Heating system and control method thereof

Abstract

The invention discloses a heating system and a control method thereof. The heating system comprises an outdoor unit, a first heat exchanger, a phase change heat storage device, a heating device and a switching device. A first heat exchange runner section and a second heat exchange runner section which can exchange heat are formed on the first heat exchanger, and the first heat exchange runner section is located on a heat supply circulating flow path formed by the outdoor unit; a heat storage runner section is formed in the phase change heat storage device, and a phase change material is arranged in the phase change heat storage device and exchanges heat with the heat storage runner section; the heating device is provided with a heating backflow main line, a heating branch line and a short-circuit branch line, the heating branch line and the short-circuit branch line are connected with the heating backflow main line and arranged in parallel, a heating assembly is arranged on the heating branch line, and the second heat exchange runner section and the heat storage runner section are both located on the heating backflow main line. Liquid on the heating backflow main line is subjected to heat exchange through the second heat exchange runner section and then flows through the heat storage runner section; the switching device switches one of the heating branch and the short-circuit branch to be communicated with the heating backflow trunk. Frequent starting and stopping of the outdoor unit are avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioners, and particularly to a heating system and a control method thereof. Background Art

[0002] A heat pump system that provides domestic hot water and heating can simultaneously meet the domestic hot water demand and heating demand of users. Among them, the heat pump system controls the start and stop of the heat pump in the system by detecting the return water temperature at the heat exchange place of the heat pump. When the return water temperature reaches the set temperature, the system will stop running.

[0003] In order to protect the safe operation of the heat pump, in the existing heat pump operation strategy, the start and stop of the unit are controlled by the return water temperature at the heat exchange place of the heat pump. However, when the heat pump is operating for heating, if the heating demand of the user is low or the heat charging power at the heating end is low, it will cause the return water temperature to quickly reach the shutdown temperature, resulting in frequent start and stop of the unit, an increase in the instantaneous power of the unit, and at the same time affecting the life of the unit. Summary of the Invention

[0004] The main object of the present invention is to provide a heating system and a control method thereof, aiming to solve the problem of frequent start and stop of the heat pump system.

[0005] To achieve the above object, the present invention provides a heating system, including:

[0006] An outdoor unit, forming a heating circulation flow path;

[0007] A first heat exchanger, forming a first heat exchange flow path section and a second heat exchange flow path section capable of heat exchange, and the first heat exchange flow path section is on the heating circulation flow path;

[0008] A phase change heat storage device, forming a heat storage flow path section, provided with a phase change material in the phase change heat storage device, and heat exchanging with the heat storage flow path section;

[0009] A heating device, forming a heating return main path, as well as a heating branch path and a short-circuit branch path that are both connected to the heating return main path and are arranged in parallel. A heating component is provided on the heating branch path. The second heat exchange flow path section and the heat storage flow path section are both on the heating return main path, and the liquid on the heating return main path flows through the heat storage flow path section after heat exchange through the second heat exchange flow path section; and,

[0010] A switching device, switching one of the heating branch path and the short-circuit branch path to be connected to the heating return main path.

[0011] Optionally, the switching device includes a first valve provided on the heating branch path and a second valve provided on the short-circuit branch path;

[0012] Select the first valve to open and the second valve to close so that the heating branch communicates with the heating return main line;

[0013] Select the first valve to close and the second valve to open so that the bypass branch communicates with the heating return main line.

[0014] Optionally, a compressor, a second heat exchanger and a four-way valve are sequentially arranged on the heating circulation pipeline;

[0015] The four-way valve is used to switch the exhaust port of the compressor to communicate with the first heat exchanger or the second heat exchanger.

[0016] Optionally, an electric auxiliary heating device is further arranged on the heating return main line, and the electric auxiliary heating device is located between the first heat exchanger and the phase change heat storage device.

[0017] Optionally, a water pump is further arranged on the heating return main line.

[0018] Optionally, the heating assembly further includes a plurality of floor heating pipes arranged in parallel.

[0019] Optionally, the phase change heat storage device includes a heat storage device housing and a finned tube heat exchanger arranged in the heat storage device housing. A heat storage channel is formed in the finned tube heat exchanger, and the phase change heat storage material is arranged between the heat storage device housing and the finned tube heat exchanger.

[0020] Optionally, an endothermic flow section is further formed in the phase change heat storage device, and the endothermic flow section is used for heat exchange with the phase change material;

[0021] The heating system further includes a water supply device, and a water flow path is formed on the water supply device. The endothermic flow section is located on the water flow path.

[0022] Optionally, the heating system further includes a temperature measuring device, and the temperature measuring device is used to detect the temperatures of the first heat exchanger, the phase change heat storage device and the heating assembly.

[0023] Optionally, the first heat exchanger includes a shell-and-tube heat exchanger or a plate heat exchanger.

[0024] The present invention further provides a control method for a heating system. Based on the heating system described in any one of the above, a first valve is arranged on the heating branch, a second valve is arranged on the bypass branch, and an electric auxiliary heating device and a water pump are further arranged on the heating return main line. The control method of the heating system includes the following steps:

[0025] Obtain the current heat storage temperature of the phase change material;

[0026] Determine the current temperature difference according to the current heat storage temperature and the phase change temperature corresponding to the phase change material;

[0027] When the current temperature difference meets the preset condition of heat supplement demand, control the water pump to start, the first valve to close, the second valve to open, and control the external unit to start heating.

[0028] Optionally, after "when the current temperature difference meets the preset condition of heat supplement demand, control the water pump to start and control the external unit to start heating", it further includes:

[0029] Monitor the current outlet water temperature of the first heat exchanger;

[0030] When the current outlet water temperature is greater than the preset shutdown temperature, control the external unit to stop heating and control the electric auxiliary heating device to start until the current temperature difference meets the preset condition for exiting heat supplement.

[0031] Optionally, it further includes the following steps:

[0032] When there is a heating demand in the heating component, obtain the target heating temperature selected by the user and the current heating return water temperature;

[0033] Determine the heating temperature difference according to the target heating temperature and the current heating return water temperature;

[0034] When the heating temperature difference meets the preset heating condition, control the water pump to start, the first valve to open, the second valve to close, and control the external unit to start heating.

[0035] Optionally, after "when the heating temperature difference meets the preset heating condition, control the water pump to start, the first valve to open, the second valve to close, and control the external unit to start heating", it further includes:

[0036] Monitor the current return water temperature and the current outlet water temperature of the first heat exchanger;

[0037] Determine the temperature demand difference according to the current return water temperature and the current outlet water temperature;

[0038] When the current outlet water temperature of the first heat exchanger is greater than the preset shutdown temperature, or the temperature demand difference is less than the working temperature difference threshold of the external unit, control the external unit to stop heating.

[0039] Optionally, it further includes:

[0040] When the external unit has a defrosting demand, respectively control the water pump to start, the first valve to close, and the second valve to open, and control the external unit to perform refrigeration so as to supply heat to the external unit through the heat storage module.

[0041] Optionally, a compressor, a second heat exchanger and a four-way valve are sequentially arranged on the heating circulation path of the outdoor unit;

[0042] The control method of the heating system further includes the following steps:

[0043] Control the compressor to start, and control the four-way valve to switch the exhaust port of the compressor to communicate with the first heat exchanger, so that the outdoor unit starts heating;

[0044] Control the compressor to start, and control the four-way valve to switch the exhaust port of the compressor to communicate with the second heat exchanger, so that the outdoor unit starts cooling;

[0045] Control the compressor to stop, so that the outdoor unit stops heating and cooling.

[0046] In the heating system provided by the present invention, a phase change heat storage device is arranged in the heating system. During the operation of the heating system, the heat generated by the outdoor unit is transferred from the first heat exchange flow path to the second heat exchange flow path section of the first heat exchanger, and then heat is transported into the heating return main road, so that the heating branch roads therein can obtain heat. Before entering the heating return main road, the heat-exchanged liquid output from the second heat exchange flow path section passes through the heat storage flow path section, transfers heat to the phase change heat storage device, enables the phase change heat storage device to store heat, and performs a primary heat absorption and temperature reduction on the high-temperature liquid output from the first heat exchanger. When heating is required, connect the heating branch roads to the heating return main road, store the excessive heat through the phase change heat storage device, and complete step-by-step temperature reduction, extend the time for the system return water temperature to reach the outdoor unit shutdown temperature, avoid frequent start and stop of the outdoor unit. At the same time, when the required heat is relatively low, heat can be directly provided by the phase change heat storage device without turning on the outdoor unit, which is convenient for the frequent start and stop of the outdoor unit when the operating frequency is low. Description of the Drawings

[0047] Figure 1 is a schematic connection structure diagram of the heating system provided by the embodiment of the present invention;

[0048] Figure 2 is Figure 1 a three-dimensional structure diagram of the phase change heat storage device in

[0049] Figure 3 is a flow block diagram of the control method of the heating system provided by the embodiment of the present invention.

[0050] Explanation of the reference numerals in the drawings:

[0051]

[0052]

[0053] The realization, functional features and advantages of the present invention will be further described in conjunction with embodiments with reference to the accompanying drawings. Detailed implementation manners

[0054] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0055] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present invention, the directional indications are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0056] In addition, if there are descriptions such as "first", "second", etc. involved in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the meaning of "and / or" appearing throughout the text includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or a solution where A and B are satisfied simultaneously. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0057] A heat pump system that provides domestic hot water and heating can simultaneously meet the domestic hot water demand and heating demand of users. Among them, the heat pump system controls the start and stop of the heat pump in the system by detecting the return water temperature at the heat pump heat exchange part. When the return water temperature reaches the set temperature, the system will stop running.

[0058] In order to protect the safe operation of the heat pump, in the existing heat pump operation strategy, the start and stop of the unit are controlled by the return water temperature at the heat pump heat exchange part. However, when the heat pump is in heating operation, if the heating demand of the user is low or the heat charging power at the heating end is low, it will cause the return water temperature to quickly reach the shutdown temperature, resulting in frequent start and stop of the unit, an increase in the instantaneous power of the unit, and at the same time affecting the life of the unit.

[0059] Please refer to Figure 1 Figure 1 , the present invention provides a heating system 100, including an outdoor unit 1, a first heat exchanger 2, a phase change heat storage device 3, a heating device 4 and a switching device; the outdoor unit 1 forms a heating circulation flow path; the first heat exchanger 2 forms a first heat exchange flow path section and a second heat exchange flow path section capable of heat exchange, and the first heat exchange flow path section is on the heating circulation flow path; the phase change heat storage device 3 forms a heat storage flow path section, a phase change material is provided in the phase change heat storage device 3 and exchanges heat with the heat storage flow path section; the heating device 4 forms a heating return main path, and a heating branch path and a short-circuit branch path that are both connected to the heating return main path and are arranged in parallel. A heating component 411 is provided on the heating branch path. The second heat exchange flow path section and the heat storage flow path section are both on the heating return main path. The liquid on the heating return main path flows through the heat storage flow path section after exchanging heat through the second heat exchange flow path section; the switching device switches one of the heating branch path and the short-circuit branch path to be connected to the heating return main path.

[0060] In the heating system provided by the present invention, the phase change heat storage device 3 is arranged in the heating system 100. Among them, during the operation of the heating system 100, the heat generated by the outdoor unit is transferred from the first heat exchange flow path to the second heat exchange flow path section of the first heat exchanger 2, and then heat is transported into the heating return main path, so that the heating branch path therein can obtain heat. Before entering the heating return main path, the heat-exchanged liquid output from the second heat exchange flow path section passes through the heat storage flow path section, and transfers heat to the phase change heat storage device 3, so that the phase change heat storage device 3 can store heat and perform a primary heat absorption and temperature reduction on the high-temperature liquid output from the first heat exchanger 2.

[0061] When heating is required, connect the heating branch path to the heating return main path, store excessive heat through the phase change heat storage device 3, and complete step-by-step temperature reduction, extend the time for the system return water temperature to reach the outdoor unit shutdown temperature, avoid frequent start and stop of the outdoor unit. At the same time, when the required heat is low, heat can be directly provided by the phase change heat storage device 3 without turning on the outdoor unit, which is convenient for the frequent start and stop of the outdoor unit when the operating frequency is low.

[0062] In addition, when heating is not required, connect the short-circuit branch path to the heating return main path, and the outdoor unit 1 can directly input heat to the phase change heat storage device 3 to achieve long-term and persistent heat storage. When heating is required later, or for other heat demands such as domestic water heating, since the heat demand is low, heat can be directly provided by the phase change heat storage device 3 without turning on the outdoor unit, avoiding frequent start and stop of the outdoor unit and affecting the service life of the outdoor unit.

[0063] It should be noted that in this embodiment, the switching device is used to switch the connection of one of the heating branch and the short - circuit branch. There are various implementation manners of the switching device. For example, a three - way valve structure is adopted. By switching the internal valve core of the three - way valve, a selection is made between the heating branch and the short - circuit branch.

[0064] Specifically, in this application, the switching device includes a first valve 51 arranged on the heating branch and a second valve 52 arranged on the short - circuit branch; when the first valve 51 is selected to be opened and the second valve 52 is closed, the heating branch is connected to the heating return main line; when the first valve 51 is selected to be closed and the second valve 52 is opened, the short - circuit branch is connected to the heating return main line. In this embodiment, the heating branch and the short - circuit branch are separately controlled by the respectively arranged first valve 51 and second valve 52, so as to facilitate quick switching of the passage. During the switching, the flow of the internal liquid will not be affected, and the problem that a single valve control may cause a short - term disconnection of the flow path during the passage switching is avoided.

[0065] A heating circulation flow path is formed in the outdoor unit 1 to heat the refrigerant therein and then exchange heat with the liquid on the heating return main line through the first heat exchanger. Among them, there are various setting manners of the outdoor unit 1, as long as the refrigerant in the heating circulation flow path therein can be heated.

[0066] Specifically, in this embodiment, a compressor 11, a second heat exchanger 12 and a four - way valve 13 are sequentially arranged on the heating circulation flow path; the four - way valve 13 is used to switch the exhaust port of the compressor 11 to be connected to the first heat exchanger 2 or the second heat exchanger 12. In this embodiment, through the compressor 11, the second heat exchanger 12 and the four - way valve 13, the outdoor unit 1 performs refrigeration or heating in a compression - expansion manner. The principle is mature and the structure is reliable, forming a heat pump structure, which has a better heating effect and is more energy - saving when long - term heating is required.

[0067] It should be noted that since heat is provided to the first heat exchanger 2 by the outdoor unit 1, and the outdoor unit 1 has a shutdown temperature, in order to avoid the problem that heating cannot continue after the outdoor unit 1 shuts down, in this embodiment, an auxiliary heating device also needs to be arranged on the heating return main line.

[0068] Specifically, in this embodiment, an electric auxiliary heating device 6 is further arranged on the heating return main line, and the electric auxiliary heating device 6 is located between the first heat exchanger 2 and the phase - change heat storage device 3. In this embodiment, heat is supplemented through the electric auxiliary heating device, the structure is simple and reliable, and at the same time, electric heating is convenient for intelligent control.

[0069] On the other hand, a water pump is also provided on the heating return main pipeline to drive the liquid flow circulation in the entire heating return main pipeline, so as to circulate and transfer heat among the first heat exchanger 2, the phase change heat storage device 3, and the heating device 4.

[0070] Specifically, in this embodiment, the heating assembly 411 further includes a plurality of floor heating pipes arranged in parallel to supply heat to the floor heating and achieve heating of the room.

[0071] On the other hand, the phase change heat storage device 3 includes a heat storage device housing 31 and a finned tube heat exchanger 32 arranged in the heat storage device housing 31. A heat storage channel is formed in the finned tube heat exchanger 32, and the phase change heat storage material is arranged between the heat storage device housing 31 and the finned tube heat exchanger 32. Through the finned tube heat exchanger 32, the heat exchange between the phase change heat storage material and the heat storage flow passage section is improved, so as to better absorb heat into the phase change material for storage.

[0072] In the heating system 100 provided by the present invention, the phase change heat storage device 3 is not only used to supply heat to the floor heating, but also can heat domestic water, improve the application range of the phase change heat storage device 3, and at the same time reduce the start frequency of the external unit 1.

[0073] Specifically, in this embodiment, an endothermic flow passage section is also formed in the phase change heat storage device 3, and the endothermic flow passage section is used for heat exchange with the phase change material; the heating system 100 further includes a water supply device 7, and a water transmission flow path is formed on the water supply device 7, and the endothermic flow passage section is located on the water transmission flow path. In this application, the water transmission flow path on the water supply device 7 forms the endothermic flow passage section. During the water use process, heat exchange will be carried out with the heat storage flow passage section to heat the water in the water transmission flow path for domestic use, so as to realize long-term domestic hot water supply without heating only when in use, and improve the use efficiency.

[0074] For the convenience of the use and control of the heating system 100, the heating system 100 further includes a temperature measuring device, and the temperature measuring device is used to detect the temperatures of the first heat exchanger, the phase change heat storage device, and the heating assembly, so as to control the entire system according to the temperatures at different positions.

[0075] In addition, in this embodiment, the first heat exchanger 2 includes a shell-and-tube heat exchanger or a plate heat exchanger to improve the heat exchange efficiency, and no specific limitation is made here.

[0076] It should be noted that the phase change temperature of the phase change material in the phase change heat accumulator needs to meet 30 - 55°C, the phase change enthalpy needs to meet 180 - 260 kJ / kg, and the solid-state thermal conductivity is 0.6 - 0.65 W / m·K, and the liquid-state thermal conductivity is 0.45 - 0.5 W / m·K. This is to ensure a high heat release power and meet the demand for domestic hot water.

[0077] In an embodiment of the present invention, the heating system 100 further includes a control device, and the control device is electrically connected to the external machine 1 and the switching device, and the control device controls the external machine 1 and the switching device to work.

[0078] Further, in an embodiment of the present invention, the control device includes a memory, a processor, and a control program for the heating system stored in the memory. The processor executes the control program of the heating system to implement the following control method for the heating system:

[0079] Obtain the current heat storage temperature of the phase change material;

[0080] Determine the current temperature difference according to the current heat storage temperature and the phase change temperature corresponding to the phase change material;

[0081] When the current temperature difference meets the preset condition for heat supplement demand, control the water pump to start, the first valve to close, the second valve to open, and control the external machine to start heating.

[0082] Optionally, after "when the current temperature difference meets the preset condition for heat supplement demand, control the water pump to start and control the external machine to start heating", it further includes:

[0083] Monitor the current outlet water temperature of the first heat exchanger;

[0084] When the current outlet water temperature is greater than the preset shutdown temperature, control the external machine to stop heating and control the electric auxiliary heating device to start until the current temperature difference meets the preset condition for exiting heat supplement.

[0085] Optionally, it further includes the following steps:

[0086] When there is a heating demand in the heating component, obtain the target heating temperature selected by the user and the current heating return water temperature;

[0087] Determine the heating temperature difference according to the target heating temperature and the current heating return water temperature;

[0088] When the heating temperature difference meets the preset heating condition, control the water pump to start, the first valve to open, the second valve to close, and control the external machine to start heating.

[0089] Optionally, after controlling the water pump to be turned on, the first valve to be turned on, the second valve to be turned off, and the outdoor unit to be turned on for heating when the heating temperature difference meets the preset heating condition, the method further includes:

[0090] Monitoring the current return water temperature and the current outlet water temperature of the first heat exchanger;

[0091] Determining the temperature demand difference according to the current return water temperature and the current outlet water temperature;

[0092] When the current outlet water temperature of the first heat exchanger is greater than the preset shutdown temperature, or the temperature demand difference is less than the working temperature difference threshold of the outdoor unit, controlling the outdoor unit to turn off heating.

[0093] Optionally, the method further includes:

[0094] When the outdoor unit has a defrosting requirement, controlling the water pump to be turned on, the first valve to be turned off, and the second valve to be turned on respectively, and controlling the outdoor unit to perform refrigeration, so as to heat the outdoor unit through the heat storage module.

[0095] Optionally, a compressor, a second heat exchanger, and a four-way valve are sequentially arranged on the heat supply circulation path of the outdoor unit;

[0096] The control method of the heating system further includes the following steps:

[0097] Controlling the compressor to be turned on, and controlling the four-way valve to switch the exhaust port of the compressor to communicate with the first heat exchanger, so that the outdoor unit turns on heating;

[0098] Controlling the compressor to be turned on, and controlling the four-way valve to switch the exhaust port of the compressor to communicate with the second heat exchanger, so that the outdoor unit turns on refrigeration;

[0099] Controlling the compressor to be turned off, so that the outdoor unit turns off heating and refrigeration.

[0100] In the control method of the heating system provided by the present invention, the current heat storage temperature of the phase change material is detected, and whether heat supplement is required is detected by comparing with the phase change temperature corresponding to the phase change material, so as to ensure that the phase change heat storage device 3 always maintains within the preset heat storage temperature, so that when heat is required outside, heat can be directly supplied through the phase change heat storage device 3 without turning on the outdoor unit, avoiding frequent startup of the outdoor unit. At the same time, by connecting the short-circuit branch, heat only circulates between the first heat exchanger 2 and the phase change heat storage device 3, realizing rapid heating of the phase change heat storage device 3.

[0101] Based on the above heating system 100, the present invention further provides a control method for a heating system, including the following steps:

[0102] S10. Obtain the current heat storage temperature of the phase change material;

[0103] Among them, in order to ensure that the heating system 100 does not need to start the outdoor unit every time when heat is needed, a phase change material is arranged in the heating system 1. Heat is provided to the outside through the phase change material, and the current heat storage temperature in the phase change material is detected in real time. Based on this, it is judged whether the phase change heat storage device 3 can provide basic heat.

[0104] S20. Determine the current temperature difference according to the current heat storage temperature and the phase change temperature corresponding to the phase change material;

[0105] Among them, after obtaining the current heat storage temperature of the phase change material, by comparing it with the phase change temperature of the phase change material, the current temperature difference between the two is determined. Through the current temperature difference, it can be judged whether the phase change heat storage device 3 meets the heat storage requirement.

[0106] S30. When the current temperature difference meets the preset condition of heat supplement requirement, control the water pump to be turned on, the first valve to be closed, the second valve to be opened, and control the outdoor unit to start heating.

[0107] Among them, when the heat storage requirement is not met, the heat at this time is insufficient. Therefore, heat supplement is required. That is, when the current temperature difference meets the preset condition of heat supplement requirement, heat needs to be delivered into the phase change heat storage device 3. At this time, the water pump is turned on so that the refrigerant in the heating main pipeline starts to flow. At the same time, the first valve 51 is closed, the second valve 52 is opened, and the short - circuit branch is connected into the heating return main pipeline, so that the heat only transfers between the first heat exchanger 2 and the phase change heat storage device 3. The outdoor unit 1 is turned on for heating, and the heat enters the first heat exchanger 2 and is transferred into the phase change heat storage device 3 to heat the phase change material therein, thereby increasing the temperature of the phase change material to meet the preset heat storage requirement.

[0108] In the control method of the heating system provided by the present invention, the current heat storage temperature of the phase change material is detected, and by comparing it with the phase change temperature corresponding to the phase change material, it is detected whether heat supplement is needed, so as to ensure that the phase change heat storage device 3 always maintains within the preset heat storage temperature, so that when heat is needed outside, heat can be directly supplied through the phase change heat storage device 3 without starting the outdoor unit, avoiding frequent startup of the outdoor unit. At the same time, by connecting the short - circuit branch, the heat only circulates between the first heat exchanger 2 and the phase change heat storage device 3, realizing rapid heating of the phase change heat storage device 3.

[0109] Further, after step S30, it further includes:

[0110] S31. Monitor the current outlet water temperature of the first heat exchanger;

[0111] Wherein, heat is provided to the first heat exchanger 2 by the outdoor unit 1 to input heat into the phase change heat storage device 3. During the input process, when the current heat storage temperature in the phase change heat storage device 3 gradually increases, the system return water temperature flowing from the phase change heat storage device 3 to the first heat exchanger 2 will also gradually increase. At this time, after being heated again by the first heat exchanger 2, the water temperature high point of the system will be reached. Before that, the water temperature in the whole system gradually increases, resulting in a decrease in the heat exchange efficiency of the first heat exchanger 2. Therefore, the whole outdoor unit 1 needs to continuously change the working frequency.

[0112] Due to the continuous rise of the current outlet water temperature, the current outlet water temperature may exceed the shutdown temperature of the outdoor unit. To avoid the compressor continuously operating overload at the shutdown temperature, it is necessary to monitor the current outlet water temperature of the first heat exchanger 2 in real time.

[0113] S32. When the current outlet water temperature is greater than the preset shutdown temperature, control the outdoor unit to turn off heating and control the electric auxiliary heating device to turn on until the current temperature difference meets the preset condition for exiting heat compensation.

[0114] Wherein, the obtained current outlet water temperature is compared with the preset shutdown temperature. When the current outlet water temperature exceeds the preset shutdown temperature, the outdoor unit 1 is turned off to avoid damage to the outdoor unit 1. At the same time, in order to ensure continuous heat supply to the phase change heat storage device 3 to meet the heat storage requirements, the electric auxiliary heating device 6 is controlled to turn on, and heat is continuously supplied by electric heating until the heating is exited when the demand is met, which can effectively protect the outdoor unit 1 and at the same time supply sufficient heat to the phase change heat storage device 3.

[0115] It should be noted that the S30 step provided in the present invention is the heat storage mode provided by the present invention. When the current temperature difference meets the preset condition for heat compensation demand, the step S30 is entered to enter the heat storage mode.

[0116] It should be noted that in this embodiment, when the current temperature difference meets the preset condition for heat compensation demand, the step S30 is entered;

[0117] Wherein, there are various implementation manners for the preset condition of heat compensation demand. In this embodiment, the preset condition of heat compensation demand is: the phase change temperature is greater than the first preset temperature difference value of the current heat storage temperature (the phase change temperature is greater than the current heat storage temperature by 2 to 4 degrees). Under the preset condition of heat compensation demand, control is entered into the step S30.

[0118] On the other hand, in this embodiment, the supplementary heating exit preset condition is that the phase change temperature is less than the second preset temperature difference value of the current heat storage temperature (the phase change temperature is less than the current heat storage temperature by 5 - 10 degrees). Based on this, it is determined whether to enter and exit the heat storage mode.

[0119] In the embodiment provided by the present invention, the control method of the heating system further includes the following steps:

[0120] S40. When there is a heating demand for the heating component, obtain the target heating temperature selected by the user and the current heating return water temperature;

[0121] Among them, when it is obtained that the heating component 411 needs to perform heating, obtain the target heating temperature and the current heating return water temperature, and judge the heating demand through the target heating temperature and the current heating temperature;

[0122] In this embodiment, in the heating device, the refrigerant on the heating return main road flows into the heating component, dissipates heat and then flows out. At this time, by detecting the heating return water temperature at the outflow point, it can be judged whether the heat flowing into the heating component 411 can meet the demand. It is necessary to ensure that the heating return water temperature at the outflow still has a certain temperature value to ensure that the refrigerant releases sufficient heat in the heating component 411.

[0123] S50. Determine the heating temperature difference according to the target heating temperature and the current heating return water temperature;

[0124] Among them, in this embodiment, by comparing the difference between the target heating temperature and the current heating return water temperature, the heating temperature difference is determined, and based on this, it is judged whether heating is required at this time.

[0125] S60. When the heating temperature difference meets the preset heating condition, control the water pump to start, the first valve to open, the second valve to close, and control the external unit to start heating.

[0126] Among them, when heating is required, control the water pump to start, so that the refrigerant in the heating return main road starts to circulate and transfer heat. At the same time, open the first valve 51 and close the second valve 52, so that the heating branch is connected to the heating return main road for heating, and heat is provided by the external unit.

[0127] In this embodiment, during the heating process, there are two cases. In the first case, there is no or insufficient heat in the phase change heat storage device 3. At this time, when using the heating system 100 for heating, the heat provided by the outdoor unit 1 first passes through the phase change heat storage device 3 for heat absorption, and then enters the heating component 411, forming a stepped heat conduction. The high temperature is stored in the phase change material, and the cooled heat is input into the heating component 411 for heat dissipation again, improving the temperature utilization rate in the heating system 100. At the same time, the return water temperature of the entire system rises slowly, delaying the time when the current outlet water temperature is greater than the preset shutdown temperature, avoiding the outdoor unit from shutting down after a short operation, and enabling the outdoor unit to work for a long time without rapid and frequent start-stop.

[0128] In the second case, at this time, the phase change heat storage device 3 is already full of heat. When using the heating system 100 for heating, when the liquid in the entire system flows, the heat in the phase change heat storage device 3 will be used to preliminarily heat the heating component 411. At the same time, the turned-on outdoor unit 1 will continuously supply heat to the phase change heat storage device 3, making the entire system in a dynamic heat compensation situation, and similarly, the shutdown time of the outdoor unit 1 can be delayed.

[0129] It should be noted that in this embodiment, there are various setting methods for the preset heating conditions. In this embodiment, when the heating temperature difference is greater than or equal to the third preset temperature difference value of the normal return water temperature difference, it indicates that a large amount of heat needs to be released at this time. Therefore, it can be determined that heating is required.

[0130] Further, when the heating temperature difference satisfies the preset heating conditions, after step S60, it further includes:

[0131] S70. Monitor the current return water temperature and the current outlet water temperature of the first heat exchanger;

[0132] Among them, during the heating process by the outdoor unit 1, in order to ensure the safety of the outdoor unit 1, the heat supply of the outdoor unit 1 needs to be protected. Therefore, it is necessary to monitor the current return water temperature and the current outlet water temperature.

[0133] S80. Determine the temperature demand difference according to the current return water temperature and the current outlet water temperature;

[0134] Among them, after obtaining the current return water temperature and the current outlet water temperature, by comparing the difference between the two, the temperature demand difference is obtained, and it is judged how much heat the outdoor unit 1 needs to release at this time, so as to facilitate the outdoor unit 1 to adjust the working frequency according to the amount of heat released.

[0135] S90. When the current outlet water temperature of the first heat exchanger is greater than the preset shutdown temperature, or when the temperature demand difference is less than the operating temperature difference threshold of the outdoor unit, control the outdoor unit to turn off the heating function.

[0136] After the heating system 100 starts heating, the outdoor unit 1 provides heat to the heating component 411. At this time, it is necessary to monitor the amount of heat required by the heating component 411. When the required heat is too small, control the outdoor unit 1 to shut down to avoid the outdoor unit 1 operating at an unreasonable operating frequency.

[0137] Similarly, in this embodiment, when the current outlet water temperature is greater than the preset shutdown temperature, it is also necessary to turn off the outdoor unit to avoid damage to the outdoor unit 1.

[0138] Among them, after the outdoor unit 1 is turned off, the water pump continues to operate to supply heat through the phase change heat storage device 3 until the temperature of the phase change heat storage device 3 drops to trigger the heat storage mode, and then heat is replenished into the phase change heat storage device 3 again.

[0139] On the other hand, the control method of the heating system further includes:

[0140] When the outdoor unit has a defrosting requirement, control the water pump to start, the first valve to close, and the second valve to open respectively, and control the outdoor unit to perform refrigeration so as to supply heat to the outdoor unit through the heat storage module.

[0141] In this embodiment, when defrosting is required, directly control the outdoor unit 1 to enter the refrigeration mode so that heat is generated on the second heat exchanger to remove the frost on the second heat exchanger.

[0142] Specifically, the control method of the heating system further includes the following steps:

[0143] Control the compressor to start, and control the four-way valve to switch the exhaust port of the compressor to communicate with the first heat exchanger so that the outdoor unit starts heating;

[0144] Control the compressor to start, and control the four-way valve to switch the exhaust port of the compressor to communicate with the second heat exchanger so that the outdoor unit starts refrigeration;

[0145] Control the compressor to turn off so that the outdoor unit turns off heating and refrigeration.

[0146] In this embodiment, through the four-way valve, the compressor can generate heat and cold on the first heat exchanger and the second heat exchanger respectively, realizing simultaneous refrigeration and heating of a single compressor. The structure is simple and reliable, and the operation mode is mature.

[0147] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be similarly included in the patent protection scope of the present invention.

Claims

1. A heating system, characterized in that, Comprising: An outdoor unit, forming a heating circulation flow path; A first heat exchanger, forming a first heat exchange flow path section and a second heat exchange flow path section capable of heat exchange, the first heat exchange flow path section being on the heating circulation flow path; A phase change heat storage device, forming a heat storage flow path section, provided with a phase change material in the phase change heat storage device, and heat exchanging with the heat storage flow path section; A heating device, forming a heating return main path, as well as a heating branch path and a short-circuit branch path that are both connected to the heating return main path and arranged in parallel, a heating component being provided on the heating branch path, the second heat exchange flow path section and the heat storage flow path section both being on the heating return main path, and the liquid on the heating return main path flows through the heat storage flow path section after heat exchange through the second heat exchange flow path section; and, A switching device for switching one of the heating branch path and the short-circuit branch path to communicate with the heating return main path.

2. The heating system according to claim 1, characterized in that, The switching device includes a first valve provided on the heating branch path and a second valve provided on the short-circuit branch path; Select to open the first valve and close the second valve so that the heating branch path communicates with the heating return main path; Select to close the first valve and open the second valve so that the short-circuit branch path communicates with the heating return main path.

3. The heating system according to claim 1, characterized in that An electric auxiliary heating device is further provided on the heating return main path, wherein the electric auxiliary heating device is between the first heat exchanger and the phase change heat storage device.

4. The heating system according to claim 1, wherein The phase change heat storage device includes a heat storage device housing and a finned tube heat exchanger provided in the heat storage device housing, the heat storage channel being formed in the finned tube heat exchanger, and the phase change heat storage material being provided between the heat storage device housing and the finned tube heat exchanger.

5. The heating system according to claim 1, wherein An endothermic flow path section is further formed in the phase change heat storage device for heat exchanging with the phase change material; The heating system further includes a water supply device, an output water flow path being formed on the water supply device, and the endothermic flow path section being on the output water flow path.

6. A control method for a heating system, characterized in that, Based on the heating system according to any one of claims 1 to 5, a first valve is provided on the heating branch path, a second valve is provided on the short-circuit branch path, an electric auxiliary heating device and a water pump are further provided on the heating return main path, and the control method of the heating system includes the following steps: Obtain the current heat storage temperature of the phase change material; Determine the current temperature difference according to the current heat storage temperature and the phase change temperature corresponding to the phase change material; When the current temperature difference meets the preset condition of heat supplement demand, control the water pump to start, the first valve to close, the second valve to open, and control the outdoor unit to start heating.

7. The control method of the heating system according to claim 6, characterized in that After the step of when the current temperature difference meets the preset condition of heat supplement demand, control the water pump to start and control the outdoor unit to start heating, further including: Monitor the current outlet water temperature of the first heat exchanger; When the current outlet water temperature is greater than the preset shutdown temperature, control the outdoor unit to stop heating and control the electric auxiliary heating device to start until the current temperature difference meets the preset condition for exiting heat supplement.

8. The control method of the heating system according to claim 6, characterized in that It further includes the following steps: When there is a heating demand in the heating component, obtain the target heating temperature selected by the user and the current heating return water temperature; Determine the heating temperature difference according to the target heating temperature and the current heating return water temperature; When the heating temperature difference meets the preset heating condition, control the water pump to start, the first valve to open, the second valve to close, and control the outdoor unit to start heating.

9. The control method of the heating system according to claim 8, characterized in that, After the step of "when the heating temperature difference meets the preset heating condition, control the water pump to start, the first valve to open, the second valve to close, and control the outdoor unit to start heating", it further includes: Monitor the current return water temperature and the current outlet water temperature of the first heat exchanger; Determine the temperature demand difference according to the current return water temperature and the current outlet water temperature; When the current outlet water temperature of the first heat exchanger is greater than the preset shutdown temperature, or the temperature demand difference is less than the working temperature difference threshold of the outdoor unit, control the outdoor unit to stop heating.

10. The control method of the heating system according to claim 6, characterized in that, It further includes: When the outdoor unit has a defrosting requirement, control the water pump to start, the first valve to close, and the second valve to open respectively, and control the outdoor unit to refrigerate, so as to heat the outdoor unit through the heat storage module.

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