Control method of heat pump unit

Abstract

The present application relates to the technical field of heat pump, and particularly provides a control method of heat pump unit, aiming at solving the problem that the heat exchange efficiency of the heat pump unit is not high due to the lack of fluorine in the refrigerant circulation loop of the existing heat pump unit. To this end, the heat pump unit comprises a refrigerant circulation loop arranged in an outdoor unit, a heat exchange water circulation loop arranged between an indoor unit and the outdoor unit, a water supplement branch and a water return branch connected with the heat exchange water circulation loop, and the water return branch is further arranged to be connected with the water supplement branch. Based on this, the present application can determine whether the refrigerant circulation loop is lack of fluorine according to the obtained water inlet temperature of the indoor unit and the operation mode of the heat pump unit, and then effectively avoid the problem that the heat exchange effect of the indoor unit and the outdoor unit is not good due to the lack of fluorine in the refrigerant circulation loop by controlling the operation of the water supplement branch, thereby effectively improving the heat exchange efficiency of the heat pump unit.

Description

Technical Field

[0001] This invention belongs to the field of heat pump technology, specifically providing a control method for a heat pump unit. Background Technology

[0002] With economic development, people have increasingly higher demands for the comfort of air conditioning, especially regarding the potential for "air conditioning sickness" from prolonged air conditioning use. Therefore, heat pump air conditioners have experienced rapid development due to their advantages such as gentle airflow, lack of harshness, and high comfort. This development has been further accelerated in recent years, particularly with the government's vigorous promotion of coal-to-electricity projects. However, this rapid development has also generated some problems. For example, the refrigerant circulation loop in the outdoor unit of existing heat pump air conditioners is prone to refrigerant depletion, leading to low heat exchange efficiency in the heat pump unit.

[0003] Accordingly, there is a need in the field for a new control method for heat pump units to solve the above problems. Summary of the Invention

[0004] The present invention aims to solve the above-mentioned technical problems, namely, to solve the problem that the refrigerant circulation loop in the outdoor unit of the existing heat pump water heater is prone to refrigerant deficiency, which leads to low heat exchange efficiency of the heat pump unit.

[0005] This invention provides a control method for a heat pump unit, the heat pump unit comprising an indoor unit, an outdoor unit, a refrigerant circulation loop, a hot water exchange circulation loop, a water supply branch, and a water return branch.

[0006] The refrigerant circulation loop is located in the outdoor unit, and the hot water circulation loop is located between the indoor unit and the outdoor unit. Furthermore, the refrigerant circulation loop is configured to exchange heat with the hot water circulation loop.

[0007] A first water tank and a second water tank are installed on the water supply branch. The first water tank is equipped with a heating device, and the second water tank is equipped with a cooling device. A connecting branch is provided between the first water tank and the second water tank, and the connecting branch is configured to connect the first water tank and the second water tank. The outlets of both the first water tank and the second water tank are connected to the first part of the hot water exchange circulation loop through the water supply branch.

[0008] The first end of the return water branch is connected to the second water tank, and the second end of the return water branch is connected to the second part of the hot water circulation loop.

[0009] Wherein, the first part of the hot water circulation loop is the part of the hot water circulation loop from the outdoor unit to the indoor unit, and the second part of the hot water circulation loop is the part of the hot water circulation loop from the indoor unit to the outdoor unit;

[0010] The control method includes:

[0011] When the water supply branch is in operation, the inlet water temperature of the indoor unit is obtained;

[0012] The operation of the water supply branch is controlled according to the inlet water temperature of the indoor unit and the operating mode of the heat pump unit.

[0013] In the preferred embodiment of the above control method, the step of "controlling the operation of the water supply branch according to the inlet water temperature of the indoor unit and the operating mode of the heat pump unit" includes:

[0014] When the heat pump unit is in heating mode, the difference between the target inlet water temperature and the inlet water temperature of the indoor unit is calculated and recorded as the first difference.

[0015] The operation of the water supply branch is controlled based on the first difference.

[0016] In the preferred embodiment of the above control method, the step of "controlling the operation of the water supply branch according to the first difference" includes:

[0017] If the first difference is greater than or equal to the first preset difference, then the outlet of the first water tank is directly connected to the water supply branch.

[0018] In the preferred embodiment of the above control method, the step of "controlling the operation of the water supply branch according to the first difference" further includes:

[0019] If the first difference is less than the first preset difference and greater than the second preset difference, then the first water tank is connected to the water supply branch through the second water tank.

[0020] In the preferred embodiment of the above control method, the step of "controlling the operation of the water supply branch according to the first difference" further includes:

[0021] If the first difference is less than or equal to the second preset difference, then the water supply branch is controlled to stop operating.

[0022] In a preferred embodiment of the above control method, where the outlet of the first water tank is directly connected to the water supply branch, the control method further includes:

[0023] The opening degree of the outlet of the first water tank is controlled according to the magnitude of the first difference.

[0024] In the preferred embodiment of the above control method, the step of "controlling the operation of the water supply branch according to the inlet water temperature of the indoor unit and the operating mode of the heat pump unit" further includes:

[0025] When the heat pump unit is in cooling mode, the difference between the inlet water temperature of the indoor unit and the target inlet water temperature is calculated and recorded as the second difference.

[0026] The opening degree of the outlet of the second water tank is controlled according to the magnitude of the second difference.

[0027] In a preferred embodiment of the above control method, the control method further includes:

[0028] If the current running time of the heat pump unit reaches the preset duration, the outlet water temperature of the outdoor unit is obtained;

[0029] Based on the outlet water temperature of the outdoor unit and the target outlet water temperature, the hot water circulation loop and the refrigerant circulation loop are selectively stopped and the return water branch is connected.

[0030] In the preferred embodiment of the above control method, the step of "selectively controlling the hot water circulation loop to stop operating and controlling the return water branch to connect according to the outlet water temperature of the outdoor unit and the target outlet water temperature" specifically includes:

[0031] If the outlet water temperature of the outdoor unit does not reach the target outlet water temperature, the hot water circulation loop and the refrigerant circulation loop are stopped and the return water branch is connected so that the water supply branch and the return water branch together form a heat exchange loop.

[0032] In a preferred embodiment of the above control method, before performing the step of "obtaining the inlet water temperature of the indoor unit", the control method further includes:

[0033] If the heat pump unit is in heating mode, then control the operation of the heating device;

[0034] If the heat pump unit is in cooling mode, then control the operation of the cooling device.

[0035] By adopting the above technical solution, the present invention, through the installation of a first water tank, a second water tank, a heating device, and a cooling device on the water supply branch, enables the heat pump unit to fully meet both the user's heating and cooling needs. Furthermore, the present invention can determine whether the refrigerant circulation loop is deficient in refrigerant based on the obtained inlet water temperature of the indoor unit and the operating mode of the heat pump unit. By controlling the operation of the water supply branch, it effectively avoids the problem of poor heat exchange performance in both the indoor and outdoor units due to refrigerant deficiency in the circulation loop, thereby effectively improving the heat exchange efficiency of the heat pump unit. Attached Figure Description

[0036] The preferred embodiments of the present invention are described below with reference to the accompanying drawings, in which:

[0037] Figure 1 This is a schematic diagram of the structure of the heat pump unit of the present invention;

[0038] Figure 2 This is a flowchart of the main steps of the control method according to the first embodiment of the present invention;

[0039] Figure 3 This is a flowchart illustrating the specific steps of the control method according to the first embodiment of the present invention;

[0040] Figure 4 This is a flowchart of the main steps of the control method according to the second embodiment of the present invention;

[0041] Figure 5 This is a flowchart illustrating the specific steps of the control method according to the second embodiment of the present invention;

[0042] Figure label:

[0043] 1. Indoor unit;

[0044] 2. Outdoor unit;

[0045] 3. Hot water circulation loop; 31. Part 1; 32. Part 2;

[0046] 4. Water supply branch; 41. First water tank; 411. Heating device; 412. First water inlet; 413. First water inlet switch; 414. Air vent valve; 42. Second water tank; 421. Refrigeration device; 422. Second water inlet; 423. Second water inlet switch; 43. Two-inlet, one-outlet three-way valve;

[0047] 5. Return water branch;

[0048] 6. Connect branch lines;

[0049] 7. Control switch;

[0050] 8. Relay pressure sensor;

[0051] 9. First control valve;

[0052] 10. Second control valve;

[0053] 11. Third control valve;

[0054] 12. Fourth control valve;

[0055] 13. First water flow monitoring device;

[0056] 14. Second water flow monitoring device;

[0057] 15. First temperature sensor;

[0058] 16. Second temperature sensor;

[0059] 17. Third temperature sensor. Detailed Implementation

[0060] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art can make adjustments as needed to adapt to specific applications. For example, the heat pump unit of the present invention can be a split-type heat pump unit or an integrated heat pump unit; these are not limiting. Those skilled in the art can define the application of the control method of the present invention according to actual usage requirements. Such changes in the application do not deviate from the basic principles of the present invention and fall within the scope of protection of the present invention.

[0061] It should be noted that in the description of this preferred embodiment, terms such as "upper," "lower," "inner," and "outer," indicating directional or positional relationships, are based on the directional or positional relationships shown in the accompanying drawings. This is merely for ease of description and does not indicate or imply that the structure must have a specific orientation, or be constructed and operated in a specific orientation; therefore, it should not be construed as a limitation of the invention. Furthermore, in the description of the invention, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, it can refer to a direct connection, an indirect connection through an intermediate medium, or a connection within two elements. Additionally, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0062] Furthermore, it should be noted that those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances. Although the steps of the control method of this invention are described in a specific order in this application, these orders are not restrictive, and those skilled in the art can perform the steps in different orders without departing from the basic principles of this invention.

[0063] First refer to Figure 1 This figure is a schematic diagram of the structure of the heat pump unit of the present invention. Specifically, as shown... Figure 1 As shown, the heat pump unit of the present invention includes an indoor unit 1, an outdoor unit 2, a refrigerant circulation loop (not shown in the figure), a hot water exchange circulation loop 3, and a water supply branch 4. The refrigerant circulation loop is located in the outdoor unit 2, and the hot water exchange circulation loop 3 is located between the indoor unit 1 and the outdoor unit 2. The refrigerant circulation loop is configured to exchange heat with the hot water exchange circulation loop 3. Refrigerant for heat exchange flows through the refrigerant circulation loop, and the refrigerant circulation loop is equipped with an evaporator, a compressor, a four-way valve, a condenser, and an electronic expansion valve. A portion of the hot water exchange circulation loop 3 is located in the evaporator or the condenser, enabling the refrigerant circulation loop to exchange heat with the hot water exchange circulation loop 3. Cooling or heating energy is then delivered to the indoor unit through the hot water exchange circulation loop 3. The refrigerant continuously circulates between the evaporator and the condenser through the refrigerant circulation loop to achieve heat exchange. When the four-way valve reverses its direction, it controls the refrigerant in the refrigerant circulation loop to reverse the flow, allowing the heat pump unit to switch between cooling and heating modes. Of course, the present invention does not impose any restrictions on the specific structure of the indoor unit 1, the outdoor unit 2, the refrigerant circulation loop and the hot water circulation loop 3, and those skilled in the art can set them according to the actual situation.

[0064] It should be noted that, in the description of this preferred embodiment, the first part 31 of the hot water circulation loop 3 is the part of the hot water circulation loop 3 from the outdoor unit 2 to the indoor unit 1, and the second part 32 of the hot water circulation loop 3 is the part of the hot water circulation loop 3 from the indoor unit 1 to the outdoor unit 2.

[0065] Furthermore, a first water tank 41 and a second water tank 42 are provided on the water supply branch 4. A heating device 411 is provided in the first water tank 41 to heat the water in the first water tank 41. A cooling device 421 is provided in the second water tank 42 to cool the water in the second water tank 42. A connecting branch 6 is provided between the first water tank 41 and the second water tank 42. The connecting branch 6 is configured to connect the first water tank 41 and the second water tank 42. Of course, the specific connection method is not limited. The outlets of the first water tank 41 and the second water tank 42 are both connected to the first part 31 of the hot water circulation loop 3 through the water supply branch 4. It should be noted that the present invention does not impose any restrictions on the specific structure of the first water tank 41 and the second water tank 42. Those skilled in the art can set it according to actual usage requirements, as long as the first water tank 41 and the second water tank 42 can store water and can be connected through the connecting branch 6; in addition, the present invention does not impose any restrictions on the specific types of the heating device 411 and the cooling device 421, as long as the heating device 411 can heat the water in the first water tank 41 and the cooling device 421 can cool the water in the second water tank 42.

[0066] Furthermore, as a preferred configuration, the first water tank 41 is also equipped with a first water inlet 412, a first water inlet switch 413, and a vent valve 414. The first water inlet switch 413 can control the opening and closing state of the first water inlet 412. The second water tank 42 is also equipped with a second water inlet 422 and a second water inlet switch 423, which can control the opening and closing state of the second water inlet 422. Of course, the present invention does not impose any restrictions on the specific shapes of the first water inlet 412 and the second water inlet 422, or the specific types of the first water inlet switch 413 and the second water inlet switch 423. Those skilled in the art can set them according to actual usage needs. The vent valve 414 can effectively prevent the first water tank 41 from bursting due to excessively high internal water temperature and pressure when the heating device 411 is turned on. That is, the vent valve 414 can effectively ensure the safety performance of the heat pump unit, thereby effectively ensuring the personal safety of the user.

[0067] Furthermore, the heat pump unit of the present invention also includes a return water branch 5, the first end of which is connected to the second water tank 42, and the second end of which is connected to the second part 32 of the hot water exchange circulation loop 3, so as to introduce water in the hot water exchange circulation loop 3 into the second water tank 42, thereby ensuring water circulation.

[0068] Based on the above structural configuration, the present invention, through the arrangement of the water supply branch 4 and the return water branch 5, enables the heat pump unit to selectively adjust the operating status of the refrigerant circulation loop, the hot water exchange circulation loop 3, the water supply branch 4, and the return water branch 5 when the refrigerant circulation loop is short of refrigerant or the hot water exchange circulation loop 3 is short of water, thereby effectively ensuring the normal operation of the heat pump unit. Furthermore, the present invention, by arranging a first water tank 41, a second water tank 42, a heating device 411, and a cooling device 421 on the water supply branch 4, ensures that the heat pump unit can fully meet both the user's heating and cooling needs. Additionally, the connection branch 6 allows the heat pump unit to selectively control the water temperature supplied to the first part 31 of the hot water exchange circulation loop 3 by controlling the water temperature in the first water tank 41 and the second water tank 42 according to its actual operating conditions.

[0069] Furthermore, it should be noted that the present invention does not impose any restrictions on the specific connection method between the water supply branch 4 and the hot water circulation loop 3, or on the specific connection method between the return water branch 5 and the hot water circulation loop 3 and the water supply branch 4. Those skilled in the art can set these methods according to the actual situation.

[0070] As a preferred embodiment, the water supply branch 4 is also equipped with a two-inlet, one-outlet three-way valve 43, the first inlet of which is ( Figure 1 The middle port (A) is connected to the outlet of the first water tank 41, and the second inlet of the two-inlet-one-outlet three-way valve 43 ( Figure 1 The B port is connected to the outlet of the second water tank 42, and the outlet of the two-in-one-out three-way valve 43 is ( Figure 1 The C port is connected to the first part 31 of the hot water circulation loop 3. The two-inlet, one-outlet three-way valve 43 allows the heat pump unit to control the water supply branch 4, the first water tank 41, and the second water tank 42 to selectively connect to the first part 31 of the hot water circulation loop 3, thereby effectively meeting the user's heating and cooling needs through the heating device 411 in the first water tank 41 and the cooling device 421 in the second water tank 42.

[0071] It should be noted that the present invention does not impose any restrictions on the specific type of the two-inlet-one-outlet three-way valve 43. It can be a pressure control valve or a control valve. These are not restrictive. As long as the two-inlet-one-outlet three-way valve 43 can control the water supply branch 4, the first water tank 41 and the second water tank 42 to selectively connect with the first part 31 of the hot water circulation loop 3, those skilled in the art can set it according to the actual situation.

[0072] Preferably, the heat pump unit further includes a control switch 7 and a relay pressure sensor 8. The heat pump unit controls the connection state of the two-inlet, one-outlet three-way valve 43 by controlling the connection state of the control switch 7 and the relay pressure sensor 8, thereby selectively controlling the operating mode of the heat pump unit. Of course, the present invention does not impose any limitations on the specific structure of the control switch 7 and the relay pressure sensor 8; those skilled in the art can set them according to actual conditions.

[0073] Furthermore, as a preferred embodiment, the heat pump unit further includes a heat mixing component (not shown in the figure). This heat mixing component is located at the connection between the water supply branch 4 and the first part 31 of the hot water exchange circulation loop 3, and is configured to mix water from the water supply branch 4 and water from the hot water exchange circulation loop 3. The heat mixing component ensures a more uniform mixing of the water from the water supply branch 4 and the water from the hot water exchange circulation loop 3, resulting in a more uniform water temperature. This effectively ensures the heat exchange stability of the heat pump unit and further enhances the user experience. It should be noted that this invention does not impose any limitations on the specific structure of the heat mixing component. For example, the heat mixing component can be a mixing tank or a stirring structure; these are not limiting factors, and those skilled in the art can design it according to the actual situation.

[0074] More preferably, the first water tank 41 is positioned higher in the vertical direction than the second water tank 42, thereby increasing the flow rate of water from both tanks 41 and 42 into the water supply branch 4, and thus effectively improving the heat exchange cycle efficiency of the heat pump unit. Of course, this invention does not impose any limitations on the specific height difference between the first water tank 41 and the second water tank 42; those skilled in the art can set this difference according to the actual heat exchange conditions of the heat pump unit.

[0075] Furthermore, in this preferred embodiment, the heat pump unit further includes a first control valve 9, a second control valve 10, a third control valve 11, and a fourth control valve 12; wherein, the first control valve 9 is disposed at the outlet end of the water supply branch 4, and the first control valve 9 is configured to control the connection state between the water supply branch 4 and the hot water exchange circulation loop 3; the second control valve 10 is disposed on the first part 31 of the hot water exchange circulation loop 3, and the second control valve 10 is configured to control the connection state of the first part 31 of the hot water exchange circulation loop 3; the third control valve 11 is disposed on the second part 32 of the hot water exchange circulation loop 3, and the third control valve 11 is configured to control the connection state of the second part 32 of the hot water exchange circulation loop 3; the fourth control valve 12 is disposed on the return water branch 5, and the fourth control valve 12 is configured to control the connection state of the return water branch 5.

[0076] It should be noted that the present invention does not impose any restrictions on the specific types of the first control valve 9, the second control valve 10, the third control valve 11, and the fourth control valve 12. The first control valve 9, the second control valve 10, the third control valve 11, and the fourth control valve 12 can be electromagnetic control valves or pressure control valves, as long as they can control the connection state of the corresponding circuit or branch.

[0077] Furthermore, it should be noted that the present invention does not impose any restrictions on the specific locations of the first control valve 9, the second control valve 10, the third control valve 11, and the fourth control valve 12; preferably, the first control valve 9 is located at the outlet of the two-inlet, one-outlet three-way valve 43. Figure 1 The first control valve 10 is located between the outdoor unit 2 and the connection between the water supply branch 4 and the first part 31 of the hot water circulation loop 3, so as to effectively prevent water from flowing back into the water supply branch 4 from the first part 31 of the hot water circulation loop 3; the second control valve 10 is located between the outdoor unit 2 and the connection between the water supply branch 4 and the first part 31 of the hot water circulation loop 3, so as to effectively control the connection state of the first part 31 of the hot water circulation loop 3; the third control valve 11 is located between the outdoor unit 2 and the connection between the second part 32 of the hot water circulation loop 3 and the return water branch 5, so as to effectively control the connection state of the second part 32 of the hot water circulation loop 3; of course, this is not restrictive, and those skilled in the art can set it according to the actual situation.

[0078] Furthermore, the heat pump unit also includes a first water flow monitoring device 13 and a second water flow monitoring device 14. The first water flow monitoring device 13 is installed on the second part 32 of the hot water exchange circulation loop 3 and is used to monitor the water flow rate in the hot water exchange circulation loop 3. The second water flow monitoring device 14 is installed on the return water branch 5 and is used to monitor the water flow rate in the return water branch 5. Of course, it should be noted that the present invention does not impose any restrictions on the specific type or specific location of the first water flow monitoring device 13 and the second water flow monitoring device 14. For example, the first water flow monitoring device 13 and the second water flow monitoring device 14 can be electromagnetic water flow meters or ultrasonic water flow meters. These are not limiting, and those skilled in the art can set them according to the actual situation.

[0079] More preferably, the heat pump unit further includes a first temperature sensor 15, a second temperature sensor 16, and a third temperature sensor 17. The first temperature sensor 15 is disposed at the outlet end of the water supply branch 4 to detect the temperature of the water supplied by the water supply branch 4 to the hot water circulation loop 3. The second temperature sensor 16 is disposed near the indoor unit 1 to detect the inlet water temperature of the indoor unit 1. The third temperature sensor 17 is disposed on the first part 31 of the hot water circulation loop 3 to detect the outlet water temperature of the outdoor unit 2.

[0080] It should be noted that the present invention does not impose any restrictions on the specific type, number, or location of the first temperature sensor 15, the second temperature sensor 16, and the third temperature sensor 17. Those skilled in the art can set them according to the actual situation.

[0081] Furthermore, the heat pump unit of the present invention also includes a controller, which is capable of acquiring the water flow rate detected by the first water flow monitoring device 13 and the second water flow monitoring device 14, as well as the temperature detected by the first temperature sensor 15, the second temperature sensor 16, and the third temperature sensor 17. It is also capable of controlling the connectivity of the refrigerant circulation loop, the hot water circulation loop 3, the water supply branch 4, and the return water branch 5, as well as the operating status of the heat pump unit. Those skilled in the art will understand that the present invention does not impose any limitations on the specific structure and model of the controller, and the controller can be either the original controller of the heat pump unit or a controller separately configured to implement the defrosting control method of the present invention. Technicians can customize the structure and model of the controller according to actual usage requirements.

[0082] First embodiment of the control method of the present invention

[0083] First refer to Figure 2 This figure is a flowchart of the main steps of the control method according to the first embodiment of the present invention. Figure 2 As shown, based on the heat pump unit described in the above embodiments, the control method of the first embodiment of the present invention mainly includes the following steps:

[0084] S11: When the hot water circulation loop is in operation, obtain the current water flow rate in the hot water circulation loop;

[0085] S12: Compare the current water flow rate in the hot water circulation loop with the preset water flow rate;

[0086] S13: Selectively control the operation of the water replenishment branch based on the comparison between the current water flow rate and the preset water flow rate in the hot water circulation loop.

[0087] First, in step S11, when the hot water circulation loop 3 is in operation, that is, when the user needs to exchange heat, the controller obtains the current water flow in the hot water circulation loop 3 through the first water flow monitoring device 13 in order to effectively determine the water flow status of the hot water circulation loop 3.

[0088] It should be noted that this invention does not impose any restrictions on the specific method or timing of obtaining the current water flow rate in the hot water circulation loop 3. The controller can obtain the flow rate at the start of the hot water circulation loop 3, or at any moment during its operation. The controller can obtain the current water flow rate in the hot water circulation loop 3 in real time, or at certain intervals; these are not limiting, and those skilled in the art can set them according to actual conditions. Preferably, the controller obtains the current water flow rate in the hot water circulation loop 3 in real time to further ensure that the heat pump unit does not suffer from low heat exchange efficiency due to water shortage.

[0089] Next, in step S12, the controller compares the current water flow rate in the hot water circulation loop 3 with the preset water flow rate. It should be noted that this invention does not impose any restrictions on the specific method of comparing the current water flow rate in the hot water circulation loop 3 with the preset water flow rate; it can be a comparison of magnitudes, or a comparison followed by comparison with other set values—none of these are limiting. Furthermore, it should also be noted that this invention does not impose any restrictions on the specific method of determining the preset water flow rate; it can be set according to the actual operating conditions of the heat pump unit, or according to the user's actual cooling or heating needs—none of these are limiting, and those skilled in the art can set it according to the actual situation.

[0090] Furthermore, in step S13, the controller can selectively control the operation of the water replenishment branch 4 based on the comparison between the current water flow rate in the hot water circulation loop 3 and the preset water flow rate. This effectively avoids the problem that the heat pump unit cannot meet the heat exchange requirements of the outdoor unit 2 due to a lack of water in the hot water circulation loop 3, thus resulting in low heat exchange efficiency of the heat pump unit. It should be noted that this invention does not impose any limitations on the specific control method described above. The controller can control the connection state of the water replenishment branch 4 based on the comparison between the current water flow rate in the hot water circulation loop 3 and the preset water flow rate, and it can also control the water flow rate in the water replenishment branch 4. These are not limiting factors, and those skilled in the art can set them according to actual conditions.

[0091] See next Figure 3 This figure is a flowchart illustrating the specific steps of the control method according to the first embodiment of the present invention. Figure 3 As shown, based on the heat pump unit described in the above preferred embodiment, the control method of the first embodiment of the present invention specifically includes the following steps:

[0092] S101: When the hot water circulation loop is in operation, obtain the current water flow rate in the hot water circulation loop;

[0093] S102: Compare the current water flow rate in the hot water circulation loop with the preset water flow rate;

[0094] S103: If the current water flow rate in the hot water circulation loop is less than the preset water flow rate by a preset percentage, then control the operation of the water replenishment branch.

[0095] S104: Obtain the water flow rate in the hot water circulation loop again;

[0096] S105: If the water flow rate in the hot water circulation loop is obtained again and reaches the preset water flow rate, the water supply branch is controlled to stop operating.

[0097] S106: After the water supply branch stops operating, obtain the trend of water flow change in the hot water circulation loop;

[0098] S107: If the water flow rate in the hot water circulation loop shows a decreasing trend, then control the operation of the water replenishment branch again;

[0099] S108: Controls the refrigerant circulation loop to stop operating;

[0100] S109: Controls the hot water circulation loop to stop operating.

[0101] First, in step S101, when the hot water circulation loop 3 is in operation, that is, when the user needs to perform heat exchange, the controller obtains the current water flow in the hot water circulation loop 3 through the first water flow monitoring device 13 in order to effectively determine the water flow status of the hot water circulation loop 3.

[0102] It should be noted that this invention does not impose any restrictions on the specific method or timing of obtaining the current water flow rate in the hot water circulation loop 3. The controller can obtain the flow rate at the start of the hot water circulation loop 3, or at any moment during its operation. The controller can obtain the current water flow rate in the hot water circulation loop 3 in real time, or at certain intervals; these are not limiting, and those skilled in the art can set them according to actual conditions. Preferably, the controller obtains the current water flow rate in the hot water circulation loop 3 in real time to further ensure that the heat pump unit does not suffer from low heat exchange efficiency due to water shortage.

[0103] Next, in step S102, the controller compares the current water flow rate in the hot water circulation loop 3 with the preset water flow rate. It should be noted that this invention does not impose any restrictions on the specific comparison method between the current water flow rate in the hot water circulation loop 3 and the preset water flow rate; it can be a comparison of magnitudes, or a comparison followed by comparison with other set values—none of these are limiting. Furthermore, it should also be noted that this invention does not impose any restrictions on the specific method of determining the preset water flow rate; it can be set according to the actual operating conditions of the heat pump unit, or according to the user's actual cooling or heating needs—none of these are limiting, and those skilled in the art can set it according to the actual situation.

[0104] Preferably, in this specific embodiment, the value of the preset water flow rate is determined by the following formula, so as to effectively adjust the operating state of the heat pump unit and thus effectively ensure the heat exchange efficiency of the heat pump unit:

[0105] W = k * X

[0106] Where W is the preset water flow rate; k is the reference coefficient; and X is the heat exchange capacity of the heat pump unit.

[0107] It should be noted that this invention does not impose any restrictions on the specific determination method of the reference coefficient and the heat exchange capacity of the heat pump unit. The heat exchange capacity of the heat pump unit can be determined based on the power, heat transfer coefficient, or heat exchange area of ​​the heat exchanger of the heat pump unit. This is not restrictive, and those skilled in the art can set it according to actual conditions. Preferably, the reference coefficient is 0.172.

[0108] Furthermore, the controller can selectively control the operation of the water replenishment branch 4 based on the comparison between the current water flow rate in the hot water circulation loop 3 and the preset water flow rate. This effectively avoids the problem that the heat pump unit cannot meet the heat exchange requirements of the outdoor unit 2 due to a lack of water in the hot water circulation loop 3, thus resulting in low heat exchange efficiency of the heat pump unit. It should be noted that this invention does not impose any limitations on the specific control method described above. The controller can control the connection state of the water replenishment branch 4 based on the comparison between the current water flow rate in the hot water circulation loop 3 and the preset water flow rate, and it can also control the water flow rate in the water replenishment branch 4. These are not limiting factors, and those skilled in the art can set them according to actual conditions.

[0109] Preferably, in step S103, if the current water flow rate in the hot water circulation loop 3 is less than the preset water flow rate by a preset percentage, the water replenishment branch 4 is controlled to operate. This effectively prevents the heat pump unit from failing to meet the heat exchange requirements of the outdoor unit 2 due to water shortage in the hot water circulation loop 3, thus ensuring the heat exchange effect of the heat pump unit. Conversely, if the current water flow rate in the hot water circulation loop 3 is greater than or equal to the preset water flow rate by a preset percentage, the water replenishment branch 4 is controlled not to operate, thereby reducing the operating energy consumption of the heat pump unit. It should be noted that the present invention does not impose any restrictions on the specific setting value of the preset percentage; preferably, the preset percentage is set to 95% to further effectively ensure the heat exchange efficiency of the heat pump unit.

[0110] Furthermore, in step S104, when the water supply branch 4 is already in operation, the controller again acquires the water flow rate in the hot water circulation loop 3, so as to selectively control the water supply branch 4 to stop operating based on the newly acquired water flow rate in the hot water circulation loop 3. Based on the above control method, the heat pump unit of the present invention can further accurately determine whether there is a water shortage problem in the outdoor unit 2 by controlling the connection status of the water supply branch 4 according to the water flow rate in the hot water circulation loop 3, that is, further effectively ensuring the heat exchange efficiency of the heat pump unit.

[0111] It should be noted that the present invention does not impose any restrictions on the specific control logic of the above control method, and those skilled in the art can set it themselves according to the actual situation. Preferably, in step S105, if the water flow rate in the hot water circulation loop 3 is obtained again and reaches the preset water flow rate, it means that there is no shortage of water in the hot water circulation loop 3 at this time, and the controller controls the water replenishment branch 4 to stop running, so as to reduce the operating energy consumption of the heat pump unit; conversely, if the water flow rate in the hot water circulation loop 3 is obtained again but has not reached the preset water flow rate, it means that the water in the hot water circulation loop 3 is still unable to meet the heat exchange requirements of the outdoor unit 2, and the controller controls the water replenishment branch 4 to continue running, so as to effectively ensure the heat exchange efficiency of the heat pump unit.

[0112] More preferably, in step S106, after the water supply branch 4 stops operating, the controller acquires the trend of water flow change in the hot water exchange circulation loop 3, and selectively controls the operation of the water supply branch 4 again based on the trend of water flow change in the hot water exchange circulation loop 3, so as to further effectively ensure the heat exchange efficiency of the heat pump unit. It should be noted that the present invention does not impose any restrictions on the specific method or timing of acquiring the trend of water flow change in the hot water exchange circulation loop 3. The controller can acquire the trend of water flow change in the hot water exchange circulation loop 3 immediately after the water supply branch 4 stops operating, or it can acquire it after a certain period of time since the water supply branch 4 has stopped operating. These are not limiting factors, and those skilled in the art can set the timing as needed.

[0113] Preferably, in step S107, if the water flow rate in the hot water circulation loop 3 shows a decreasing trend, it indicates a risk of continuous water leakage in the hot water circulation loop 3. This inevitably leads to the inability to meet the actual heat exchange requirements of the indoor unit 1. In this case, the controller controls the water supply branch 4 to operate again to effectively ensure the heat exchange effect of the indoor unit 1, thereby effectively ensuring the heat exchange efficiency of the heat pump unit. Conversely, if the water flow rate in the hot water circulation loop 3 does not show a decreasing trend, the water supply branch 4 continues to remain in a non-operating state.

[0114] Furthermore, in steps S108 and S109, after controlling the operation of the water supply branch 4 again, the controller controls the refrigerant circulation loop and the hot water exchange circulation loop 3 to stop operating, so as to effectively ensure the heat exchange requirements of the indoor unit 1 while maximizing the energy efficiency of the heat pump unit. It should be noted that the present invention does not impose any restrictions on the specific execution order of steps S108 and S109; they can be executed simultaneously or sequentially without regard to order. This is not restrictive, and those skilled in the art can set the order according to the actual situation.

[0115] Furthermore, before, simultaneously with, or after executing the step of "controlling the refrigerant circulation loop to stop operating", the controller can also control the operation of the heating device 411 or the cooling device 421 according to the operating mode of the heat pump unit; specifically, when the heat pump unit is in heating mode, the controller controls the heating device 411 to operate accordingly; when the heat pump unit is in cooling mode, the controller controls the cooling device 421 to operate accordingly.

[0116] Second embodiment of the control method of the present invention

[0117] First refer to Figure 4 This figure is a flowchart of the main steps of the control method according to the second embodiment of the present invention. Figure 4As shown, based on the heat pump unit described in the above embodiments, the control method of the second embodiment of the present invention mainly includes the following steps:

[0118] S21: Obtain the inlet water temperature of the indoor unit when the water supply branch is in operation;

[0119] S22: Control the operation of the water supply branch according to the inlet water temperature of the indoor unit and the operating mode of the heat pump unit.

[0120] First, in step S21, when the water supply branch 4 is in operation, the controller obtains the inlet water temperature of the indoor unit 1 through the second temperature sensor. It should be noted that this invention does not impose any restrictions on the specific conditions for starting the operation of the water supply branch 4; those skilled in the art can set these conditions according to actual usage requirements.

[0121] It should be noted that this invention does not impose any restrictions on the specific method or timing of obtaining the inlet water temperature of the indoor unit 1. The controller can obtain the temperature at the start of operation of the water supply branch 4, or at any time during operation of the water supply branch 4. The controller can obtain the inlet water temperature of the indoor unit 1 in real time, or at certain intervals; these are not limiting, and those skilled in the art can set them according to actual conditions. Preferably, the controller obtains the inlet water temperature of the indoor unit 1 in real time to further ensure that the heat pump unit does not suffer from low heat exchange efficiency due to refrigerant deficiency.

[0122] Next, in step S22, the controller can control the operation of the water supply branch 4 according to the inlet water temperature of the indoor unit 1 and the operating mode of the heat pump unit.

[0123] It should be noted that the present invention does not impose any restrictions on the specific control methods described above. The controller can control the connection status of the water supply branch 4 according to the inlet water temperature of the indoor unit 1 and the operating mode of the heat pump unit, and can also control the flow rate of water in the water supply branch 4. These are not limiting, and those skilled in the art can set them according to the actual situation.

[0124] Furthermore, it should be noted that the present invention does not impose any restrictions on the specific operating modes of the heat pump unit. It can be a heating mode, a cooling mode, or a defrosting mode. These are not restrictive, and those skilled in the art can set them according to the actual situation.

[0125] See next Figure 5 This figure is a flowchart illustrating the specific steps of the control method according to the second embodiment of the present invention. Figure 5As shown, based on the heat pump unit described in the preferred embodiment above, the control method of the second embodiment of the present invention specifically includes the following steps:

[0126] S201: Obtain the inlet water temperature of the indoor unit when the water supply branch is in operation;

[0127] S202: When the heat pump unit is in heating mode, calculate the difference between the target inlet water temperature and the inlet water temperature of the indoor unit, and record it as the first difference.

[0128] S203: If the first difference is greater than or equal to the first preset difference, then control the outlet of the first water tank to be directly connected to the water supply branch.

[0129] S204: Control the opening degree of the outlet of the first water tank according to the magnitude of the first difference;

[0130] S205: If the first difference is less than the first preset difference and greater than the second preset difference, then control the first water tank to connect to the water supply branch through the second water tank;

[0131] S206: If the first difference is less than or equal to the second preset difference, the water supply branch is controlled to stop operating;

[0132] S207: When the heat pump unit is in cooling mode, calculate the difference between the indoor unit's inlet water temperature and the target inlet water temperature, and record it as the second difference.

[0133] S208: Control the opening degree of the outlet of the second water tank according to the magnitude of the second difference.

[0134] In this preferred embodiment, before step S201, and while the water supply branch 4 is in operation, if the heat pump unit is in heating mode, the controller controls the heating device 411 to operate accordingly; if the heat pump unit is in cooling mode, the controller controls the cooling device 421 to operate accordingly, so as to effectively meet the heating or cooling requirements of the heat pump unit.

[0135] Next, in step S201, with the water supply branch 4 in operation, the controller obtains the inlet water temperature of the indoor unit 1 through the second temperature sensor. It should be noted that this invention does not impose any restrictions on the specific conditions for starting the operation of the water supply branch 4; those skilled in the art can set these conditions according to actual usage requirements.

[0136] It should be noted that this invention does not impose any restrictions on the specific method or timing of obtaining the inlet water temperature of the indoor unit 1. The controller can obtain the temperature at the start of operation of the water supply branch 4, or at any time during operation of the water supply branch 4. The controller can obtain the inlet water temperature of the indoor unit 1 in real time, or at certain intervals; these are not limiting, and those skilled in the art can set them according to actual conditions. Preferably, the controller obtains the inlet water temperature of the indoor unit 1 in real time to further ensure that the heat pump unit does not suffer from low heat exchange efficiency due to refrigerant deficiency.

[0137] Next, the controller can control the operation of the water supply branch 4 according to the inlet water temperature of the indoor unit 1 and the operating mode of the heat pump unit. It should be noted that this invention does not impose any limitations on the specific control method described above. The controller can control the connection status of the water supply branch 4 according to the inlet water temperature of the indoor unit 1 and the operating mode of the heat pump unit, and can also control the water flow rate in the water supply branch 4. These are not limiting; those skilled in the art can set them according to actual conditions.

[0138] Furthermore, it should be noted that the present invention does not impose any restrictions on the specific operating modes of the heat pump unit. It can be a heating mode, a cooling mode, or a defrosting mode. These are not restrictive, and those skilled in the art can set them according to the actual situation.

[0139] In a preferred embodiment, firstly, in step S202, when the heat pump unit is in heating mode, the difference between the target inlet water temperature and the inlet water temperature of the indoor unit 1 is calculated and recorded as the first difference. Of course, this invention does not impose any restrictions on the specific setting value of the target inlet water temperature under heating mode; it can be set according to the actual operating conditions of the heat pump unit or according to the actual usage needs of the user, and these are not limiting factors.

[0140] Next, the controller controls the operation of the water supply branch 4 according to the first difference. It can control the connection state of the water supply branch 4 and the water flow rate in the water supply branch 4, which can be set by those skilled in the art.

[0141] Specifically, in step S203, if the first difference is greater than or equal to the first preset difference, it indicates that the indoor unit 1 may be unable to meet the user's heating needs due to a lack of refrigerant in the refrigerant circulation loop. In this case, the A and C ports of the two-inlet-one-outlet three-way valve 43 are in the open state to achieve connection, and the B port is in the closed state. The controller controls the outlet of the first water tank 41 to be directly connected to the water replenishment branch 4, so as to ensure that the water heated by the heating device 411 can flow directly from the outlet of the first water tank 41 to the hot water circulation loop 3, thereby quickly meeting the heating needs of the indoor unit 1.

[0142] Preferably, in step S204, the controller can also control the opening degree of the outlet of the first water tank 41 according to the magnitude of the first difference, that is, by controlling the opening degree of the outlet of the first water tank 41, the amount of hot water flowing into the hot water circulation loop 3 is controlled, so as to further accurately control the indoor unit 1 to meet the user's heating needs.

[0143] Further, in step S205, if the first difference is less than the first preset difference and greater than the second preset difference, it indicates that although the refrigerant circulation loop cannot meet the user's actual heating needs, its actual heating capacity is not much different from the actual needs. In this case, the A and B ports of the two-inlet-one-outlet three-way valve 43 are in the open state to achieve connection, and the C port is in the closed state. The controller controls the first water tank 41 to connect with the water supply branch 4 through the second water tank 42, that is, the water heated by the heating device 411 is mixed with the room temperature water in the second water tank 42 and then supplied to the hot water circulation loop 3, so as to maximize the stability of the water supply temperature, thereby further accurately controlling the indoor unit 1 to meet the user's heating needs.

[0144] More preferably, in step S206, if the first difference is less than or equal to the second preset difference, it means that the refrigerant in the refrigerant circulation loop can meet the heat exchange requirements of the indoor unit 1. In this case, the C port of the two-inlet-one-outlet three-way valve 43 is closed, and the controller can control the water supply branch 4 to stop operating, so as to reduce the operating energy consumption of the heat pump unit.

[0145] Furthermore, in step S207, when the heat pump unit is in cooling mode, the difference between the inlet water temperature of the indoor unit 1 and the target inlet water temperature is calculated and recorded as the second difference. Of course, this invention does not impose any restrictions on the specific setting value of the target inlet water temperature in cooling mode; it can be set according to the actual operating conditions of the heat pump unit or according to the actual usage needs of the user, and these are not limiting factors.

[0146] Next, in step S208, the controller controls the opening degree of the outlet of the second water tank 42 according to the value of the second difference, that is, controls the water flow rate supplied by the second water tank 42 to the hot water circulation loop 3, so that the water cooled by the refrigeration device 421 flows into the hot water circulation loop 3 through the water supply branch 4 to meet the actual cooling needs of the indoor unit 1; at this time, the B and C ports of the two-inlet-one-outlet three-way valve 43 are in the open state, and the controller can also selectively open the A port of the two-inlet-one-outlet three-way valve 43 according to the specific heat exchange situation of the indoor unit 1. The present invention can further accurately control the cooling capacity of the indoor unit 1 by controlling the opening degree of the outlet of the second water tank 42, which can effectively ensure the heat exchange efficiency of the heat pump unit and effectively reduce the operating energy consumption of the heat pump unit.

[0147] It should be noted that the present invention does not impose any restrictions on the specific setting values ​​of the first preset difference, the second preset difference, and the target inlet water temperature. These values ​​can be set according to the actual operating conditions of the heat pump unit or according to the actual usage needs of the user. These are not restrictive, and those skilled in the art can set them according to the actual situation.

[0148] Furthermore, in this preferred embodiment, when the current running time of the heat pump unit reaches the preset duration, the controller can also obtain the outlet water temperature of the outdoor unit 2 through the third temperature sensor 17, so as to effectively determine the heat exchange capacity of the refrigerant circulation loop, thereby effectively determining whether the refrigerant circulation loop has problems such as refrigerant deficiency or electrical control failure that cause it to be unable to exchange heat normally, and control the connection status of the refrigerant circulation loop and the hot water circulation loop 3 according to the outlet water temperature of the outdoor unit 2 and the target outlet water temperature.

[0149] Specifically, if the outlet water temperature of outdoor unit 2 does not reach the target outlet water temperature, the hot water circulation loop 3 and the refrigerant circulation loop are stopped, and the return water branch 5 is connected, so that the water supply branch 4 and the return water branch 5 together form a heat exchange loop. Stopping the refrigerant circulation loop saves energy, while controlling the water supply branch 4 and the return water branch 5 to form a heat exchange loop effectively ensures the heat exchange capacity of the heat pump unit, thereby effectively meeting the heat exchange requirements of indoor unit 1. It should be noted that this invention does not impose any restrictions on the specific setting value of the target outlet water temperature of outdoor unit 2; those skilled in the art can set it according to actual usage requirements.

[0150] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A control method for a heat pump unit, characterized in that, The heat pump unit includes an indoor unit, an outdoor unit, a refrigerant circulation loop, a hot water exchange circulation loop, a water supply branch, and a return water branch. The refrigerant circulation loop is located in the outdoor unit, and the hot water circulation loop is located between the indoor unit and the outdoor unit. Furthermore, the refrigerant circulation loop is configured to exchange heat with the hot water circulation loop. A first water tank and a second water tank are installed on the water supply branch. The first water tank is equipped with a heating device, and the second water tank is equipped with a cooling device. A connecting branch is provided between the first water tank and the second water tank, and the connecting branch is configured to connect the first water tank and the second water tank. The outlets of both the first water tank and the second water tank are connected to the first part of the hot water exchange circulation loop through the water supply branch. The first end of the return water branch is connected to the second water tank, and the second end of the return water branch is connected to the second part of the hot water circulation loop. Wherein, the first part of the hot water circulation loop is the part of the hot water circulation loop from the outdoor unit to the indoor unit, and the second part of the hot water circulation loop is the part of the hot water circulation loop from the indoor unit to the outdoor unit; The control method includes: When the water supply branch is in operation, the inlet water temperature of the indoor unit is obtained; Based on the inlet water temperature of the indoor unit and the operating mode of the heat pump unit, the operation of the water replenishment branch is controlled. The steps include: when the heat pump unit is in heating mode, calculating the difference between the target inlet water temperature and the inlet water temperature of the indoor unit, and recording this as a first difference; based on the first difference, controlling the operation of the water replenishment branch, the steps include: If the first difference is greater than or equal to the first preset difference, then the outlet of the first water tank is directly connected to the water supply branch. If the first difference is less than the first preset difference and greater than the second preset difference, then the first water tank is connected to the water supply branch through the second water tank. The water heated by the heating device is mixed with the room temperature water in the second water tank and then supplied to the hot water circulation loop. If the first difference is less than or equal to the second preset difference, then control the water supply branch to stop operating; Before performing the step of "obtaining the inlet water temperature of the indoor unit", the control method further includes: If the heat pump unit is in heating mode, then the heating device is controlled to operate.

2. The control method according to claim 1, characterized in that, In the case where the outlet of the first water tank is directly connected to the water supply branch, the control method further includes: The opening degree of the outlet of the first water tank is controlled according to the magnitude of the first difference.

3. The control method according to claim 1, characterized in that, The step of "controlling the operation of the water supply branch according to the inlet water temperature of the indoor unit and the operating mode of the heat pump unit" further includes: When the heat pump unit is in cooling mode, the difference between the inlet water temperature of the indoor unit and the target inlet water temperature is calculated and recorded as the second difference. The opening degree of the outlet of the second water tank is controlled according to the magnitude of the second difference. Before performing the step of "obtaining the inlet water temperature of the indoor unit", the control method further includes: If the heat pump unit is in cooling mode, then control the operation of the cooling device.

4. The control method according to any one of claims 1 to 3, characterized in that, The control method further includes: If the current running time of the heat pump unit reaches the preset duration, the outlet water temperature of the outdoor unit is obtained; Based on the outlet water temperature of the outdoor unit and the target outlet water temperature, the hot water circulation loop and the refrigerant circulation loop are selectively stopped and the return water branch is connected.

5. The control method according to claim 4, characterized in that, The steps of "selectively controlling the hot water circulation loop to stop operating and controlling the return water branch to connect, based on the outlet water temperature of the outdoor unit and the target outlet water temperature" specifically include: If the outlet water temperature of the outdoor unit does not reach the target outlet water temperature, the hot water circulation loop and the refrigerant circulation loop are stopped and the return water branch is connected so that the water supply branch and the return water branch together form a heat exchange loop.

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