Heat pump system and control method thereof

Abstract

The invention provides a heat pump system and a control method thereof. The reliability of anti-freezing protection of a refrigerant-water heat exchanger can be improved. The heat pump system comprises an outdoor unit, an intermediate heat exchange unit, a hydrothermal terminal, a detection unit and a control unit, the intermediate heat exchange unit is provided with a refrigerant-water heat exchanger, a refrigerant piping and a water piping, and the intermediate heat exchange unit is connected with the outdoor unit through the refrigerant piping to form a refrigerant loop; the refrigerant-water heat exchanger is connected with the middle heat exchange unit through a refrigerant loop, the refrigerant loop is connected with the water heat tail end through a water distribution pipe to form a water loop, a refrigerant in the refrigerant loop and water in the water loop are subjected to heat exchange through the refrigerant-water heat exchanger, and the detection unit detects the outdoor environment temperature Tair, the inlet water temperature Tin of the water distribution pipe in the middle heat exchange unit and the outlet water temperature Tout of the water distribution pipe in the middle heat exchange unit; and when any one of the detection results of the detection unit reaches a first preset condition, the control unit controls the water in the water loop to circularly flow.

Description

Technical Field

[0001] The invention relates to a heat pump system and a control method thereof. Background Art

[0002] In previous heat pump systems, if the outdoor unit stops operating, the drop in ambient temperature may cause the refrigerant-water heat exchanger in the intermediate heat exchange unit to freeze and break. Once the refrigerant-water heat exchanger is frozen and cracked, the water and refrigerant in the refrigerant-water heat exchanger will mix, and the mixed fluid will flow into the refrigerant circuit, which may cause the entire heat pump system to be scrapped.

[0003] In order to prevent the refrigerant-water heat exchanger from freezing and being damaged, it is possible to consider installing a temperature sensor to detect the outdoor temperature. When the outdoor temperature detected by the temperature sensor is lower than the threshold, the water pump is operated, that is, the water in the water circuit is circulated to achieve antifreeze protection.

[0004] However, when the above-mentioned air temperature sensor fails, antifreeze protection cannot be achieved. Summary of the invention

[0005] The present invention is completed in view of the above-mentioned problems, and its purpose is to provide a heat pump system and a control method thereof, which are helpful to improve the reliability of antifreeze protection of the refrigerant-water heat exchanger.

[0006] In order to achieve the above-mentioned purpose, the present invention provides a heat pump system, including an outdoor unit, an intermediate heat exchange unit, a water-heating terminal, a detection unit and a control unit, wherein the intermediate heat exchange unit has a refrigerant-water heat exchanger, a refrigerant piping and a water piping, the intermediate heat exchange unit is connected to the outdoor unit through the refrigerant piping to form a refrigerant circuit, and is connected to the water-heating terminal through the water piping to form a water circuit, the refrigerant in the refrigerant circuit and the water in the water circuit are heat exchanged through the refrigerant-water heat exchanger, wherein the detection unit detects the outdoor ambient temperature Tair, the inlet water temperature Tin of the water piping in the intermediate heat exchange unit and the outlet water temperature Tout of the water piping in the intermediate heat exchange unit, and when any one of the detection results of the detection unit reaches a first preset condition, the control unit controls the circulation of water in the water circuit.

[0007] Here, the so-called "when any one of the detection results of the detection unit reaches the first preset condition" means "the outdoor ambient temperature Tair reaches the corresponding first preset condition, or the inlet water temperature Tin reaches the corresponding first preset condition, or the outlet water temperature Tout reaches the corresponding first preset condition". The first preset condition corresponding to the outdoor ambient temperature Tair, the first preset condition corresponding to the inlet water temperature Tin, and the first preset condition corresponding to the outlet water temperature Tout can be set separately, and the same applies below.

[0008] According to the heat pump system of the present invention, when the outdoor unit stops running and the temperature of the environment around the intermediate heat exchange unit drops, as long as any one of the outdoor environment temperature Tair detected by the detection unit, the inlet water temperature Tin of the water pipe in the intermediate heat exchange unit and the outlet water temperature Tout of the water pipe in the intermediate heat exchange unit reaches the first preset condition, the control unit controls the circulation of water in the water circuit. Therefore, compared with the situation where the circulation of water in the water circuit is controlled only based on the detection result of the outdoor environment temperature sensor, it helps to improve the reliability of the antifreeze protection of the refrigerant-water heat exchanger; especially when the detection result of the outdoor environment temperature sensor is abnormal, the water temperature detection result can be used to make the water in the water circuit circulate.

[0009] In addition, in the heat pump system of the present invention, it is preferred that after the water in the water circuit circulates for a first period of time, the detection unit detects the inlet water temperature Tin or the outlet water temperature Tout, and when the detection result of the detection unit reaches a second preset condition, the control unit controls the heat pump system to perform heating operation on the water in the refrigerant-water heat exchanger.

[0010] Here, the so-called "when the detection result of the detection unit reaches the second preset condition" means "the inlet water temperature Tin reaches the corresponding second preset condition, or the outlet water temperature Tout reaches the corresponding second preset condition". The second preset condition corresponding to the inlet water temperature Tin and the second preset condition corresponding to the outlet water temperature Tout can be set separately, and the same applies below.

[0011] According to the heat pump system of the present invention, when the outdoor unit stops operating and the temperature of the environment around the intermediate heat exchange unit drops and the water temperature in the water pipe continues to be low, the water in the refrigerant-water heat exchanger can be heated to prevent the refrigerant-water heat exchanger from freezing or being damaged, which helps to improve the reliability of the overall freezing protection of the heat pump system.

[0012] Furthermore, in the heat pump system of the present invention, it is preferred that a water pump is provided in the water circuit, and the water pump drives the water in the water circuit to circulate.

[0013] Furthermore, in the heat pump system of the present invention, preferably, in the heating operation, the water in the refrigerant-water heat exchanger is heated by the refrigerant, or the water in the refrigerant-water heat exchanger is heated by the heating module.

[0014] Furthermore, in the heat pump system of the present invention, it is preferred that the heat pump system further includes a fault detection unit, and the control unit controls the operation of the heat pump system according to the type of fault detected by the fault detection unit.

[0015] The heat pump system according to the present invention is helpful to further improve the reliability of the antifreeze protection of the refrigerant-water heat exchanger.

[0016] In addition, in the heat pump system of the present invention, it is preferred that after the heating operation is performed for a second period of time, the detection unit detects the inlet water temperature Tin and the outlet water temperature Tout, and when the detection results of the detection unit reach a third preset condition, the control unit controls the heat pump system to stop the heating operation, and the third preset condition is greater than the second preset condition.

[0017] The heat pump system according to the present invention helps to stop the heating operation in time, effectively realizes freezing protection and also achieves energy saving.

[0018] Furthermore, in the heat pump system of the present invention, preferably, after the heat pump system stops the heating operation, the control unit controls the water in the water circuit to continue to circulate for a third time period.

[0019] According to the heat pump system of the present invention, it is possible to prevent the water temperature in a local area (eg, at the intermediate heat exchange unit or the electric heater) from rising by allowing the water in the water circuit to continue to circulate.

[0020] In addition, in the heat pump system of the present invention, the detection unit preferably also includes a flow sensor, which detects the flow rate of water flowing through the water pipe. When the detection result of the flow sensor does not meet the preset conditions, the control unit also allows the water in the water circuit to continue to circulate.

[0021] In the case of insufficient water flow, there may be a water pump failure or leakage. At this time, the water pump is idling and usually stops.

[0022] However, according to the heat pump system of the present invention, even when the water flow detected by the flow sensor is insufficient, the water pump continues to operate, and the water circulates even if the water flow is insufficient, and anti-freeze protection is given priority. Therefore, the reliability of the freezing protection of the refrigerant-water heat exchanger can be further improved.

[0023] In addition, in order to achieve the above-mentioned purpose, the present invention provides a control method for a heat pump system, wherein the heat pump system includes an outdoor unit, an intermediate heat exchange unit, a water thermal terminal and a detection unit, wherein the intermediate heat exchange unit has a refrigerant-water heat exchanger, a refrigerant piping and a water piping, wherein the intermediate heat exchange unit is connected to the outdoor unit through the refrigerant piping to form a refrigerant circuit, and is connected to the water thermal terminal through the water piping to form a water circuit, and the refrigerant in the refrigerant circuit and the water in the water circuit are heat exchanged through the refrigerant-water heat exchanger, wherein the detection unit detects the outdoor ambient temperature Tair, the inlet water temperature Tin of the water piping in the intermediate heat exchange unit and the outlet water temperature Tout of the water piping in the intermediate heat exchange unit, and when any one of the detection results of the detection unit reaches a first preset condition, the water circulation in the water circuit is controlled.

[0024] According to the control method of the heat pump system of the present invention, when the outdoor unit stops running and the temperature of the environment around the intermediate heat exchange unit drops, as long as any one of the outdoor ambient temperature Tair detected by the detection unit, the inlet water temperature Tin of the water pipe in the intermediate heat exchange unit and the outlet water temperature Tout of the water pipe in the intermediate heat exchange unit reaches a first preset condition, the water circulation in the water circuit is controlled. Therefore, compared with the situation where the water circulation in the water circuit is controlled only based on the detection result of the outdoor ambient temperature sensor, it helps to improve the reliability of the antifreeze protection of the refrigerant-water heat exchanger; especially when the detection result of the outdoor ambient temperature sensor is abnormal, the water temperature detection result can be used to make the water in the water circuit circulate.

[0025] In addition, in the control method of the heat pump system of the present invention, it is preferred that after the water in the water circuit circulates for a first period of time, the detection unit detects the inlet water temperature Tin or the outlet water temperature Tout, and when the detection result of the detection unit reaches a second preset condition, the heat pump system is controlled to perform heating operation on the water in the refrigerant-water heat exchanger.

[0026] According to the control method of the heat pump system of the present invention, when the outdoor unit stops operating and the temperature of the environment around the intermediate heat exchange unit drops and the water temperature in the water pipe continues to be low, the water in the refrigerant-water heat exchanger can be heated to prevent the refrigerant-water heat exchanger from freezing or breaking, which helps to improve the reliability of the overall antifreeze protection of the heat pump system.

[0027] In addition, in the control method of the heat pump system of the present invention, it is preferred that after the heating operation is performed for a second period of time, the detection unit detects the inlet water temperature Tin and the outlet water temperature Tout, and when the detection results of the detection unit reach a third preset condition, the heat pump system is controlled to stop the heating operation, and the third preset condition is greater than the second preset condition.

[0028] The control method of the heat pump system according to the present invention is helpful to stop the heating operation in time, effectively realize freezing protection and achieve energy saving.

[0029] Furthermore, in the control method of the heat pump system of the present invention, it is preferred that after the heat pump system stops the heating operation, the water in the water circuit is controlled to continue to circulate for a third time period.

[0030] According to the control method of the heat pump system of the present invention, the water temperature in a local area (such as the intermediate heat exchange unit or the electric heater) can be prevented from rising by allowing the water in the water circuit to continue to circulate.

[0031] In addition, in the control method of the heat pump system of the present invention, the heat pump system preferably also includes a flow sensor, which detects the flow rate of water flowing through the water pipe. When the detection result of the flow sensor does not meet the preset condition, the control unit also allows the water in the water circuit to continue to circulate.

[0032] In the case of insufficient water flow, there may be a water pump failure or leakage. At this time, the water pump is idling and usually stops.

[0033] However, according to the control method of the heat pump system of the present invention, even when the water flow detected by the flow sensor is insufficient, the water pump continues to operate, and the water circulates even if the water flow is insufficient, and antifreeze protection is given priority. Therefore, the reliability of the antifreeze protection of the refrigerant-water heat exchanger can be further improved.

[0034] (Effects of the Invention)

[0035] According to the present invention, when the outdoor unit stops running and the temperature of the environment around the intermediate heat exchange unit drops, as long as any one of the outdoor environment temperature Tair detected by the detection unit, the inlet water temperature Tin of the water pipe in the intermediate heat exchange unit and the outlet water temperature Tout of the water pipe in the intermediate heat exchange unit reaches the first preset condition, the water circulation in the water circuit is controlled. Therefore, compared with the situation where the water circulation in the water circuit is controlled only according to the detection result of the outdoor environment temperature sensor, it helps to improve the reliability of the antifreeze protection of the refrigerant-water heat exchanger; especially when the detection result of the outdoor environment temperature sensor is abnormal, the water temperature detection result can be used to make the water in the water circuit circulate; and, when the outdoor unit stops running and the temperature of the environment around the intermediate heat exchange unit drops and the water temperature in the water pipe continues to be low, the water in the refrigerant-water heat exchanger can be started to perform heating operation to prevent the refrigerant-water heat exchanger from freezing and damage, which helps to improve the reliability of the antifreeze protection of the heat pump system as a whole. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 1 is a circuit diagram schematically showing a heat pump system according to an embodiment of the present invention.

[0037] Figure 2 1 is a flowchart schematically showing a control method of a heat pump system according to an embodiment of the present invention.

[0038] (Explanation of symbols)

[0039] 10 Outdoor unit

[0040] 11. Compressor

[0041] 12 Outdoor heat exchanger

[0042] 13 Fluid storage tank

[0043] 14 Outdoor air supply device

[0044] 20 Intermediate heat exchange unit

[0045] 21 Refrigerant-water heat exchanger

[0046] 30 Water Pump

[0047] 40 Hydrothermal end

[0048] PZ refrigerant pipe

[0049] PS water piping

[0050] PY Liquid side connecting pipe

[0051] PQ Gas side connecting pipe

[0052] P1 liquid side piping

[0053] P2 Gas side piping

[0054] P3 connection pipe

[0055] P4 connection pipe

[0056] VC1 First stop valve

[0057] VC2 Second stop valve

[0058] Po compressor discharge pipe

[0059] Pi compressor suction line

[0060] V1 Valve

[0061] VF1 Four-way Switching Valve

[0062] a The first port of the four-way switching valve

[0063] b The second port of the four-way switching valve

[0064] c The third port of the four-way switching valve

[0065] d The fourth port of the four-way switching valve DETAILED DESCRIPTION

[0066] Next, combine Figure 1 and Figure 2 A heat pump system according to an embodiment of the present invention will be described.

[0067] (Overall structure of heat pump system)

[0068] Figure 1 1 is a circuit diagram schematically showing a heat pump system according to an embodiment of the present invention.

[0069] like Figure 1 As shown, the heat pump system includes an outdoor unit 10, an intermediate heat exchange unit 20, a water thermal terminal 40, a detection unit (not shown) and a control unit (not shown). The intermediate heat exchange unit 20 has a refrigerant-water heat exchanger 21, a refrigerant pipe PZ and a water pipe PS. The intermediate heat exchange unit 20 is connected to the outdoor unit 10 through the refrigerant pipe PZ to form a refrigerant circuit, and is connected to the water thermal terminal 40 through the water pipe PS to form a water circuit. The refrigerant in the refrigerant circuit and the water in the water circuit exchange heat through the refrigerant-water heat exchanger 21.

[0070] Here, if Figure 1 As shown, a water pump 30 is provided in the water circuit, and the water pump 30 drives the water in the water circuit to circulate. The water pump 30 can be provided in the shell of the intermediate heat exchange unit 20, or it can be provided independently. The water pump 30 can be one, or an auxiliary water pump can be provided additionally according to the actual length of the water circuit.

[0071] In addition, if Figure 1 As shown, the outdoor unit 10 is connected to the intermediate heat exchange unit 20 via a liquid-side connecting pipe PY and a gas-side connecting pipe PQ. Specifically, the outdoor unit 10 includes a liquid-side pipe P1 and a gas-side pipe P2. The liquid-side pipe P1 is connected to one end ( Figure 1 The gas side pipe P2 is connected to the other end (the upper end) of the refrigerant pipe PZ of the intermediate heat exchange unit 20 via the gas side connecting pipe PQ. Figure 1 In addition, a first stop valve VC1 is provided at the connection between the liquid side piping P1 and the liquid side connecting piping PY, and a second stop valve VC2 is provided at the connection between the gas side piping P2 and the gas side connecting piping PQ. Under normal circumstances, the first stop valve VC1 and the second stop valve VC2 are in a normally open state. Of course, the first stop valve VC1 and the second stop valve VC2 may be omitted depending on the situation.

[0072] In addition, the intermediate heat exchange unit 20 and the outdoor unit 10 may be integrated; or they may be separated, and the intermediate heat exchange unit 20 is an independently arranged water module.

[0073] In addition, if Figure 1 As shown, the water heat terminal 40 is connected to the water pipe PS of the intermediate heat exchange unit 20 via the connecting pipe P3 and the connecting pipe P4, thereby forming a water circuit. The water pump 30 is arranged in the middle of the connecting pipe P4. The water heat terminal 40 can be one or more, and can be one type such as floor heating (or faucet, water heater, etc.), or multiple types such as floor heating + water heater, etc., and can also include a heat storage module such as a heat storage tank.

[0074] In addition, although not shown, the heat pump system also includes one or more indoor units connected to the outdoor unit 10. Furthermore, the outdoor unit 10 and the indoor unit may be of a two-pipe type (the outdoor unit 10 is connected to the indoor unit via a liquid pipe and a gas pipe) or a three-pipe type (the outdoor unit 10 is connected to the three-pipe indoor unit via a liquid pipe, a high-low pressure pipe, and a gas pipe). The indoor unit may switch between heating and cooling, for example.

[0075] In addition, although not shown in the figure, the detection unit includes: an outdoor ambient temperature sensor for detecting the outdoor ambient temperature Tair; an inlet water temperature sensor for detecting the inlet water temperature Tin of the water pipe PS in the intermediate heat exchange unit 10; and an outlet water temperature sensor for detecting the outlet water temperature Tout of the water pipe PS in the intermediate heat exchange unit 10.

[0076] In addition, the control unit controls the operation of the heat pump system to perform antifreeze protection of the refrigerant-water heat exchanger 21 and the like.

[0077] (Structure of outdoor unit)

[0078] like Figure 1 As shown, the outdoor unit 10 is provided with a compressor 11, an outdoor heat exchanger 12, a valve V1, a liquid storage tank 13, and a four-way switching valve VF1.

[0079] Here, if Figure 1 As shown, the outdoor unit 10 is further provided with an outdoor air supply device 14 for supplying air to the outdoor heat exchanger 12 .

[0080] In addition, if Figure 1 As shown, the discharge side of the compressor 11 is connected to one end of the compressor discharge pipe Po, and the other end of the compressor discharge pipe Po is connected to the first port a of the four-way switching valve VF1. In addition, the suction side of the compressor 11 is connected to one end of the compressor suction pipe Pi, and the other end of the suction pipe Pi is connected to the third port c of the four-way switching valve VF1. In addition, the second port b of the four-way switching valve VF1 is connected to the gas side piping P2, and the fourth port d of the four-way switching valve VF1 is connected to the liquid side piping P1.

[0081] In addition, if Figure 1 As shown, the liquid storage tank 13 is arranged in the middle of the compressor suction pipe Pi. Of course, the liquid storage tank 13 may not be arranged in the middle of the compressor suction pipe Pi.

[0082] In addition, the four-way switching valve VF1 can switch between a first switching state and a second switching state. In the first switching state, the first port a is connected to the second port b and the third port c is connected to the fourth port d, thereby connecting the compressor discharge pipe Po to the gas side pipe P2 and connecting the compressor suction pipe Pi to the liquid side pipe P1. In the second switching state, the first port a is connected to the fourth port d and the third port c is connected to the second port b, thereby connecting the compressor discharge pipe Po to the liquid side pipe P1 and connecting the compressor suction pipe Pi to the gas side pipe P2. Furthermore, in the first switching state, the heat pump system can perform operations such as heating (the flow direction of the refrigerant at this time refers to Figure 1 On the other hand, in the second switching state, the heat pump system can perform operations such as defrosting (the flow direction of the refrigerant at this time refers to Figure 1 light-colored arrow in the figure).

[0083] In addition, if Figure 1 As shown, the outdoor heat exchanger 12 and the valve V1 are provided in the middle of the liquid-side pipe P1.

[0084] Although not shown in the drawings, the outdoor unit 10 further includes an outdoor ambient temperature sensor for detecting the outdoor ambient temperature Tair.

[0085] (Structure of intermediate heat exchange unit)

[0086] As described above, the intermediate heat exchange unit 20 includes the refrigerant-water heat exchanger 21 , the refrigerant pipe PZ, and the water pipe PS.

[0087] Here, if Figure 1 As shown, the intermediate heat exchange unit 20 further includes: an inlet water temperature sensor for detecting an inlet water temperature Tin of the water pipe PS; and an outlet water temperature sensor for detecting an outlet water temperature Tout of the water pipe PS.

[0088] (Control method of heat pump system)

[0089] Figure 2 1 is a flowchart schematically showing a control method of a heat pump system according to an embodiment of the present invention.

[0090] like Figure 2 As shown, in the heat pump system, when any one of the outdoor ambient temperature Tair detected by the detection unit, the inlet water temperature Tin of the water pipe in the intermediate heat exchange unit, and the outlet water temperature Tout of the water pipe in the intermediate heat exchange unit reaches a first preset condition, the control unit controls the circulation of water in the water circuit (for example, operates the water pump 30, refer to step ST1), and the circulating water can be prevented from freezing.

[0091] Here, the first preset condition of the outdoor ambient temperature Tair is set to Tsair (for example, 4°C), the first preset condition of the inlet water temperature Tin is set to Tsin (for example, 5°C), and the first preset condition of the outlet water temperature Tout is set to Tsout (for example, 5°C), wherein Tsair is preferably less than Tsin and less than Tsout. In addition, according to the actual use environment and installation environment of the heat pump system, for example, the intermediate heat exchange unit 20 is installed indoors in the form of an independent water module, the first preset condition Tsair of the outdoor ambient temperature Tair can also be >0°C; the first preset condition Tsin of the inlet water temperature Tin is in the range of 0°C-6°C; the first preset condition Tsout of the outlet water temperature Tout is in the range of 0°C-6°C.

[0092] In addition, after the water in the water circuit circulates for a first period of time (for example, 4-10 minutes), the detection unit detects the inlet water temperature Tin or the outlet water temperature Tout. When the detection result of the detection unit reaches a second preset condition, the control unit controls the heat pump system to perform heating operation on the water in the refrigerant-water heat exchanger 21 (refer to step ST2).

[0093] Here, when the second preset condition is set to Tson, it is preferred that Tson (for example, 6° C.) is lower than Tsin and Tsout, that is, the water in the water circuit is still at risk of freezing, and heating operation is used to prevent the water in the water circuit from freezing.

[0094] (Main Effects of the Present Embodiment)

[0095] According to the heat pump system and the control method of the heat pump system in the present embodiment, when the outdoor unit 10 stops running and the temperature of the environment around the intermediate heat exchange unit 20 drops, as long as any one of the outdoor ambient temperature Tair detected by the detection unit, the inlet water temperature Tin of the water pipe in the intermediate heat exchange unit and the outlet water temperature Tout of the water pipe in the intermediate heat exchange unit reaches the first preset condition, the control unit controls the circulation of water in the water circuit. Therefore, compared with the situation where the circulation of water in the water circuit is controlled only based on the detection result of the outdoor ambient temperature sensor, it can effectively avoid the problem that the control unit cannot send the water circuit circulation operation instruction in time due to inaccurate detection of the outdoor ambient temperature sensor, failure of the water temperature sensor, etc., which leads to freezing of the refrigerant-water heat exchanger 21, which helps to improve the reliability of the anti-freeze protection of the refrigerant-water heat exchanger 21; especially when the detection result of the outdoor ambient temperature sensor is abnormal, the water temperature detection result can be used to make the water in the water circuit circulate.

[0096] In addition, according to the heat pump system of this embodiment, when the outdoor unit 10 stops operating and the temperature of the environment around the intermediate heat exchange unit 20 drops and the water temperature in the water pipe PS continues to be low, the heating operation of the water in the refrigerant-water heat exchanger 21 can be started to prevent the refrigerant-water heat exchanger 21 from freezing or damage, which helps to improve the reliability of the antifreeze protection of the refrigerant-water heat exchanger 21.

[0097] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned embodiments.

[0098] For example, in the above-mentioned embodiment, the heat pump system includes one or more indoor units connected to the outdoor unit 10, but the present invention is not limited thereto, and the indoor unit may be omitted depending on circumstances.

[0099] In addition, in the above embodiment, when performing the heating operation, the outdoor unit 10 can be operated to heat the water in the refrigerant-water heat exchanger 21 with the refrigerant (forcing the heating operation to increase the water temperature), or a heating module (such as an electric heater) can be used to heat the water in the refrigerant-water heat exchanger 21. In addition, during the heating operation, the load required for the heat pump system to perform the heating operation or the required time for the heating operation (such as a minimum heating operation of 10 minutes) can be adjusted according to the difference between the current inlet / outlet water temperature and the preset condition.

[0100] In addition, in the above embodiment, it can also be arranged that: the heat pump system further includes a fault detection unit, and the control unit controls the operation of the heat pump system according to the fault type detected by the fault detection unit.

[0101] Here, as the fault type, some temperature sensors are abnormal, all temperature sensors are abnormal, water pump fault, outdoor unit fault, etc. are included.

[0102] When some temperature sensors are abnormal, for example, the following control can be performed: when the outdoor ambient temperature sensor cannot detect the temperature normally, the outlet water temperature can be used as a substitute for protection; on the other hand, when the outlet water temperature cannot be detected normally, the inlet water temperature can be used as a substitute for protection. The three temperature sensors can have a priority order as above, or they can replace each other for protection. The detection results of multiple temperature sensors (detection elements) can be used individually or in combination, which is conducive to realizing multiple protections against freezing of the heat pump system.

[0103] When all the temperature sensors are abnormal, for example, the following control may be performed: the water in the water circuit is directly caused to start circulating (ie, the water pump is operated).

[0104] When the water pump fails or the water flow rate is below the minimum water flow rate, for example, the following control can be performed: a water circuit abnormality alarm is issued, and the heat pump system is made to heat so that the hot refrigerant flows through the refrigerant-water heat exchanger. In addition, the refrigerant flow rate flowing through the refrigerant-water heat exchanger is adjustable, and the refrigerant flow rate can be adjusted according to actual needs.

[0105] When the outdoor unit fails (outdoor unit is abnormal), for example, the following control may be performed: the water in the water circuit is directly caused to start circulating (ie, the water pump is operated).

[0106] In addition, when an abnormality occurs, users can be reminded through text messages, APP push reminders, etc. to drain the water in the refrigerant-water heat exchanger to prevent freezing, and replace the components of the faulty part as soon as possible.

[0107] In addition, in the above embodiment, it can also be configured that: when frost occurs on the outdoor unit 10, the heat pump system can switch between a first mode in which the indoor unit is used for defrosting and a second mode in which the intermediate heat exchange unit 20 is used for defrosting, and at least one of Tsair, Tsin and Tsout is smaller in the first mode than in the second mode (for example, Tsin and Tsout in the first mode are 6°C, respectively, while Tsin and Tsout in the second mode are 12°C, respectively). This helps to avoid the risk of freezing the refrigerant-water heat exchanger 21 due to defrosting when the water pump 30 starts to operate. In some use cases, it can also be that in the first mode, the range of Tsin and Tsout is 4°C-8°C, and in the second mode, the range of Tsin and Tsout is 10°C-15°C.

[0108] In addition, in the above embodiment, after the heating operation is performed for a second time (e.g., 8-15 minutes), the detection unit detects the inlet water temperature Tin and the outlet water temperature Tout. When the detection results of the detection unit reach the third preset condition, the control unit controls the heat pump system to stop the heating operation, and the third preset condition is greater than the second preset condition. When the third preset condition is set to Toff, it is preferred that Toff (e.g., 15°C) is greater than Tsin and Tsout. In some use cases, the range of Toff may also be 12°C-16°C; or the heating may be continued for a third time (e.g., 8-15 minutes) after the temperature reaches the Toff setting value.

[0109] In the above case, when the inlet water temperature Tin and the outlet water temperature Tout are both greater than Toff after the heating operation is performed for a second period of time (e.g. 8-15 minutes) and the heating operation is stopped, the water pump 30 continues to operate for a third period of time (e.g. 8-15 minutes).

[0110] In addition, in the above embodiment, it can also be arranged that: the heat pump system includes a flow sensor, the flow sensor detects the flow of water flowing through the water pipe, and when the detection result of the flow sensor does not meet the preset conditions, the control unit also allows the water in the water circuit to continue to circulate.

[0111] In the above case, the water pump 30 may be stopped when the inlet water temperature Tin and the outlet water temperature Tout rise to certain values.

[0112] In addition, in the above embodiment, the water circulation volume of the water circuit can also be adjusted according to the difference between the detected temperature and the preset temperature.

[0113] In addition, in the above embodiment, a manifold may be provided on the water circuit of the heat pump system. When the water heating terminal 40 is a plurality of floor heating modules, the manifold may be used to distribute the amount of water flowing into each floor heating module.

[0114] In addition, in the above embodiment, when any one of the outdoor ambient temperature Tair detected by the detection unit, the inlet water temperature Tin of the water pipe in the intermediate heat exchange unit, and the outlet water temperature Tout of the water pipe in the intermediate heat exchange unit reaches the first preset condition, the control unit compares the actually detected values ​​of Tair, Tin, and Tout with the first preset condition (that is, compares Tair, Tin, and Tout with Tsair, Tsin, and Tsout, respectively). If at least one comparison result is a large difference, the control unit can control the water in all or most of the floor heating to circulate to prevent the water in the water circuit from freezing; if all comparison results are small differences, the control unit can control the water in part of the floor heating to circulate, or circulate with a smaller amount of water to prevent the water in the water circuit from freezing.

[0115] In the above case, when the heat pump system is stopped, the water in multiple floor heating systems can all be allowed to circulate, or the temperature of the room where each floor heating system is located can be used to determine which floor heating system's water is to circulate (if the room temperature is high, the water temperature in the corresponding floor heating system will also be higher).

[0116] In addition, in the above-mentioned embodiment, the flow direction of water flowing through the water pipe PS may also be set to Figure 1 on the contrary.

[0117] It should be understood that within the scope of the present invention, various parts in the embodiments can be freely combined, or various parts in the embodiments can be appropriately deformed or omitted.

Claims

1. A heat pump system, comprising an outdoor unit, an intermediate heat exchange unit, a water heat terminal, a detection unit and a control unit, wherein the intermediate heat exchange unit has a refrigerant-water heat exchanger, a refrigerant pipe and a water pipe, wherein the intermediate heat exchange unit is connected with the outdoor unit through the refrigerant pipe to form a refrigerant circuit, and is connected with the water heat terminal through the water pipe to form a water circuit, and the refrigerant in the refrigerant circuit and the water in the water circuit are heat exchanged through the refrigerant-water heat exchanger, It is characterized in that The detection unit detects the outdoor ambient temperature Tair, the inlet water temperature Tin of the water pipe in the intermediate heat exchange unit, and the outlet water temperature Tout of the water pipe in the intermediate heat exchange unit. When any one of the detection results of the detection unit reaches a first preset condition, the control unit controls the water in the water circuit to circulate.

2. The heat pump system according to claim 1, It is characterized in that After the water in the water circuit circulates for a first period of time, the detection unit detects the inlet water temperature Tin or the outlet water temperature Tout, When the detection result of the detection unit reaches a second preset condition, the control unit controls the heat pump system to perform a heating operation on the water in the refrigerant-water heat exchanger.

3. The heat pump system according to claim 1, It is characterized in that A water pump is provided in the water circuit, and the water pump drives the water in the water circuit to circulate.

4. The heat pump system according to claim 2, It is characterized in that In the heating operation, the water in the refrigerant-water heat exchanger is heated by the refrigerant, or the water in the refrigerant-water heat exchanger is heated by the heating module.

5. The heat pump system according to claim 1, It is characterized in that The heat pump system further comprises a fault detection unit, The control unit controls the operation of the heat pump system according to the fault type detected by the fault detection unit.

6. The control method of the heat pump system according to claim 2, It is characterized in that After the heating operation is performed for a second time period, the detection unit detects the inlet water temperature Tin and the outlet water temperature Tout. When the detection results of the detection units all reach a third preset condition, the control unit controls the heat pump system to stop the heating operation, and the third preset condition is greater than the second preset condition.

7. The control method of the heat pump system according to claim 6, It is characterized in that After the heat pump system stops the heating operation, the control unit controls the water in the water circuit to continue to circulate for a third time period.

8. The control method of the heat pump system according to claim 1, It is characterized in that The detection unit further includes a flow sensor, which detects the flow rate of water flowing through the water pipe. When the detection result of the flow sensor does not meet the preset condition, the control unit also enables the water in the water circuit to continue to circulate.

9. A control method for a heat pump system, the heat pump system comprising an outdoor unit, an intermediate heat exchange unit, a water heat terminal and a detection unit, the intermediate heat exchange unit having a refrigerant-water heat exchanger, a refrigerant pipe and a water pipe, the intermediate heat exchange unit being connected with the outdoor unit through the refrigerant pipe to form a refrigerant circuit, and being connected with the water heat terminal through the water pipe to form a water circuit, the refrigerant in the refrigerant circuit and the water in the water circuit exchanging heat through the refrigerant-water heat exchanger, It is characterized in that The detection unit detects the outdoor ambient temperature Tair, the inlet water temperature Tin of the water pipe in the intermediate heat exchange unit, and the outlet water temperature Tout of the water pipe in the intermediate heat exchange unit. When any one of the detection results of the detection unit reaches a first preset condition, the water in the water circuit is controlled to circulate.

10. The control method of the heat pump system according to claim 9, It is characterized in that After the water in the water circuit circulates for a first period of time, the detection unit detects the inlet water temperature Tin or the outlet water temperature Tout, When the detection result of the detection unit reaches a second preset condition, the heat pump system is controlled to perform a heating operation on the water in the refrigerant-water heat exchanger.

11. The control method of the heat pump system according to claim 10, It is characterized in that After the heating operation is performed for a second time period, the detection unit detects the inlet water temperature Tin and the outlet water temperature Tout. When the detection results of the detection units all reach a third preset condition, the heat pump system is controlled to stop the heating operation, and the third preset condition is greater than the second preset condition.

12. The control method of the heat pump system according to claim 11, It is characterized in that After the heat pump system stops the heating operation, the water in the water circuit is controlled to continue to circulate for a third time period.

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