Air conditioning system

Abstract

The invention discloses an air conditioning system. The air conditioning system comprises a water tank; a first heat exchanger; a second heat exchanger; a third heat exchanger; a compressor; a first pipeline, a second pipeline and a third pipeline; a control valve; the controller is configured to determine the refrigeration load according to the working state parameters of the third heat exchanger after determining that the current temperature of the water tank is lower than the maximum allowable water temperature under the refrigeration working condition; determining a heating water load according to the working state parameter of the second heat exchanger; and target heat recovery modes are determined according to the refrigeration load and the heating water load, wherein the target heat recovery modes at least comprise a partial heat recovery mode and a total heat recovery mode. According to the air conditioning system, the target heat recovery mode can be intelligently switched to be matched with changes of heat recovery requirements, the heat recovery efficiency is improved while the refrigeration effect is not affected, and the use experience of a user is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and in particular to an air conditioning system. Background Technology

[0002] With the increasing popularity of air conditioning products, users are paying more and more attention to the utilization of waste heat from air conditioners. In order to solve the problem of high energy consumption of air conditioning systems and achieve energy conservation and emission reduction, air conditioning systems can recover the waste heat generated by cooling. This heat can be recovered through a water tank and used to provide domestic hot water. This can realize the recycling and reuse of waste heat, reduce system carbon emissions, and reduce energy consumption.

[0003] In existing technologies, air conditioning systems can recover and reuse waste heat through partial heat recovery mode or full heat recovery mode. However, during the operation of the air conditioning system, the heat recovery requirements of the whole unit will also change accordingly. Existing air conditioning systems can only operate in partial heat recovery mode or full heat recovery mode, which cannot match the changes in heat recovery requirements, thus affecting the cooling effect and heat recovery efficiency, and providing users with a poor user experience. Summary of the Invention

[0004] This invention aims to at least solve one of the technical problems existing in the prior art. Therefore, one objective of this invention is to provide an air conditioning system that can intelligently switch target heat recovery modes to match changes in heat recovery demand, improving heat recovery efficiency without affecting cooling performance and ensuring a superior user experience.

[0005] A first aspect of this invention provides an air conditioning system, comprising: a water tank for storing domestic water; a first heat exchanger located outdoors for exchanging heat with circulating refrigerant; a second heat exchanger connected to the water tank for exchanging heat with the domestic water; a third heat exchanger located indoors for regulating indoor temperature; a compressor having an exhaust port and an intake port; a first pipeline, a second pipeline, and a third pipeline, wherein the beginning ends of the first pipeline and the second pipeline are both connected to the exhaust port, the ends of the first pipeline and the second pipeline are both connected to the beginning ends of the third pipeline, and the end of the third pipeline is connected to the exhaust port; the first heat exchanger is located outdoors for exchanging heat with circulating refrigerant; a second heat exchanger connected to the water tank for exchanging heat with circulating refrigerant; a third heat exchanger located indoors for regulating indoor temperature; a compressor having an exhaust port and an intake port; a first pipeline, a second pipeline, and a third pipeline, wherein the beginning ends of the first pipeline and the second pipeline are both connected to the exhaust port, the ends of the first pipeline and the second pipeline are both connected to the exhaust port, and the first heat exchanger is located outdoors for exchanging heat with circulating refrigerant; the first heat exchanger is located outdoors for exchanging heat with circulating refrigerant; the second heat exchanger has an exhaust port and an intake port; the first pipeline is located outdoors for exchanging heat with circulating refrigerant; the second heat exchanger has an exhaust port and an intake port; the first pipeline is located outdoors for exchanging heat with circulating refrigerant; the first heat exchanger has an exhaust port and an intake port ... The first pipeline has a second heat exchanger located on it, and the third heat exchanger is located on it. A control valve is located between the compressor and the first, second, and third pipelines, and is used to selectively control the circulation of the refrigerant in the first, second, and / or third pipelines. A controller is configured to: determine the cooling load based on the operating parameters of the third heat exchanger after determining that the current water tank temperature is lower than the maximum allowable water temperature under cooling conditions; determine the hot water load based on the operating parameters of the second heat exchanger; and determine a target heat recovery mode based on the cooling load and the hot water load, wherein the target heat recovery mode includes at least a partial heat recovery mode and a full heat recovery mode.

[0006] According to the air conditioning system of the present invention, based on the changes in cooling load and hot water load, a suitable target heat recovery mode is intelligently selected to match the changes in the heat recovery demand of the air conditioning system. Compared with the prior art, which can only operate a single partial heat recovery mode or a full heat recovery mode, this application controls the opening and closing state of the control valve 6 based on the cooling load and hot water load, thereby controlling the circulation path of the refrigerant and realizing the switching of the target operation recovery mode. The cooling effect and heat recovery efficiency are not affected under various operating conditions, expanding the application scenarios of the air conditioning system and ensuring the user experience.

[0007] In some embodiments, the cooling load is the cooling capacity. For determining the cooling load based on the operating state parameters of the third heat exchanger, the controller is specifically configured to: determine the cooling capacity based on the first inlet water temperature of the third heat exchanger, the first outlet water temperature of the third heat exchanger, and the volumetric flow rate of the water pump on the outlet side of the third heat exchanger.

[0008] In some embodiments, for the cooling capacity, the controller is specifically configured to: calculate a first temperature difference between the first inlet water temperature and the first outlet water temperature; calculate the product of the first temperature difference, the water pump volumetric flow rate on the outlet side of the third heat exchanger, and the water specific heat capacity to obtain the cooling capacity.

[0009] In some embodiments, the hot water load is the hot water production capacity. For determining the hot water load based on the operating state parameters of the second heat exchanger, the controller is specifically configured to: determine the hot water production capacity based on the second inlet water temperature of the second heat exchanger, the second outlet water temperature of the second heat exchanger, and the volumetric flow rate of the water pump on the outlet side of the second heat exchanger.

[0010] In some embodiments, for the hot water production capacity, the controller is specifically configured to: calculate a second temperature difference between the second outlet water temperature and the second inlet water temperature; calculate the product of the second temperature difference, the volumetric flow rate of the water pump on the outlet side of the second heat exchanger, and the specific heat capacity of the water to obtain the hot water production capacity.

[0011] In some embodiments, for determining the target heat recovery mode based on the cooling load and the hot water load, the controller is specifically configured to: if the cooling load is lower than a first reference value, determine the target heat recovery mode as a total heat recovery mode, wherein the first reference value is the product of the hot water load and a first proportional coefficient.

[0012] In some embodiments, the total heat recovery mode includes a first heat recovery mode and a second heat recovery mode. For determining the target heat recovery mode based on the cooling load and the hot water load, the controller is specifically configured to: select either the first heat recovery mode or the second heat recovery mode based on the cooling load and a second reference value, wherein the second reference value is the product of the hot water load and a second proportional coefficient, and the first proportional coefficient is greater than the second proportional coefficient; wherein, in the first heat recovery mode, the control valve controls the refrigerant to enter the second pipeline, and at the end of the second pipeline, it is diverted to the first pipeline and the third pipeline, finally converging into the compressor; in the second heat recovery mode, the control valve controls the refrigerant to sequentially enter the second pipeline and the third pipeline before returning to the compressor.

[0013] In some embodiments, when selecting the target heat recovery mode as the first heat recovery mode or the second heat recovery mode based on the cooling load and the second reference value, the controller is specifically configured to: if the cooling load is lower than the second reference value, select the target heat recovery mode as the first heat recovery mode; if the cooling load is higher than the second reference value, select the target heat recovery mode as the second heat recovery mode.

[0014] In some embodiments, for determining the target heat recovery mode based on the cooling load and the hot water load, the controller is specifically configured to: if the cooling load is higher than a first reference value, determine the target heat recovery operation mode as a partial heat recovery mode, wherein the first reference value is the product of the hot water load and a first proportional coefficient; wherein, in the partial heat recovery mode, the control valve controls the refrigerant to flow into the first pipeline and the second pipeline, and after converging at the end of the first pipeline and the end of the second pipeline, it flows back to the compressor through the third pipeline.

[0015] In some embodiments, the controller is further configured to: when it is determined that the current water tank temperature is higher than the maximum allowable water temperature, control the air conditioning system to exit the target heat recovery mode and maintain operation in the cooling condition.

[0016] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of an air conditioning system according to an embodiment of the present invention; Figure 2 This is a flowchart of controller configuration according to an embodiment of the present invention; Figure 3 This is a schematic diagram of refrigerant circulation in an air conditioning system according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the refrigerant circulation of an air conditioning system according to another embodiment of the present invention; Figure 5 This is a schematic diagram of the refrigerant circulation of an air conditioning system according to another embodiment of the present invention; Figure 6 This is a flowchart of controller configuration according to another embodiment of the present invention; Figure 7 This is a flowchart of controller configuration according to another embodiment of the present invention; Figure 8 This is a schematic diagram of the refrigerant circulation of an air conditioning system according to another embodiment of the present invention; Figure 9 This is a schematic diagram of a controller configuration according to another embodiment of the present invention.

[0018] Figure label: Air conditioning system 100; Water tank 1; First heat exchanger 2; Second heat exchanger 3; Third heat exchanger 4; Compressor 5; Control valve 6; Gas-liquid separator 7; First four-way valve 61; Second four-way valve 62; Three-way valve 63; First electronic expansion valve 64; Second electronic expansion valve 65; Third electronic expansion valve 66. Detailed Implementation

[0019] The embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. The embodiments of the present invention are described in detail below.

[0020] In existing technologies, air conditioning systems can recover and reuse waste heat through partial heat recovery mode or full heat recovery mode. However, during the operation of the air conditioning system, the heat recovery requirements of the whole unit will also change accordingly. Existing air conditioning systems can only operate in partial heat recovery mode or full heat recovery mode, which cannot match the changes in heat recovery requirements, thus affecting the cooling effect and heat recovery efficiency, and providing users with a poor user experience.

[0021] To address the aforementioned issues, the first aspect of this invention proposes an air conditioning system that can dynamically switch target heat recovery modes to match changes in heat recovery demand, thereby improving heat recovery efficiency without affecting the cooling effect and ensuring a superior user experience.

[0022] Face reference Figure 1 An air conditioning system 100 according to an embodiment of the present invention is described. The air conditioning system 100 includes a water tank 1, a first heat exchanger 2, a second heat exchanger 3, a third heat exchanger 4, a compressor 5, and a control valve 6.

[0023] The water tank 1 is used to store domestic water; the first heat exchanger 2 is located outdoors and is used to exchange heat with the circulating refrigerant; the second heat exchanger 3 is connected to the water tank 1 and is used to exchange heat with the domestic water; the third heat exchanger 4 is located indoors and is used to regulate the indoor temperature; the compressor 5 has an exhaust port and an intake port; the control valve 6 is located between the compressor 5 and the first, second, and third pipelines, and the control valve 6 is used to selectively control the circulation of refrigerant in the first, second, and / or third pipelines.

[0024] The first end of the first pipeline and the first end of the second pipeline are both used to connect to the exhaust port. The end of the first pipeline and the end of the second pipeline are both used to connect to the first end of the third pipeline. The end of the third pipeline is used to connect to the exhaust port. The first heat exchanger 2 is located on the first pipeline, the second heat exchanger 3 is located on the second pipeline, and the third heat exchanger 4 is located on the third pipeline.

[0025] The control valve 6 includes a first four-way valve 61, a second four-way valve 62, a three-way valve 63, a first electronic expansion valve 64, a second electronic expansion valve 65, and a third electronic expansion valve 66.

[0026] The first four-way valve 61 has its D end connected to the exhaust port, its C end connected to the beginning of the second pipeline, and its E end connected to its S end and then to the air inlet. The second four-way valve 62 has its D end connected to the exhaust port, its E end connected to the end of the third pipeline, and its S end connected to the air inlet. The three-way valve 63 has its first end connected to the beginning of the first pipeline, its second end connected to its C end of the second four-way valve 62, and its third end connected to the air inlet. The system is configured such that: a first electronic expansion valve 64 is installed on the first pipeline, and the first end of the first electronic expansion valve 64 is connected to the second end of the first heat exchanger 2; a second electronic expansion valve 65 is installed on the second pipeline, and the first end of the second electronic expansion valve 65 is connected to the fourth end of the second heat exchanger 3; a third electronic expansion valve 66 is installed on the third pipeline, and the first end of the third electronic expansion valve 66 is connected to the second end of the first electronic expansion valve 64 and the second end of the second electronic expansion valve 65, and the second end of the third electronic expansion valve 66 is connected to the fourth end of the third heat exchanger 4.

[0027] It should be noted that the heat exchanger types of the second heat exchanger 3 and the third heat exchanger 4 can be set according to the actual situation. For example, the second heat exchanger 3 and the third heat exchanger 4 can be plate heat exchangers. No specific restrictions are imposed here.

[0028] Based on the architecture of the air conditioner 100 described above, refer to Figure 2 As shown, the controller of the air conditioning system is configured to perform the following steps S1-S3.

[0029] Step S1: After determining that the current water tank temperature is lower than the maximum allowable water temperature under refrigeration conditions, determine the refrigeration load based on the operating status parameters of the third heat exchanger.

[0030] Specifically, such as Figure 3As shown, under refrigeration conditions, compressor 5 discharges refrigerant in a high-temperature, high-pressure state. If waste heat recovery is not performed, the first and second ends of the three-way valve 63 are open, while the third end is closed. The D and E ends of the first four-way valve 61 are connected, and the C and D ends of the second four-way valve 62 are connected. The first electronic expansion valve 64 and the third electronic expansion valve 66 are open, and the second electronic expansion valve 65 is closed. Thus, the high-temperature, high-pressure refrigerant discharged from the exhaust port of compressor 5 can all pass through the second four-way valve 62, undergo heat exchange in the first heat exchanger 2, pass through the first electronic expansion valve 64, and then pass through the third electronic expansion valve 66 for throttling and pressure reduction before entering the third... Heat exchange occurs in heat exchanger 3, providing cooling to the room and lowering the indoor temperature. The refrigerant then returns to compressor 5 through the air inlet. During this refrigerant cycle, all waste heat generated by the air conditioning system 100 is released outdoors. If the current water tank temperature is determined to be lower than the maximum allowable water temperature, the air conditioning system 100 has a hot water production requirement. It can transfer the waste heat lost to the outdoor environment to heat domestic hot water, thus achieving waste heat reuse. However, the heat recovery requirement of the air conditioning system 100 changes during operation. If the heat recovery mode fails to change accordingly, it will not only affect the cooling effect and heat recovery efficiency but also provide a poor user experience. The cooling load can be expressed as cooling energy demand or cooling capacity. Cooling energy demand is the amount of heat theoretically required to be removed by the air conditioning system to reach the set cooling temperature, while cooling capacity is the maximum cooling capacity provided by the air conditioning system per unit time. The hot water production load can be expressed as hot water production energy demand or hot water production capacity. Hot water production energy demand is the amount of heat theoretically required by the air conditioning system to reach the set hot water production temperature, while hot water production capacity is the maximum amount of hot water produced by the air conditioning system per unit time.

[0031] The third heat exchanger 4 serves as the refrigeration output. Its operating status parameters, such as exhaust temperature, condensing temperature, or outlet water flow rate, can be obtained by installing sensors to acquire the refrigeration load and determine the heat recovery requirements.

[0032] Due to the existence of heating inertia, a safety value can be set for the maximum allowable operating water temperature to reduce the maximum allowable operating water temperature, thereby providing overheat protection in advance and avoiding equipment overheating damage.

[0033] Step S2: Determine the hot water production load based on the operating status parameters of the second heat exchanger.

[0034] Specifically, the air conditioning system 100 uses refrigerant to heat the domestic hot water in the water tank to recover waste heat. The second heat exchanger 3 is used as the hot water output. Its operating status parameters, such as the hot water set temperature, the water flow rate, or the exhaust temperature, can be obtained by installing sensors to assess the refrigerant heat recovery of the current air conditioning system 100 or the amount of hot water provided per unit time, so as to determine the heat recovery requirements.

[0035] Step S3: Determine the target heat recovery mode based on the cooling load and hot water production load. The target heat recovery mode includes at least a partial heat recovery mode and a full heat recovery mode.

[0036] Specifically, in existing technologies, air conditioning systems can only operate in partial or full heat recovery mode, and cannot match the appropriate heat recovery mode according to changes in heat recovery demand. This affects the cooling effect and heat recovery efficiency, providing a poor user experience. When the heat recovery demand is high, if the air conditioning system 100 is in partial heat recovery mode, the heat recovery efficiency will decrease, and the water tank temperature will drop significantly, affecting the user experience. When the heat recovery demand is low, if the air conditioning system 100 is in full heat recovery mode, the heat recovery efficiency will decrease, and the cooling effect will also be affected. Compared with existing technologies, this application determines the heat recovery demand of the air conditioning system 100 by measuring the cooling load and the hot water load. Based on changes in heat recovery demand, it intelligently selects the target heat recovery mode, ensuring that the cooling effect and heat recovery efficiency are not affected under various operating conditions, thus guaranteeing the user experience.

[0037] The target heat recovery mode can be switched by controlling the on / off state of control valve 6, that is, controlling the path of refrigerant circulation. (Refer to...) Figure 4 As shown, Figure 4 This is a schematic diagram of refrigerant flow in the air conditioning system under total heat recovery mode. The first and third ends of the three-way valve 63 are open while the second end is closed. Ends C and D of the first four-way valve 61 are connected, as are ends C and D of the second four-way valve 62. All the high-temperature, high-pressure refrigerant discharged from the compressor 5 flows into the second heat exchanger 3, where it exchanges heat with the domestic water in the water tank 1. At this time, the second heat exchanger 3 utilizes all the heat from the refrigerant to heat the domestic water in the water tank 1. Therefore, the target heat recovery mode of the air conditioning system 100 is the total heat recovery mode. (Reference) Figure 5 As shown, Figure 5 This is a schematic diagram of the refrigerant flow in the air conditioning system under partial heat recovery mode. The first and second ends of the three-way valve 63 are open while the third end is closed. The C and D ends of the first four-way valve 61 are connected, and the C and D ends of the second four-way valve are connected. A portion of the high-temperature and high-pressure refrigerant discharged from the exhaust port of the compressor 5 flows into the second four-way valve 62 and enters the first heat exchanger 2 to exchange heat with the outdoor air. That is, the refrigerant releases heat to the outdoor air to lower the refrigerant temperature. Another portion of the refrigerant passes through the first four-way valve 61 and enters the second heat exchanger 3 to exchange heat with the domestic water in the water tank 1. At this time, the second heat exchanger 3 uses the heat of a portion of the refrigerant to heat the domestic water in the water tank 1. That is, the target heat recovery mode required by the air conditioning system 100 is in partial heat recovery mode.

[0038] According to the air conditioning system 100 of the present invention, based on the changes in cooling load and hot water load, an appropriate target heat recovery mode is intelligently selected to match the changes in the heat recovery demand of the air conditioning system. Compared with the prior art, which can only operate a partial heat recovery mode or a full heat recovery mode, this application controls the opening and closing state of the control valve 6 based on the cooling load and hot water load, thereby controlling the circulation path of the refrigerant and realizing the switching of the target operation recovery mode. The cooling effect and heat recovery efficiency are not affected under various operating conditions, expanding the application scenarios of the air conditioning system and ensuring the user experience.

[0039] In some embodiments, the cooling load is the cooling capacity. For determining the cooling load based on the operating parameters of the third heat exchanger, refer to... Figure 6 As shown, the controller is specifically configured to perform the following steps, which are as follows.

[0040] Step S4: Determine the cooling capacity based on the first inlet water temperature of the third heat exchanger, the first outlet water temperature of the third heat exchanger, and the volumetric flow rate of the water pump on the outlet side of the third heat exchanger.

[0041] Specifically, by installing temperature sensors on the water pumps at the inlet and outlet sides of the third heat exchanger 4, the first inlet water temperature and the first outlet water temperature can be accurately measured; and by installing a flow meter to obtain the volumetric flow rate of the water pump at the outlet side of the third heat exchanger 4. During the heat exchange process, water, as the heat exchange medium, absorbs or releases heat that is related to the mass of the water, its specific heat capacity, and temperature change. By measuring the first inlet water temperature and the first outlet water temperature of the third heat exchanger, the temperature change of the water after passing through the third heat exchanger 4 can be obtained. The volumetric flow rate of the water pump, combined with the density of the water, can be used to calculate the mass of water flowing through the heat exchanger per unit time. Therefore, based on the heat calculation formula in the heat exchange process, the cooling capacity that the air conditioning system can provide per unit time can be obtained.

[0042] In some embodiments, for cooling capacity, the controller is specifically configured to: calculate a first temperature difference between a first inlet water temperature and a first outlet water temperature; calculate the product of the first temperature difference, the water pump volumetric flow rate on the outlet side of the third heat exchanger, and the water specific heat capacity to obtain the cooling capacity.

[0043] Specifically, the cooling capacity can be determined based on the heat calculation formula in the heat exchange process. Referring to Formula 1, by accurately calculating the cooling capacity, a more accurate heat recovery requirement can be obtained, thereby switching the target heat recovery mode in a timely manner. This improves heat recovery efficiency without affecting the cooling effect and ensures the user experience. Here, Q1 is the cooling capacity; q1 is the water pump volume flow rate on the outlet side of the third heat exchanger; T1 is the first inlet water temperature; and T2 is the first outlet water temperature.

[0044] Q1=4186×q1×(T1-T2)×1000 / 3600 formula 1 In some embodiments, the hot water load is the hot water production capacity. For determining the hot water load based on the operating parameters of the second heat exchanger, refer to... Figure 7 As shown, the controller is specifically configured to perform the following steps, which are as follows.

[0045] Step S5: Determine the hot water production capacity based on the second inlet water temperature of the second heat exchanger, the second outlet water temperature of the second heat exchanger, and the volumetric flow rate of the water pump on the outlet side of the second heat exchanger.

[0046] Specifically, by installing temperature sensors on the water pumps at the inlet and outlet sides of the second heat exchanger 3, the second inlet water temperature and the second outlet water temperature can be accurately measured; and a flow meter is installed to obtain the volumetric flow rate of the water pump at the outlet side of the second heat exchanger 3. Based on the basic laws of heat exchange, during the hot water production process, water acts as a heat carrier, absorbing heat in the second heat exchanger 3 and its temperature rises. By measuring the inlet and outlet water temperatures of the second heat exchanger 3, the temperature change of water in the second heat exchanger 3 can be obtained. The volumetric flow rate of the water pump, combined with the density of water, can be used to calculate the mass of water flowing through the heat exchanger per unit time. Then, based on the heat calculation formula in the heat exchange process, the amount of hot water produced per unit time, i.e., the hot water production capacity, can be calculated.

[0047] In some embodiments, for hot water production capacity, the controller is specifically configured to: calculate a second temperature difference between the second outlet water temperature and the second inlet water temperature; calculate the product of the second temperature difference, the water pump volume flow rate on the outlet side of the second heat exchanger, and the water specific heat capacity to obtain the hot water production capacity.

[0048] Specifically, the heat calculation formula in the heat exchange process can calculate the amount of hot water produced per unit time, i.e., the hot water production capacity. As shown in Formula 2, by accurately calculating the hot water production capacity, a more accurate heat recovery demand can be obtained, thereby switching the target heat recovery mode in a timely manner. This improves heat recovery efficiency without affecting the cooling effect and ensures the user experience. Here, Q2 is the hot water production capacity; q2 is the water pump volume flow rate on the outlet side of the second heat exchanger; T4 is the second outlet water temperature; and T3 is the second inlet water temperature.

[0049] Q2=4186×q2×(T4-T3)×1000 / 3600 formula 2 In some embodiments, for determining the target heat recovery mode based on the cooling load and the hot water load, the controller is specifically configured to: if the cooling load is lower than a first reference value, determine the target heat recovery mode as a total heat recovery mode, wherein the first reference value is the product of the hot water load and a first proportional coefficient.

[0050] Specifically, if the cooling load is lower than the first reference value, the waste heat generated by the cooling capacity per unit time of the current air conditioning system 100 is insufficient to heat the domestic water on the hot water side. If a large amount of water is used by users, the temperature of the domestic water in the water tank will drop too quickly, affecting the user experience. Therefore, this application uses the second heat exchanger 3 to use all the heat of the refrigerant to heat the domestic water in the water tank 1, that is, the target heat recovery mode of the air conditioning system 100 is in the total heat recovery mode. The first proportional coefficient can be set according to the actual situation, and no specific restrictions are made here.

[0051] In some embodiments, the total heat recovery mode includes a first heat recovery mode and a second heat recovery mode. For determining the target heat recovery mode based on the cooling load and the hot water load, the controller is specifically configured to: select the target heat recovery mode as the first heat recovery mode or the second heat recovery mode based on the cooling load and a second reference value, wherein the second reference value is the product of the hot water load and a second proportional coefficient, and the first proportional coefficient is greater than the second proportional coefficient; wherein, in the first heat recovery mode, the control valve controls the refrigerant to enter the second pipeline, and at the end of the second pipeline, it is diverted to the first pipeline and the third pipeline, and finally flows into the compressor; in the second heat recovery mode, the control valve controls the refrigerant to enter the second pipeline and the third pipeline in sequence and then flow back into the compressor.

[0052] Specifically, based on the comparison between the cooling load and the second reference value, the difference between the waste heat generated by the cooling capacity per unit time on the cooling side of the current air conditioning system 100 and the waste heat required for heating domestic water on the hot water side can be determined. This allows for a judgment on whether the waste heat generated by cooling can meet the waste heat supply required for heating domestic water on the hot water side. If the difference is too large, both the first heat exchanger 2 and the third heat exchanger 4 need to act as evaporators to output cooling capacity, thus meeting the waste heat supply requirements for heating domestic water on the hot water side. If the difference is small, only the third heat exchanger 4 needs to act as an evaporator to output cooling capacity, avoiding waste of cooling capacity. The second proportional coefficient can be set according to actual conditions and is not specifically limited here.

[0053] In some embodiments, when selecting a target heat recovery mode as a first heat recovery mode or a second heat recovery mode based on the cooling load and a second reference value, the controller is specifically configured to: select the target heat recovery mode as the first heat recovery mode if the cooling load is lower than the second reference value; and select the target heat recovery mode as the second heat recovery mode if the cooling load is higher than the second reference value.

[0054] Specifically, if the cooling load is lower than the second reference value, the waste heat generated by cooling cannot meet the waste heat supply required for heating domestic water on the hot water side. Therefore, both the first heat exchanger 2 and the third heat exchanger 4 need to act as evaporators to provide cooling output, preventing the inability to heat the water in the tank in a timely manner and affecting the user experience. In this case, the target heat recovery mode is determined to be the first recovery mode, referencing... Figure 4 As shown, this application controls the first and third ends of the three-way valve 63 to be open while the second end is closed via a controller. The C and D ends of the first four-way valve 61 and the C and D ends of the second four-way valve 62 are connected. Simultaneously, the first electronic expansion valve 64, the second electronic expansion valve 65, and the third electronic expansion valve 66 are opened. All the high-temperature, high-pressure refrigerant discharged from the compressor 5's exhaust port passes through the first four-way valve 61 into the second heat exchanger 3, where it exchanges heat with the domestic water in the water tank 1. At this time, the second heat exchanger 3 utilizes all the heat from the refrigerant... The refrigerant is used to heat the domestic water in the water tank 1. On the other hand, the refrigerant after heat exchange is split at the end of the second pipeline. One path is throttled by the third electronic expansion valve 66 and enters the third heat exchanger 4 to provide cooling for the room. The other path is throttled by the first electronic expansion valve 64 and enters the first heat exchanger 2. The first heat exchanger 2 is used as an evaporator to discharge the cooling to the outside, so as to ensure that the heat generated by the refrigerant on the cooling side can meet the heat recovery of the refrigerant on the hot water side. Finally, the two refrigerant paths merge and enter the gas-liquid separator 7, and return to the compressor 5 through the air inlet to complete the cycle.

[0055] If the cooling load exceeds the second reference value, the waste heat generated by cooling cannot meet the waste heat supply required for heating domestic water on the hot water side. To avoid wasting cooling capacity, the reference value should be adjusted accordingly. Figure 8 As shown, this application controls the first and third ends of the three-way valve 63 to be open while the second end is closed via a controller. The C and D ends of the first four-way valve 61 and the C and D ends of the second four-way valve 62 are connected. At the same time, the first electronic expansion valve 64 is closed, while the second electronic expansion valve 65 and the third electronic expansion valve 66 are open. The high-temperature and high-pressure refrigerant discharged from the exhaust port of the compressor 5 passes through the first four-way valve 61 and enters the second heat exchanger 3 to exchange heat with the domestic water in the water tank 1. At this time, the second heat exchanger 3 uses all the heat of the refrigerant to heat the domestic water in the water tank 1. After passing through the second electronic expansion valve 65, the refrigerant passes through the third electronic expansion valve 66 and enters the third heat exchanger 4 to exchange heat with the indoor air, thus cooling the room. Finally, it returns to the compressor 5 via the gas-liquid separator 7 to complete the refrigerant cycle.

[0056] In some embodiments, for determining the target heat recovery mode based on the cooling load and the hot water load, the controller is specifically configured to: if the cooling load is higher than a first reference value, determine the target heat recovery operation mode as a partial heat recovery mode, wherein the first reference value is the product of the hot water load and a first proportional coefficient; wherein, in the partial heat recovery mode, the control valve controls the refrigerant to flow into the first pipeline and the second pipeline, and after converging at the end of the first pipeline and the end of the second pipeline, it flows back to the compressor through the third pipeline.

[0057] Specifically, if the cooling load exceeds the first reference value, water tank 1 needs to recover refrigerant heat through water temperature to heat the domestic water in the tank. Excessive hot water load will cause excessively high condensing temperatures, leading to reduced heat exchange efficiency and affecting the cooling effect on the evaporator side, thus impacting the user experience. Therefore, the reference value should be adjusted accordingly. Figure 5 As shown, in this application, the first heat exchanger 2 is used as a condenser for heating. The controller controls the first and second ends of the three-way valve 63 to be open while the third end is closed. The C and D ends of the first four-way valve 61 and the C and D ends of the second four-way valve are connected. Simultaneously, the first electronic expansion valve 64, the second electronic expansion valve 65, and the third electronic expansion valve 66 are open. A portion of the high-temperature, high-pressure refrigerant discharged from the compressor 5's exhaust port flows into the second four-way valve 62 and enters the first heat exchanger 2, where it exchanges heat with the outdoor air, i.e., the refrigerant... Heat is released to the outdoor air to lower the refrigerant temperature. Another portion of the refrigerant enters the second heat exchanger 3 through the first four-way valve 61 to exchange heat with the domestic water in the water tank 1. The refrigerant that has passed through the first heat exchanger 2 and the second heat exchanger 3 merges after passing through the first electronic expansion valve 64 and the second electronic expansion valve 65 respectively. After being throttled by the third electronic expansion valve 66, it enters the third heat exchanger 4 to exchange heat with the indoor air to cool the room. Finally, it returns to the compressor 5 through the gas-liquid separator 7 to complete the refrigerant cycle.

[0058] In some embodiments, the controller is further configured to: when it is determined that the current water tank temperature is higher than the maximum allowable water temperature, control the air conditioning system to exit the target heat recovery mode and maintain operation in the cooling condition.

[0059] Specifically, if it is determined that the current water tank temperature is higher than the maximum allowable water temperature, the air conditioning system has no need for heat recovery. Therefore, the air conditioning system is controlled to exit the target heat recovery mode and continue to operate in the cooling mode.

[0060] For example, refer to Figure 9The controller configuration shown in this embodiment of the invention is as follows: When the air conditioning system 100 is in cooling mode, the current water tank temperature and the maximum allowable water temperature are compared. If the current water tank temperature is lower than the maximum allowable water temperature, the air conditioning system 100 can perform waste heat recovery; otherwise, waste heat recovery cannot be performed, and the cooling mode continues to operate. When performing waste heat recovery, a target operating mode needs to be determined. The target operating mode can be determined based on the cooling load and the hot water load. If the cooling load is higher than a first reference value, the target operating mode is determined to be a partial heat recovery mode; if the cooling load is lower than the first reference value but higher than a second reference value, the target heat recovery mode is determined to be a second heat recovery mode; if the cooling load is lower than the second reference value, the target heat recovery mode is determined to be a first heat recovery mode, and the comparison between the current water tank temperature and the maximum allowable water temperature is repeated. If the current water tank temperature is greater than or equal to the maximum allowable water temperature, the target operating mode is exited, and waste heat recovery is stopped; otherwise, the target operating mode is determined again. The target operating mode is dynamically matched according to the changes in the cooling load and the hot water load.

[0061] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0062] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. An air conditioning system, characterized in that, include: Water tank, the water tank being used to store domestic water; The first heat exchanger, located outdoors, is used to exchange heat with the circulating refrigerant; The second heat exchanger is connected to the water tank and is used to exchange heat with the domestic water. The third heat exchanger, located indoors, is used to regulate the indoor temperature; The compressor has an exhaust port and an intake port; A first pipeline, a second pipeline, and a third pipeline, wherein the beginning ends of the first pipeline and the second pipeline are both used to connect to the exhaust port, the ends of the first pipeline and the second pipeline are both used to connect to the beginning end of the third pipeline, and the end of the third pipeline is used to connect to the exhaust port. The first heat exchanger is located on the first pipeline, the second heat exchanger is located on the second pipeline, and the third heat exchanger is located on the third pipeline. A control valve is provided between the compressor and the first pipeline, the second pipeline, and the third pipeline, and the control valve is used to selectively control the circulation of the refrigerant in the first pipeline, the second pipeline, and / or the third pipeline; The controller is configured to: After determining that the current water tank temperature is lower than the maximum allowable water temperature under refrigeration conditions, the refrigeration load is determined based on the operating status parameters of the third heat exchanger. The hot water load is determined based on the operating status parameters of the second heat exchanger. The target heat recovery mode is determined based on the cooling load and the hot water production load, and the target heat recovery mode includes at least a partial heat recovery mode and a full heat recovery mode.

2. The air conditioning system according to claim 1, characterized in that, The cooling load is the cooling capacity. To determine the cooling load based on the operating parameters of the third heat exchanger, the controller is specifically configured as follows: The cooling capacity is determined based on the first inlet water temperature of the third heat exchanger, the first outlet water temperature of the third heat exchanger, and the volumetric flow rate of the water pump on the outlet side of the third heat exchanger.

3. The air conditioning system according to claim 2, characterized in that, Regarding the cooling capacity, the controller is specifically configured as follows: Calculate the first temperature difference between the first inlet water temperature and the first outlet water temperature; The cooling capacity is obtained by calculating the product of the first temperature difference, the volumetric flow rate of the water pump on the outlet side of the third heat exchanger, and the specific heat capacity of the water.

4. The air conditioning system according to claim 1, characterized in that, The hot water production load is the hot water production capacity. To determine the hot water production load based on the operating parameters of the second heat exchanger, the controller is specifically configured as follows: The hot water production capacity is determined based on the second inlet water temperature of the second heat exchanger, the second outlet water temperature of the second heat exchanger, and the volumetric flow rate of the water pump on the outlet side of the second heat exchanger.

5. The air conditioning system according to claim 4, characterized in that, Regarding the hot water production capacity, the controller is specifically configured as follows: Calculate the second temperature difference between the second outlet water temperature and the second inlet water temperature; The hot water production capacity is obtained by calculating the product of the second temperature difference, the volumetric flow rate of the water pump on the outlet side of the second heat exchanger, and the specific heat capacity of the water.

6. The air conditioning system according to any one of claims 1-5, characterized in that, The controller is specifically configured to determine the target heat recovery mode based on the cooling load and the hot water production load as follows: If the cooling load is lower than the first reference value, the target heat recovery mode is determined to be the total heat recovery mode, wherein the first reference value is the product of the hot water production load and the first proportional coefficient.

7. The air conditioning system according to claim 6, characterized in that, The total heat recovery mode includes a first heat recovery mode and a second heat recovery mode. To determine the target heat recovery mode based on the cooling load and the hot water production load, the controller is specifically configured as follows: The target heat recovery mode is selected as either the first heat recovery mode or the second heat recovery mode based on the cooling load and the second reference value, wherein the second reference value is the product of the hot water production load and the second proportional coefficient, and the first proportional coefficient is greater than the second proportional coefficient. In the first heat recovery mode, the control valve controls the refrigerant to enter the second pipeline, and at the end of the second pipeline, it is diverted to the first pipeline and the third pipeline, and finally flows into the compressor. In the second heat recovery mode, the control valve controls the refrigerant to sequentially enter the second pipeline and the third pipeline before flowing back into the compressor.

8. The air conditioning system according to claim 7, characterized in that, The controller is specifically configured to select either the first heat recovery mode or the second heat recovery mode based on the cooling load and the second reference value. If the cooling load is lower than the second reference value, then the target heat recovery mode is selected as the first heat recovery mode; If the cooling load is higher than the second reference value, then the target heat recovery mode is selected as the second heat recovery mode.

9. The air conditioning system according to any one of claims 1-5, characterized in that, The controller is specifically configured to determine the target heat recovery mode based on the cooling load and the hot water production load as follows: If the cooling load is higher than the first reference value, then the target heat recovery operation mode is determined to be a partial heat recovery mode, wherein the first reference value is the product of the hot water production load and the first proportional coefficient; In the partial heat recovery mode, the control valve controls the refrigerant to flow into the first pipeline and the second pipeline, and after converging at the end of the first pipeline and the end of the second pipeline, it flows back to the compressor through the third pipeline.

10. The air conditioning system according to claim 1, characterized in that, The controller is also configured to: When the current water tank temperature is determined to be higher than the maximum allowable water temperature, the air conditioning system is controlled to exit the target heat recovery mode and continue to operate in the cooling condition.

Images