Energy-saving system for optimizing and adjusting operation number and frequency of chilled water secondary pumps
By using PLC controller to monitor water pressure and temperature in HVAC systems, adjusting the number and frequency of the refrigerated water secondary pump, the problem that the cold water secondary pump is not in the efficient frequency range is solved, and the refrigerated water secondary pump is realized Optimized energy-saving operation.
Patent Information
- Application Number
- CN202420214057.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-29
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2034-01-29
AI Technical Summary
The initial number and frequency of cold water secondary pumps in HVAC systems are usually determined through management experience, resulting in waste of time and increased energy consumption, and their operation is not in the efficient frequency range and cannot be optimized and adjusted.
Design a system including a refrigerated water supply main pipe, a distribution pipe, a refrigeration water return main pipe, a refrigeration device, a PLC controller, a water supply pressure sensor and a return water pressure sensor, monitor the water pressure and temperature through the PLC controller to regulate the freezing The number and frequency of the water secondary pump runs, find the balance point between the pressure difference and the efficient operation frequency.
It realizes the optimized energy-saving operation of the refrigerated water secondary pump, ensures the cooling capacity conveying function, and reduces energy consumption.
Smart Images
Figure CN222187240U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of heating and ventilation, and in particular to an energy-saving system for optimizing and regulating the number and frequency of running secondary pumps of chilled water. Background Art
[0002] There are 6 secondary chilled water pumps in the HVAC system. At present, the initial number of secondary chilled water pumps is usually determined by management experience. And increasing the number of running pumps one by one (from 1 to n) wastes time and increases energy consumption. As the HVAC system runs smoothly, the secondary chilled water pump may not be running at an efficient frequency, or the frequency may not be in the efficient frequency range due to the limitation of the number of running pumps.
[0003] Therefore, in view of the shortcomings of the existing technology, it is necessary to design an energy-saving system that optimizes and adjusts the number and frequency of operating chilled water secondary pumps to solve the above problems. Utility Model Content
[0004] In order to overcome the above-mentioned deficiencies in the prior art, the utility model aims to provide an energy-saving system for optimizing and adjusting the number and frequency of operating secondary chilled water pumps.
[0005] To achieve the above-mentioned purpose and other related purposes, the technical solution provided by the utility model is: an energy-saving system for optimizing and adjusting the number and frequency of operation of chilled water secondary pumps, comprising a chilled water supply main, a distribution pipe, a chilled water return main, a refrigeration device, multiple groups of chilled water secondary pumps, a PLC controller, a water supply pressure sensor and a return water pressure sensor, the water inlet end of the refrigeration device is connected to the chilled water return main through a pipeline, the water outlet end of the refrigeration device is connected to the distribution pipe through a pipeline, the water inlet ends of multiple groups of the chilled water secondary pumps are respectively connected to the distribution pipe through a pipeline, the water outlet ends of multiple groups of the chilled water secondary pumps are respectively connected to the chilled water supply main through a pipeline, the water supply pressure sensor is arranged in the chilled water supply main, the return water pressure sensor is arranged in the chilled water return main, and the PLC controller is simultaneously connected to multiple groups of the chilled water secondary pumps, the water supply pressure sensor and the return water pressure sensor.
[0006] The preferred technical solution is: the refrigeration device is composed of multiple groups of refrigeration units, the water inlet ends of the multiple groups of refrigeration units are respectively connected to the chilled water return main pipe through pipelines, and the water outlet ends of the multiple groups of refrigeration units are respectively connected to the distribution pipe through pipelines.
[0007] The preferred technical solution is: it also includes a water supply temperature sensor and a return water temperature sensor, and the water supply temperature sensor and the return water temperature sensor are both connected to the PLC controller.
[0008] Due to the application of the above technical solution, the utility model has the following beneficial effects:
[0009] The utility model provides an energy-saving system for optimizing and adjusting the number and frequency of operating secondary chilled water pumps. The system controls the number and frequency of operating secondary chilled water pumps through a PLC controller to find the balance point among the "pressure difference" of the chilled water supply and return water mains, the number of operating secondary chilled water pumps, and the efficient operating frequency, thereby ensuring the basic function of delivering cold water and achieving optimized energy-saving operation. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Figure 1 This is a schematic diagram of the energy-saving system involved in the utility model. DETAILED DESCRIPTION
[0011] The following is a description of the implementation of the present invention by means of specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.
[0012] See also Figure 1 . It should be noted that in the description of the present utility model, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the utility model product is usually placed when in use. They are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", "third" and the like are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. Terms such as "horizontal", "vertical", and "overhanging" do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.
[0013] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, it can be a mechanical connection, it can be an electrical connection, it can be a direct connection, it can be indirectly connected through an intermediate medium, and it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0014] Example:
[0015] like Figure 1As shown, according to an overall technical concept of the utility model, an energy-saving system for optimizing and adjusting the number and frequency of operation of chilled water secondary pumps is provided, comprising a chilled water supply main pipe 1, a distribution pipe 2, a chilled water return main pipe 3, a refrigeration device 4, multiple groups of cold water secondary pumps 5, a PLC controller 6, a water supply pressure sensor 7 and a return water pressure sensor 8, the water inlet end of the refrigeration device 4 is connected to the chilled water return main pipe 3 through a pipeline, the water outlet end of the refrigeration device 4 is connected to the distribution pipe 2 through a pipeline, the water inlet ends of the multiple groups of cold water secondary pumps 5 are respectively connected to the distribution pipe 2 through a pipeline, the water outlet ends of the multiple groups of cold water secondary pumps 5 are respectively connected to the chilled water supply main pipe 1 through a pipeline, the water supply pressure sensor 7 is arranged in the chilled water supply main pipe 1, the return water pressure sensor 8 is arranged in the chilled water return main pipe 3, and the PLC controller 6 is simultaneously connected to the multiple groups of cold water secondary pumps 5, the water supply pressure sensor 7 and the return water pressure sensor 8. The water supply pressure sensor 7 is used to monitor the water pressure P1 in the chilled water supply main 1, and the return water pressure sensor 8 is used to monitor the water pressure P2 in the chilled water return main 3. The PLC controller 6 calculates the supply and return water pressure difference ΔP based on P1 and P2.
[0016] like Figure 1 As shown, in an exemplary embodiment of the utility model, the refrigeration device 4 is composed of multiple groups of refrigeration units 41, the water inlet ends of the multiple groups of refrigeration units 41 are respectively connected to the chilled water return main pipe 3 through pipelines, and the water outlet ends of the multiple groups of refrigeration units 41 are respectively connected to the distribution pipe 2 through pipelines.
[0017] like Figure 1 As shown, in an exemplary embodiment of the present utility model, a water supply temperature sensor 9 and a return water temperature sensor 10 are also included, and both the water supply temperature sensor 9 and the return water temperature sensor 10 are connected to the PLC controller 6. The water supply temperature sensor 9 is used to monitor the water temperature T1 in the chilled water supply main pipe 1, and the return water temperature sensor 10 is used to monitor the water temperature T2 in the chilled water return main pipe 3. The PLC controller 6 calculates the supply water and return water temperature difference ΔT according to T1 and T2.
[0018] The control system, based on the manager's task form instructions and through a specific logic algorithm, predicts that the initial number of cold water "secondary pumps" to be turned on is n, and the set frequency of 42.5Hz remains unchanged (assuming that the "efficiency-frequency" characteristic curve of the cold water secondary pump has a frequency efficiency range of 40-45Hz corresponding to the high-efficiency zone).
[0019] If the initial ΔP is higher than the set value, reduce one unit; keep n-1 units running for 300s. If ΔP is still higher than the set value, reduce one unit again; keep n-2 units running for 300s. Continue to reduce in this way until ΔP is lower than the set value. The control system maintains the critical number of running units unchanged, gradually increases the frequency, speed, and flow rate, and maintains ΔP not lower than the set value.
[0020] If the initial ΔP is lower than the set value, add 1 unit; keep n+1 units running for 300s. If ΔP is still lower than the set value, add another unit; keep n-2 units running for 300s. Continue to increase in this way until ΔP is higher than the set value. The control system maintains the critical number of running units unchanged, gradually lowers the frequency, speed, and flow rate, and maintains ΔP not lower than the set value.
[0021] To maintain "pressure, pressure difference" and balance point speed, the control system can increase the temperature difference between the supply and return water mains and reduce the chilled water flow of the secondary pump accordingly, thereby increasing the "pressure difference" of the chilled water supply and return water mains. This can just reduce the frequency of the cold water secondary pump, further reducing the transportation energy consumption and achieving the optimal balance point operating condition of "large temperature difference and small flow".
[0022] Therefore, the utility model has the following advantages:
[0023] The utility model provides an energy-saving system for optimizing and adjusting the number and frequency of operating secondary chilled water pumps. The system controls the number and frequency of operating secondary chilled water pumps through a PLC controller to find the balance point among the "pressure difference" of the chilled water supply and return water mains, the number of operating secondary chilled water pumps, and the efficient operating frequency, thereby ensuring the basic function of delivering cold water and achieving optimized energy-saving operation.
[0024] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or alter the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.
Claims
1. An energy-saving system for optimizing and adjusting the number and frequency of operation of secondary chilled water pumps, characterized in that: It includes a chilled water supply main, a distribution pipe, a chilled water return main, a refrigeration device, multiple groups of cold water secondary pumps, a PLC controller, a water supply pressure sensor and a return water pressure sensor. The water inlet end of the refrigeration device is connected to the chilled water return main through a pipeline, and the water outlet end of the refrigeration device is connected to the distribution pipe through a pipeline. The water inlet ends of the multiple groups of cold water secondary pumps are respectively connected to the distribution pipe through a pipeline, and the water outlet ends of the multiple groups of cold water secondary pumps are respectively connected to the chilled water supply main through a pipeline. The water supply pressure sensor is arranged in the chilled water supply main, and the return water pressure sensor is arranged in the chilled water return main. The PLC controller is simultaneously connected to the multiple groups of cold water secondary pumps, the water supply pressure sensor and the return water pressure sensor.
2. The energy-saving system for optimizing and adjusting the number and frequency of operation of secondary chilled water pumps according to claim 1 is characterized in that: The refrigeration device is composed of multiple groups of refrigeration units, the water inlet ends of the multiple groups of refrigeration units are connected to the chilled water return main pipe through pipelines, and the water outlet ends of the multiple groups of refrigeration units are connected to the distribution pipe through pipelines.
3. The energy-saving system for optimizing and adjusting the number and frequency of operation of secondary chilled water pumps according to claim 1 is characterized in that: It also includes a water supply temperature sensor and a return water temperature sensor, and both the water supply temperature sensor and the return water temperature sensor are connected to the PLC controller.