Heat recovery system and control method thereof

Abstract

The invention provides a heat recovery system and a control method thereof. The control method of the heat recovery system comprises the steps that demand information is obtained; when the refrigeration requirement and the water heating requirement are met at the same time, the current water temperature Tw of the water heater and the set water temperature T1 are obtained; the water temperature difference value between the water temperature Tw of the water heater and the set water temperature T1 is calculated; and according to the water temperature difference value, a main refrigeration and auxiliary water heating mode or a main water heating and auxiliary refrigeration mode is selected to operate. According to the control method of the heat recovery system, the operation efficiency of the heat recovery system can be improved, and the energy utilization rate is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning, and in particular to a heat recovery system and a control method thereof. Background Art

[0002] With the rapid development of social economy and the significant improvement of people's living standards, families have a growing demand for comfortable life. Among many home appliances, air conditioners and water heaters have become a must-have for families because of their important role in regulating indoor temperature and providing hot water.

[0003] Existing household air source water heaters and household air conditioning systems usually adopt independent designs, which means they need to be installed and operated separately. This design not only increases the installation cost of the household, but also takes up more space.

[0004] In summer and transitional seasons, the air conditioning system generates a lot of waste heat during the cooling process, while the water heater consumes energy to heat the water. If these two devices can work together and use the waste heat of the air conditioner for heating the water heater, it will greatly improve energy utilization efficiency and reduce energy waste. The independent operation of the air conditioner and the water heater not only leads to energy waste, but also may have a negative impact on the environment, increasing the emission of harmful gases and the greenhouse effect during the operation of the air conditioner.

[0005] At present, the condensation heat generated by the air-conditioning system under refrigeration conditions is as high as about 1.3 times the refrigeration capacity. It is directly discharged into the atmosphere without being effectively utilized, resulting in energy waste. At the same time, it increases the ambient temperature, causes heat pollution, and aggravates the urban "heat island effect". In summer, users need to use air conditioning for refrigeration while preparing domestic hot water. A large amount of waste heat generated by air conditioning condensation cannot be effectively utilized and is discharged into the atmosphere. The heating of domestic hot water requires another heat source to prepare heat. The irrational use of heat in and out generates energy waste.

[0006] With the dual demands of air conditioning for cooling in summer and heating in winter, there are currently some products that attempt to integrate air conditioners and water heaters together, so that the air conditioner can not only provide cooling in summer but also have the function of preparing hot water to meet users' hot water needs.

[0007] However, the existing air conditioners currently have unreasonable allocation of indoor cooling and hot water, which not only reduces the operating efficiency of the air conditioner, but also reduces the energy utilization rate. Summary of the invention

[0008] The main purpose of the present invention is to provide a heat recovery system and a control method thereof, which can improve the operating efficiency of the heat recovery system and improve energy utilization.

[0009] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a heat recovery system is provided, including an air-conditioning system and a hot water system, the air-conditioning system including a compressor, an indoor heat exchanger, an outdoor heat exchanger and a second throttling device, the hot water system including a water heater and a hot water pipeline, the water heater is arranged on the hot water pipeline, the first end of the hot water pipeline is connected to the exhaust port of the compressor, the second end of the hot water pipeline is connected to the pipeline between the indoor heat exchanger and the outdoor heat exchanger, and the second end of the hot water pipeline is provided with a first throttling device.

[0010] Furthermore, the air-conditioning system also includes a four-way valve, the exhaust port of the compressor is connected to the first interface of the four-way valve, the intake port of the compressor is connected to the second interface of the four-way valve, the indoor heat exchanger is connected to the third interface of the four-way valve, the outdoor heat exchanger is connected to the fourth interface of the four-way valve, and the exhaust port of the compressor is selectively connected to the four-way valve and the water heater.

[0011] Furthermore, a one-way valve is provided at the second end of the hot water pipeline to prevent the refrigerant from flowing back to the water heater.

[0012] Furthermore, a first solenoid valve is arranged on the connecting pipeline between the compressor and the four-way valve, a second solenoid valve is arranged on the first end of the hot water pipeline, a third solenoid valve is arranged on the pipeline between the outdoor heat exchanger and the hot water pipeline, and a second throttling device is arranged on the pipeline between the indoor heat exchanger and the hot water pipeline.

[0013] According to another aspect of the present invention, there is provided a control method for the above-mentioned heat recovery system, comprising:

[0014] Obtain demand information;

[0015] When there is a cooling demand and a hot water demand at the same time, obtain the current water heater water temperature Tw and the set water temperature T1;

[0016] Calculate the water temperature difference between the water heater water temperature Tw and the set water temperature T1;

[0017] According to the water temperature difference, select the main cooling and auxiliary hot water mode or the main hot water and auxiliary cooling mode.

[0018] Further, the step of selecting to operate the primary cooling and secondary hot water production mode or the primary hot water production and secondary cooling mode according to the water temperature difference includes:

[0019] If T1-Tw

[0020] If T1-Tw≥h1, the heat recovery system is controlled to enter the main hot water production and auxiliary cooling mode.

[0021] Furthermore, the steps of controlling the heat recovery system to enter the primary cooling and secondary hot water making mode include:

[0022] ​Control the first solenoid valve, the second solenoid valve and the third solenoid valve to open;

[0023] The first throttling device and the second throttling device are controlled to adjust the refrigerant flow rate, a small part of the refrigerant is controlled to flow through the water heater for heating, and most of the refrigerant is controlled to flow through the outdoor heat exchanger for heat exchange.

[0024] Furthermore, the control method further includes:

[0025] After the main cooling and auxiliary hot water mode runs for t1 time, the current water heater water temperature Tw and the set water temperature T1 are detected;

[0026] Calculate the water temperature difference between the water heater water temperature Tw and the set water temperature T1;

[0027] Select the control strategy based on the water temperature difference between the water heater water temperature Tw and the set water temperature T1.

[0028] Furthermore, the step of selecting a control strategy according to the water temperature difference between the water temperature Tw of the water heater and the set water temperature T1 includes:

[0029] If T1-Tw≤h2, enter the single hot water mode;

[0030] Control the first solenoid valve to close, the second solenoid valve and the third solenoid valve to open, the second throttling device to close, and the indoor heat exchanger to be in a standby state;

[0031] When the current water temperature Tw of the water heater reaches the set water temperature T1, it switches to the single cooling mode, controls the first solenoid valve and the third solenoid valve to open, the second solenoid valve to close, and the second throttling device to open.

[0032] Furthermore, the step of selecting a control strategy according to the water temperature difference between the water temperature Tw of the water heater and the set water temperature T1 includes:

[0033] If T1-Tw>h2, the heat recovery system is controlled to enter the main hot water and auxiliary cooling mode;

[0034] Control the first solenoid valve, the second solenoid valve and the third solenoid valve to open;

[0035] The first throttling device and the second throttling device are controlled to adjust the refrigerant flow rate, and most of the refrigerant is controlled to flow through the water heater for heating, and a small part of the refrigerant is controlled to flow through the outdoor heat exchanger for heat exchange.

[0036] Furthermore, the control method further includes:

[0037] After the main hot water and auxiliary cooling modes are operated for t2 time, the current indoor temperature Tn and the set room temperature T2 are detected;

[0038] Calculate the room temperature difference between the indoor temperature Tn and the set room temperature T2;

[0039] The control strategy is selected according to the room temperature difference between the indoor temperature Tn and the set room temperature T2.

[0040] Further, the step of selecting a control strategy according to the room temperature difference between the indoor temperature Tn and the set room temperature T2 includes:

[0041] If Tn-T2≤m, switch to separate hot water mode;

[0042] Control the second solenoid valve and the third solenoid valve to open, control the first solenoid valve to close, adjust the flow of the first throttling device, control the second throttling device to close, put the air conditioner indoor unit on standby, and control the refrigerant to flow through the outdoor heat exchanger for heat exchange;

[0043] If Tn-T2>m, switch to the main cooling and auxiliary hot water mode;

[0044] Control the first solenoid valve, the second solenoid valve and the third solenoid valve to open;

[0045] The first throttling device and the second throttling device are controlled to adjust the refrigerant flow rate, a small part of the refrigerant is controlled to flow through the water heater for heating, and most of the refrigerant is controlled to flow through the outdoor heat exchanger for heat exchange.

[0046] Furthermore, the steps of controlling the heat recovery system to enter the main hot water production and auxiliary cooling mode include:

[0047] Control the first solenoid valve, the second solenoid valve and the third solenoid valve to open;

[0048] Control the first throttling device and the second throttling device to adjust the refrigerant flow rate, control most of the refrigerant to flow through the water heater for heating, and control a small part of the refrigerant to flow through the outdoor heat exchanger for heat exchange;

[0049] After the main hot water and auxiliary cooling mode runs for t2 time, the current water heater water temperature Tw and the set water temperature T1 are detected;

[0050] Calculate the water temperature difference between the water heater water temperature Tw and the set water temperature T1;

[0051] If T1-Tw≤h2, enter the separate hot water production mode.

[0052] Applying the technical solution of the present invention, the control method of the heat recovery system includes: obtaining demand information; when there is a cooling demand and a hot water demand at the same time, obtaining the current water heater water temperature Tw and the set water temperature T1; calculating the water temperature difference between the water heater water temperature Tw and the set water temperature T1; and selecting to operate the main cooling and auxiliary hot water mode or the main hot water and auxiliary cooling mode according to the water temperature difference. The control method of the heat recovery system adopts a comprehensive method of the air conditioning system and the hot water system to adjust the indoor temperature and make hot water, and reasonably allocates the refrigerant ratio of cooling and hot water according to the relationship between the water heater water temperature and the set water temperature, so that the appropriate operation mode can be selected according to the needs, and the indoor cooling and hot water coordination can be achieved, and the indoor heat and outdoor condensation heat can be fully utilized to achieve effective and full utilization of heat recovery, and the heat recovery efficiency can be improved, the operation efficiency of the heat recovery system can be improved, and the energy utilization rate can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0054] Figure 1 A structural principle diagram showing a heat recovery system according to an embodiment of the present invention in a first operation mode;

[0055] Figure 2 A structural principle diagram showing a heat recovery system according to an embodiment of the present invention in the second and third operating modes;

[0056] Figure 3 A structural principle diagram showing a heat recovery system according to an embodiment of the present invention in a fourth operation mode;

[0057] Figure 4 A schematic diagram showing a control method of a heat recovery system according to an embodiment of the present invention; and

[0058] Figure 5 A control flow chart of a heat recovery system according to an embodiment of the present invention is shown.

[0059] The above drawings include the following reference numerals:

[0060] 1. Compressor; 2. Indoor heat exchanger; 3. Outdoor heat exchanger; 4. Second throttling device; 5. Water heater; 6. Hot water pipeline; 7. First throttling device; 8. Four-way valve; 9. Check valve; 10. First solenoid valve; 11. Second solenoid valve; 12. Third solenoid valve. DETAILED DESCRIPTION

[0061] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0062] See also Figures 1 to 3 As shown, according to an embodiment of the present invention, the heat recovery system includes an air-conditioning system and a hot water system, the air-conditioning system includes a compressor 1, an indoor heat exchanger 2, an outdoor heat exchanger 3 and a second throttling device 4, the hot water system includes a water heater 5 and a hot water pipeline 6, the water heater 5 is arranged on the hot water pipeline 6, the first end of the hot water pipeline 6 is connected to the exhaust port of the compressor 1, the second end of the hot water pipeline 6 is connected to the pipeline between the indoor heat exchanger 2 and the outdoor heat exchanger 3, and the second end of the hot water pipeline 6 is provided with a first throttling device 7.

[0063] The heat recovery system integrates the air conditioning system and the hot water system, so that the heat recovery system can be used to regulate the indoor temperature and heat the water heater. Therefore, under the premise of satisfying the normal refrigeration function of users, the condensation heat discharged by the air conditioner can be recovered for the preparation of domestic hot water, realizing the effective utilization of the thermal energy of the whole house, improving energy utilization rate and reducing the impact of the air conditioning system on the surrounding environment.

[0064] In this embodiment, the heat pump technology is combined with the condensation heat recovery technology to prepare domestic hot water. By sharing part of the basic equipment, the utilization rate of the basic equipment is greatly increased, which is conducive to the promotion and application of household air-conditioning heat pump water heaters. By switching between multiple operating modes of a set of systems, it not only provides air-conditioning refrigeration function, but also has the function of preparing domestic hot water. It can prepare hot water on the basis of meeting the user's refrigeration needs or when the refrigeration demand is small in the transition season, after meeting the basic needs, the heat can be concentrated on heating domestic hot water, reasonably allocating and utilizing energy, and improving energy utilization.

[0065] The hot water pipeline 6 here refers to a refrigerant pipeline flowing through the water heater 5 . The refrigerant in the hot water pipeline 6 exchanges heat with the water in the water heater 5 , thereby heating the water in the water heater 5 .

[0066] In one embodiment, the air conditioning system also includes a four-way valve 8, the exhaust port of the compressor 1 is connected to the first interface of the four-way valve 8, the intake port of the compressor 1 is connected to the second interface of the four-way valve 8, the indoor heat exchanger 2 is connected to the third interface of the four-way valve 8, the outdoor heat exchanger 3 is connected to the fourth interface of the four-way valve 8, and the exhaust port of the compressor 1 is selectively connected to the four-way valve 8 and the water heater 5.

[0067] In this embodiment, by adding a four-way valve 8, the indoor cooling and heating switching of the heat recovery system can be realized, so that the system operation can have more modes, better meet the user's use needs, and further improve energy utilization. The design of the four-way valve 8 enables the system to flexibly switch between cooling and heating modes, and can also direct part of the heat energy to the water heater when necessary, meeting the use needs of different seasons and different times, and enhancing the applicability of the system and user experience.

[0068] The exhaust port of the compressor 1 is selectively connected to the four-way valve 8 and the water heater 5, which means that the exhaust port of the compressor can be connected to the first interface of the four-way valve 8, or to the water heater 5, or to the first interface of the four-way valve 8 and the water heater 5 at the same time. By adjusting a variety of connection modes, switching of a variety of operation modes can be achieved, which can more effectively and reasonably allocate and utilize energy and improve energy utilization.

[0069] In one embodiment, a one-way valve 9 is further provided at the second end of the hot water pipeline 6 to prevent the refrigerant from flowing back to the water heater 5 .

[0070] The setting of the one-way valve 9 ensures the one-way flow of the refrigerant in the hot water pipeline 6, prevents the backflow of the refrigerant when the system is switched, and protects the stable operation of the water heater and the entire system. It is particularly suitable for environments where the cooling and heating modes are frequently switched.

[0071] In one embodiment, a first solenoid valve 10 is provided on the connecting pipeline between the compressor 1 and the four-way valve 8, a second solenoid valve 11 is provided at the first end of the hot water pipeline 6, a third solenoid valve 12 is provided on the pipeline between the outdoor heat exchanger 3 and the hot water pipeline 6, and the second throttling device 4 is provided on the pipeline between the indoor heat exchanger 2 and the hot water pipeline 6.

[0072] The precise control of the solenoid valve and throttling device enables the system to dynamically adjust the flow direction and flow of the refrigerant according to actual needs, which not only improves the energy utilization efficiency, but also ensures the precise control of the indoor temperature and the water temperature of the water heater, which can more effectively improve the energy utilization efficiency and improve the heat recovery efficiency.

[0073] See also Figure 4 and Figure 5 As shown, according to an embodiment of the present invention, the control method of the above-mentioned heat recovery system includes: obtaining demand information; when there is a cooling demand and a hot water demand at the same time, obtaining the current water heater water temperature Tw and the set water temperature T1; calculating the water temperature difference between the water heater water temperature Tw and the set water temperature T1; and selecting to operate the main cooling and auxiliary hot water mode or the main hot water and auxiliary cooling mode according to the water temperature difference.

[0074] The control method of the heat recovery system adopts a comprehensive approach of the air-conditioning system and the hot water system to adjust the indoor temperature and make hot water, and reasonably allocates the refrigerant ratio for cooling and hot water according to the relationship between the water temperature of the water heater and the set water temperature, so that the appropriate operation mode can be selected as needed, which can achieve the coordination of indoor cooling and hot water, make full use of indoor heat and outdoor condensation heat, realize effective and full use of heat recovery, improve the heat recovery efficiency, improve the operation efficiency of the heat recovery system, and improve energy utilization.

[0075] By intelligently judging the difference between the water temperature of the water heater and the set water temperature, the system can automatically select the most appropriate operating mode, which not only ensures indoor comfort but also quickly increases the water temperature of the water heater. It is especially suitable for the hot summer season when users need to use air conditioning cooling and hot water at the same time.

[0076] In this embodiment, since it is aimed at the coexistence of indoor cooling and water heater hot water, it is necessary to absorb indoor heat while cooling the room and release this part of heat at the same time to achieve heat exchange. If this part of heat is released directly to the outside, it will cause the external environment temperature to rise, and this part of heat will be wasted. The water heater 5 needs to absorb heat to make hot water. Therefore, the heat absorbed during the indoor cooling process can be transferred to the water heater 5 to heat the water in the water heater 5, so as to avoid wasting the indoor heat that needs to be exchanged, so that the indoor heat can be more fully utilized. At the same time, since the water heater 5 absorbs the indoor heat, there is no need to absorb additional heat from the outside, or the additional heat required to be absorbed from the outside is greatly reduced, which greatly reduces energy loss and improves energy utilization.

[0077] While the room is being cooled and the water heater 5 is being used to heat water, since at least a portion of the heat absorbed by the water heater 5 comes from the room, the temperature rise of the water heater 5 will inevitably lead to a decrease in the indoor temperature. According to the temperature difference between the water temperature Tw of the water heater 5 and the set water temperature T1, the main cooling and auxiliary hot water making mode or the main hot water making and auxiliary cooling mode can be reasonably selected, thereby improving the heating efficiency of the water in the water heater 5 and the indoor cooling efficiency, and improving energy utilization.

[0078] In this embodiment, there are four operating modes in the heat recovery system. The first operating mode is the single cooling mode. In this case, the heat recovery system does not produce hot water, which is equivalent to a refrigeration air conditioner; the second operating mode is the main cooling and auxiliary hot water mode. In this case, there is both cooling demand and hot water demand, but the cooling demand is greater than the hot water demand. Therefore, most of the refrigerant is used for indoor cooling, and a small part is used for hot water; the third operating mode is the main hot water mode and auxiliary cooling mode. In this case, there is both cooling demand and hot water demand, and the hot water demand is greater than the cooling demand. Therefore, most of the refrigerant is used for hot water, and a small part is used for indoor cooling; the fourth operating mode is the single hot water mode. In this case, only the indoor temperature is maintained or the indoor cooling is turned off, and the heat required for hot water is provided by the outdoor heat exchanger 3. The heat recovery system is equivalent to an air-energy water heater.

[0079] The first operating mode and the fourth operating mode mentioned above can be freely selected by the user according to needs.

[0080] In one embodiment, the step of selecting to operate the primary cooling and secondary hot water production mode or the primary hot water production and secondary cooling mode according to the water temperature difference includes:

[0081] If T1-Tw

[0082] If T1-Tw≥h1, the heat recovery system is controlled to enter the main hot water production and auxiliary cooling mode.

[0083] When T1-Tw

[0084] This mode selection mechanism ensures that when the water temperature of the water heater is close to the set value, the indoor cooling demand is met first, and when the water temperature difference is large, the water temperature of the water heater is increased first. It is suitable for environments that need to balance cooling and hot water demands, and effectively avoids energy waste.

[0085] The steps of controlling the heat recovery system to enter the main cooling and auxiliary hot water mode include:

[0086] Control the first solenoid valve 10, the second solenoid valve 11 and the third solenoid valve 12 to open;

[0087] The first throttling device 7 and the second throttling device 4 are controlled to adjust the refrigerant flow rate, a small part of the refrigerant is controlled to flow through the water heater 5 for heating, and most of the refrigerant is controlled to flow through the outdoor heat exchanger 3 for heat exchange.

[0088] ​​Since the difference between the water temperature in the water heater 5 and the set water temperature in this case is not large, and within this temperature range, the water heater has not reached the high-efficiency heating range, indoor cooling can be given priority. While the indoor temperature is adjusted, a small part of the indoor heat is allocated to the water heater 5, and the water temperature in the water heater 5 is heated at the same time. Since a small part of the refrigerant flows through the water heater 5 for heating, and most of the refrigerant flows through the outdoor heat exchanger 3 for heat exchange, the maximum cooling capacity can be exerted to ensure the indoor cooling effect at the initial stage of the air conditioner being turned on, and meet the user's comfort requirements.

[0089] In the main cooling and secondary hot water mode, the system can ensure the indoor cooling effect while using the waste heat generated by the air conditioning operation to heat the water heater. It is suitable for situations where continuous cooling is required but the water temperature of the water heater is close to the set value, such as a residential environment during the day in summer.

[0090] The control method also includes:

[0091] After the main cooling and auxiliary hot water mode runs for t1 time, the current water heater water temperature Tw and the set water temperature T1 are detected;

[0092] Calculate the water temperature difference between the water heater water temperature Tw and the set water temperature T1;

[0093] Select the control strategy based on the water temperature difference between the water heater water temperature Tw and the set water temperature T1.

[0094] By regularly detecting the difference between the water temperature of the water heater and the set water temperature, the system can adjust the operating mode in time to avoid overheating. At the same time, it can ensure the rational allocation of energy so that the energy utilization efficiency can be maximized.

[0095] In one embodiment, the step of selecting a control strategy according to the water temperature difference between the water temperature Tw of the water heater and the set water temperature T1 includes:

[0096] If T1-Tw≤h2, enter the single hot water mode;

[0097] The first solenoid valve 10 is controlled to be closed, the second solenoid valve 11 and the third solenoid valve 12 are controlled to be open, the second throttling device 4 is controlled to be closed, and the indoor heat exchanger 2 is controlled to be in a standby state;

[0098] When the current water temperature Tw of the water heater reaches the set water temperature T1, it switches to the single cooling mode, controls the first solenoid valve 10 and the third solenoid valve 12 to open, the second solenoid valve 11 to close, and the second throttling device 4 to open. Among them, h2

[0099] ​If T1-Tw≤h2, it is judged that the current water temperature in the water heater is relatively high, and the estimated temperature rise margin is within the water heater's efficient heating range. Therefore, in this case, the water temperature can be quickly heated to the user-set temperature, thereby making the water heater 5 have the highest hot water production efficiency, thereby improving the overall operating efficiency of the heat recovery system.

[0100] When the water temperature in the water heater 5 reaches the set water temperature, there is no longer a need for hot water production, so the system operation mode can be switched to a single cooling mode, so that the heat recovery system only retains the cooling function, so that the indoor temperature can quickly reach the set temperature.

[0101] This mode switching mechanism ensures that after the water temperature of the water heater reaches the set value, the system automatically switches to the single cooling mode, avoiding overheating of the water heater, while ensuring that indoor cooling needs are met, avoiding energy waste and reduced system operating efficiency.

[0102] In one embodiment, the step of selecting a control strategy according to the water temperature difference between the water temperature Tw of the water heater and the set water temperature T1 includes:

[0103] If T1-Tw>h2, the heat recovery system is controlled to enter the main hot water and auxiliary cooling mode;

[0104] Control the first solenoid valve 10, the second solenoid valve 11 and the third solenoid valve 12 to open;

[0105] The first throttling device 7 and the second throttling device 4 are controlled to adjust the refrigerant flow rate, most of the refrigerant is controlled to flow through the water heater 5 for heating, and a small part of the refrigerant is controlled to flow through the outdoor heat exchanger 3 for heat exchange.

[0106] If T1-Tw>h2, it is judged that the current water temperature in the water heater is significantly different from the user-set water temperature, and is still not in the water heater's efficient heating range, and cannot be quickly heated to the set temperature. Therefore, in this case, the operation strategy needs to be adjusted so that the heat recovery system enters the main hot water and auxiliary cooling mode, so that most of the refrigerant flows through the water heater for heating, and a small part of the refrigerant flows through the condenser for heat exchange, and the air conditioner outdoor unit runs at a low speed for energy saving. At this time, the indoor temperature difference ensures the indoor cooling effect when the air conditioner is turned on in the initial stage, meeting the user's comfort requirements.

[0107] In one embodiment, the control method further includes:

[0108] After the main hot water and auxiliary cooling modes are operated for t2 time, the current indoor temperature Tn and the set room temperature T2 are detected;

[0109] Calculate the room temperature difference between the indoor temperature Tn and the set room temperature T2;

[0110] The control strategy is selected according to the room temperature difference between the indoor temperature Tn and the set room temperature T2.

[0111] When the main hot water production and auxiliary cooling mode is running, there will be a temperature with low indoor cooling efficiency. Therefore, it is necessary to detect the indoor temperature after a period of time, and judge whether the indoor temperature adjustment meets the demand based on the room temperature difference between the indoor temperature Tn and the set room temperature T2. The system operation mode can be flexibly adjusted according to the test results, so that the indoor temperature adjustment can meet the user's comfort requirements.

[0112] By monitoring the difference between the indoor temperature and the set room temperature, the system can intelligently adjust the operating mode to ensure the indoor temperature is comfortable.

[0113] In one embodiment, the step of selecting a control strategy according to the room temperature difference between the indoor temperature Tn and the set room temperature T2 includes:

[0114] If Tn-T2≤m, switch to separate hot water mode;

[0115] The second solenoid valve 11 and the third solenoid valve 12 are controlled to open, the first solenoid valve 10 is controlled to close, the flow of the first throttling device 7 is adjusted, the second throttling device 4 is controlled to close, the air conditioner indoor unit is on standby, and the refrigerant is controlled to flow through the outdoor heat exchanger 3 for heat exchange.

[0116] If Tn-T2≤m, it is judged that the indoor cooling effect is good, and the system will shut down when the temperature point is reached. At this time, the indoor heat load is low, and the efficiency of collecting heat to prepare hot water is low. It will switch to the separate hot water making mode. At this time, the indoor unit of the air conditioner is on standby and the outdoor unit is on. The highest efficiency is equivalent to that of an air-to-water heater, and all the condensation heat is used to heat hot water.

[0117] If Tn-T2>m, switch to the main cooling and auxiliary hot water mode;

[0118] Control the first solenoid valve 10, the second solenoid valve 11 and the third solenoid valve 12 to open;

[0119] The first throttling device 7 and the second throttling device 4 are controlled to adjust the refrigerant flow rate, a small part of the refrigerant is controlled to flow through the water heater 5 for heating, and most of the refrigerant is controlled to flow through the outdoor heat exchanger 3 for heat exchange.

[0120] If Tn-T2>m, it is judged that the indoor cooling rate is slow. At this time, the cooling effect is prioritized to meet the indoor comfort requirements. The system enters the primary cooling and secondary hot water mode. After the room temperature drops to meet the user's needs, it gradually switches to the priority hot water preparation mode. In this mode, a small part of the refrigerant is controlled to flow through the water heater 5 for heating, and most of the refrigerant flows through the outdoor heat exchanger 3 for heat exchange to maximize the cooling capacity.

[0121] In one embodiment, the step of controlling the heat recovery system to enter a primary hot water production and secondary cooling mode includes:

[0122] Control the first solenoid valve 10, the second solenoid valve 11 and the third solenoid valve 12 to open;

[0123] The first throttling device 7 and the second throttling device 4 are controlled to adjust the refrigerant flow rate, most of the refrigerant is controlled to flow through the water heater 5 for heating, and a small part of the refrigerant is controlled to flow through the outdoor heat exchanger 3 for heat exchange; the air conditioner outdoor unit operates at a low speed to save energy.

[0124] After the main hot water and auxiliary cooling mode runs for t2 time, the current water heater water temperature Tw and the set water temperature T1 are detected;

[0125] Calculate the water temperature difference between the water heater water temperature Tw and the set water temperature T1;

[0126] If T1-Tw≤h2, enter the separate hot water production mode.

[0127] After the system has been running for t2 time, if the indoor cooling judgment requirement is met, it is necessary to determine whether the water temperature of the water heater is in the high-efficiency heating range of the water heater. If it is in the high-efficiency heating range, the ordinary heat recovery heating mode (ie the second operating mode or the third operating mode) is used when the water temperature is high, which has low energy efficiency and long heating time. At this time, it is more efficient to enter the fourth operating mode to prepare hot water.

[0128] The above h1 is, for example, 15°C to 20°C, h2 is, for example, 5°C to 7°C, m is, for example, 6°C to 8°C, t1 is, for example, 3h to 5h, t2 is, for example, 3h to 5h, and t2 is, for example, 3h to 5h.

[0129] The heat recovery system and control method of the present application realize the dual needs of cooling and hot water production by intelligently controlling the distribution of refrigerant between the air conditioning system and the hot water system, effectively improving energy utilization efficiency, reducing energy waste, and providing users with a more comfortable and economical use experience. Especially when cooling and hot water are required at the same time, by dynamically adjusting the refrigerant flow, the water temperature of the water heater can be quickly increased while meeting the indoor temperature regulation, showing significant practical effect improvement and application benefits. In addition, the system also has the ability of self-diagnosis and self-adjustment, and can automatically optimize the operation strategy according to environmental changes and user needs, further improving the stability and reliability of the system.

[0130] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0131] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0132] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A heat recovery system, characterized in that: The invention comprises an air conditioning system and a hot water system, wherein the air conditioning system comprises a compressor (1), an indoor heat exchanger (2), an outdoor heat exchanger (3) and a second throttling device (4); the hot water system comprises a water heater (5) and a hot water pipeline (6); the water heater (5) is arranged on the hot water pipeline (6); a first end of the hot water pipeline (6) is connected to an exhaust port of the compressor (1); a second end of the hot water pipeline (6) is connected to a pipeline between the indoor heat exchanger (2) and the outdoor heat exchanger (3); and a first throttling device (7) is arranged at the second end of the hot water pipeline (6).

2. The heat recovery system according to claim 1, characterized in that: The air conditioning system further comprises a four-way valve (8), the exhaust port of the compressor (1) being connected to a first interface of the four-way valve (8), the air intake port of the compressor (1) being connected to a second interface of the four-way valve (8), the indoor heat exchanger (2) being connected to a third interface of the four-way valve (8), the outdoor heat exchanger (3) being connected to a fourth interface of the four-way valve (8), and the exhaust port of the compressor (1) being selectively connected to the four-way valve (8) and the water heater (5).

3. The heat recovery system according to claim 2, characterized in that: The second end of the hot water pipeline (6) is also provided with a one-way valve (9) for preventing the refrigerant from flowing back to the water heater (5).

4. The heat recovery system according to claim 2, characterized in that: A first solenoid valve (10) is provided on the connecting pipeline between the compressor (1) and the four-way valve (8), a second solenoid valve (11) is provided on the first end of the hot water pipeline (6), a third solenoid valve (12) is provided on the pipeline between the outdoor heat exchanger (3) and the hot water pipeline (6), and the second throttling device (4) is provided on the pipeline between the indoor heat exchanger (2) and the hot water pipeline (6).

5. A control method for a heat recovery system according to any one of claims 1 to 4, characterized in that: include: Obtain demand information; When there is a cooling demand and a hot water demand at the same time, obtain the current water heater water temperature Tw and the set water temperature T1; Calculate the water temperature difference between the water heater water temperature Tw and the set water temperature T1; According to the water temperature difference, select the main cooling and auxiliary hot water mode or the main hot water and auxiliary cooling mode.

6. The control method of the heat recovery system according to claim 5, characterized in that: The steps of selecting the main cooling and auxiliary hot water mode or the main hot water and auxiliary cooling mode according to the water temperature difference include: If T1-Tw<h1, the heat recovery system is controlled to enter the main cooling and auxiliary hot water mode; If T1-Tw≥h1, the heat recovery system is controlled to enter the main hot water production and auxiliary cooling mode.

7. The control method of the heat recovery system according to claim 6, characterized in that: The steps of controlling the heat recovery system to enter the main cooling and auxiliary hot water mode include: Controlling the first solenoid valve (10), the second solenoid valve (11) and the third solenoid valve (12) to open; The first throttling device (7) and the second throttling device (4) are controlled to adjust the refrigerant flow rate, a small portion of the refrigerant is controlled to flow through the water heater (5) for heating, and most of the refrigerant is controlled to flow through the outdoor heat exchanger (3) for heat exchange.

8. The control method of the heat recovery system according to claim 7, characterized in that: The control method further comprises: after the main cooling and auxiliary hot water making mode operates for t1 time, detecting the current water temperature Tw of the water heater and the set water temperature T1; Calculate the water temperature difference between the water heater water temperature Tw and the set water temperature T1; Select the control strategy based on the water temperature difference between the water heater water temperature Tw and the set water temperature T1.

9. The control method of the heat recovery system according to claim 8, characterized in that: The steps of selecting a control strategy according to the water temperature difference between the water temperature Tw of the water heater and the set water temperature T1 include: If T1-Tw≤h2, enter the single hot water mode; Controlling the first solenoid valve (10) to be closed, the second solenoid valve (11) and the third solenoid valve (12) to be open, the second throttling device (4) to be closed, and controlling the indoor heat exchanger (2) to be in a standby state; When the current water temperature Tw of the water heater reaches the set water temperature T1, it switches to the single cooling mode, controls the first solenoid valve (10) and the third solenoid valve (12) to open, the second solenoid valve (11) to close, and the second throttling device (4) to open.

10. The control method of the heat recovery system according to claim 8, characterized in that: The steps of selecting a control strategy according to the water temperature difference between the water temperature Tw of the water heater and the set water temperature T1 include: If T1-Tw>h2, the heat recovery system is controlled to enter the main hot water and auxiliary cooling mode; Controlling the first solenoid valve (10), the second solenoid valve (11) and the third solenoid valve (12) to open; The first throttling device (7) and the second throttling device (4) are controlled to adjust the refrigerant flow rate, and most of the refrigerant is controlled to flow through the water heater (5) for heating, and a small part of the refrigerant is controlled to flow through the outdoor heat exchanger (3) for heat exchange.

11. The control method of the heat recovery system according to claim 10, characterized in that: The control method further comprises: after the main hot water production and auxiliary cooling mode are operated for t2 time, detecting the current indoor temperature Tn and setting the room temperature T2; Calculate the room temperature difference between the indoor temperature Tn and the set room temperature T2; The control strategy is selected according to the room temperature difference between the indoor temperature Tn and the set room temperature T2.

12. The control method of the heat recovery system according to claim 11, characterized in that: The steps of selecting a control strategy according to the room temperature difference between the indoor temperature Tn and the set room temperature T2 include: If Tn-T2≤m, switch to separate hot water mode; Controlling the second solenoid valve (11) and the third solenoid valve (12) to open, controlling the first solenoid valve (10) to close, adjusting the flow of the first throttling device (7), controlling the second throttling device (4) to close, putting the indoor unit of the air conditioner in standby mode, and controlling the refrigerant to flow through the outdoor heat exchanger (3) for heat exchange; If Tn-T2>m, switch to the main cooling and auxiliary hot water mode; Controlling the first solenoid valve (10), the second solenoid valve (11) and the third solenoid valve (12) to open; The first throttling device (7) and the second throttling device (4) are controlled to adjust the refrigerant flow rate, a small portion of the refrigerant is controlled to flow through the water heater (5) for heating, and most of the refrigerant is controlled to flow through the outdoor heat exchanger (3) for heat exchange.

13. The control method of the heat recovery system according to claim 6, characterized in that: The steps of controlling the heat recovery system to enter the main hot water production and auxiliary cooling mode include: Controlling the first solenoid valve (10), the second solenoid valve (11) and the third solenoid valve (12) to open; Controlling the first throttling device (7) and the second throttling device (4) to adjust the flow rate of the refrigerant, controlling most of the refrigerant to flow through the water heater (5) for heating, and controlling a small part of the refrigerant to flow through the outdoor heat exchanger (3) for heat exchange; After the main hot water and auxiliary cooling mode runs for t2 time, the current water heater water temperature Tw and the set water temperature T1 are detected; Calculate the water temperature difference between the water heater water temperature Tw and the set water temperature T1; If T1-Tw≤h2, enter the separate hot water production mode.

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