A method for cooling and antifreeze control of a heat pump

Abstract

This invention discloses a cooling and antifreeze control method for a heat pump, characterized by comprising: generating a first antifreeze strategy based on the water circulation loop information of the heat pump; generating a second antifreeze strategy based on the refrigerant circulation loop information of the heat pump; generating a cooling and antifreeze strategy based on the first and second antifreeze strategies; performing cooling and antifreeze control on the heat pump based on the cooling and antifreeze strategy; and when any antifreeze condition is reached, issuing frequency limiting or frequency reduction commands to the unit through the heat pump control system to cause the heat pump to exit the active antifreeze condition or maintain it so that it does not continue to reach the passive antifreeze condition. By adding judgment conditions, the reliability of antifreeze judgment is improved, avoiding antifreeze failure caused by component problems.

Description

Technical Field

[0001] This invention relates to the field of heat pump unit refrigeration and antifreeze technology, and in particular to a heat pump refrigeration and antifreeze control method. Background Technology

[0002] While existing air source heat pump units have relatively comprehensive anti-freeze measures for summer cooling, they do not pay enough attention to anti-freeze during summer cooling, often causing the heat exchanger to freeze and break during cooling. The main reason is that the existing anti-freeze detection measures for air source heat pumps are too simplistic, and cannot accurately determine when the air source heat pump unit enters or exits anti-freeze mode. This leads to frequent anti-freeze failures and frequent anti-freeze protection activations, affecting the efficient operation of the heat pump. Summary of the Invention

[0003] This invention aims to at least partially solve one of the technical problems in the aforementioned technologies. Therefore, the purpose of this invention is to propose a cooling antifreeze control method for a heat pump. This method presets active and passive antifreeze entry conditions (outlet water temperature) for the water circulation loop, and simultaneously presets active and passive antifreeze entry conditions (low-pressure value) for the refrigerant side. When any antifreeze condition is reached, the heat pump control system issues frequency limiting or frequency reduction commands to the unit, causing the heat pump to exit the active antifreeze condition or maintain it so that it does not continue to reach the passive antifreeze condition. By adding judgment conditions, the reliability of antifreeze judgment is improved, avoiding antifreeze failure due to component problems.

[0004] To achieve the above objectives, embodiments of the present invention propose a cooling and antifreeze control method for a heat pump, comprising:

[0005] Based on the water circulation loop information of the heat pump, a first antifreeze strategy is generated.

[0006] A second antifreeze strategy is generated based on the refrigerant circulation loop information of the heat pump.

[0007] A refrigeration and antifreeze strategy is generated based on the first and second antifreeze strategies.

[0008] Cooling and antifreeze control of heat pumps is based on cooling and antifreeze strategies.

[0009] Preferably, the generation of the first antifreeze strategy based on the heat pump's water circulation loop information includes:

[0010] Based on the water circulation loop information, determine the flow rate of water in the water circulation loop;

[0011] The flow rate of water in the water circulation loop is compared with the first preset water flow rate threshold to determine the first active antifreeze strategy.

[0012] Detect the outlet temperature of the water in the water circulation loop;

[0013] The outlet water temperature is compared with a preset water temperature threshold to determine the first passive antifreeze strategy;

[0014] Based on the first active antifreeze strategy and the first passive antifreeze strategy, a first antifreeze strategy is generated.

[0015] Preferably, the generation of the second antifreeze strategy based on the refrigerant circulation loop information of the heat pump includes:

[0016] Periodically monitor the inlet and outlet water temperatures of the heat exchanger that exchanges heat with the refrigerant circulation loop in the water circulation loop.

[0017] Calculate the rate of change of inlet and outlet water temperatures;

[0018] The inlet and outlet water temperature change rate is compared with the preset temperature change rate to determine the second active antifreeze strategy;

[0019] The low-pressure value in the refrigerant circulation loop is obtained based on a low-pressure sensor.

[0020] The low-pressure value is compared with a preset low-pressure threshold to determine the second passive antifreeze strategy;

[0021] A second antifreeze strategy is generated based on the second active antifreeze strategy and the second passive antifreeze strategy.

[0022] Preferably, the first active antifreeze strategy is to enter the antifreeze operation mode when the water flow rate is greater than 0 and less than or equal to the first preset water flow rate threshold, and to periodically start and stop the water pump in the water circulation path.

[0023] The first passive antifreeze strategy is to enter the antifreeze operation mode when the outlet water temperature is lower than the preset water temperature threshold, and to issue frequency limiting or frequency reduction commands to the heat pump unit through the heat pump control system.

[0024] The second active antifreeze strategy is to enter the antifreeze operation mode when the inlet and outlet water temperature change rate is greater than or equal to the preset temperature change rate, and to issue frequency limiting or frequency reduction commands to the heat pump unit through the heat pump control system.

[0025] The second passive antifreeze strategy is to enter the antifreeze operation mode when the low pressure value is less than the preset low pressure threshold, and to issue frequency limiting or frequency reduction commands to the heat pump unit through the heat pump control system.

[0026] Preferably, before determining the flow rate of water in the water circulation loop based on the water circulation loop information, the method further includes:

[0027] Acquire data from various preset water quality sensors, flow rate sensors, and temperature sensors in the water circulation loop;

[0028] The blockage coefficient of the water circulation loop is calculated based on the preset water quality sensor data, flow rate sensor data, and temperature sensor data in the water circulation loop using a preset algorithm.

[0029] The blockage coefficient is compared with a preset blockage coefficient;

[0030] If the blockage coefficient is greater than or equal to the preset blockage coefficient, an alarm will be issued and a maintenance work order will be generated to arrange for maintenance personnel to carry out the maintenance.

[0031] If the blockage coefficient is less than the preset blockage coefficient, the water pump in the water circulation loop is started, and the water flow switch is detected to determine the flow rate of the water in the water circulation loop.

[0032] Preferably, the blockage coefficient of the water circulation loop is calculated based on a preset algorithm using data from various preset water quality sensors, flow rate sensors, and temperature sensors in the water circulation loop, including:

[0033]

[0034] Where T represents the blockage coefficient of the water circulation loop; F i V represents the water quality data of the i-th water quality sensor in the water circulation loop; n represents the number of water quality sensors in the water circulation loop; q This represents the flow velocity data of the q-th flow velocity sensor in the water circulation loop; m represents the number of flow velocity sensors in the water circulation loop; t s represents the water temperature data of the s-th temperature sensor in the water circulation loop; p represents the number of temperature sensors in the water circulation loop.

[0035] Preferably, the cooling and antifreeze control of the heat pump based on the cooling and antifreeze strategy includes:

[0036] When the current antifreeze strategy is the first active antifreeze strategy, it is determined in real time whether the current water flow rate exceeds the second preset water flow rate threshold. If so, the antifreeze operation mode of the first active antifreeze strategy is exited; the second preset water flow rate threshold is greater than the first preset water flow rate threshold.

[0037] When the current antifreeze strategy is the first passive antifreeze strategy, it is determined in real time whether the outlet water temperature is the preset water temperature threshold. If so, the antifreeze operation mode of the first passive antifreeze strategy is exited.

[0038] When the current antifreeze strategy is the second active antifreeze strategy, the inlet and outlet water temperature change rate is calculated in real time to see if it is less than the preset temperature change rate. If it is, the antifreeze operation mode of the second active antifreeze strategy is exited.

[0039] When the current antifreeze strategy is the first passive antifreeze strategy, it is determined in real time whether the low pressure value is greater than the preset low pressure threshold. If so, the antifreeze operation mode of the strategy is exited and the second passive antifreeze strategy is adopted.

[0040] Preferably, the process of controlling the heat pump for cooling and freezing based on the cooling and freezing strategy also includes:

[0041] Obtain information on the refrigerant charge at each node in the refrigerant circulation loop of the heat pump;

[0042] The loss coefficient of refrigerant in the refrigerant circulation loop is calculated based on the refrigerant dosage information of each node.

[0043] The loss coefficient is compared with a preset loss coefficient threshold.

[0044] When the loss coefficient is determined to be greater than or equal to a preset loss coefficient threshold, the refrigerant in the refrigerant circulation loop is replenished, and the specific location of refrigerant loss is determined. Maintenance is then performed based on the specific location of refrigerant loss.

[0045] Preferably, the calculation of the refrigerant loss coefficient in the refrigerant circulation loop based on the refrigerant dosage information of each node includes:

[0046]

[0047] Where S represents the refrigerant loss coefficient in the refrigerant circulation loop, A1 represents the current ambient temperature; A2 represents the current average temperature in the refrigerant circulation loop; θ represents the measurement temperature error coefficient, ranging from [0.5, 1]; n represents the number of nodes in the refrigerant circulation loop; j i This represents the amount of refrigerant that passes through the i-th node at a preset rate within a preset time period; This represents the average cooling dose when passing through all nodes at a preset rate within a preset time period.

[0048] Preferably, determining the specific location of refrigerant loss includes:

[0049] Select the evaporator inlet position in the refrigerant circulation loop as the starting node, and arbitrarily select any other node besides the starting node as the target node;

[0050] Calculate the loss coefficient of the corresponding cooling dose from the starting node to the target node to obtain the sub-loss coefficient; traverse all nodes to obtain several sub-loss coefficients.

[0051] Calculate the difference between two adjacent sub-loss coefficients to obtain the target difference;

[0052] The target difference is compared with a preset difference threshold. When the target difference is determined to be greater than or equal to the preset difference threshold, the location between the two corresponding nodes is taken as the specific location of the cooling capacity loss.

[0053] This invention discloses a cooling and antifreeze control method for a heat pump, which comprehensively considers information from both the water circulation loop and the refrigerant circulation loop, improving the comprehensiveness and accuracy of the antifreeze strategy. The generated cooling and antifreeze strategy can better adapt to the working conditions of the heat pump, improving the reliability of antifreeze control. It can effectively avoid problems such as heat exchanger freezing during the cooling process, reducing equipment damage and maintenance costs. It enhances the adaptability and stability of the air source heat pump unit under different environmental conditions. When any antifreeze condition is reached, the heat pump control system issues frequency limiting or frequency reduction commands to the unit to cause the heat pump to exit the active antifreeze condition or maintain it so that it does not continue to reach the passive antifreeze condition. By adding judgment conditions, the reliability of antifreeze judgment is improved, avoiding antifreeze failure caused by component problems.

[0054] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings.

[0055] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0056] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0057] Figure 1 This is a flowchart of a cooling and antifreeze control method for a heat pump according to an embodiment of the present invention;

[0058] Figure 2 This is a flowchart of generating a first antifreeze strategy based on water circulation loop information of a heat pump according to an embodiment of the present invention.

[0059] Figure 3 This is a flowchart of generating a second antifreeze strategy based on refrigerant circulation loop information of a heat pump according to an embodiment of the present invention;

[0060] Figure 4 This is a schematic diagram of a heat pump according to an embodiment of the present invention.

[0061] In the diagram: 1. Refrigerant tank; 2. Compressor; 3. Low-pressure sensor; 4. Evaporator; 5. Heat exchange equipment; 6. Inlet water temperature sensor; 7. Outlet water temperature sensor; A. Refrigerant circulation loop; B. Water circulation loop; C. User side. Detailed Implementation

[0062] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0063] Figure 4 A schematic diagram of the connection piping of a heat pump is given as an example; Figure 4 The system is divided into three parts: A) refrigerant circulation loop, B) water circulation loop, and C) user side. The refrigerant circulation loop includes a refrigerant tank 1, a compressor 2, an evaporator 4, a low-pressure sensor 3, and a heat exchange device 5. In this loop, the refrigerant stored in the refrigerant tank 1 is transported to the compressor 2 via refrigerant piping. The compressor 22 compresses the refrigerant and outputs high-temperature, high-pressure refrigerant. This high-temperature, high-pressure refrigerant is then transported to the evaporator 4 and, after passing through the low-pressure sensor, to the heat exchange device 5. At the heat exchange device 5, the refrigerant exchanges heat with the water in the water circulation loop, cooling the water and thus providing cooling to the user side. The water circulation loop uses an inlet water temperature sensor 7 to detect the inlet water temperature and an outlet water temperature sensor 7 to detect the outlet water temperature.

[0064] Example 1

[0065] like Figure 1 As shown, a cooling and antifreeze control method for a heat pump includes S1-S4:

[0066] S1: Generate the first antifreeze strategy based on the water circulation loop information of the heat pump;

[0067] S2: Generate a second antifreeze strategy based on the refrigerant circulation loop information of the heat pump;

[0068] S3: Generate a refrigeration and antifreeze strategy based on the first and second antifreeze strategies;

[0069] S4: Cooling and antifreeze control of the heat pump based on the cooling and antifreeze strategy.

[0070] In this embodiment, the water circulation loop of the heat pump includes an inlet water temperature sensor 6, a heat exchange device 5, and an outlet water temperature sensor 7.

[0071] In this embodiment, the refrigerant circulation loop of the heat pump includes a refrigerant tank 1, a compressor 2, an evaporator 4, and a low-pressure sensor 3.

[0072] In this embodiment, the water circulation loop information includes the inlet and outlet water temperatures, water flow rate, and water quality information in the water circulation loop.

[0073] In this embodiment, the refrigerant circulation loop information includes low-pressure sensor information, inlet and outlet water temperature information of the heat exchanger that exchanges heat with the refrigerant circulation loop, and temperature sensor information in the refrigerant circulation loop.

[0074] In this embodiment, the first antifreeze strategy includes a first active antifreeze strategy and a first passive antifreeze strategy.

[0075] In this embodiment, the second antifreeze strategy includes a second active antifreeze strategy and a second passive antifreeze strategy.

[0076] In this embodiment, the cooling and antifreeze control of the heat pump includes exiting the antifreeze operation state based on various antifreeze strategies.

[0077] The beneficial effects of the above technical solution are as follows: It comprehensively considers information from both the water circulation loop and the refrigerant circulation loop, improving the comprehensiveness and accuracy of the antifreeze strategy; the generated refrigeration antifreeze strategy can better adapt to the working conditions of the heat pump, improving the reliability of antifreeze control; it can effectively avoid problems such as heat exchanger freezing during the cooling process, reducing equipment damage and maintenance costs; it enhances the adaptability and stability of the air source heat pump unit under different environmental conditions; when any antifreeze condition is reached, the heat pump control system issues frequency limiting or frequency reduction commands to the unit, prompting the heat pump to exit the active antifreeze condition or maintain it so that it does not continue to reach the passive antifreeze condition. By adding judgment conditions, the reliability of antifreeze judgment is improved, avoiding antifreeze failure caused by component problems.

[0078] Example 2

[0079] like Figure 2 As shown, the generation of the first antifreeze strategy based on the water circulation loop information of the heat pump includes S11-S15:

[0080] S11: Based on the water circulation loop information, determine the flow rate of water in the water circulation loop;

[0081] S12: Compare the flow rate of water in the water circulation loop with the first preset water flow rate threshold to determine the first active antifreeze strategy;

[0082] S13: Detect the outlet water temperature in the water circulation loop;

[0083] S14: Compare the outlet water temperature with a preset water temperature threshold to determine the first passive antifreeze strategy;

[0084] S15: Generate a first antifreeze strategy based on the first active antifreeze strategy and the first passive antifreeze strategy.

[0085] In this embodiment, the flow rate of water in the water circulation loop is determined based on the flow rate data from the flow rate sensor in the water circulation loop and a preset time.

[0086] In this embodiment, the outlet temperature of the water in the water circulation loop is detected based on a temperature sensor in the water circulation loop.

[0087] In this embodiment, when the outlet water temperature is lower than the preset temperature, especially in low-temperature environments, the water in the water circulation system is more likely to reach the freezing point, thereby increasing the risk of freezing.

[0088] The beneficial effects of the above technical solution are: it can accurately monitor the water flow in the water circulation loop and detect abnormalities in a timely manner; based on the comparison between the flow rate and the preset threshold, the first active antifreeze strategy can take measures in advance to enhance the antifreeze effect; by detecting the outlet water temperature and comparing it with the preset water temperature threshold, the first passive antifreeze strategy can take emergency measures when the temperature is too low to avoid freezing damage; it comprehensively considers active and passive antifreeze strategies, improving the reliability and comprehensiveness of antifreeze; it can flexibly adjust the strategy according to the actual situation to adapt to different working environments and requirements; and it effectively protects the equipment in the water circulation loop and reduces the risk of equipment damage.

[0089] Example 3

[0090] like Figure 3 As shown, the second antifreeze strategy is generated based on the refrigerant circulation loop information of the heat pump, including S21-S26:

[0091] S21: Periodically monitor the inlet and outlet water temperatures of the heat exchanger that exchanges heat with the refrigerant circulation loop in the water circulation loop;

[0092] S22: Calculate the rate of change of inlet and outlet water temperatures;

[0093] S23: Compare the inlet and outlet water temperature change rate with the preset temperature change rate to determine the second active antifreeze strategy;

[0094] S24: Obtain the low-pressure value in the refrigerant circulation loop based on the low-pressure sensor;

[0095] S25: Compare the low pressure value with the preset low pressure threshold to determine the second passive antifreeze strategy;

[0096] S26: Generate a second antifreeze strategy based on the second active antifreeze strategy and the second passive antifreeze strategy.

[0097] In this embodiment, the rate of change of inlet and outlet water temperature is the ratio of the absolute value of the difference between inlet and outlet water temperatures to the inlet water temperature.

[0098] In this embodiment, when the low pressure is too low, the evaporator surface is prone to frost or ice formation; this not only affects the cooling effect but may also damage the system; the instability of the low pressure may exacerbate the frost or ice formation on the evaporator surface.

[0099] In this embodiment, the large temperature change rate of the inlet and outlet water may cause the system to freeze frequently, which not only increases the difficulty of system maintenance, but may also damage the system.

[0100] The beneficial effects of the above technical solution are as follows: Regularly monitoring the inlet and outlet water temperatures of the heat exchanger allows for timely detection of temperature changes; calculating the inlet and outlet water temperature change rate provides a more sensitive reflection of heat exchange conditions, helping to identify potential problems early; comparing the inlet and outlet water temperature change rate with a preset temperature change rate allows for a more accurate determination of whether antifreeze measures are needed; by acquiring the low-pressure value in the refrigerant circulation loop and comparing it with a preset low-pressure threshold, a second passive antifreeze strategy can be implemented promptly in case of abnormal pressure, preventing equipment damage; comprehensively considering both active and passive antifreeze strategies improves the reliability and comprehensiveness of antifreeze protection; the strategy can be dynamically adjusted according to actual conditions to adapt to different working conditions and environmental changes; it effectively protects equipment such as heat exchangers in the refrigerant circulation loop, extending equipment lifespan; and it reduces the risk of system failure, improving the stability and reliability of the heat pump system.

[0101] Example 4

[0102] The first active antifreeze strategy is to enter the antifreeze operation mode when the water flow rate is greater than 0 and less than or equal to the first preset water flow rate threshold, and to periodically start and stop the water pump in the water circulation circuit.

[0103] The first passive antifreeze strategy is to enter the antifreeze operation mode when the outlet water temperature is lower than the preset water temperature threshold, and to issue frequency limiting or frequency reduction commands to the heat pump unit through the heat pump control system.

[0104] The second active antifreeze strategy is to enter the antifreeze operation mode when the inlet and outlet water temperature change rate is greater than or equal to the preset temperature change rate, and to issue frequency limiting or frequency reduction commands to the heat pump unit through the heat pump control system.

[0105] The second passive antifreeze strategy is to enter the antifreeze operation mode when the low pressure value is less than the preset low pressure threshold, and to issue frequency limiting or frequency reduction commands to the heat pump unit through the heat pump control system.

[0106] In this embodiment, the first active antifreeze strategy is that when the water flow rate is greater than 0 and less than or equal to the first preset water flow rate threshold, the water flow rate in the water circulation loop decreases, and it is necessary to increase the water flow rate in the water circulation loop by periodically starting and stopping the water pump.

[0107] In this embodiment, by using frequency limiting or frequency reduction commands, the control system can reduce the heat output of the heat pump unit, thereby lowering the unit's temperature and preventing the unit from freezing or being damaged inside in low-temperature environments. In abnormal situations, such as pipe blockage or water pump failure, the control system can reduce the unit's operating frequency or shut it down to avoid further damage to the equipment or more serious consequences.

[0108] The beneficial effects of the above technical solution are as follows: By adopting the first active antifreeze strategy and the first passive antifreeze strategy, potential freezing problems can be detected and addressed in a timely manner; when the water flow rate is low, the periodic start-stop of the water pump ensures both antifreeze effect and water conservation; by monitoring the inlet and outlet water temperature change rate and low-pressure value, the operating status of the heat pump unit can be controlled more accurately; the issuance of frequency limiting or frequency reduction commands helps to reduce energy consumption and improve the system's energy efficiency ratio; it effectively prevents damage to the heat pump unit and water circulation circuit caused by freezing, extending the service life of the equipment; it enables the system to operate stably in cold climate conditions, improving system reliability; it automatically switches the antifreeze operation mode according to actual conditions, realizing intelligent control; and it reduces failures and repairs caused by freezing, lowering system maintenance costs.

[0109] Example 5

[0110] Before determining the flow rate of water in the water circulation loop based on the water circulation loop information, the following steps are also included:

[0111] Acquire data from various preset water quality sensors, flow rate sensors, and temperature sensors in the water circulation loop;

[0112] The blockage coefficient of the water circulation loop is calculated based on the preset water quality sensor data, flow rate sensor data, and temperature sensor data in the water circulation loop using a preset algorithm.

[0113] The blockage coefficient is compared with a preset blockage coefficient;

[0114] If the blockage coefficient is greater than or equal to the preset blockage coefficient, an alarm will be issued and a maintenance work order will be generated to arrange for maintenance personnel to carry out the maintenance.

[0115] If the blockage coefficient is less than the preset blockage coefficient, the water pump in the water circulation loop is started, and the water flow switch is detected to determine the flow rate of the water in the water circulation loop.

[0116] In this embodiment, the circulating water may contain a large amount of impurities and chemicals, such as sand, mud, rust, etc. These substances will gradually accumulate in the pipes during long-term circulation, eventually forming blockages. Especially in areas with hard water, minerals such as calcium and magnesium in the water are prone to forming scale in the pipes, further aggravating the risk of blockages. Even if it is not completely blocked, it will affect the flow rate measurement of water in the water circulation loop, which may cause the heat pump system to mistakenly enter the anti-freeze mode, resulting in reduced performance. Therefore, it is necessary to regularly check the blockage in the water circulation loop.

[0117] In this embodiment, if the blockage coefficient is greater than or equal to the preset blockage coefficient, the possible consequence is that the heat pump system frequently enters the antifreeze mode, affecting the efficient operation of the heat pump. Therefore, it is necessary to issue an alarm and generate a maintenance work order to arrange maintenance personnel to carry out maintenance.

[0118] In this embodiment, if the blockage coefficient is less than the preset blockage coefficient, it means that the current blockage situation has not affected the antifreeze mode of the heat pump system. Based on the difference between the specific blockage coefficient and the preset blockage coefficient, a periodic inspection work order is generated.

[0119] The beneficial effects of the above technical solution are as follows: by acquiring data from various preset sensors, it is possible to understand the water quality, flow rate, and temperature of the water circulation loop in real time; calculating the blockage coefficient can detect potential blockages in the water circulation loop in advance and issue timely alarm prompts; generating maintenance work orders to arrange maintenance personnel for repairs, ensuring the normal operation of the system; avoiding system failures or damages caused by blockages, thus improving equipment safety; adjusting the operating status of the water pump according to the blockage coefficient to achieve precise control; timely detection and resolution of blockage problems helps improve system efficiency and performance; reducing maintenance costs and production losses caused by failures; and achieving intelligent management and maintenance based on preset algorithms for calculation and judgment.

[0120] Example 6

[0121] Based on preset water quality sensor data, flow rate sensor data, and temperature sensor data in the water circulation loop, the blockage coefficient of the water circulation loop is calculated using a preset algorithm, including:

[0122]

[0123] Where T represents the blockage coefficient of the water circulation loop; F i V represents the water quality data of the i-th water quality sensor in the water circulation loop; n represents the number of water quality sensors in the water circulation loop; q This represents the flow velocity data of the q-th flow velocity sensor in the water circulation loop; m represents the number of flow velocity sensors in the water circulation loop; t srepresents the water temperature data of the s-th temperature sensor in the water circulation loop; p represents the number of temperature sensors in the water circulation loop.

[0124] The beneficial effects of the above technical solution are: by calculating the blockage coefficient by comprehensively considering multiple parameters such as water quality, flow rate, and water temperature, the condition of the water circulation loop can be assessed more comprehensively; a quantitative method is provided to determine the degree of blockage in the water circulation loop, which helps to more accurately identify and solve problems; the blockage coefficient is calculated based on real-time sensor data, which allows for timely understanding of the system's operating status; it is applicable to water circulation loops of different scales and complexities, and has strong versatility; it provides a basis for automatic control, enabling automatic adjustment of the system's operating strategy based on the blockage coefficient.

[0125] Example 7

[0126] Cooling and antifreeze control of heat pumps based on cooling and antifreeze strategies includes:

[0127] When the current antifreeze strategy is the first active antifreeze strategy, it is determined in real time whether the current water flow rate exceeds the second preset water flow rate threshold. If so, the antifreeze operation mode of the first active antifreeze strategy is exited; the second preset water flow rate threshold is greater than the first preset water flow rate threshold.

[0128] When the current antifreeze strategy is the first passive antifreeze strategy, it is determined in real time whether the outlet water temperature is the preset water temperature threshold. If so, the antifreeze operation mode of the first passive antifreeze strategy is exited.

[0129] When the current antifreeze strategy is the second active antifreeze strategy, the inlet and outlet water temperature change rate is calculated in real time to see if it is less than the preset temperature change rate. If it is, the antifreeze operation mode of the second active antifreeze strategy is exited.

[0130] When the current antifreeze strategy is the first passive antifreeze strategy, it is determined in real time whether the low pressure value is greater than the preset low pressure threshold. If so, the antifreeze operation mode of the strategy is exited and the second passive antifreeze strategy is adopted.

[0131] The beneficial effects of the above technical solutions are as follows: By implementing various antifreeze strategies, problems such as frost and freezing of heat pumps in low-temperature environments can be effectively avoided, improving the operational stability of the system; by taking corresponding antifreeze control measures according to different situations, energy efficiency can be achieved, energy consumption can be reduced, and environmental impact can be minimized; effective antifreeze measures can reduce equipment wear and damage, and extend the service life of the equipment; it can adapt to different environmental conditions and usage scenarios, improving the versatility and flexibility of the heat pump system; and it enables real-time monitoring and precise control of the heat pump system, ensuring that the system is always in optimal operating condition.

[0132] Example 8

[0133] The process of controlling the cooling and antifreeze of a heat pump based on a cooling and antifreeze strategy also includes:

[0134] Obtain information on the refrigerant charge at each node in the refrigerant circulation loop of the heat pump;

[0135] The loss coefficient of refrigerant in the refrigerant circulation loop is calculated based on the refrigerant dosage information of each node.

[0136] The loss coefficient is compared with a preset loss coefficient threshold.

[0137] When the loss coefficient is determined to be greater than or equal to a preset loss coefficient threshold, the refrigerant in the refrigerant circulation loop is replenished, and the specific location of refrigerant loss is determined. Maintenance is then performed based on the specific location of refrigerant loss.

[0138] In this embodiment, the information on the amount of refrigerant passing through each node includes the amount of refrigerant passing through the node at a preset rate within a preset time period.

[0139] In this embodiment, refrigerant loss in the refrigeration cycle is a common and concerning issue, which can be caused by various factors. First, refrigerant leakage is one of the main causes of refrigerant loss in the refrigeration system. Leaks can occur in any part of the refrigeration system, including pipes, connectors, valves, and seals. Causes of leakage include metal corrosion, aging of refrigeration pipes, loose connections in the refrigeration system pipes, and damage to components. Symptoms of leakage typically include decreased cooling performance. Second, air leakage in the refrigeration system can be caused by poor sealing at refrigeration pipe joints, aging of refrigeration system components, and prolonged use of the refrigeration system. Symptoms of air leakage typically include decreased cooling performance and prolonged cooling time.

[0140] The beneficial effects of the above technical solution are as follows: timely replenishment of refrigerant ensures the normal cooling function of the heat pump and guarantees the continuous and stable operation of the system; timely detection and handling of refrigerant loss reduces energy waste and improves the efficiency of the entire system; it prevents equipment wear and failure due to insufficient refrigerant, extending the service life of the heat pump; accurately determining the specific location of refrigerant loss facilitates targeted maintenance and repair, improving maintenance efficiency and quality; and maintaining the high-efficiency operation of the system helps reduce energy consumption and carbon dioxide emissions, thus providing certain environmental benefits.

[0141] Example 9

[0142] The calculation of the refrigerant loss coefficient in the refrigerant circulation loop based on the refrigerant dosage information of each node includes:

[0143]

[0144] Where S represents the refrigerant loss coefficient in the refrigerant circulation loop, A1 represents the current ambient temperature, A2 represents the current average temperature in the refrigerant circulation loop, θ represents the measurement temperature error coefficient, with a value range of [0.5, 1], and n represents the number of nodes in the refrigerant circulation loop; J i This represents the amount of refrigerant that passes through the i-th node at a preset rate within a preset time period; This represents the average cooling dose when passing through all nodes at a preset rate within a preset time period.

[0145] The beneficial effects of the above technical solution are as follows: It comprehensively considers multiple factors such as ambient temperature, average temperature in the refrigerant circulation loop, error coefficient of temperature measurement, number of nodes, and amount of refrigerant passing through nodes, making the calculation results more accurate and comprehensive; it accurately reflects the refrigerant loss in the circulation loop, helping to promptly identify and resolve potential problems and ensure the normal operation of the system; by representing the loss coefficient with specific numerical values, the degree of refrigerant loss can be intuitively understood, providing a basis for subsequent replenishment and maintenance; based on the accurate loss coefficient, the refrigerant replenishment strategy can be optimized, improving system efficiency and economy; timely refrigerant replenishment can guarantee the system's cooling effect, reduce the risk of equipment failure, and thus ensure the safe and stable operation of the system.

[0146] Example 10

[0147] Determining the specific location of refrigerant loss includes:

[0148] Select the evaporator inlet position in the refrigerant circulation loop as the starting node, and arbitrarily select any other node besides the starting node as the target node;

[0149] Calculate the loss coefficient of the corresponding cooling dose from the starting node to the target node to obtain the sub-loss coefficient; traverse all nodes to obtain several sub-loss coefficients.

[0150] Calculate the difference between two adjacent sub-loss coefficients to obtain the target difference;

[0151] The target difference is compared with a preset difference threshold. When the target difference is determined to be greater than or equal to the preset difference threshold, the location between the two corresponding nodes is taken as the specific location of the cooling capacity loss.

[0152] In this embodiment, it is assumed that the evaporator inlet position in the refrigerant circulation loop is the starting node A, and the other target nodes besides point A include B and C. Assuming that the loss coefficient between points A and B is 0.1 and the loss coefficient between points A and C is 0.5, the target difference is AC-AB = 0.4. Assuming that the difference threshold is 0.2, then 0.4>0.2, and the specific location of the cooling capacity loss is between B and C.

[0153] In this embodiment, there are many factors that cause refrigerant loss. This embodiment uses the same external factors to detect the refrigerant circuit.

[0154] The beneficial effects of the above technical solution are as follows: by calculating the difference between adjacent sub-loss coefficients, the specific location of refrigerant loss can be accurately determined, which helps to quickly locate and solve problems; the specific location of loss can be found quickly, reducing the time and effort spent by maintenance personnel during the troubleshooting process and improving maintenance efficiency; based on the specific location of loss, more targeted maintenance strategies can be formulated, reducing maintenance costs and the impact on the system; timely detection and repair of refrigerant loss location helps to ensure the stable operation of the system and improve the system's reliability and performance; early detection of the specific location of refrigerant loss can prevent the problem from escalating further and reduce subsequent possible failures and damage.

[0155] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for controlling the cooling and antifreeze properties of a heat pump, characterized in that, include: Based on the water circulation loop information of the heat pump, a first antifreeze strategy is generated. A second antifreeze strategy is generated based on the refrigerant circulation loop information of the heat pump. A refrigeration and antifreeze strategy is generated based on the first and second antifreeze strategies. Cooling and antifreeze control of heat pumps is based on cooling and antifreeze strategies. The water circulation loop information based on the heat pump generates a first antifreeze strategy, including: Based on the water circulation loop information, determine the flow rate of water in the water circulation loop; The flow rate of water in the water circulation loop is compared with the first preset water flow rate threshold to determine the first active antifreeze strategy. Detect the outlet temperature of the water in the water circulation loop; The outlet water temperature is compared with a preset water temperature threshold to determine the first passive antifreeze strategy; Based on the first active antifreeze strategy and the first passive antifreeze strategy, a first antifreeze strategy is generated; The refrigerant circulation loop information based on the heat pump is used to generate a second antifreeze strategy, including: Periodically monitor the inlet and outlet water temperatures of the heat exchanger that exchanges heat with the refrigerant circulation loop in the water circulation loop. Calculate the rate of change of inlet and outlet water temperatures; The inlet and outlet water temperature change rate is compared with the preset temperature change rate to determine the second active antifreeze strategy; The low-pressure value in the refrigerant circulation loop is obtained based on a low-pressure sensor. The low-pressure value is compared with a preset low-pressure threshold to determine the second passive antifreeze strategy; A second antifreeze strategy is generated based on the second active antifreeze strategy and the second passive antifreeze strategy. The first active antifreeze strategy is to enter the antifreeze operation mode when the water flow rate is greater than 0 and less than or equal to the first preset water flow rate threshold, and to periodically start and stop the water pump in the water circulation circuit. The first passive antifreeze strategy is to enter the antifreeze operation mode when the outlet water temperature is lower than the preset water temperature threshold, and to issue frequency limiting or frequency reduction commands to the heat pump unit through the heat pump control system. The second active antifreeze strategy is to enter the antifreeze operation mode when the inlet and outlet water temperature change rate is greater than or equal to the preset temperature change rate, and to issue frequency limiting or frequency reduction commands to the heat pump unit through the heat pump control system. The second passive antifreeze strategy is to enter the antifreeze operation mode when the low pressure value is less than the preset low pressure threshold, and to issue frequency limiting or frequency reduction commands to the heat pump unit through the heat pump control system.

2. The cooling and antifreeze control method for a heat pump as described in claim 1, characterized in that, Before determining the flow rate of water in the water circulation loop based on the water circulation loop information, the following steps are also included: Acquire data from various preset water quality sensors, flow rate sensors, and temperature sensors in the water circulation loop; The blockage coefficient of the water circulation loop is calculated based on the preset water quality sensor data, flow rate sensor data, and temperature sensor data in the water circulation loop using a preset algorithm. The blockage coefficient is compared with a preset blockage coefficient; If the blockage coefficient is greater than or equal to the preset blockage coefficient, an alarm will be issued and a maintenance work order will be generated to arrange for maintenance personnel to carry out the maintenance. If the blockage coefficient is less than the preset blockage coefficient, the water pump in the water circulation loop is started, and the water flow switch is detected to determine the flow rate of the water in the water circulation loop.

3. The cooling and antifreeze control method for a heat pump as described in claim 2, characterized in that, Based on preset water quality sensor data, flow rate sensor data, and temperature sensor data in the water circulation loop, the blockage coefficient of the water circulation loop is calculated using a preset algorithm, including: in, This indicates the blockage coefficient of the water circulation loop; This represents the water quality data of the i-th water quality sensor in the water circulation loop; n represents the number of water quality sensors in the water circulation loop. This represents the flow velocity data from the q-th flow velocity sensor in the water circulation loop; This indicates the number of flow rate sensors in the water circulation loop; This represents the water temperature data from the s-th temperature sensor in the water circulation loop. This indicates the number of temperature sensors in the water circulation loop.

4. The cooling and antifreeze control method for a heat pump as described in claim 1, characterized in that, Cooling and antifreeze control of heat pumps based on cooling and antifreeze strategies includes: When the current antifreeze strategy is the first active antifreeze strategy, it is determined in real time whether the current water flow rate exceeds the second preset water flow rate threshold. If so, the antifreeze operation mode of the first active antifreeze strategy is exited; the second preset water flow rate threshold is greater than the first preset water flow rate threshold. When the current antifreeze strategy is the first passive antifreeze strategy, it is determined in real time whether the outlet water temperature is the preset water temperature threshold. If so, the antifreeze operation mode of the first passive antifreeze strategy is exited. When the current antifreeze strategy is the second active antifreeze strategy, the inlet and outlet water temperature change rate is calculated in real time to see if it is less than the preset temperature change rate. If it is, the antifreeze operation mode of the second active antifreeze strategy is exited. When the current antifreeze strategy is the first passive antifreeze strategy, it is determined in real time whether the low pressure value is greater than the preset low pressure threshold. If so, the antifreeze operation mode of the strategy is exited and the second passive antifreeze strategy is adopted.

5. The cooling and antifreeze control method for a heat pump as described in claim 1, characterized in that, The process of controlling the cooling and antifreeze of a heat pump based on a cooling and antifreeze strategy also includes: Obtain information on the refrigerant charge at each node in the refrigerant circulation loop of the heat pump; The loss coefficient of refrigerant in the refrigerant circulation loop is calculated based on the refrigerant dosage information of each node. The loss coefficient is compared with a preset loss coefficient threshold. When the loss coefficient is determined to be greater than or equal to a preset loss coefficient threshold, the refrigerant in the refrigerant circulation loop is replenished, and the specific location of refrigerant loss is determined. Maintenance is then performed based on the specific location of refrigerant loss.

6. The cooling and antifreeze control method for a heat pump as described in claim 5, characterized in that, The calculation of the refrigerant loss coefficient in the refrigerant circulation loop based on the refrigerant dosage information of each node includes: in, This represents the refrigerant loss coefficient in the refrigerant circulation loop. This indicates the current ambient temperature. This indicates the average temperature in the refrigerant circulation loop at the current moment; The error coefficient representing the measured temperature, with a range of values. ; Indicates the number of nodes in the refrigerant circulation loop; This represents the amount of refrigerant that passes through the i-th node at a preset rate within a preset time period; This represents the average cooling dose when passing through all nodes at a preset rate within a preset time period.

7. The cooling and antifreeze control method for a heat pump as described in claim 6, characterized in that, Determining the specific location of refrigerant loss includes: Select the evaporator inlet position in the refrigerant circulation loop as the starting node, and arbitrarily select any other node besides the starting node as the target node; Calculate the loss coefficient of the corresponding cooling dose from the starting node to the target node to obtain the sub-loss coefficient; traverse all nodes to obtain several sub-loss coefficients. Calculate the difference between two adjacent sub-loss coefficients to obtain the target difference; The target difference is compared with a preset difference threshold. When the target difference is determined to be greater than or equal to the preset difference threshold, the location between the two corresponding nodes is taken as the specific location of the cooling capacity loss.

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