113. Meanwhile, in this embodiment, a second cooling water inlet pipe 115 is provided between the third heat exchanger 112 and the reclaimed water intake pool 106, that is, on the reclaimed water-side cooling water inlet pipe 115 connecting the third heat exchanger 112 and the reclaimed water intake pool 106. Accordingly, in this embodiment of the invention, the reclaimed water intake tank 106, the second cooling water pump 114, the third heat exchanger 112, and the reclaimed water discharge tank 107 are connected by corresponding reclaimed water side water pipes, including a reclaimed water side cooling water inlet pipe 115 and a reclaimed water side cooling water outlet pipe 116. The third heat exchanger 112 and the reclaimed water discharge tank 107 are connected through the reclaimed water side cooling water outlet pipe 116, thereby forming a first open-type direct-flow heat exchange pipeline, i.e., an open-type direct-flow heat exchange is adopted. In this embodiment of the invention, the second cooling water pump 114 delivers the reclaimed water side cooling water in the first open-type direct-flow heat exchange pipeline, thereby enabling the centralized cooling station 113 to perform heat exchange based on the reclaimed water from the pre-designated wastewater treatment plant 104. For example, the second cooling water pump 114 transports the low-temperature reclaimed water (fluid in the reclaimed water side cooling water inlet pipe 115) from the reclaimed water intake pool 106 to the reclaimed water side condenser heat exchanger (third heat exchanger 112) of the centralized cooling station 113 for indirect heat exchange, forming high-temperature cooling water (fluid in the reclaimed water side cooling water outlet pipe 116), and then transports it back to the reclaimed water discharge pool 107 of the preset sewage treatment plant 104 for discharge. Alternatively, if the preset discharge conditions are met, it can also be discharged directly near the centralized cooling station 113, which can reduce the energy consumption of transportation.
[0030] Reference Figure 2In some embodiments of the present invention, the second-stage heat exchange unit further includes a plate heat exchanger 118 and a third cooling water pump 117. Specifically, if the reclaimed water does not meet the cooling water quality requirements, the embodiments of the present invention add a third cooling water pump 117 and a plate heat exchanger 118 near the reclaimed water intake pool 106 to provide cooling water to the centralized cooling station 113 in a closed-loop cycle. In the embodiments of the present invention, the plate heat exchanger 118 includes a first fluid flow channel and a second fluid flow channel. The input end of the first fluid flow channel is connected to the reclaimed water intake pool 106 via a reclaimed water pipe 119, while the output end of the first fluid flow channel is connected to the reclaimed water discharge pool. Furthermore, in the embodiments of the present invention, the reclaimed water intake pool 106, the first fluid flow channel of the plate heat exchanger 118, and the reclaimed water discharge pool 107 constitute a second open-loop direct-flow heat exchange pipeline. Accordingly, in this embodiment of the invention, the output end of the second fluid channel of the plate heat exchanger 118 is sequentially connected to the input end of the second cooling water pump 114 and the third heat exchanger 112 via the regenerated water side cooling water inlet pipe 115. Simultaneously, the input end of the second fluid channel is connected to the output end of the third heat exchanger 112, thereby forming a second closed-loop heat exchange circuit between the second fluid channel of the plate heat exchanger 118, the second cooling water pump 114, and the third heat exchanger 112. Further, in this embodiment of the invention, the third cooling water pump 117 is positioned between the input end of the first fluid channel and the regenerated water intake tank 106, and heat exchange is performed by outputting regenerated water from the second open-loop direct-flow heat exchange pipeline through the third cooling water pump 117.
[0031] Reference Figure 1 In some embodiments of the present invention, both the reclaimed water intake pool 106 and the reclaimed water discharge pool 107 are located on the reclaimed water channel 105 on the reclaimed water side of the pre-designated wastewater treatment plant 104. Accordingly, the reclaimed water intake pool 106 is located upstream of the reclaimed water discharge pool 107, thereby facilitating the flow of reclaimed water from the reclaimed water intake pool 106 to the reclaimed water discharge pool 107 along the reclaimed water pipe, effectively improving heat exchange efficiency.
[0032] In some embodiments of the present invention, the desired channel parameters of the raw water channel 101 are determined by the preset wiping conditions of the first heat exchanger 102. Specifically, in the embodiments of the present invention, the raw water channel 101 is configured according to the raw water side heat exchange tube (first heat exchanger 102), and its desired channel parameters, including width and depth, are adjusted. Since the raw water is relatively dirty, the raw water channel 101 needs to meet the preset wiping conditions of the raw water side heat exchange tube, that is, the automatic wiping requirement, to ensure that the raw water side heat exchange tube is smooth and improve the heat exchange efficiency.
[0033] It should be noted that in this embodiment of the invention, the water resources of a pre-designated wastewater treatment plant 104 are used to replace the cooling water cooling equipment of the centralized cooling station. Therefore, the location of the centralized cooling station 113 should be as close as possible to the pre-designated wastewater treatment plant 104 to reduce pipeline resistance losses such as cooling water pipes on the raw water side and cooling water pipes on the reclaimed water side when using raw water and reclaimed water, and to effectively utilize the inlet and outlet water channels such as the raw water ditch 101 and reclaimed water ditch 105 of the wastewater treatment plant. In addition, the treatment capacity of the pre-designated wastewater treatment plant 104 determines whether the raw water and reclaimed water meet the cooling water requirements of the centralized cooling station 113. Accordingly, in this embodiment of the invention, the raw water is utilized using a closed-loop heat exchange system. The cooling water in the heat exchange pipes buried in the raw water ditch 101 exchanges heat with the raw water of the pre-designated wastewater treatment plant 104. Some indicators in the raw water, such as turbidity, total solids, hardness, and algae, affect the heat exchange effect and the frequency of sludge and algae removal of the first heat exchanger 102. Accordingly, the utilization method of reclaimed water in this embodiment of the invention adopts open direct current heat exchange, which is based on testing and meeting the standards of some indicators in the reclaimed water, such as hardness, chloride ions, and turbidity. If the quality of the reclaimed water does not meet the requirements for cooling water of the centralized cooling station 113 air conditioning system, it is necessary to add secondary heat exchange equipment or strengthen the material requirements of the heat exchange tube of the chiller condenser.
[0034] Furthermore, when constructing a centralized cooling station system based on a wastewater treatment plant in this embodiment of the invention, it is necessary to consider the pipeline routing and installation method connecting the raw water side cooling water inlet pipe 108, the raw water side cooling water outlet pipe 110, the reclaimed water side cooling water inlet pipe 115, and the reclaimed water side cooling water outlet pipe 116 from the raw water ditch 101, the reclaimed water intake pool 106, the reclaimed water discharge pool 107 to the chiller unit in the centralized cooling station 113. The closer the wastewater treatment plant 104 is to the centralized cooling station 113, the shorter the pipeline length, the lower the installation difficulty, the lower the system resistance, and the better the economic benefits. If the wastewater treatment plant 104 and the centralized cooling station 113 can be combined for unified planning and construction, the resistance loss of the raw water side and the reclaimed water side pipelines can be effectively reduced, pipeline construction excavation can be reduced, and the application efficiency of this embodiment of the invention can be maximized.
[0035] For example, during the raw water utilization process, if the average monthly temperature of the raw water from January to December is between 19.8 and 28°C, and the average monthly temperature of the centralized cooling station during the air-conditioning season from April to October is between 24.4 and 28°C, the heat exchange efficiency of the raw water side heat exchange tubes is lower than that of plate heat exchangers. In this embodiment of the invention, the heat exchange temperature difference is controlled at 2-3°C through the design of the tube length and diameter, so that the cooling water temperature t5=35-37°C in the raw water side cooling water outlet pipe 110 reaches the range of t4=30-32°C after passing through the raw water side heat exchange tube (first heat exchanger 102) into the raw water side cooling water inlet pipe 108. Correspondingly, during the reclaimed water utilization process, if the average monthly temperature t3 of the reclaimed water from January to December is between 19.4 and 29°C, and the average monthly temperature of the centralized cooling station 113 during the air-conditioning season from April to October is between 22.8 and 29°C, the heat exchange efficiency of the raw water side heat exchange tubes is lower than that of plate heat exchangers. If the reclaimed water is relatively clean, heat exchange can be directly performed in the reclaimed water side condenser heat exchanger (second heat exchanger 111) provided that the cooling water quality is met. Therefore, the cooling water temperature t6 in the reclaimed water side cooling water inlet pipe 115 is less than 29℃, and the cooling water temperature t7 in the reclaimed water side cooling water outlet pipe 116 after heat exchange is less than 34℃. Alternatively, if the reclaimed water does not meet the cooling water quality requirements, a reclaimed water pump (third cooling water pump 117) and a plate heat exchanger 118 can be added near the reclaimed water intake pool 106 to provide cooling water to the centralized cooling station 113 in a closed-loop circulation. The heat exchange temperature difference of the plate heat exchanger 118 is about 1-2℃. At this time, the provided low-temperature cooling water temperature t6' is about 30-31℃, and the high-temperature cooling water temperature t7' of the centralized cooling station 113 is about 35-36℃, both of which meet the cooling water temperature requirements of the centralized cooling station 113.
[0036] The control method for a centralized cooling station cooling system based on a wastewater treatment plant provided in this invention can effectively alleviate the cooling water source problem of the centralized cooling station and effectively improve the heat exchange efficiency of the cooling station. (Refer to...) Figure 3 The method in this embodiment of the invention includes, but is not limited to, steps S210 to S230.
[0037] Specifically, the application of the control method of the present invention to the above-mentioned centralized cooling station cooling system based on a sewage treatment plant includes, but is not limited to, the following steps: Step S210: Obtain the chiller unit load data of the centralized cooling station.
[0038] Step S220: Dynamically collect preset temperature data. The preset temperature data includes raw water temperature data at the raw water inlet and reclaimed water temperature data at the reclaimed water inlet.
[0039] Step S230: Determine the target operating mode based on the chiller unit load data, raw water temperature data, and reclaimed water temperature data, and then control the first-stage heat exchange unit and the second-stage heat exchange unit according to the target operating mode.
[0040] In the operation of this specific embodiment, the present invention first acquires the chiller unit load data of the centralized cooling station and dynamically collects preset temperature data. Then, based on the chiller unit load data and preset temperature data, it analyzes the data to determine the target operating modes of the first-stage and second-stage heat exchange units, and controls the first-stage and second-stage heat exchange units according to the target operating modes. Specifically, in this embodiment, the chiller unit load data refers to the target load of the water-cooled units of the centralized cooling station, such as full-load operation or partial-load operation. Correspondingly, the preset temperature data includes the raw water temperature data at the raw water inlet side and the reclaimed water temperature data at the reclaimed water side. This invention combines chiller load data, raw water temperature data, and reclaimed water temperature data for analysis to select at least one heat exchange unit from the first-stage and second-stage heat exchange units to perform heat exchange. That is, it determines the target operating mode of the first-stage and second-stage heat exchange units, and then controls the first-stage and second-stage heat exchange units according to the determined target operating mode. This realizes the control of the centralized chiller cooling system based on the sewage treatment plant, which can effectively alleviate the cooling water source problem of the centralized chiller and effectively improve the heat exchange efficiency of the chiller.
[0041] In some embodiments of the present invention, a target operating mode is determined based on chiller unit load data, raw water temperature data, and reclaimed water temperature data. Then, the first-stage heat exchange unit and the second-stage heat exchange unit are controlled according to the target operating mode, including but not limited to the following steps: When the chiller unit load data is determined to be greater than or equal to the preset load threshold, the target operating mode is determined to be the full-load operation mode, and then the first-stage heat exchange unit and the second-stage heat exchange unit are controlled to exchange heat according to the full-load operation mode.
[0042] Alternatively, when the chiller unit load data is determined to be less than a preset load threshold, the target operating mode is determined to be a partial load operation mode. Then, based on the raw water temperature data and reclaimed water temperature data, the target heat exchange unit is determined, and heat exchange is controlled to operate within the target heat exchange unit according to the partial load operation mode. The target heat exchange unit includes one of the first-stage heat exchange unit and one of the second-stage heat exchange units.
[0043] In this specific embodiment, the present invention first determines the target operating mode by comparing the chiller unit load data with a preset threshold. Then, it determines the target heat exchange unit from the first-stage and second-stage heat exchange units by combining raw water temperature data and reclaimed water temperature data, and controls the target heat exchange unit to perform heat exchange according to the corresponding target operating mode. Specifically, the preset load threshold in this embodiment refers to a pre-set unit load threshold. Accordingly, when the chiller unit load data is determined to be greater than or equal to the preset load threshold, the present invention determines the target operating mode as a full-load operation mode. At this time, the present invention controls the first-stage and second-stage heat exchange units to perform heat exchange according to the full-load operation mode. For example, when all chiller units in the centralized cooling plant are operating at full load, the raw water side cooling water pump (first cooling water pump) and the reclaimed water side cooling water pump (second cooling water pump) can both be simultaneously started and put into use to meet the condensation heat exchange requirements of the chiller units in the centralized cooling plant.
[0044] Furthermore, when the chiller unit load data is determined to be less than a preset load threshold, the target operating mode is determined to be a partial load operation mode. In this case, the embodiment of the invention determines the target heat exchange unit from the first-stage and second-stage heat exchange units based on the raw water temperature data and the reclaimed water temperature data, and then controls it to perform heat exchange. For example, when it is determined that the chiller unit load data is less than the preset load threshold, it means that the first-stage and second-stage heat exchange units do not need to perform heat exchange simultaneously, and the partial load operation mode is executed. Accordingly, the embodiment of the invention analyzes the raw water temperature data corresponding to the first-stage heat exchange unit and the reclaimed water temperature data corresponding to the second-stage heat exchange unit to determine the target heat exchange unit from the first-stage and second-stage heat exchange units, and then controls the corresponding target heat exchange unit to perform heat exchange.
[0045] In some embodiments of the present invention, a target heat exchange unit is determined based on raw water temperature data and reclaimed water temperature data, and the target heat exchange unit is controlled to perform heat exchange according to a partial load operation mode, including but not limited to the following steps: Based on preset priority principles, raw water temperature data and reclaimed water temperature data are analyzed to determine the target heat exchange units. These preset priority principles include a priority principle based on condensation heat exchange efficiency.
[0046] The target heat exchange unit is controlled to perform heat exchange according to the partial load operation mode.
[0047] In this specific embodiment, the present invention first analyzes the raw water temperature data and reclaimed water temperature data according to a preset priority principle to determine the target heat exchange unit, and then controls the target heat exchange unit to perform heat exchange according to the partial load operation mode. Specifically, the preset priority principle in the present invention includes a priority principle for condensation heat exchange efficiency. Accordingly, the present invention analyzes the condensation heat exchange efficiency through the raw water temperature data and reclaimed water temperature data, and then determines the target heat exchange unit from the first-stage heat exchange unit and the second-stage heat exchange unit according to the priority principle for condensation heat exchange efficiency, that is, heat exchange units with high condensation heat exchange efficiency are given priority, and controls the target heat exchange unit to perform heat exchange according to the partial load operation mode. For example, when the unit is running at partial load in a centralized cooling station, by comparing the raw water temperature t1 in the raw water ditch and the reclaimed water temperature t3 in the reclaimed water ditch, with the principle of improving the condensation heat exchange efficiency of the chiller unit, the cooling water system on the raw water side or the reclaimed water side is selected based on the priority of water temperature, that is, the first-stage heat exchange unit or the second-stage heat exchange unit is selected as the target heat exchange unit.
[0048] In some embodiments of the present invention, the raw water temperature data and reclaimed water temperature data are analyzed according to a preset priority principle to determine the target heat exchange unit, including but not limited to the following steps: When the raw water temperature is determined to be lower than the reclaimed water temperature, the first-stage heat exchange unit is determined to meet the priority principle of condensation heat exchange efficiency, and thus the first-stage heat exchange unit is selected as the target heat exchange unit.
[0049] Alternatively, if the raw water temperature is determined to be greater than the reclaimed water temperature, and the second-stage heat exchange unit is determined to meet the priority principle of condensation heat exchange efficiency, then the second-stage heat exchange unit can be used as the target heat exchange unit.
[0050] In this specific embodiment, the present invention determines the target heat exchange unit that meets the priority principle of condensation heat exchange efficiency by comparing the raw water temperature data and the reclaimed water temperature data. Specifically, when the raw water temperature data is determined to be lower than the reclaimed water temperature data, it indicates that the raw water can provide a larger heat exchange temperature difference, and the first-stage heat exchange unit is determined to meet the priority principle of condensation heat exchange efficiency. In this embodiment, the first-stage heat exchange unit is selected as the target heat exchange unit. Correspondingly, when the raw water temperature data is determined to be higher than the reclaimed water temperature data, it indicates that the reclaimed water can provide a larger heat exchange temperature difference, that is, the heat exchange efficiency of the second-stage heat exchange unit is higher than that of the first-stage heat exchange unit. In this case, the second-stage heat exchange unit is selected as the target heat exchange unit.
[0051] It should be noted that, in this embodiment of the invention, the temperature difference between the water temperature t5 in the raw water side cooling water outlet pipe and the water temperature t4 in the raw water side cooling water inlet pipe is based on the condensing temperature difference of the chiller unit in the centralized cooling station, and is achieved by adjusting the cooling water volume by controlling the frequency of the raw water side cooling water pump. Similarly, the temperature difference between the water temperature t7 in the reclaimed water side cooling water outlet pipe and the water temperature t6 in the reclaimed water side cooling water inlet pipe is based on the rated condensing temperature difference of the chiller unit in the centralized cooling station (generally 5℃, depending on the unit requirements), and is achieved by adjusting the cooling water volume by controlling the frequency of the raw water side cooling water pump.
[0052] The following section provides a detailed introduction and explanation of the solution in this embodiment of the invention, using a specific application scenario of a centralized cooling station system based on a wastewater treatment plant as an example: For example, data from a wastewater treatment plant shows that the average monthly temperature of raw water from January to December is between 19.8 and 28°C, while the average monthly temperature during the centralized cooling station's operation from April to October is between 24.4 and 28°C. Raw water within this temperature range is very suitable as an indirect heat exchange source for the centralized cooling station's cooling water system. Accordingly, in this embodiment of the invention, the first stage of utilizing wastewater resources, i.e., raw water utilization, takes place in a raw water ditch. Raw water-side heat exchange pipes are arranged in the raw water ditch. Low-temperature raw water undergoes water-to-water heat exchange with high-temperature cooling water in the raw water-side heat exchange pipes through flushing and flow, transforming the low-temperature raw water into high-temperature raw water. This high-temperature raw water is then fed into the wastewater treatment plant for treatment, transforming the high-temperature cooling water into low-temperature cooling water for use by the centralized cooling station. Correspondingly, in this embodiment of the invention, the second stage of utilizing the wastewater treatment plant's water resources refers to reclaimed water that has undergone purification treatment of raw water through physical, chemical, and biological processes at the wastewater treatment plant to meet specific water quality standards. Data from a wastewater treatment plant shows that the average monthly temperature of reclaimed water from January to December ranges from 19.4 to 29°C, while the average monthly temperature during the centralized cooling station's operation from April to October ranges from 22.8 to 29°C. Reclaimed water within this temperature range is highly suitable as an indirect heat exchange source for the centralized cooling station's cooling water system. Accordingly, the second stage of wastewater resource utilization in this embodiment, namely reclaimed water utilization, mainly involves sending the low-temperature reclaimed water from the wastewater treatment plant's reclaimed water channel to the centralized cooling station's reclaimed water side condenser heat exchanger for indirect heat exchange with the refrigeration unit's refrigerant, forming high-temperature cooling water, which is then returned to the wastewater treatment plant's reclaimed water discharge pond for discharge. Combining the wastewater treatment plant and the centralized cooling station for unified planning and construction effectively reduces pipeline resistance losses on both the raw water and reclaimed water sides, minimizes pipeline excavation, and maximizes the application efficiency of this embodiment.
[0053] It is readily understood that in this embodiment of the invention, the cooling water available for the centralized cooling plant is entirely obtained by the centralized cooling plant through the first and second stages of wastewater resource utilization, adjusted according to actual needs. Specifically, when all chiller units in the centralized cooling plant are operating at full load, both the raw water-side cooling water pumps and the reclaimed water-side cooling water pumps are simultaneously activated to meet the condensation heat exchange requirements of the chiller units. When the units in the centralized cooling plant are operating at partial load, the raw water temperature in the raw water channel and the reclaimed water temperature in the reclaimed water channel are compared to optimize the condensation heat exchange efficiency of the chiller units. The raw water-side or reclaimed water-side cooling water system is selected based on water temperature priority, thereby effectively improving the heat exchange efficiency of the cooling plant. Furthermore, by fully utilizing the stable temperature and guaranteed flow of raw water and effluent (reclaimed water) from wastewater treatment plants, this embodiment of the invention effectively alleviates many defects and difficulties associated with the installation of cooling towers in centralized cooling plants. It saves cooling tower land, improves the condensation heat exchange efficiency of the chiller units, and mitigates cooling tower drift and white mist problems, achieving the goals of land saving, water saving, energy saving, noise reduction, and hygiene improvement.
[0054] The embodiments described in this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. As those skilled in the art will know, with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.
[0055] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of this application, and may include more or fewer steps than shown, or combine certain steps, or different steps.
[0056] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.
[0057] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.
[0058] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0059] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.
[0060] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of the units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.
[0061] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.
[0062] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.
[0063] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.
Claims
1. A centralized cooling station cooling system based on a sewage treatment plant, characterized in that, The system includes: A centralized cooling station, used for centralized cooling supply; The first-stage heat exchange unit is located between the raw water inlet side of the pre-designed wastewater treatment plant and the centralized cooling station. The first-stage heat exchange unit is used to perform heat exchange between the raw water at the raw water inlet side and the cooling water of the centralized cooling station. The second-stage heat exchange unit is located between the reclaimed water side of the pre-designed wastewater treatment plant and the centralized cooling station. The second-stage heat exchange unit is used to exchange heat between the reclaimed water on the reclaimed water side and the cooling water of the cooling station. The centralized cooling station and the pre-designed wastewater treatment plant are planned and constructed in a coordinated manner as a whole.
2. The system according to claim 1, characterized in that, The first-stage heat exchange unit includes: The first heat exchanger is buried in the raw water ditch on the side of the raw water inlet and is used for indirect heat exchange with the raw water. The second heat exchanger is installed in the centralized cooling station and is used to exchange heat with the cooling water of the cooling station. The first cooling water pump is located between the first heat exchanger and the second heat exchanger. The first heat exchanger, the second heat exchanger, and the first cooling water pump are connected by a raw water side water pipe to form a first closed-loop heat exchange circuit. The first cooling water pump is used to transport raw water side cooling water in the first closed-loop heat exchange circuit.
3. The system according to claim 1, characterized in that, The second-stage heat exchange unit includes: The third heat exchanger has its input end connected to the reclaimed water intake pool on the reclaimed water side and its output end connected to the reclaimed water discharge pool on the reclaimed water side. The third heat exchanger is used to exchange heat with the cooling water of the cold station. The second cooling water pump is located between the third heat exchanger and the reclaimed water intake pool. The reclaimed water intake pool, the second cooling water pump, the third heat exchanger, and the reclaimed water discharge pool are connected by a reclaimed water side water pipe to form a first open direct current heat exchange pipeline. The second cooling water pump is used to transport reclaimed water side cooling water in the first open direct current heat exchange pipeline.
4. The system according to claim 3, characterized in that, The second-stage heat exchange unit also includes: A plate heat exchanger includes a first fluid channel and a second fluid channel. The input end of the first fluid channel is connected to the reclaimed water intake tank, and the output end of the first fluid channel is connected to the reclaimed water discharge tank. The reclaimed water intake tank, the first fluid channel, and the reclaimed water discharge tank constitute a second open-loop direct-flow heat exchange pipeline. The input end of the second fluid channel is connected to the output end of a third heat exchanger, and the output end of the second fluid channel is connected to the input end of the third heat exchanger via a second cooling water pump. The second fluid channel, the second cooling water pump, and the third heat exchanger constitute a second closed-loop circulation heat exchange circuit. The third cooling water pump is located between the input end of the first fluid flow channel and the regenerated water intake pool. The third cooling water pump is used to transport regenerated water in the second open DC heat exchange pipeline.
5. The system according to claim 3, characterized in that, Both the reclaimed water intake pool and the reclaimed water discharge pool are located on the reclaimed water channel on the reclaimed water side, and the reclaimed water intake pool is located upstream of the reclaimed water discharge pool.
6. The system according to claim 2, characterized in that, The desired water channel parameters of the raw water channel are determined by the preset wiping conditions of the first heat exchanger.
7. A control method for a centralized cooling station cooling system in a wastewater treatment plant, characterized in that, Applied to the system of claim 1, the method includes the following steps: Obtain the load data of the chiller units in the centralized cooling plant; Dynamically collect preset temperature data; wherein, the preset temperature data includes raw water temperature data at the raw water inlet side and reclaimed water temperature data at the reclaimed water side; The target operating mode is determined based on the chiller unit load data, the raw water temperature data, and the reclaimed water temperature data, and then the first-stage heat exchange unit and the second-stage heat exchange unit are controlled according to the target operating mode.
8. The method according to claim 7, characterized in that, The step of determining a target operating mode based on the chiller unit load data, the raw water temperature data, and the reclaimed water temperature data, and then controlling the first-stage heat exchange unit and the second-stage heat exchange unit according to the target operating mode, includes: When the chiller unit load data is determined to be greater than or equal to the preset load threshold, the target operating mode is determined to be the full-load operation mode, and then the first-stage heat exchange unit and the second-stage heat exchange unit are controlled to exchange heat according to the full-load operation mode. Alternatively, when it is determined that the chiller unit load data is less than the preset load threshold, the target operating mode is determined to be a partial load operation mode. Then, a target heat exchange unit is determined based on the raw water temperature data and the reclaimed water temperature data, so as to control the target heat exchange unit to perform heat exchange according to the partial load operation mode; wherein, the target heat exchange unit includes one of the first-stage heat exchange unit and the second-stage heat exchange unit.
9. The method according to claim 8, characterized in that, The step of determining the target heat exchange unit based on the raw water temperature data and the reclaimed water temperature data, and controlling the target heat exchange unit to perform heat exchange according to the partial load operation mode, includes: The raw water temperature data and the reclaimed water temperature data are analyzed according to a preset priority principle to determine the target heat exchange unit; wherein, the preset priority principle includes a priority principle for condensation heat exchange efficiency; The target heat exchange unit is controlled to perform heat exchange according to the partial load operation mode.
10. The method according to claim 9, characterized in that, The step of analyzing the raw water temperature data and the reclaimed water temperature data according to a preset priority principle to determine the target heat exchange unit includes: When it is determined that the raw water temperature data is less than the reclaimed water temperature data, it is determined that the first-stage heat exchange unit meets the priority principle of condensation heat exchange efficiency, and then the first-stage heat exchange unit is taken as the target heat exchange unit. Alternatively, if it is determined that the raw water temperature data is greater than the reclaimed water temperature data, and the second-stage heat exchange unit meets the priority principle of condensation heat exchange efficiency, then the second-stage heat exchange unit is selected as the target heat exchange unit.