Heat recovery system and control method thereof

Abstract

The invention provides a control method of a heat recovery system. The control method of the heat recovery system comprises the steps that demand information is obtained; when the heating requirement and the water heating requirement are met at the same time, the current indoor temperature Tn and the set indoor temperature Ts are obtained; calculating a room temperature difference value between the indoor temperature Tn and the set room temperature Ts; selecting a system operation mode according to the room temperature difference value; wherein the system operation modes comprise an independent heating mode, a main heating and auxiliary water heating mode, a main water heating and auxiliary heating mode and an independent water heating mode. 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 cooling in summer and air conditioning 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 heat in winter 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 heating 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 object, according to one aspect of the present invention, a control method for a heat recovery system is provided, wherein the heat recovery system comprises an air conditioning system and a hot water system, the air conditioning system comprises a compressor, an indoor heat exchanger, an outdoor heat exchanger, a second throttling device and a four-way valve, the hot water system comprises a water heater, a hot water pipeline and a first throttling device, a first solenoid valve is arranged on a connecting pipeline between the compressor and the four-way valve, a second solenoid valve is arranged on a first end of the hot water pipeline, a third solenoid valve is arranged on a pipeline between the outdoor heat exchanger and the hot water pipeline, and the second throttling device is arranged on a pipeline between the indoor heat exchanger and the hot water pipeline; the control method comprises:

[0010] Obtain demand information;

[0011] When there is a heating demand and a hot water demand at the same time, obtain the current indoor temperature Tn and the set room temperature Ts;

[0012] Calculate the room temperature difference between the indoor temperature Tn and the set room temperature Ts;

[0013] Select the system operation mode according to the room temperature difference;

[0014] The system operation modes include separate heating mode, main heating and auxiliary hot water mode, main hot water and auxiliary heating mode and separate hot water mode.

[0015] Further, the step of selecting to operate the main heating and auxiliary hot water production mode or the main hot water production and auxiliary heating mode according to the room temperature difference includes:

[0016] When Ts-Tn≥w, the control system enters the single heating mode;

[0017] When Ts-Tn<w, the control system enters the primary heating and secondary hot water mode.

[0018] Furthermore, the steps of controlling the system to enter the single heating mode include:

[0019] The first solenoid valve and the third solenoid valve are controlled to be opened, the second solenoid valve is controlled to be closed, and the second throttling device is controlled to adjust the refrigerant flow rate so that all the refrigerant is used for indoor heating.

[0020] Furthermore, the control method further includes:

[0021] After running in the heating mode alone for t1 time, obtain the current indoor temperature Tn;

[0022] Calculate the room temperature difference between the indoor temperature Tn and the set room temperature Ts;

[0023] When Ts-Tn≥w, maintain the single heating mode;

[0024] When Ts-Tn<w, the control system enters the primary heating and secondary hot water mode.

[0025] Furthermore, the steps of controlling the system to enter the primary heating and secondary hot water production mode include:

[0026] The first solenoid valve, the second solenoid valve and the third solenoid valve are controlled to open, the first throttling device and the second throttling device are controlled to adjust the refrigerant flow, a small part of the refrigerant is controlled to flow through the water heater for preheating, and most of the refrigerant is controlled to heat the room.

[0027] Furthermore, the control method further includes:

[0028] After running the main heating and auxiliary hot water mode for t2 time, check whether the indoor temperature reaches the set room temperature;

[0029] If the set room temperature has not been reached, the main heating and auxiliary hot water mode is maintained until the room temperature is reached, and after the room temperature is reached, the control system operates the main hot water and auxiliary heating mode.

[0030] Furthermore, the steps of controlling the system to operate the main hot water production and auxiliary heating mode include:

[0031] The first solenoid valve, the second solenoid valve and the third solenoid valve are controlled to open, the first throttling device and the second throttling device are controlled to adjust the refrigerant flow, most of the refrigerant is controlled to flow through the water heater for preheating, and a small part of the refrigerant is controlled to heat the room indoors to maintain the room temperature.

[0032] Furthermore, the control method further includes:

[0033] After running the main hot water and auxiliary heating modes for t3 time, obtain the current water heater water temperature Tw and the set water temperature T1;

[0034] Calculate the water temperature difference between the water heater water temperature Tw and the set water temperature T1;

[0035] Select the system operation mode according to the water temperature difference.

[0036] Furthermore, the step of selecting the system operation mode according to the room temperature difference includes:

[0037] If Tw-T1≥h1, the main hot water and auxiliary heating modes are maintained until the water temperature of the water heater reaches the set water temperature;

[0038] If Tw-T1

[0039] Furthermore, the control method further includes:

[0040] When the water temperature of the water heater reaches the set water temperature, the control system enters the independent heating mode;

[0041] ​The first solenoid valve and the third solenoid valve are controlled to be opened, the second solenoid valve is controlled to be closed, and the second throttling device is controlled to adjust the refrigerant flow rate so that all the refrigerant is used for indoor heating.

[0042] Applying the technical solution of the present invention, the control method of the heat recovery system includes: obtaining demand information; when there is a heating demand and a hot water demand at the same time, obtaining the current indoor temperature Tn and the set room temperature Ts; calculating the room temperature difference between the indoor temperature Tn and the set room temperature Ts; selecting the system operation mode according to the room temperature difference; wherein the system operation mode includes a separate heating mode, a main heating and a secondary hot water mode, a main hot water and a secondary heating mode, and a separate hot water mode. 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 heating and hot water according to the relationship between the indoor temperature and the set room temperature, so that the appropriate operation mode can be selected according to the needs, and the indoor heating and hot water can be coordinated, the outdoor heat can be fully utilized, and the effective and full use of heat recovery can be achieved, 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

[0043] 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:

[0044] Figure 1 A structural principle diagram showing a heat recovery system according to an embodiment of the present invention in a first operation mode;

[0045] 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;

[0046] Figure 3 A structural principle diagram showing a heat recovery system according to an embodiment of the present invention in a fourth operation mode;

[0047] Figure 4 A schematic diagram showing a control method of a heat recovery system according to an embodiment of the present invention; and

[0048] Figure 5 A control flow chart of a heat recovery system according to an embodiment of the present invention is shown.

[0049] The above drawings include the following reference numerals:

[0050] 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

[0051] 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.

[0052] See also Figures 1 to 5 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.

[0053] 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 cooling and heating functions of users, the condensation heat discharged by the air conditioner can be recovered for the preparation of domestic hot water, thereby 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.

[0054] In this embodiment, heat pump technology is combined with 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 multiple operating modes of a set of systems, it not only provides air-conditioning cooling and heating functions, but also has the function of preparing domestic hot water. It can prepare hot water on the basis of meeting the cooling and heating needs of users, or when the cooling and heating needs in the transition season are small, after meeting the basic needs, the heat can be concentrated on heating domestic hot water, reasonably allocating and utilizing energy, and improving energy utilization.

[0055] 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 .

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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 .

[0060] 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.

[0061] 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.

[0062] 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.

[0063] See also Figure 4 and Figure 5 As shown, according to an embodiment of the present invention, the control method of the heat recovery system includes: obtaining demand information;

[0064] When there is a heating demand and a hot water demand at the same time, obtain the current indoor temperature Tn and the set room temperature Ts;

[0065] Calculate the room temperature difference between the indoor temperature Tn and the set room temperature Ts;

[0066] Select the system operation mode according to the room temperature difference;

[0067] The system operation modes include separate heating mode, main heating and auxiliary hot water mode, main hot water and auxiliary heating mode and separate hot water mode.

[0068] The control method of the heat recovery system adopts a comprehensive approach of air conditioning system and hot water system to adjust indoor temperature and produce hot water, and reasonably allocates the refrigerant ratio for heating and hot water according to the relationship between the indoor temperature and the room temperature difference, so that the appropriate operation mode can be selected according to needs, which can achieve the coordination of indoor heating and hot water, make full use of outdoor condensation heat, realize effective and full use of heat recovery, improve the heat recovery utilization efficiency, improve the operation efficiency of the heat recovery system, and improve energy utilization.

[0069] By intelligently judging the difference between the indoor temperature and the set room 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 low temperature weather in winter or transitional seasons, when users need to use air conditioning heating and hot water at the same time.

[0070] In this embodiment, since it is aimed at the coexistence of indoor heating and water heater hot water, the indoor heating needs to absorb outdoor heat while the water heater needs to absorb outdoor heat to make hot water. The two form a competitive relationship for the outdoor heat. Therefore, in this case, it is necessary to focus on indoor temperature control to first meet the indoor temperature requirements, improve indoor comfort, and improve user experience, and then consider the demand for hot water. Therefore, when the heat recovery system is working, it first focuses on detecting the room temperature so that the indoor temperature can be quickly increased. When the indoor temperature meets the requirements, it switches to focusing on hot water production and reasonably allocates outdoor heat.

[0071] In this embodiment, there are four operating modes in the heat recovery system. The first operating mode is the separate heating mode. In this case, the heat recovery system does not produce hot water, which is equivalent to a heating air conditioner; the second operating mode is the main heating and auxiliary hot water mode. In this case, there is both heating demand and hot water demand, but the heating demand is greater than the hot water demand, so most of the refrigerant is used for indoor heating, and a small part is used for hot water; the third operating mode is the main hot water and auxiliary heating mode. In this case, there is both heating demand and hot water demand, and the hot water demand is greater than the heating demand, so most of the refrigerant is used for hot water, and a small part is used for indoor heating; the fourth operating mode is the separate hot water mode. In this case, only the indoor temperature is maintained or the indoor heating 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.

[0072] The first operating mode and the fourth operating mode mentioned above can be freely selected by the user according to needs.

[0073] By dividing the operating modes of the heat recovery system into four types, the operating modes can be subdivided according to the user's direct needs, the actual working parameters and working efficiency of heating and hot water production, so that the appropriate operating mode can be selected under different temperature conditions, which can not only meet the user's usage needs but also improve the operating efficiency of the heat recovery system.

[0074] In one embodiment, the step of selecting to operate the primary heating and secondary hot water production mode or the primary hot water production and secondary heating mode according to the room temperature difference includes:

[0075] When Ts-Tn≥w, the control system enters the single heating mode;

[0076] When Ts-Tn<w, the control system enters the primary heating and secondary hot water mode.

[0077] In one embodiment, the step of controlling the system to enter the heating-only mode includes:

[0078] The first solenoid valve 10 and the third solenoid valve 12 are controlled to be opened, the second solenoid valve 11 is controlled to be closed, and the second throttling device 4 is controlled to adjust the refrigerant flow rate so that all the refrigerant is used for indoor heating.

[0079] When Ts-Tn≥w, it is judged that the indoor temperature at this time is far from the user's ideal room temperature. To ensure the comfort of air conditioning heating, the system enters the independent heating mode, the water heater branch is disconnected, and all the heat of the air conditioner is used for indoor heating, ensuring the indoor heating effect at the initial stage of air conditioning startup and meeting the user's comfort requirements. At this time, the device is equivalent to a heat pump air conditioner.

[0080] By setting the room temperature difference w, the system can automatically determine whether the indoor temperature needs to be met first, so as to ensure indoor comfort while reasonably utilizing waste heat to heat water. This is especially suitable for cold areas in winter, which can not only keep the indoor temperature warm, but also ensure the supply of hot water. In practical applications, this dynamic mode switching strategy is particularly effective. For example, in cold northern regions, when the indoor temperature is much lower than the set temperature, the system will automatically enter the separate heating mode to quickly increase the indoor temperature. When the indoor temperature approaches the set value, the system will automatically adjust to a mode in which heating is the main mode and hot water is the auxiliary mode, which not only ensures the comfort of the indoor temperature, but also preheats the hot water, prepares for the hot water needs of family members, and improves the availability of hot water.

[0081] In one embodiment, the control method further includes: obtaining the current indoor temperature Tn after the heating mode is operated for t1 time;

[0082] Calculate the room temperature difference between the indoor temperature Tn and the set room temperature Ts;

[0083] When Ts-Tn≥w, maintain the single heating mode;

[0084] When Ts-Tn<w, the control system enters the primary heating and secondary hot water mode.

[0085] When Ts-Tn<w, it is judged that the indoor temperature at this time is moderately different from the user's ideal room temperature. To ensure the comfort of air-conditioning heating, the control system enters the main heating and auxiliary hot water mode, controls a small part of the refrigerant to flow through the water heater for preheating, and uses most of the refrigerant for heating, thereby maximizing the heating capacity and meeting the user's comfort requirements.

[0086] By setting the time t1 and the room temperature difference w, the system can dynamically adjust the operation mode to avoid overheating and use waste heat to preheat water. It is suitable for scenarios where you need to quickly raise the indoor temperature and prepare hot water. When the indoor temperature approaches the set value, the system will automatically adjust to a mode where heating is the main mode and hot water is the auxiliary mode. While preheating the water, it also avoids overheating and saves energy.

[0087] In one embodiment, the steps of controlling the system to enter the primary heating and secondary hot water production mode include:

[0088] The first solenoid valve 10, the second solenoid valve 11 and the third solenoid valve 12 are controlled to open, the first throttling device 7 and the second throttling device 4 are controlled to adjust the refrigerant flow, a small part of the refrigerant is controlled to flow through the water heater 5 for preheating, and most of the refrigerant is controlled for indoor heating.

[0089] In this mode, the system preheats hot water while meeting the indoor heating demand. It is suitable for scenarios with many family members and frequent hot water demand, ensuring the rapid supply of hot water while maintaining a comfortable indoor temperature. This mode can respond quickly and ensure an adequate supply of hot water without sacrificing indoor comfort. It can effectively improve the availability of hot water and the overall efficiency of the system, reduce the waiting time for hot water, and improve the quality of life.

[0090] In one embodiment, the control method further includes: after running the main heating and auxiliary hot water mode for t2 time, detecting whether the indoor temperature reaches the set room temperature; if the set room temperature has not been reached, maintaining the main heating and auxiliary hot water mode until the room temperature is reached, and controlling the system to run the main hot water and auxiliary heating mode after the room temperature is reached.

[0091] By setting the time t2, the system can ensure that the indoor temperature reaches the set value before adjusting to the mode of mainly hot water production and auxiliary heating. This is suitable for scenarios where continuous hot water supply is required after the indoor temperature stabilizes in winter, such as when families use hot water frequently in winter. This ensures sufficient hot water supply while maintaining a comfortable indoor temperature. After the indoor temperature stabilizes in winter, when the demand for hot water increases, the system can automatically adjust to the mode of mainly hot water production and auxiliary heating, ensuring sufficient hot water supply while maintaining a comfortable indoor temperature. This mode is particularly suitable for situations where families use hot water frequently in winter, such as the hot water demand of large families in winter. It can effectively improve the efficiency of hot water supply, reduce the waiting time for hot water, and improve the comfort and quality of life of family members. It also saves energy and reduces operating costs.

[0092] In one embodiment, the steps of controlling the system to operate in the primary hot water production and secondary heating mode include:

[0093] The first solenoid valve 10, the second solenoid valve 11 and the third solenoid valve 12 are controlled to open, the first throttling device 7 and the second throttling device 4 are controlled to adjust the refrigerant flow, most of the refrigerant is controlled to flow through the water heater 5 for preheating, and a small part of the refrigerant is controlled to heat the room indoors to maintain the room temperature.

[0094] In this mode, after the indoor temperature reaches the preset room temperature, the system will give priority to outdoor heat to meet the hot water demand, and use a small amount of refrigerant to maintain the indoor temperature to ensure the timely supply of hot water. It also improves the utilization efficiency of outdoor heat and the temperature rise efficiency of hot water.

[0095] In one embodiment, the control method further includes:

[0096] After running the main hot water and auxiliary heating modes for t3 time, obtain the current water heater water temperature Tw and the set water temperature T1;

[0097] Calculate the water temperature difference between the water heater water temperature Tw and the set water temperature T1;

[0098] Select the system operation mode according to the water temperature difference.

[0099] After the main hot water and auxiliary heating modes are operated for t3 time, the indoor temperature is basically adjusted to the required temperature. Therefore, in this case, the hot water of the water heater can be heated as the main method to improve the efficiency of hot water production and ensure the supply demand of hot water. While producing hot water, the appropriate operation mode can be selected according to the water temperature difference to further improve the energy utilization efficiency.

[0100] By setting time t3, the system can dynamically adjust the operating mode to ensure that the hot water temperature reaches the set value.

[0101] In one embodiment, the step of selecting a system operation mode according to the room temperature difference includes:

[0102] If T1-Tw≥h1, the main hot water and auxiliary heating modes are maintained until the water temperature of the water heater reaches the set water temperature;

[0103] If T1-Tw

[0104] If T1-Tw≥h1, it is judged that the current water temperature in the water heater is low or the preheating result does not meet expectations, and the expected temperature rise margin is large. At this time, maintain the third operating mode and continue preheating until the water temperature of the water heater meets the standard.

[0105] If T1-Tw

[0106] In one embodiment, the control method further includes:

[0107] When the water temperature of the water heater reaches the set water temperature, the control system enters the independent heating mode;

[0108] The first solenoid valve 10 and the third solenoid valve 12 are controlled to be opened, the second solenoid valve 11 is controlled to be closed, and the second throttling device 4 is controlled to adjust the refrigerant flow rate so that all the refrigerant is used for indoor heating.

[0109] When the water temperature Tw of the water heater reaches the user-set water temperature T1, the system enters the first operating mode, disconnects from the water heater branch, and freely adjusts the room temperature. At this time, the system is equivalent to a heat pump air conditioner.​​

[0110] In this mode, the system concentrates all energy on indoor heating. It is suitable for scenarios where the indoor temperature needs to be maintained continuously after the hot water demand is met, ensuring the continuous stability of the indoor temperature while avoiding energy waste in the hot water system. After the hot water demand is met, the system can automatically switch to the separate heating mode and concentrate all energy on indoor heating. It is especially suitable for situations at night when the hot water demand is reduced but the indoor temperature needs to be kept stable. This mode can ensure the continuous stability of the indoor temperature, avoid energy waste in the hot water system, improve energy utilization efficiency, reduce operating costs, and also ensure user comfort.

[0111] This control method realizes efficient coordination between the air conditioning system and the hot water system by intelligently adjusting the solenoid valve and the throttling device. While meeting the indoor heating demand, the waste heat of the air conditioning system is fully utilized for hot water preheating, which effectively improves energy utilization efficiency and reduces energy waste. When the indoor temperature is close to the set temperature, it automatically adjusts to a mode in which hot water production is the main mode and heating production is the auxiliary mode, ensuring the rapid supply of hot water while maintaining a comfortable indoor temperature. When the hot water temperature reaches the set value, the system can quickly switch back to the separate heating mode to ensure the continuous stability of the indoor temperature. This intelligent control strategy not only improves the user experience, but also achieves the goal of energy conservation and emission reduction, with significant economic and environmental benefits. In practical applications, this method can be flexibly adjusted according to user needs and environmental changes, ensuring the efficiency and economy of system operation, and is an important part of energy-saving control in modern smart home systems.

[0112] 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.

[0113] 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.

[0114] 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 control method for a heat recovery system, characterized in that: The heat recovery system comprises an air conditioning system and a hot water system, the air conditioning system comprises a compressor (1), an indoor heat exchanger (2), an outdoor heat exchanger (3), a second throttling device (4) and a four-way valve (8), the hot water system comprises a water heater (5), a hot water pipeline (6) and a first throttling device (7), a first solenoid valve (10) is arranged on the connecting pipeline between the compressor (1) and the four-way valve (8), a second solenoid valve (11) is arranged at the first end of the hot water pipeline (6), a third solenoid valve (12) is arranged on the pipeline between the outdoor heat exchanger (3) and the hot water pipeline (6), and the second throttling device (4) is arranged on the pipeline between the indoor heat exchanger (2) and the hot water pipeline (6); the control method comprises: Obtain demand information; When there is a heating demand and a hot water demand at the same time, obtain the current indoor temperature Tn and the set room temperature Ts; Calculate the room temperature difference between the indoor temperature Tn and the set room temperature Ts; Select the system operation mode according to the room temperature difference; The system operation modes include separate heating mode, main heating and auxiliary hot water mode, main hot water and auxiliary heating mode and separate hot water mode.

2. The control method according to claim 1, characterized in that: The steps of selecting the main heating and auxiliary hot water mode or the main hot water and auxiliary heating mode according to the room temperature difference include: When Ts-Tn≥w, the control system enters the single heating mode; When Ts-Tn<w, the control system enters the primary heating and secondary hot water mode.

3. The control method according to claim 2, characterized in that: The steps of controlling the control system to enter the single heating mode include: controlling the first solenoid valve (10) and the third solenoid valve (12) to open, controlling the second solenoid valve (11) to close, and controlling the second throttling device (4) to adjust the refrigerant flow so that all the refrigerant is used for indoor heating.

4. The control method according to claim 3, characterized in that: The control method further comprises: After running in the heating mode alone for t1 time, obtain the current indoor temperature Tn; Calculate the room temperature difference between the indoor temperature Tn and the set room temperature Ts; When Ts-Tn≥w, maintain the single heating mode; When Ts-Tn<w, the control system enters the primary heating and secondary hot water mode.

5. The control method according to claim 2, characterized in that: The steps for the control system to enter the main heating and auxiliary hot water mode include: The first solenoid valve (10), the second solenoid valve (11) and the third solenoid valve (12) are controlled to open, the first throttling device (7) and the second throttling device (4) are controlled to adjust the refrigerant flow, a small portion of the refrigerant is controlled to flow through the water heater (5) for preheating, and most of the refrigerant is controlled to heat the room.

6. The control method according to claim 5, characterized in that: The control method further comprises: After running the main heating and auxiliary hot water mode for t2 time, check whether the indoor temperature reaches the set room temperature; If the set room temperature has not been reached, the main heating and auxiliary hot water mode is maintained until the room temperature is reached, and after the room temperature is reached, the control system operates the main hot water and auxiliary heating mode.

7. The control method according to claim 6, characterized in that: The steps of the control system operating the main hot water and auxiliary heating mode include: The first solenoid valve (10), the second solenoid valve (11) and the third solenoid valve (12) are controlled to open, the first throttling device (7) and the second throttling device (4) are controlled to adjust the refrigerant flow, most of the refrigerant is controlled to flow through the water heater (5) for preheating, and a small part of the refrigerant is controlled to heat the room indoors to maintain the room temperature.

8. The control method according to claim 7, characterized in that: The control method further comprises: After running the main hot water and auxiliary heating modes for t3 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; Select the system operation mode according to the water temperature difference.

9. The control method according to claim 8, characterized in that: The steps of selecting the system operation mode according to the room temperature difference include: If Tw-T1≥h1, the main hot water and auxiliary heating modes are maintained until the water temperature of the water heater reaches the set water temperature; If Tw-T1<h1, 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 second throttling device (4) is controlled to close, the indoor heat exchanger (2) is on standby, the outdoor heat exchanger (3) is turned on, and the refrigerant is controlled to be used entirely for heating hot water.

10. The control method according to claim 9, characterized in that: The control method further comprises: When the water temperature of the water heater reaches the set water temperature, the control system enters the independent heating mode; The first solenoid valve (10) and the third solenoid valve (12) are controlled to open, the second solenoid valve (11) is controlled to close, and the second throttling device (4) is controlled to adjust the refrigerant flow rate so that all the refrigerant is used for indoor heating.

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