A control method of a heat pump device, a heat pump device, and a combined heating system

Abstract

This invention belongs to the field of heating technology, specifically disclosing a control method for a heat pump device, a heat pump device, and a combined heating system. The heat pump device includes a heat pump assembly, a heat exchanger, and an inner tank. The heat pump assembly includes a compressor, a main heat exchanger, and an electronic expansion valve connected end-to-end. A second heat exchange channel of the heat exchanger is connected in series between the electronic expansion valve and the compressor. The control method includes: acquiring the evaporation temperature of the refrigerant currently flowing into the second heat exchange channel and the heat exchange outlet temperature of the heat exchange medium flowing out of the first heat exchange channel; when the evaporation temperature is less than or equal to a first preset evaporation temperature and the heat exchange outlet temperature is less than or equal to a preset medium temperature, increasing the flow rate of the heat exchange medium flowing into the first heat exchange channel until the heat exchange outlet temperature is greater than the preset medium temperature, and the preset medium temperature is greater than the freezing temperature of the heat exchange medium. This invention can improve the safety and reliability of the heat pump device and the combined heating system.

Description

Technical Field

[0001] This invention relates to the field of heating technology, and in particular to a control method for a heat pump device, a heat pump device, and a combined heating system. Background Technology

[0002] Hot water equipment is a common device that uses electricity, gas combustion heat, solar energy or other energy sources to heat water and supply it to the user. Based on the heating method, it is generally divided into electric water heaters, gas water heaters, solar water heaters or heat pump water heaters, etc.

[0003] The prior art provides a combined heating system, which includes a heat pump unit, a floor heating system, and a heat exchange component. The heat pump unit includes a water tank liner and a heat pump component. The heat pump component includes a compressor, a condenser, and an electronic expansion valve connected in sequence. The heat exchange component includes an inlet pipe, a plate heat exchanger, and an outlet pipe connected in series. The inlet pipe is connected to the heating pipe of the floor heating system, and the outlet pipe is connected to the return pipe of the heating system. Another heat exchange channel of the plate heat exchanger is connected in series between the compressor inlet and the electronic expansion valve.

[0004] Existing technologies provide combined heat pump and underfloor heating systems that heat the refrigerant returning to the compressor by exchanging heat between the underfloor heating water and refrigerant at a plate heat exchanger. However, during the transitional season before the underfloor heating system is operational, the underfloor heating water flowing into the plate heat exchanger is at a low temperature. After heat exchange with the refrigerant, the underfloor heating water is prone to freezing, affecting the normal operation of both the underfloor heating system and the combined heating system, and consequently impacting the safety and reliability of the combined heating system. Summary of the Invention

[0005] One of the technical problems solved by this invention is to provide a control method for a heat pump device, which can effectively solve the problem of icing risk on the heat exchange medium side of existing heat pump devices and improve the safety and reliability of the heat pump device.

[0006] The second technical problem solved by this invention is to provide a heat pump device that can effectively solve the problem of icing risk on the heat exchange medium side of existing heat pump devices, and improve the safety and reliability of the heat pump device.

[0007] The third technical problem solved by this invention is to provide a combined heating system that can effectively solve the problem of icing risk on the refrigerant side or heat exchange medium side of existing combined heating systems, and improve the safety and reliability of the combined heating system.

[0008] The first technical problem mentioned above is solved by the following technical solution:

[0009] A control method for a heat pump device, the heat pump device including a heat pump assembly, a heat exchanger and an inner tank, the heat exchanger having a first heat exchange channel and a second heat exchange channel, the first heat exchange channel being used to introduce a heat exchange medium, the heat pump assembly including a compressor, a main heat exchanger and an electronic expansion valve connected end to end along the refrigerant flow direction, the second heat exchange channel being connected in series between the outlet of the electronic expansion valve and the inlet of the compressor, and the main heat exchanger being used to exchange heat with water in the inner tank;

[0010] The control method includes:

[0011] The evaporation temperature of the refrigerant currently located between the electronic expansion valve and the second heat exchange channel, and the heat exchange outlet temperature of the heat exchange medium flowing out of the first heat exchange channel are obtained.

[0012] When the evaporation temperature is less than or equal to the first preset evaporation temperature and the heat exchange outlet temperature is less than or equal to the preset medium temperature, the flow rate of the heat exchange medium flowing to the first heat exchange channel is increased until the heat exchange outlet temperature is greater than the preset medium temperature, and the preset medium temperature is greater than the freezing temperature of the heat exchange medium.

[0013] Compared with the prior art, the control method of the heat pump device described in this invention has the following advantages: When the evaporation temperature of the refrigerant flowing out of the electronic expansion valve is lower than the first preset evaporation temperature and the heat exchange outlet temperature of the heat exchange medium flowing out of the first heat exchange channel is lower than the preset medium temperature, it indicates that there is a risk of the heat exchange medium freezing after heat exchange. At this time, by increasing the flow rate of the heat exchange medium flowing to the first heat exchange channel, the amount of heat available for refrigerant heat exchange in the heat exchange medium at the first heat exchange channel can be increased, thereby avoiding the problem of the heat exchange medium being overheated at the first heat exchange channel, which would cause the temperature of the heat exchange medium to drop to the point of freezing risk. This reduces the probability of freezing on the heat exchange medium side and improves the safety and reliability of the heat pump device.

[0014] In one embodiment, the first heat exchange channel is connected to a water pump;

[0015] Increasing the flow rate of the heat exchange medium to the first heat exchange channel specifically includes increasing the operating frequency of the water pump.

[0016] In one embodiment, increasing the operating frequency of the water pump includes:

[0017] If the operating frequency of the water pump is lower than the maximum allowable operating frequency, the operating frequency of the water pump shall be increased until the heat exchange outlet temperature is greater than the preset medium temperature.

[0018] If the current operating frequency reaches the maximum allowable operating frequency, the heat pump device is controlled to shut down.

[0019] In one embodiment, the control method further includes: when the evaporation temperature is equal to or lower than the first preset evaporation temperature and the heat exchange outlet temperature is higher than the preset medium temperature, performing return gas superheat control adjustment on the electronic expansion valve;

[0020] And / or, when the evaporation temperature is higher than the first preset evaporation temperature and lower than the second preset evaporation temperature, the electronic expansion valve is subjected to return gas superheat control adjustment, wherein the second preset evaporation temperature is higher than the first preset evaporation temperature.

[0021] In one embodiment, the control method further includes: when the evaporation temperature is greater than or equal to a second preset evaporation temperature, reducing the flow rate of the heat exchange medium to the first heat exchange channel until the evaporation temperature is less than the second preset evaporation temperature and the second preset evaporation temperature is greater than the first preset evaporation temperature.

[0022] In one embodiment, the heat pump device includes a heat exchange inlet pipe, an auxiliary heat exchanger, and a connecting pipe connected in series. The connecting pipe is connected to the inlet end of the first heat exchange channel. A bypass pipe is connected between the connecting pipe and the heat exchange inlet pipe. The bypass pipe is located outside the inner tank. The auxiliary heat exchanger is located inside the inner tank or surrounds the outer wall of the inner tank. The heat exchange inlet pipe is selectively connected to the bypass pipe or the auxiliary heat exchanger.

[0023] The control method further includes:

[0024] When the inlet temperature of the heat exchange medium in the heat exchange inlet pipe is lower than or equal to the water temperature in the inner tank, the heat exchange inlet pipe is connected to the bypass pipe.

[0025] When the medium inlet temperature is higher than the water temperature inside the inner tank, the heat exchange inlet pipe is connected to the auxiliary heat exchanger; or when the medium inlet temperature is higher than the water temperature inside the inner tank and a preset connection condition is met, the heat exchange inlet pipe is connected to the auxiliary heat exchanger.

[0026] In one embodiment, the preset connectivity conditions include: the user selects the rapid heating mode or there is water being used at the water outlet;

[0027] And / or, the preset connection condition includes: the water temperature inside the inner tank is lower than the preset insulation temperature.

[0028] The second technical problem mentioned above is solved by the following technical solution:

[0029] A heat pump device includes a heat pump assembly, a heat exchanger, and an inner tank. The heat exchanger has a first heat exchange channel and a second heat exchange channel. The first heat exchange channel is used to introduce a heat exchange medium. The heat pump assembly includes a compressor, a main heat exchanger, and an electronic expansion valve connected end-to-end along the refrigerant flow direction. The second heat exchange channel is connected in series between the outlet of the electronic expansion valve and the inlet of the compressor. The main heat exchanger is used to exchange heat with water in the inner tank. The heat pump device is controlled by the control method described above.

[0030] Compared with the prior art, the heat pump device described in this invention has the following advantages: by using the above-mentioned control method to control the heat pump device, the risk of icing of the heat pump device can be reduced, and the operational safety and reliability of the heat pump device can be improved.

[0031] In one embodiment, the main heat exchanger is coiled around the outside of the inner tank, and the heat pump device further includes a heat exchange inlet pipe, an auxiliary heat exchanger, and a connecting pipe connected in series. The connecting pipe is connected to the inlet end of the first heat exchange channel, and a bypass pipe is connected between the connecting pipe and the heat exchange inlet pipe. The auxiliary heat exchanger is located inside the inner tank, and the heat exchange inlet pipe is selectively connected to the bypass pipe or the auxiliary heat exchanger.

[0032] The third technical problem mentioned above is solved by the following technical solution:

[0033] A combined heating system includes underfloor heating equipment, characterized in that it further includes a heat pump device as described above, wherein the first heat exchange channel is connected to the underfloor heating equipment.

[0034] Compared with the prior art, the combined heating system of the present invention has the following advantages: by adopting the above-mentioned heat pump device, the risk of icing in the combined heating system can be reduced, and the safety and reliability of the combined heating system can be improved. Attached Figure Description

[0035] Figure 1 A flowchart of the control method for the heat pump device provided in Embodiment 1 of the present invention;

[0036] Figure 2 This is a flowchart of the control method for the heat pump device provided in Embodiment 2 of the present invention;

[0037] Figure 3 This is a schematic diagram of the structure of the heat pump device provided in Embodiment 2 of the present invention;

[0038] Figure 4 A flowchart of the control method for the heat pump device provided in Embodiment 3 of the present invention;

[0039] Figure 5This is a schematic diagram of the structure of the heat pump device provided in Embodiment 3 of the present invention;

[0040] Figure 6 A flowchart illustrating the control method of the heat pump device provided in this invention is provided.

[0041] Figure 7 This is a schematic diagram of the structure of the heat pump device provided in Embodiment 4 of the present invention;

[0042] Figure 8 This is a schematic diagram of the structure of the heat pump device provided in Embodiment 5 of the present invention.

[0043] Label Explanation:

[0044] 1. Inner tank; 2. Compressor; 3. Main heat exchanger; 4. Electronic expansion valve; 5. Heat exchanger; 6. Water pump; 7. Auxiliary heat exchanger; 8. Three-way valve; 9. Switch valve; 10. Heating element; 20. Anode rod; 30. First filter; 40. Second filter; 50. Housing; 60. Controller; 70. Display screen; 80. Exhaust valve; 90. Pressure switch;

[0045] 101. Evaporation temperature sensor; 102. Inlet temperature sensor; 103. Outlet temperature sensor; 104. Exhaust temperature sensor; 105. Water tank temperature sensor;

[0046] 201. Heat pump piping; 202. Heat exchanger inlet piping; 203. Heat exchanger outlet piping; 204. Connecting piping; 205. Bypass piping; 206. Water tank inlet pipe; 207. Water tank outlet pipe. Detailed Implementation

[0047] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0048] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0049] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0050] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0051] Example 1

[0052] like Figure 1 As shown, this embodiment provides a heat pump device and its control method to improve the safety and reliability of the heat pump device while reducing its energy consumption.

[0053] The heat pump unit includes an inner tank, a heat pump assembly, and a heat exchange assembly. The inner tank has a water storage compartment, a cold water inlet connected to the inner tank, and a hot water outlet connected to the inner tank. The heat pump assembly includes a compressor, a main heat exchanger, and an electronic expansion valve connected sequentially via heat pump piping. The main heat exchanger heats the water in the inner tank. The heat exchange assembly includes a heat exchanger with a first heat exchange channel and a second heat exchange channel. The first heat exchange channel is connected in series with an external heating system so that the external heating system provides the heat exchange medium to the first heat exchange channel. The second heat exchange channel is connected in series between the outlet of the electronic expansion valve and the inlet of the compressor.

[0054] The heat pump device provided in this embodiment has a heat exchanger connected to an external heating system. This allows the heat exchange medium of the external heating system to flow through the first heat exchange channel and exchange heat with the refrigerant in the second heat exchange channel. The refrigerant absorbs heat from the heat exchange medium at the heat exchanger, heats up, and flows back to the compressor, improving the heat utilization of the heat exchange medium in the external heating system. The high-temperature, high-pressure refrigerant formed by the compressor flows to the main heat exchanger and exchanges heat with the water in the inner tank. This causes the water in the inner tank to heat up, while the refrigerant dissipates heat and cools down, forming a high-temperature, high-pressure liquid. After the high-temperature, high-pressure liquid is throttled and depressurized by the electronic expansion valve, it becomes a low-temperature, low-pressure two-phase refrigerant. When the refrigerant flows through the second heat exchange channel, it exchanges heat with the heat exchange medium in the first heat exchange channel, causing the refrigerant to absorb heat and become a medium-temperature, low-pressure refrigerant before flowing back to the compressor, thus forming a refrigerant cycle.

[0055] The control method includes the following steps:

[0056] S1100: Obtain the evaporation temperature of the refrigerant currently located between the electronic expansion valve and the second heat exchange channel, and the heat exchange outlet temperature of the heat exchange medium flowing out of the first heat exchange channel.

[0057] S1200: When the evaporation temperature is less than or equal to the first preset evaporation temperature and the heat exchange outlet temperature is less than or equal to the preset medium temperature, increase the flow rate of the heat exchange medium flowing to the first heat exchange channel until the heat exchange outlet temperature is greater than the preset medium temperature and the preset medium temperature is greater than the freezing temperature of the heat exchange medium.

[0058] The control method for the heat exchange tank provided in this embodiment indicates that when the evaporation temperature of the refrigerant flowing out of the electronic expansion valve is lower than the first preset evaporation temperature and the heat exchange outlet temperature of the heat exchange medium flowing out of the first heat exchange channel is lower than the preset medium temperature, it indicates that there is a risk of the heat exchange medium freezing after heat exchange. At this time, by increasing the flow rate of the heat exchange medium to the first heat exchange channel, the amount of heat available for heat exchange by the heat exchange medium at the first heat exchange channel can be increased without affecting the heat exchange between the refrigerant and the water in the inner tank. This avoids the problem of the heat exchange medium being overheated at the first heat exchange channel, which would cause the temperature of the heat exchange medium to drop to the point of freezing risk. This reduces the probability of freezing on the heat exchange medium side and improves the safety and reliability of the heat pump device.

[0059] In one embodiment, the first preset evaporation temperature is higher than the refrigerant freezing point temperature, where the refrigerant freezing point temperature is the temperature at which the refrigerant freezes. This is to avoid icing caused by control errors, control lags, or other reasons when the first preset evaporation temperature equals the refrigerant freezing point temperature, thereby reducing the probability of refrigerant icing. The difference between the preset refrigerant freezing point temperature and the refrigerant freezing point temperature is preferably 2°C to 7°C. Further, the first preset evaporation temperature is 1°C to 5°C.

[0060] To reduce the cost of the heat pump device, water is used as the heat exchange medium. The first heat exchange channel can be connected to a floor heating system, meaning the heat exchange medium flowing into the first heat exchange channel is floor heating water. In other embodiments, the first heat exchange channel can also be connected to other types of external heating systems, such as solar heating systems or other types of heating systems.

[0061] In one embodiment, the preset medium temperature is higher than the freezing point temperature of the heat exchange medium to prevent the heat exchange medium from cooling down and freezing when flowing to the external heating system, thus providing a margin for subsequent temperature drop of the heat exchange medium. The difference between the preset medium temperature and the freezing point temperature of the medium is 3°C to 8°C. For example, when the heat exchange medium is water, the preset medium temperature is 3°C to 8°C.

[0062] Example 2

[0063] This embodiment provides a control method for a heat pump device and a heat pump device. The control method for the heat pump device provided in this embodiment is a further improvement based on the above embodiments. This embodiment will not repeat the same content as the above embodiments.

[0064] like Figure 2 and Figure 3 As shown, in this embodiment, the heat exchange assembly includes a heat exchange inlet pipe 202 and a heat exchange outlet pipe 203. The first heat exchange channel is connected in series between the heat exchange inlet pipe 202 and the heat exchange outlet pipe 203 to facilitate the connection between the heat exchange water tank and the external heating system.

[0065] To improve the convenience of flow control in the first heat exchange channel, a water pump 6 is connected to the first heat exchange channel. Increasing the flow to the first heat exchange channel specifically includes increasing the operating frequency of the water pump 6. This control method can improve the accuracy and flexibility of the inlet water flow control of the heat exchange inlet pipe 202. In other embodiments, a flow control valve can be installed on the heat exchange inlet pipe 202. Increasing the flow to the first heat exchange channel specifically includes increasing the opening degree of the flow control valve.

[0066] In one embodiment, a water pump 6 is provided on the heat exchange inlet pipe 202, and in another embodiment, a water pump 6 is provided on the heat exchange outlet pipe 203.

[0067] The heat pump device also includes a controller 60. The compressor 2, water pump 6 and electronic expansion valve 4 are all connected to the controller 60 in communication so that the controller 60 controls the operation of the compressor 2, water pump 6 and electronic expansion valve 4.

[0068] In this embodiment, increasing the operating frequency of the water pump includes:

[0069] If the current operating frequency of water pump 6 is lower than the maximum allowable operating frequency, increase the operating frequency of water pump 6 until the heat exchange outlet temperature is greater than the preset medium temperature.

[0070] If the current operating frequency reaches the maximum allowable operating frequency, the heat pump unit will stop operating.

[0071] This configuration avoids the probability of water pump 6 being damaged due to excessive adjustment of its operating frequency, thus improving the operational reliability of the heat pump unit. Simultaneously, if the heat exchange outlet temperature is equal to or lower than the preset medium temperature when the water pump 6's current operating frequency reaches the maximum allowable operating frequency, it indicates a potential system fault such as pipe blockage preventing an increase in heat exchange medium flow or excessively low heat exchange outlet temperature in the heat exchange inlet pipe 202. In such cases, the heat pump unit needs to be stopped for troubleshooting, preventing damage caused by operating the heat pump unit under incorrect conditions, improving the operational safety and reliability of the heat pump unit, and extending its service life.

[0072] Furthermore, to reduce control complexity, when increasing the operating frequency of water pump 6, the operating frequency of water pump 6 is increased by a preset frequency increment. After each increase in the operating frequency of water pump 6, the heat exchange outlet temperature is detected to determine whether the heat exchange outlet temperature has reached the preset medium temperature. That is, the adjustment of the operating frequency of water pump 6 is a dynamic adjustment process, and the heat exchange outlet temperature and the refrigerant evaporation temperature are under real-time monitoring.

[0073] To prompt users to promptly troubleshoot malfunctions in the hot water tank, in one embodiment, when the heat pump unit shuts down due to the aforementioned reasons, the control system issues a first preset alarm to remind the user that the hot water tank is faulty, facilitating early detection and handling of the problem. The first preset alarm may, but is not limited to, an audible alarm, a visual alarm, or a combination of both.

[0074] In one embodiment, the control method further includes: when the evaporation temperature of the refrigerant is less than or equal to the first preset evaporation temperature and the heat exchange outlet temperature is greater than the preset medium temperature, performing return gas superheat control on the electronic expansion valve 4. That is, although the evaporation temperature is less than or equal to the first preset evaporation temperature, because the heat exchange outlet temperature is greater than the preset medium temperature, the refrigerant has a sufficient temperature rise after absorbing heat through the second heat exchange channel, which can effectively prevent ice formation on the refrigerant side. At this time, the electronic expansion valve 4 can be adjusted only according to the return gas superheat of the compressor 2 to avoid excessively high return gas temperature causing damage to the compressor 2 and further improve the operational safety and reliability of the heat pump device.

[0075] In one embodiment, the control method further includes: when the evaporation temperature is greater than or equal to the second preset evaporation temperature, reducing the flow rate of the heat exchange medium to the first heat exchange channel until the evaporation temperature is less than the second preset evaporation temperature and the second preset evaporation temperature is greater than the first preset evaporation temperature.

[0076] When the refrigerant evaporation temperature is higher than the second preset evaporation temperature, it indicates that compressor 2 is at risk of overload. To avoid overload, the flow rate of the heat exchange medium to the first heat exchange channel is reduced, and the heat absorption of the refrigerant in the second heat exchange channel is reduced. Thus, when the refrigerant evaporation temperature is high, the heat absorption is reduced to lower the temperature of the refrigerant flowing back into compressor 2. This ensures that the exhaust temperature is within a reasonable range, reduces the risk of compressor 2 overload, improves the operational safety and reliability of the heat pump device, and reduces the operating energy consumption of the heat pump device.

[0077] Furthermore, the second preset evaporation temperature is the maximum allowable evaporation temperature of compressor 2, determined by the compressor 2 MAP diagram; that is, different models of compressor 2 have different second preset evaporation temperatures. Typically, the second preset evaporation temperature is 10℃~18℃.

[0078] That is, in one embodiment, the control method includes:

[0079] Step S2100: Start the heat pump device;

[0080] Step S2200: Obtain the evaporation temperature of the refrigerant located between the electronic expansion valve and the second heat exchange channel, and the heat exchange outlet temperature of the heat exchange medium flowing out of the first heat exchange channel.

[0081] Step S2300: Determine whether the evaporation temperature of the refrigerant is greater than or equal to the second preset evaporation temperature. If not, proceed to step S2311; if yes, proceed to step S2321.

[0082] Step S2311: Determine whether the evaporation temperature is less than or equal to the first preset evaporation temperature. If not, proceed to step S2312; if yes, proceed to step S2313.

[0083] Step S2312: Execute return gas superheat control and return to step S2200;

[0084] Step S2313: Determine whether the heat exchange outlet temperature is less than or equal to the preset medium temperature. If not, proceed to step S2314; if yes, proceed to step S2315.

[0085] Step S2313: Execute return gas superheat control and return to step S2311;

[0086] Step S2314: Determine whether the operating frequency of water pump 6 has reached the maximum operating frequency. If not, proceed to step S2316; if yes, proceed to step S2317.

[0087] Step S2316: Increase the operating frequency of water pump 6 and return to step S2313;

[0088] Step S2317: Control the heat pump device to stop and issue the first preset alarm;

[0089] Step S2321: Reduce the operating frequency of water pump 6 and return to step S2200.

[0090] In one embodiment, the heat pump device further includes a housing 50, with the inner tank 1, heat pump assembly, and heat exchange assembly all disposed inside the housing 50. The heat pump assembly is located between the housing 50 and the inner tank 1, and the heat exchange inlet pipe 202, heat exchange outlet pipe 203, and heat exchanger 5 are located between the housing 50 and the inner tank 1. The heat pump device also includes a water tank outlet pipe 207 and a water tank inlet pipe 206. One end of both the water tank inlet pipe 206 and the water tank outlet pipe 207 is located outside the housing 50, and the other end is installed and inserted into the inner tank 1, so that the heat pump device can be connected to external water-using equipment. The inlet section of the heat exchange inlet pipe 202 and the outlet end of the heat exchange outlet pipe 203 both extend outside the housing 50 to connect to an external heating system.

[0091] The heat pump unit also includes a display screen 70, which is communicatively connected to the controller 60 and is mounted on the housing 50. The display screen 70 is used to display the operating parameters of the heat pump unit, such as the water temperature inside the tank, so that the user can view the operating status of the heat pump unit.

[0092] In one embodiment, to detect the evaporation temperature of the refrigerant, the heat pump device includes an evaporation temperature detection element 101, which is disposed on the heat pump pipeline 201 and located between the second heat exchange channel and the electronic expansion valve 4. The evaporation temperature detection element 101 is used for communication connection with the controller 60.

[0093] To detect the temperature of the heat exchange medium flowing out of the first heat exchange channel, an outlet temperature sensor 103 is installed on the heat exchange outlet pipe 203, and the outlet temperature sensor 103 is communicatively connected to the controller 60. Furthermore, to control the on / off state of the heat exchange inlet pipe 202, a switching valve 9 is installed on the heat exchange inlet pipe 202. The switching valve 9 is communicatively connected to the controller 60.

[0094] To detect the exhaust temperature of compressor 2, an exhaust temperature sensor 104 is installed on the heat pump line 201. The exhaust temperature sensor 104 is located between compressor 2 and main heat exchanger 3, and is positioned near the outlet of compressor 2. The exhaust temperature sensor 104 is communicatively connected to controller 60.

[0095] In one embodiment, the heat pump device includes a first filter 30, which is disposed on the heat pump pipeline 201 and located upstream of the inlet of the electronic expansion valve 4, to filter impurities in the refrigerant flowing to the electronic expansion valve 4, thereby preventing impurities from clogging the electronic expansion valve 4 and improving the operational safety of the heat pump components and the heat pump device.

[0096] In one embodiment, the heat pump device further includes a second filter 40 located upstream of the first heat exchange channel to filter the heat exchange medium flowing into the first heat exchange channel, thereby preventing impurities in the first heat exchange channel from clogging the first heat exchange channel.

[0097] In one embodiment, a pressure switch 90 is also provided on the heat pump pipeline 201. The pressure switch 90 is located between the compressor 2 and the main heat exchanger 3, and the pressure switch 90 is located close to the compressor 2.

[0098] Example 3

[0099] This embodiment also provides a heat pump device and a control method for the heat pump device. The heat pump device and control method provided in this embodiment are further improvements based on the above embodiments. This embodiment will not repeat the same structure as the above embodiments.

[0100] like Figure 4 and Figure 5 As shown, in this embodiment, the main heat exchanger 3 is coiled around the outside of the inner liner 1 so that the heat of the refrigerant inside the main heat exchanger 3 can be transferred to the inner liner through heat exchange between the main heat exchanger 3 and the liner wall. This reduces the difficulty of installing the heat pump assembly on the inner liner 1 and reduces the processing cost of the heat pump device.

[0101] In this embodiment, the heat pump device includes a heat exchange inlet pipe 202, an auxiliary heat exchanger 7, and a connecting pipe 204 connected in series. The connecting pipe 204 is connected to the inlet end of the first heat exchange channel. A bypass pipe 205 is connected between the connecting pipe 204 and the heat exchange inlet pipe 202. The auxiliary heat exchanger 7 is located inside the inner tank. The heat exchange inlet pipe 202 is selectively connected to the bypass pipe 205 or the auxiliary heat exchanger 7.

[0102] Control methods also include:

[0103] When the inlet temperature of the heat exchange medium in the heat exchange inlet pipe 202 is lower than or equal to the water temperature in the inner tank 1, the heat exchange inlet pipe 202 is connected to the bypass pipe 205.

[0104] When the medium inlet temperature is higher than the water temperature inside the inner tank 1 and the preset connection conditions are met, the heat exchange inlet pipe 202 is connected to the auxiliary heat exchanger 7, or when the medium inlet temperature is higher than the water temperature inside the inner tank 1 and the preset connection conditions are met, the heat exchange inlet pipe 202 is connected to the auxiliary heat exchanger 7.

[0105] In this embodiment, when the heat exchange inlet temperature is higher than the water temperature in the inner tank 1, the heat exchange medium entering through the heat exchange inlet pipe 202 can first enter the auxiliary heat exchanger 7, where it exchanges heat with the water in the inner tank, causing the water in the inner tank to heat up and the heat exchange medium to cool down. After the temperature drop, the heat exchange medium continues to exchange heat with the low-temperature, low-pressure refrigerant in the second heat exchange channel in the first heat exchange channel, thereby improving the heat utilization rate of the heat exchange medium. When the heat exchange inlet temperature is lower than the water temperature in the inner tank 1, the heat exchange inlet pipe 202 can be connected to the bypass pipe 205, so that the heat exchange medium will not flow to the auxiliary heat exchanger 7 to exchange heat with the water in the storage tank, but will directly go to the first heat exchange channel through the bypass pipe 205 for heat exchange. This avoids the problem of ineffective heat exchange between the heat exchange medium and the water in the storage tank due to the low temperature of the heat exchange medium entering the heat pump device or the high temperature of the water in the storage tank, thereby reducing the energy consumption of the heat pump device and ensuring the operating efficiency of the heat pump device.

[0106] Specifically, the control methods include:

[0107] Step S3100: Obtain the inlet temperature of the heat exchange medium and the temperature of the water inside the inner tank 1;

[0108] Step S3200: Determine whether the medium inlet temperature is less than or equal to the water temperature inside the inner tank 1. If yes, proceed to step S3300; otherwise, proceed to step S3400.

[0109] Step S3300: Connect the heat exchange inlet pipe 202 to the bypass pipe 205;

[0110] Step S3400: Determine whether the preset connectivity conditions are met. If yes, proceed to step S3500; otherwise, return to step S3300.

[0111] Step S3500: Control the connection between the heat exchange inlet pipe 202 and the auxiliary heat exchanger 7.

[0112] In other embodiments, preset connection conditions may not be set, and the connection between the heat exchange inlet pipe 202 and the auxiliary heat exchanger 7 may be controlled as long as the medium inlet temperature is greater than that of the water in the inner tank 1, thereby simplifying the control process.

[0113] In one embodiment, the main heat exchanger 3 preferably adopts a microchannel heat exchanger to reduce the overall footprint of the main heat exchanger 3, thereby reducing the overall size of the heat pump device and lowering its cost while ensuring the water storage volume of the inner tank. The specific structure of the microchannel heat exchanger and its installation structure on the inner tank 1 can be set with reference to the prior art, which is not the focus of this invention and will not be described in detail here.

[0114] In one embodiment, the heat pump device includes a three-way valve 8. The first and second ports of the three-way valve 8 are connected in series to the heat exchange inlet pipe 202. The inlet end of the bypass pipe 205 is connected to the third port of the three-way valve 8. The first port is selectively connected to either the second or third port. Thus, the three-way valve 8 controls the connection between the heat exchange inlet pipe 202 and the auxiliary heat exchanger 7 or the bypass pipe 205. In other embodiments, a first control valve can be installed on the heat exchange inlet pipe 202, and a second control valve can be installed on the bypass pipe 205. The first control valve is located downstream of the junction of the bypass pipe 205 and the heat exchange inlet pipe 202. Thus, the first and second control valves control the on / off connection between the heat exchange inlet pipe 202 and the auxiliary heat exchanger 7 or the bypass pipe 205.

[0115] An inlet temperature sensor 102 is also installed on the heat exchange inlet pipe 202 to detect the heat exchange inlet temperature of the heat exchange medium flowing into the heat exchange inlet pipe 202. The inlet temperature sensor 102 is connected to the controller 60.

[0116] To detect the temperature inside the inner tank 1, a water tank temperature sensor 105 is installed inside the inner tank 1, and the water tank temperature sensor 105 is communicatively connected to the controller 60. Furthermore, an anode rod 20 is also installed inside the inner tank 1.

[0117] To further improve the operational safety of the heat pump device, in one embodiment, the heat pump device further includes an exhaust valve 80, which is located at the high point of the heat exchange pipeline formed by the heat exchange inlet pipe 202, the auxiliary heat exchanger 7, the connecting pipe 204, the heat exchanger 5, and the heat exchange outlet pipe 203 connected in series, in order to exhaust the gas in the heat exchange pipeline.

[0118] Example 4

[0119] This embodiment provides a heat pump device and its control method. The control method of the heat pump device provided in this embodiment is a further improvement based on the above embodiments. This embodiment will not repeat the same content as the above embodiments.

[0120] like Figure 6 and Figure 7 As shown, in this embodiment, the preset connection conditions include the user terminal having water usage and the water temperature in the inner tank 1 being lower than the preset water usage temperature.

[0121] When water is being used at the user end, hot water flows out of the inner tank 1 and cold water flows in. At this time, the water in the inner tank 1 can be heated by the heat exchange medium in the auxiliary heat exchanger 7. At the same time, the heat pump component is used to heat the water in the inner tank 1, increasing the heating efficiency of the water in the inner tank 1, realizing rapid heating of the water in the inner tank 1, and improving the user's water use experience.

[0122] In other embodiments, the heat pump device can be set to a conventional heating mode and a rapid heating mode. In the conventional heating mode, the heat exchange inlet pipe 202 is connected to the connecting pipe, and the heat pump assembly operates, so that the heat exchange medium only exchanges heat with the refrigerant in the heat exchanger 5, and the water in the water storage tank is heated only by the heat pump assembly. In the rapid heating mode selected by the user, the heat exchange inlet pipe 202 is connected to the auxiliary heat exchanger 7, the water pump 6 and the heat pump assembly operate simultaneously, and the main heat exchanger 3 and the auxiliary heat exchanger 7 heat the water in the inner tank 1 simultaneously, thereby improving the heating efficiency.

[0123] That is, in other embodiments, the preset connectivity conditions include: the user selects the rapid heating mode.

[0124] It is worth noting that when a user selects the speed mode, there may be no water usage at the user's end; that is, the operation of the fast heating mode does not depend on whether there is water usage at the user's end.

[0125] In one embodiment, the preset connection condition further includes: the water temperature inside the inner tank 1 is lower than the preset insulation temperature.

[0126] That is, in this embodiment, the heat pump device has a heat preservation function. When the water temperature in the inner tank 1 is lower than the preset heat preservation temperature, the heat exchange medium is used to exchange heat with the water in the inner tank 1 through the auxiliary heat exchanger 7 to achieve preheating and heat preservation of the water in the inner tank 1. This avoids the water temperature in the inner tank 1 being too low to meet the requirement of rapid heating to the preset outlet water temperature, and also avoids the water temperature in the inner tank 1 being too low to cause freezing problems.

[0127] It is worth noting that when the heat exchange medium is used to heat and keep the water in the inner tank 1, the heat pump component is in a stopped state.

[0128] When it is necessary to keep the water in the inner tank 1 warm, but the heat exchange inlet temperature of the heat exchange medium is lower than the water temperature in the inner tank 1, it is impossible to use the heat exchange medium to preheat and keep the water in the inner tank 1 warm. To ensure the normal operation of the heat pump device's insulation function, in one embodiment, the control method further includes:

[0129] When the water temperature in the water storage tank is lower than the preset insulation temperature and the inlet temperature of the heat exchange medium is lower than the water temperature in the inner tank 1, the heat exchange inlet pipe 202 is connected to the bypass pipe 205, and the heat pump assembly and water pump 6 are operated.

[0130] That is, when the heat pump device needs to be kept warm but the heat exchange medium cannot preheat the inner tank 1, the heat pump component is used to preheat the water in the inner tank 1.

[0131] Specifically, the control method includes the following steps:

[0132] Step S4100: The heat pump unit starts operating;

[0133] Step S4200: Determine if water is being used. If yes, proceed to step S4211; otherwise, proceed to step S4221.

[0134] Step S4211: Determine whether the water temperature inside the inner tank 1 is higher than the preset outlet water temperature. If yes, return to step S4200; otherwise, proceed to step S4212.

[0135] Step S4212: Determine whether the medium inlet temperature is less than or equal to the water temperature inside the inner tank 1. If yes, proceed to step S4213; otherwise, proceed to step S4214.

[0136] In step S4213, the heat pump assembly and water pump 6 are both started and running, and the heat exchange inlet pipe 202 is connected to the auxiliary heat exchanger 7.

[0137] In step S4214, the heat pump assembly and water pump 6 are both started and running, and the heat exchange inlet pipe 202 is connected to the bypass pipe 205;

[0138] Step S4221: Is the water temperature inside the inner tank 1 lower than the preset insulation temperature? If yes, proceed to step S4222; otherwise, return to step S4200.

[0139] Step S4222: Determine whether the medium inlet temperature is less than or equal to the water temperature inside the inner tank 1. If not, proceed to step S4223; if yes, proceed to step S4224.

[0140] Step S4223: The heat pump assembly stops, the water pump 6 starts, and the heat exchange inlet pipe 202 is connected to the auxiliary heat exchanger 7.

[0141] In step S4224, both the heat pump assembly and the water pump are started and running, and the heat exchange inlet pipe 202 is connected to the bypass pipe 205.

[0142] Example 5

[0143] This embodiment provides a heat pump device and its control method. The heat pump device and its control method provided in this embodiment are further improvements based on the above embodiments. This embodiment will not repeat the same content as the above embodiments.

[0144] like Figure 8 As shown, in this embodiment, the heat pump device also includes an electric heating element 10, which is installed inside the inner tank 1 to heat the water in the inner tank 1 by means of electricity, thereby serving as an auxiliary heating method for the heat pump device. This ensures that the heat pump device can maintain the outlet water temperature when the heat pump component fails and cannot heat the inner tank 1 or the water in the inner tank 1 is not heated enough, thus improving the reliability of the heat pump device.

[0145] The control method also includes: controlling the heating element to start operation when the preset electrothermal conditions are met.

[0146] In one embodiment, the preset electric heating conditions include: the water temperature in the inner tank 1 is lower than the preset heat preservation temperature and the heat exchange inlet temperature of the heat exchange medium is lower than the water temperature in the inner tank 1.

[0147] When the water in the inner tank 1 needs to be kept warm but the heat exchange medium cannot heat the water in the inner tank 1, the electric heating element 10 is activated to heat the water in the inner tank 1. This satisfies the heat preservation requirements while avoiding problems such as high heat preservation energy consumption and loud operating noise caused by the operation of the heat pump components, thereby reducing the operating energy consumption of the heat pump device and improving the user experience of the heat pump device.

[0148] In one embodiment, the preset electric heating conditions include: water is being used at the water outlet, the water temperature in the inner tank 1 is lower than the preset outlet water temperature, and the heat pump assembly is malfunctioning.

[0149] That is, when there is water to be used and the water in the inner tank 1 needs to be heated, but the heat pump component fails and cannot heat the inner tank 1 or the water temperature heated by the heat pump component cannot meet the preset outlet water temperature, the electric heating element 10 is activated to assist in heating the water in the inner tank 1 to meet the user's normal water use needs.

[0150] Determining whether the heat pump component is faulty includes: after the heat pump component has been running for a preset time, the temperature rise of the water in the inner tank 1 is lower than the preset temperature rise.

[0151] If, after the heat pump assembly has been running continuously for a preset time, the temperature rise of the water in the inner tank 1 is lower than the preset temperature rise, it indicates that the heat pump assembly has failed to heat the water in the inner tank 1, or that the heating efficiency of the water in the inner tank 1 is low. In this case, the heating element 10 should be activated to heat the water in the inner tank 1. In the specific details of the above embodiments, the technical features can be combined in any non-contradictory way. For the sake of brevity, not all possible combinations of the above technical features have been described. However, as long as the combination of these technical features is not contradictory, it should be considered within the scope of this specification.

[0152] Example 6

[0153] This embodiment provides a combined heating system, including a floor heating system and a heat pump device from any of the above embodiments, with a first heat exchange channel connected to the floor heating system. By employing the aforementioned heat pump device, the combined heating system provided in this embodiment can reduce the risk of icing and improve the safety and reliability of the combined heating system.

[0154] Specifically, the underfloor heating system has a heating pipe and a return pipe. The inlet end of the first heat exchange channel is connected to the heating pipe or the return pipe, and the outlet end of the first heat exchange channel is connected to the return pipe.

[0155] The specific embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A control method for a heat pump device, characterized in that, The heat pump device includes a heat pump assembly, a heat exchanger (5) and an inner tank (1). The heat exchanger (5) has a first heat exchange channel and a second heat exchange channel. The first heat exchange channel is used to introduce a heat exchange medium. The heat pump assembly includes a compressor (2), a main heat exchanger (3) and an electronic expansion valve (4) connected end to end along the refrigerant flow direction. The second heat exchange channel is connected in series between the outlet of the electronic expansion valve (4) and the inlet of the compressor (2). The main heat exchanger (3) is used to exchange heat with the water in the inner tank (1). The control method includes: Obtain the evaporation temperature of the refrigerant currently located between the electronic expansion valve (4) and the second heat exchange channel, and the heat exchange outlet temperature of the heat exchange medium flowing out of the first heat exchange channel; When the evaporation temperature is less than or equal to the first preset evaporation temperature and the heat exchange outlet temperature is less than or equal to the preset medium temperature, the flow rate of the heat exchange medium flowing to the first heat exchange channel is increased until the heat exchange outlet temperature is greater than the preset medium temperature, and the preset medium temperature is greater than the freezing temperature of the heat exchange medium.

2. The control method according to claim 1, characterized in that, The first heat exchange channel is connected to a water pump (6); Increasing the flow rate of the heat exchange medium to the first heat exchange channel specifically includes increasing the operating frequency of the water pump (6).

3. The control method according to claim 2, characterized in that, The increase in the operating frequency of the water pump (6) includes: If the current operating frequency of the water pump (6) is lower than the maximum allowable operating frequency, the operating frequency of the water pump (6) shall be increased until the heat exchange outlet temperature is greater than the preset medium temperature. If the current operating frequency reaches the maximum allowable operating frequency, the heat pump device is controlled to shut down.

4. The control method according to claim 1, characterized in that, The control method further includes: when the evaporation temperature is equal to or lower than the first preset evaporation temperature and the heat exchange outlet temperature is higher than the preset medium temperature, performing return gas superheat control adjustment on the electronic expansion valve (4); And / or, when the evaporation temperature is higher than the first preset evaporation temperature and lower than the second preset evaporation temperature, the electronic expansion valve (4) is subjected to return gas superheat control adjustment, and the second preset evaporation temperature is higher than the first preset evaporation temperature.

5. The control method according to claim 1, characterized in that, The control method further includes: When the evaporation temperature is greater than or equal to the second preset evaporation temperature, the flow rate of the heat exchange medium to the first heat exchange channel is reduced until the evaporation temperature is less than the second preset evaporation temperature and the second preset evaporation temperature is greater than the first preset evaporation temperature.

6. The control method according to any one of claims 1-5, characterized in that, The heat pump device further includes a heat exchange inlet pipe (202), an auxiliary heat exchanger (7) and a connecting pipe (204) connected in series. The connecting pipe (204) is connected to the inlet end of the first heat exchange channel. A bypass pipe (205) is connected between the connecting pipe (204) and the heat exchange inlet pipe (202). The bypass pipe (205) is located outside the inner liner (1). The auxiliary heat exchanger (7) is located inside the inner liner (1) or surrounds the outer wall of the inner liner (1). The heat exchange inlet pipe (202) is selectively connected to the bypass pipe (205) or the auxiliary heat exchanger (7). The control method further includes: When the inlet temperature of the heat exchange medium in the heat exchange inlet pipe (202) is lower than or equal to the water temperature in the inner tank (1), the heat exchange inlet pipe (202) is connected to the bypass pipe (205). When the temperature at the medium inlet is higher than the water temperature inside the inner tank (1), the heat exchange inlet pipe (202) is connected to the auxiliary heat exchanger (7), or when the temperature at the medium inlet is higher than the water temperature inside the inner tank (1) and the preset connection conditions are met, the heat exchange inlet pipe (202) is connected to the auxiliary heat exchanger (7).

7. The control method according to claim 6, characterized in that, The preset connection conditions include: the user selects the fast heating mode or there is water being used at the water end and the water temperature in the inner tank (1) is lower than the preset outlet water temperature; And / or, the preset connection condition includes: the water temperature inside the inner tank (1) is lower than the preset insulation temperature.

8. A heat pump device, characterized in that, The heat pump device includes a heat pump assembly, a heat exchanger (5), and an inner tank (1). The heat exchanger (5) has a first heat exchange channel and a second heat exchange channel. The first heat exchange channel is used to introduce a heat exchange medium. The heat pump assembly includes a compressor (2), a main heat exchanger (3), and an electronic expansion valve (4) connected end to end along the refrigerant flow direction. The second heat exchange channel is connected in series between the outlet of the electronic expansion valve (4) and the inlet of the compressor (2). The main heat exchanger (3) is used to exchange heat with the water in the inner tank (1). The heat pump device is controlled by the control method described in any one of claims 1-7.

9. The heat pump device according to claim 8, characterized in that, The main heat exchanger (3) is coiled around the outside of the inner liner (1). The heat pump device also includes a heat exchange inlet pipe (202), an auxiliary heat exchanger (7) and a connecting pipe (204) connected in series. The connecting pipe (204) is connected to the inlet end of the first heat exchange channel. A bypass pipe (205) is connected between the connecting pipe (204) and the heat exchange inlet pipe (202). The auxiliary heat exchanger (7) is located inside the inner liner (1). The heat exchange inlet pipe (202) is selectively connected to the bypass pipe (205) or the auxiliary heat exchanger (7).

10. A combined heating system, including underfloor heating equipment, characterized in that, It also includes the heat pump device as described in claim 8 or 9, wherein the first heat exchange channel is connected to the underfloor heating equipment.

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