Control method for heat pump system and heat pump system

Abstract

The invention provides a control method for a heat pump system and the heat pump system. The heat pump system comprises a compressor, a hot water heat exchanger, an external air heat exchanger, a cold water heat exchanger and a gas-liquid separator which are communicated through a circulation pipeline assembly, and the circulation pipeline assembly comprises an output pipe, a first input pipe, a second input pipe and a third input pipe; a first pipeline assembly arranged on the liquid side of the external air heat exchanger is communicated with a second pipeline assembly composed of a first input pipe and an output pipe and a third pipeline assembly composed of a second input pipe and a third input pipe. The technical problems that when the refrigerant amount of a refrigerant medium in an existing heat pump system is maximum, a refrigeration main body mode is adopted, after the heat pump system is filled with the refrigerant amount, under other refrigeration modes, heating modes and heating main body modes, redundant refrigerant liquid is retained in a condenser, the supercooling degree of the refrigerant medium is too large, and the refrigerant amount is too large are solved. Therefore, the heat exchange effect of the heat pump system is influenced.

Description

Technical Field

[0001] The present invention relates to the technical field of heat pumps, and in particular to a control method for a heat pump system and a heat pump system. Background Art

[0002] As a highly efficient and energy-saving device that makes full use of low-grade thermal energy, the heat pump system has air conditioning functions (including cooling and heating functions), hot water making functions and chilled water functions in actual applications, meeting users' needs for hot water making and air conditioning.

[0003] However, there is at least one of the following problems in the related technology: the refrigerant amount of the refrigerant in the existing heat pump system (here it refers to the volume L rather than the flow rate kg / s) is the largest in the cooling main mode. After the refrigerant is filled into the heat pump system, in other cooling modes, heating modes, and heating main modes, excess refrigerant liquid is retained in the condenser, causing the refrigerant to be too supercooled, causing the condensation temperature of the refrigerant to rise, thereby affecting the heat exchange effect of the heat pump system. Summary of the invention

[0004] The technical problem solved by the present invention is that the refrigerant amount (here it refers to the volume L rather than the flow rate kg / s) of the refrigerant in the existing heat pump system is the largest in the refrigeration main mode. After the refrigerant is filled into the heat pump system, in other refrigeration modes, heating modes, and heating main modes, excess refrigerant liquid is retained in the condenser, resulting in excessive supercooling of the refrigerant, causing the condensation temperature of the refrigerant to rise, thereby affecting the heat exchange effect of the heat pump system.

[0005] To solve the above problems, on the one hand, the present invention provides a heat pump system, which includes a compressor, a hot water heat exchanger, an outdoor air heat exchanger, a cold water heat exchanger, and a gas-liquid separator connected by a circulation pipeline assembly through which a cooling medium circulates, and the circulation pipeline assembly includes: an output pipe, the output pipe is arranged on the discharge side of the hot water heat exchanger; a first input pipe, the first input pipe is arranged at the first connecting end of the hot water heat exchanger, and the first input pipe is connected to the output pipe; a second input pipe, the second input pipe is arranged at the second connecting end of the hot water heat exchanger; a third input pipe, one end of the third input pipe is connected to the first input pipe, and the other end is connected to the second input pipe; wherein the first pipeline assembly arranged on the liquid side of the outdoor air heat exchanger is connected to the second pipeline assembly composed of the first input pipe and the output pipe, the third pipeline assembly composed of the second input pipe and the third input pipe, and the first connecting pipe arranged between the cold water heat exchanger and the gas-liquid separator.

[0006] Compared with the prior art, the technical effect achieved by adopting this technical scheme is as follows: this scheme is connected with the second pipeline assembly and the third pipeline assembly through the first pipeline assembly, so that after the heat pump system is filled with the refrigerant amount required in the refrigeration main mode, in the refrigeration mode, the excess refrigerant can be stored in the stopped warm water heat exchanger, in the heating mode, the excess refrigerant can be stored in the stopped cold water heat exchanger, and in the heating main mode, the excess refrigerant can be stored in the gas-liquid separator, thereby avoiding the situation in which the refrigerant in the heat pump system is overcooled, causing the condensation temperature of the refrigerant to rise, thereby improving the heat exchange effect of the heat pump system.

[0007] In one example of the present invention, the first pipeline assembly includes a first branch pipe arranged between the external air heat exchanger and the second pipeline assembly, and a second branch pipe arranged between the second pipeline assembly and the third pipeline assembly, and the heat pump system also includes: a three-way pipe a, which is arranged at the connection between the third pipeline assembly and the second pipeline assembly to connect the second branch pipe, the second input pipe and the third input pipe; a switching valve a, which is arranged on the second branch pipe; wherein, when the switching valve a is in an open state, the third pipeline assembly is connected to the second pipeline assembly, and when the switching valve a is in a closed state, the connection between the third pipeline assembly and the second pipeline assembly is closed.

[0008] Compared with the prior art, the technical effect achieved by adopting this technical scheme is as follows: this scheme controls the opening and closing state of the switching valve a to accurately control the flow direction of the refrigerant medium in the second branch pipe when the heat pump system is executing the refrigeration main mode, refrigeration mode, heating mode, and heating main mode, thereby improving the heat exchange effect of the heat pump system.

[0009] In one example of the present invention, the first pipeline assembly also includes a third branch pipe, and the heat pump system also includes: a switching valve b, which is arranged at one end of the second input pipe close to the three-way pipe a; a switching valve c, which is arranged at one end of the second input pipe close to the first input pipe; wherein the third branch pipe is arranged between the switching valve b and the switching valve c, and when the switching valve b is in an open state and the switching valve c is in a closed state, the third branch pipe is used to connect the first connecting pipe and the second input pipe; when the switching valve b is in a closed state and the switching valve c is in an open state, the third branch pipe is used to connect the first connecting pipe and the third input pipe.

[0010] Compared with the prior art, the technical effect achieved by adopting this technical scheme is as follows: this scheme switches the flow direction of the refrigerant between the first connecting pipe and the second input pipe or the third input pipe by switching the opening and closing states of the switching valve b and the switching valve c, thereby avoiding unnecessary refrigerant circulation of the refrigerant, thereby reducing the energy consumption of the heat pump system, and further improving the heat exchange effect of the heat pump system.

[0011] In one example of the present invention, the circulation pipeline also includes: a second connecting pipe, which is used to connect the exhaust end of the compressor with the hot water heat exchanger; a fourth pipeline assembly, which is arranged on the air side of the external air heat exchanger, and the fourth pipeline assembly is connected to the second connecting pipe through the three-way pipe b; a switching valve d, which is arranged between the second connecting pipe and the three-way pipe b; a switching valve e, which is arranged between the external air heat exchanger and the three-way pipe b; wherein, when the switching valve d is in an open state and the switching valve e is in a closed state, the compressor is connected to the hot water heat exchanger; when the switching valve d is in a closed state and the switching valve e is in an open state, the compressor is connected to the external air heat exchanger; when the switching valve d and the switching valve e are both in an open state, the compressor is connected to the hot water heat exchanger and the external air heat exchanger, respectively.

[0012] Compared with the prior art, the technical effect achieved by adopting this technical scheme is as follows: this scheme controls the opening and closing states of the switching valve d and the switching valve e to switch the flow direction of the refrigerant medium flowing through the compressor, the hot water heat exchanger, and the outdoor air heat exchanger when the heat pump system operates in different modes, thereby improving the energy utilization efficiency of the heat pump system.

[0013] In one example of the present invention, the first pipeline assembly also includes a fourth branch pipe, one end of the fourth branch pipe is connected between the switching valve e and the external air heat exchanger, and the other end is connected to the third branch pipe and the first connecting pipe through the four-way valve b, and the circulation pipeline also includes: a switching valve f, the switching valve f is arranged on the fourth branch pipe; a switching valve g, the switching valve g is arranged at one end of the first connecting pipe close to the cold water heat exchanger; wherein, when the switching valve f is in an open state, the external air heat exchanger is connected to the gas-liquid separator, and when the switching valve f is in a closed state, the connection between the external air heat exchanger and the gas-liquid separator is closed; when the switching valve g is in an open state, the cold water heat exchanger is connected to the gas-liquid separator, and when the switching valve g is in a closed state, the connection between the cold water heat exchanger and the gas-liquid separator is closed.

[0014] Compared with the prior art, the technical effect achieved by adopting this technical scheme is as follows: this scheme controls the opening and closing states of the switching valve f and the switching valve g, and adjusts the connectivity between the gas-liquid separator and the external air heat exchanger or the cold water heat exchanger to ensure that the gas and liquid can be effectively separated in the heating mode, cooling mode, heating main mode or cooling main mode, thereby avoiding the situation where liquid enters the compressor and causes damage to the compressor, thereby extending the service life of the compressor.

[0015] In one example of the present invention, the first pipeline assembly is connected to the second pipeline assembly by a four-way valve a, and the heat pump system also includes: a first expansion valve, which is arranged on the first branch pipe; a switching valve h, which is arranged on the first branch pipe, and the switching valve h is connected in parallel with the first expansion valve; a second expansion valve, which is arranged at one end of the first input pipe close to the four-way valve a; and a switching valve i, which is arranged at one end of the output pipe close to the four-way valve a; wherein, when either the first expansion valve or the switching valve h is in an open state, the liquid side of the external air heat exchanger is connected to the first pipeline assembly.

[0016] Compared with the prior art, the technical effect achieved by adopting this technical scheme is as follows: this scheme regulates the flow rate of liquid refrigerant by setting a first expansion valve and a second expansion valve, thereby preventing the liquid refrigerant from entering the compressor, thereby avoiding liquid hammer and extending the service life of the compressor.

[0017] On the other hand, the present invention also provides a control method for a heat pump system, which is used to control a heat pump system as described in any of the above technical solutions, and the control method includes: obtaining refrigerant parameters of the refrigerant medium during the operation of the heat pump system according to the user-set mode; judging whether the refrigerant medium is in a supercooling state based on the refrigerant parameters; if the refrigerant is in a supercooling state, controlling the heat pump system to enter a refrigerant recovery mode; wherein the user-set mode includes a heating mode, a heating main mode, and a cooling mode.

[0018] Compared with the prior art, the technical effect achieved by adopting this technical scheme is as follows: this scheme can understand the state of the refrigerant in the system in real time by monitoring the refrigerant parameters of the refrigerant, thereby avoiding the instability of the system caused by overcooling of the refrigerant, and when it is detected that the refrigerant is in an overcooled state, the heat pump system is controlled to enter the refrigerant recovery mode, thereby avoiding the situation in which the refrigerant in the heat pump system is overcooled, causing the condensation temperature of the refrigerant to rise, thereby improving the heat exchange effect of the heat pump system.

[0019] In one example of the present invention, the refrigerant parameters include a first temperature of the refrigerant when it flows through the four-way valve a and a first pressure on the exhaust side of the compressor; based on the refrigerant parameters, determining whether the refrigerant is in a supercooling state includes: obtaining the saturation temperature of the refrigerant at the first pressure; based on the first temperature and the saturation temperature, obtaining the degree of supercooling of the refrigerant; and regulating the circulation pipeline based on the degree of supercooling so that the heat pump system enters the refrigerant recovery mode.

[0020] Compared with the prior art, the technical effect achieved by adopting this technical scheme is as follows: this scheme judges whether the refrigerant is in a supercooled state by the first temperature of the refrigerant when it flows through the four-way valve a, the first pressure on the exhaust side of the compressor, and the saturation temperature of the refrigerant at the first pressure, thereby improving the accuracy of the judgment result on the supercooling degree of the refrigerant.

[0021] In one embodiment of the present invention, when the user sets the mode to the cooling mode, the first expansion valve, the switching valve c, the switching valve d, the switching valve f and the switching valve i are all in a closed state, and the second expansion valve, the switching valve e, the switching valve g and the switching valve h are all in an open state; the circulation pipeline is regulated according to the supercooling degree, including: When A<A1, the switching valve b is controlled to open, and the switching valve a is controlled to close; When A>A2, the switching valve b is controlled to be closed, and the switching valve a is controlled to be opened; When A1≤A≤A2, the switching valve b and the switching valve a are controlled to be closed; Wherein, A is the degree of supercooling, A1 and A2 are preset values, and A1<A2.

[0022] Compared with the prior art, the technical effect achieved by adopting this technical scheme is as follows: in the cooling mode, this scheme accurately controls the flow direction of the refrigerant according to the supercooling degree of the refrigerant, thereby avoiding the situation where excess refrigerant is retained in the external air heat exchanger, resulting in excessive supercooling of the refrigerant and the condensation temperature of the refrigerant rising, thereby further improving the heat exchange effect of the heat pump system in the cooling mode.

[0023] In one embodiment of the present invention, when the user sets the mode to heating mode, the switching valve d, the first expansion valve and the switching valve f are all in an open state, and the switching valve a, the switching valve b, the switching valve e, the switching valve g, the switching valve h and the switching valve i are all in a closed state; the circulation pipeline is regulated according to the degree of supercooling, including: When A<A3, the second expansion valve is controlled to be closed, and the switching valve c is controlled to be opened; When A>A4, the second expansion valve is controlled to open, and the switching valve c is controlled to close; When A3≤A≤A4, the second expansion valve and the switching valve c are controlled to be closed; Wherein, A is the degree of supercooling, A3 and A4 are preset values, and A3<A4.

[0024] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: in the heating mode, this solution accurately controls the flow direction of the refrigerant medium according to the supercooling degree of the refrigerant medium, thereby avoiding excess refrigerant medium from being retained in the hot water heat exchanger, thereby further improving the heat exchange effect of the heat pump system in the heating mode.

[0025] In one embodiment of the present invention, when the user sets the mode to the heating main mode, the first expansion valve, the second expansion valve, the switching valve d, the switching valve f, the switching valve g and the switching valve i are all in an open state, and the switching valve a, the switching valve c, the switching valve e and the switching valve h are all in a closed state; the circulation pipeline is regulated according to the supercooling degree, including: When A<A5, the switching valve b is controlled to close; When A>A6, the control switching valve b is opened; Wherein, A is the degree of supercooling, A5 and A6 are preset values, and A5<A6.

[0026] Compared with the prior art, the technical effect achieved by adopting this technical scheme is as follows: in the main heating mode, this scheme accurately controls the flow direction of the refrigerant medium according to the supercooling degree of the refrigerant medium, thereby avoiding excess refrigerant medium from being retained in the hot water heat exchanger, thereby further improving the heat exchange effect of the heat pump system in the main heating mode.

[0027] After adopting the technical solution of the present invention, the following technical effects can be achieved: (1) The present invention provides a heat pump system, which is connected to the second pipe assembly and the third pipe assembly through a first pipe assembly, so that after the heat pump system is filled with the refrigerant required in the cooling main mode, in the cooling mode, the excess refrigerant can be stored in the stopped warm water heat exchanger, in the heating mode, the excess refrigerant can be stored in the stopped cold water heat exchanger, and in the heating main mode, the excess refrigerant can be stored in the gas-liquid separator, thereby avoiding the situation where the refrigerant in the heat pump system is too overcooled, causing the condensation temperature of the refrigerant to rise, thereby improving the heat exchange effect of the heat pump system; (2) A control method for a heat pump system, which can monitor the refrigerant parameters of the refrigerant to understand the state of the refrigerant in the system in real time, thereby avoiding system instability caused by overcooling of the refrigerant, and controlling the heat pump system to enter a refrigerant recovery mode when it is detected that the refrigerant is in an overcooled state, thereby avoiding the situation in which the refrigerant in the heat pump system is overcooled, causing the condensation temperature of the refrigerant to rise, thereby improving the heat exchange effect of the heat pump system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings to be used in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. Figure 1A schematic structural diagram of a heat pump device provided by an embodiment of the present invention; Figure 2 A schematic diagram of a refrigerant in a heat pump device provided by an embodiment of the present invention when operating in a cooling main mode; Figure 3 One of the schematic diagrams of a refrigerant in a heat pump device provided by an embodiment of the present invention when operating in a cooling mode; Figure 4 A second schematic diagram of a refrigerant in a heat pump device in a cooling mode provided by an embodiment of the present invention; Figure 5 A third schematic diagram of a refrigerant in a heat pump device in a cooling mode provided by an embodiment of the present invention; Figure 6 One of the schematic diagrams of a refrigerant in a heat pump device provided by an embodiment of the present invention when operating in a heating mode; Figure 7 A second schematic diagram of a refrigerant in a heat pump device in a heating mode provided by an embodiment of the present invention; Figure 8 A third schematic diagram of a refrigerant in a heat pump device in a heating mode provided by an embodiment of the present invention; Fig. 9 One of the schematic diagrams of a refrigerant in a heat pump device provided by an embodiment of the present invention when operating in a main heating mode; Fig.10 The second schematic diagram of the refrigerant of a heat pump device provided by an embodiment of the present invention when operating in a main heating mode.

[0029] Description of reference numerals: 100, compressor; 110, first pressure sensor; 200, hot water heat exchanger; 210, second connection end; 220, second water inlet; 230, second water outlet; 240, hot water temperature sensor; 300, outside air heat exchanger; 400, cold water heat exchanger; 410, first connection end; 420, first connecting pipe; 421, switching valve g; 430, second connecting pipe; 431, three-way pipe b; 432, switching valve d; 440, first water inlet; 450, first water outlet; 460, cold water temperature sensor; 500, gas-liquid separator; 510, second pressure sensor; 520, second temperature sensor; 600, first pipeline assembly; 6 10. First branch pipe; 611. Three-way pipe a; 612. First expansion valve; 613. Switching valve h; 620. Second branch pipe; 621. Switching valve a; 630. Third branch pipe; 640. Fourth branch pipe; 641. Switching valve f; 650. Four-way valve a; 660. Four-way valve b; 700. Second pipeline assembly; 710. Output pipe; 711. Switching valve i; 720. First input pipe; 721. Second expansion valve; 730. First temperature sensor; 800. Third pipeline assembly; 810. Second input pipe; 820. Third input pipe; 821. Switching valve b; 822. Switching valve c; 900. Fourth pipeline assembly; 910. Switching valve e. DETAILED DESCRIPTION

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0031] The technical problem solved by the present invention is that the refrigerant amount (here it refers to the volume L rather than the flow rate kg / s) of the refrigerant in the existing heat pump system is the largest in the refrigeration main mode. After the refrigerant is filled into the heat pump system, in other refrigeration modes, heating modes, and heating main modes, excess refrigerant liquid is retained in the condenser, resulting in excessive supercooling of the refrigerant, causing the condensation temperature of the refrigerant to rise, thereby affecting the heat exchange effect of the heat pump system.

[0032] To solve the above problems, on the one hand, Figures 1 to 10As shown, the present invention provides a heat pump device, which includes a compressor 100, a hot water heat exchanger 200, an outdoor air heat exchanger 300, a cold water heat exchanger 400, and a gas-liquid separator 500 connected by a circulation pipeline assembly for circulating a cooling medium, and the circulation pipeline assembly includes an output pipe 710, a first input pipe 720, a second input pipe 810, and a third input pipe 820. Among them, the output pipe 710 is arranged on the discharge side of the hot water heat exchanger 200, the first input pipe 720 is arranged at the first connection end 410 of the hot water heat exchanger 200, and the first input pipe 720 is connected to the output pipe 710, the second input pipe 810 is arranged at the second connection end 210 of the hot water heat exchanger 200, one end of the third input pipe 820 is connected to the first input pipe 720, and the other end is connected to the second input pipe 810, and the first pipeline assembly 600 arranged on the liquid side of the external air heat exchanger 300 is connected to the second pipeline assembly 700 composed of the first input pipe 720 and the output pipe 710, the third pipeline assembly 800 composed of the second input pipe 810 and the third input pipe 820, and the first connecting pipe 420 arranged between the cold water heat exchanger 400 and the gas-liquid separator 500.

[0033] This solution is connected to the second pipeline assembly 700 and the third pipeline assembly 800 through the first pipeline assembly 600, so that after the heat pump device is filled with the refrigerant amount required in the refrigeration main mode, in the refrigeration mode, the excess refrigerant can be stored in the stopped warm water heat exchanger, in the heating mode, the excess refrigerant can be stored in the stopped cold water heat exchanger 400, and in the heating main mode, the excess refrigerant can be stored in the gas-liquid separator 500, thereby avoiding the situation where the refrigerant in the heat pump device is too overcooled, causing the condensation temperature of the refrigerant to rise, thereby improving the heat exchange effect of the heat pump device.

[0034] Further, such as Figure 1 As shown, the first pipeline assembly 600 includes a first branch pipe 610 disposed between the outside air heat exchanger 300 and the second pipeline assembly 700, and a second branch pipe 620 disposed between the second pipeline assembly 700 and the third pipeline assembly 800, and the heat pump device further includes a three-way pipe a611 and a switching valve a621. The three-way pipe a611 is disposed at the connection between the third pipeline assembly 800 and the second pipeline assembly 700 to connect the second branch pipe 620, the second input pipe 810 and the third input pipe 820, and the switching valve a621 is disposed on the second branch pipe 620, and when the switching valve a621 is in an open state, the third pipeline assembly 800 is connected to the second pipeline assembly 700; when the switching valve a621 is in a closed state, the connection between the third pipeline assembly 800 and the second pipeline assembly 700 is closed.

[0035] This solution controls the opening and closing state of the switching valve a621 to accurately control the flow direction of the refrigerant medium in the second branch pipe 620 when the heat pump device is executing the cooling main mode, cooling mode, heating mode, and heating main mode, thereby improving the heat exchange effect of the heat pump device.

[0036] Further, such as Figure 1 As shown, the first pipeline assembly 600 further includes a third branch pipe 630, and the heat pump device further includes a switching valve b821 and a switching valve c822. The switching valve b821 is arranged at one end of the second input pipe 810 close to the three-way pipe a611, the switching valve c822 is arranged at one end of the second input pipe 810 close to the first input pipe 720, and the third branch pipe 630 is arranged between the switching valve b821 and the switching valve c822, and when the switching valve b821 is in an open state and the switching valve c822 is in a closed state, the third branch pipe 630 is used to connect the first connecting pipe 420 with the second input pipe 810; when the switching valve b821 is in a closed state and the switching valve c822 is in an open state, the third branch pipe 630 is used to connect the first connecting pipe 420 with the third input pipe 820.

[0037] This solution switches the flow direction of the refrigerant between the first connecting pipe 420 and the second input pipe 810 or the third input pipe 820 by switching the opening and closing states of the switching valve b821 and the switching valve c822, thereby avoiding unnecessary refrigerant circulation of the refrigerant, thereby reducing the energy consumption of the heat pump device and further improving the heat exchange effect of the heat pump device.

[0038] Furthermore, Figure 1 As shown, the circulation pipeline also includes a second connecting pipe 430, a fourth pipeline assembly 900, a switching valve d432, and a switching valve e910. Specifically, the second connecting pipe 430 is used to connect the exhaust end of the compressor 100 and the hot water heat exchanger 200, the fourth pipeline assembly 900 is arranged on the air side of the external air heat exchanger 300, and the fourth pipeline assembly 900 is connected to the second connecting pipe 430 through the three-way pipe b431, the switching valve d432 is arranged between the second connecting pipe 430 and the three-way pipe b431, and the switching valve e910 is arranged between the external air heat exchanger 300 and the three-way pipe b431; wherein, when the switching valve d432 is in an open state and the switching valve e910 is in a closed state, the compressor 100 is connected to the hot water heat exchanger 200; when the switching valve d432 is in a closed state and the switching valve e910 is in an open state, the compressor 100 is connected to the external air heat exchanger 300; when the switching valve d432 and the switching valve e910 are both in an open state, the compressor 100 is connected to the hot water heat exchanger 200 and the external air heat exchanger 300, respectively.

[0039] This solution controls the opening and closing states of the switching valve d432 and the switching valve e910 to switch the flow direction of the refrigerant medium flowing through the compressor 100, the hot water heat exchanger 200, and the outdoor air heat exchanger 300 when the heat pump device operates in different modes, thereby improving the energy utilization efficiency of the heat pump device.

[0040] Furthermore, Figure 1 As shown, the first pipeline assembly also includes a fourth branch pipe, one end of the fourth branch pipe is connected between the switching valve e and the external air heat exchanger, and the other end is connected to the third branch pipe and the first connecting pipe through the four-way valve b660, and the circulation pipeline also includes a fourth branch pipe 640, a switching valve f641, and a switching valve g421. Specifically, the switching valve f641 is arranged on the fourth branch pipe 640, and the switching valve g421 is arranged on one end of the first connecting pipe 420 close to the cold water heat exchanger 400; wherein, when the switching valve f641 is in an open state, the external air heat exchanger 300 is connected to the gas-liquid separator 500, and when the switching valve f641 is in a closed state, the connection between the external air heat exchanger 300 and the gas-liquid separator 500 is closed; when the switching valve g421 is in an open state, the cold water heat exchanger 400 is connected to the gas-liquid separator 500, and when the switching valve g421 is in a closed state, the connection between the cold water heat exchanger 400 and the gas-liquid separator 500 is closed.

[0041] This solution controls the opening and closing states of the switching valve f641 and the switching valve g421 to adjust the connectivity between the gas-liquid separator 500 and the external air heat exchanger 300 or the cold water heat exchanger 400, thereby ensuring that gas and liquid can be effectively separated in the heating mode, cooling mode, heating main mode or cooling main mode, thereby avoiding the situation where liquid enters the compressor 100 and causes damage to the compressor 100, thereby extending the service life of the compressor 100.

[0042] Furthermore, Figure 1 As shown, the first pipeline assembly 600 is connected to the second pipeline assembly 700 by a four-way valve a650, and the heat pump device further includes a first expansion valve 612, a second expansion valve 721, a switching valve h613, and a switching valve i711. Specifically, the first expansion valve 612 is arranged on the first branch pipe 610, the switching valve h613 is arranged on the first branch pipe 610, and the switching valve h613 is connected in parallel with the first expansion valve 612, the second expansion valve 721 is arranged on one end of the first input pipe 720 close to the four-way valve a650, and the switching valve i711 is arranged on one end of the output pipe 710 close to the four-way valve a650; wherein, when either the first expansion valve 612 or the switching valve h613 is in an open state, the liquid side of the external air heat exchanger 300 is connected to the first pipeline assembly 600.

[0043] This solution regulates the flow rate of the liquid refrigerant by setting the first expansion valve 612 and the second expansion valve 721 to prevent the liquid refrigerant from entering the compressor 100 , thereby avoiding liquid hammer and extending the service life of the compressor 100 .

[0044] Furthermore, Figure 1 As shown, the circulation pipeline assembly further includes a first pressure sensor 110 and a first temperature sensor 730. Specifically, the first pressure sensor 110 is disposed at the exhaust side of the compressor 100, and is used to detect the first pressure at the exhaust side of the compressor 100. The first temperature sensor 730 is disposed at the connection between the first pipeline assembly 600 and the second pipeline assembly 700, and is used to detect the first temperature when the refrigerant medium flows through the four-way valve a650. Furthermore, Figure 1 As shown, the circulation pipeline assembly also includes a second pressure sensor 510 and a second temperature sensor 520 arranged at one end of the first connecting pipe 420 close to the liquid-gas separator, which are used to detect the second temperature and the second pressure of the refrigerant before entering the liquid-gas separator; specifically, the second pressure sensor 510 and the second temperature sensor 520 are communicated with the first expansion valve 612 and the second expansion valve 721, so that when the heat pump device is executing the cooling mode, the cooling main mode or the heating main mode, the superheat of the heat pump device is adjusted by adjusting the opening of the second expansion valve 721; when the heat pump device is executing the heating mode, the superheat of the heat pump device is adjusted by adjusting the opening of the first expansion valve 612.

[0045] Furthermore, Figure 1 As shown, the cold water heat exchanger 400 is provided with a first water inlet 440 and a first water outlet 450, and a cold water temperature sensor 460 is provided at the first water outlet 450, and the cold water temperature sensor 460 is communicated with the compressor 100 and the first expansion valve 612, so that when the heat pump device operates in the cooling mode and the cooling main mode, the user adjusts the speed of the compressor 100 so that the measured value of the cold water temperature sensor 460 reaches the first preset value set by the user, and when the heat pump device operates in the heating main mode, the user adjusts the opening of the first expansion valve 612 so that the measured value of the cold water temperature sensor 460 reaches the second preset value set by the user.

[0046] Furthermore, Figure 1As shown, the hot water heat exchanger 200 is provided with a second water inlet 220 and a second water outlet 230, and a hot water temperature sensor 240 is provided at the second water outlet 230, and the hot water temperature sensor 240 is communicatively connected with the compressor 100 and the first expansion valve 612, so that when the heat pump device operates in the heating mode and the heating main mode, the user adjusts the speed of the compressor 100 so that the measured value of the hot water temperature sensor 240 reaches the third preset value set by the user; when the heat pump device operates in the cooling main mode, the user adjusts the opening of the first expansion valve 612 so that the measured value of the hot water temperature sensor 240 reaches the fourth preset value set by the user.

[0047] On the other hand, the present invention also provides a control method for a heat pump device, which is used to control the heat pump device as described in any of the above technical solutions, and the control method includes: obtaining the refrigerant parameters of the refrigerant medium during the operation of the heat pump device according to the user-set mode; judging whether the refrigerant medium is in a supercooling state based on the refrigerant parameters; if the refrigerant is in a supercooling state, controlling the heat pump device to enter a refrigerant recovery mode; wherein the user-set mode includes a heating mode, a heating main mode, and a cooling mode.

[0048] By monitoring the refrigerant parameters of the refrigerant, this solution can understand the state of the refrigerant in the system in real time, avoiding system instability caused by overcooling of the refrigerant, and controlling the heat pump device to enter the refrigerant recovery mode when it is detected that the refrigerant is in an overcooled state, thereby avoiding the situation where the refrigerant in the heat pump device is overcooled, causing the condensation temperature of the refrigerant to rise, thereby improving the heat exchange effect of the heat pump device.

[0049] Furthermore, the refrigerant parameters include a first temperature of the refrigerant when it flows through the four-way valve a650 and a first pressure on the exhaust side of the compressor 100; based on the refrigerant parameters, determining whether the refrigerant is in a supercooling state includes: obtaining the saturation temperature of the refrigerant at the first pressure; based on the first temperature and the saturation temperature, obtaining the degree of supercooling of the refrigerant; and regulating the circulation pipeline based on the degree of supercooling so that the heat pump device enters the refrigerant recovery mode.

[0050] This solution determines whether the refrigerant is in a supercooled state through the first temperature of the refrigerant when it flows through the four-way valve a650, the first pressure on the exhaust side of the compressor 100, and the saturation temperature of the refrigerant at the first pressure, thereby improving the accuracy of the judgment result on the supercooling degree of the refrigerant.

[0051] like Figure 2As shown, when the user sets the mode to the refrigeration main mode, the first expansion valve 612, the second expansion valve 721, the switching valve d432, the switching valve e910, the switching valve g421 and the switching valve i711 are all in the open state; the switching valve a621, the switching valve b821, the switching valve c822, the switching valve f641 and the switching valve h613 are all in the closed state, and the heat pump device does not perform supercooling control at this time.

[0052] Furthermore, Figures 3 to 5 As shown, when the user sets the mode to cooling mode, the first expansion valve 612, the switching valve c822, the switching valve d432, the switching valve f641 and the switching valve i711 are all in the closed state, and the second expansion valve 721, the switching valve e910, the switching valve g421 and the switching valve h613 are all in the open state; the circulation pipeline is regulated according to the supercooling degree, including: When A<A1, the switching valve b821 is controlled to open, and the switching valve a621 is controlled to close; When A>A2, the switching valve b821 is controlled to be closed, and the switching valve a621 is controlled to be opened; When A1≤A≤A2, the switching valve b821 and the switching valve a621 are controlled to be closed; Wherein, A is the degree of supercooling, A1 and A2 are preset values, and A1<A2.

[0053] It should be noted that, when A>A2, the switching valve b821 is controlled to be closed, and the switching valve a621 is controlled to be opened. At this time, the refrigerant medium flows from the circulating pipeline assembly to the stopped hot water heat exchanger 200 for temporary storage. When A<A1, the switching valve b821 is controlled to be opened, and the switching valve a621 is controlled to be closed. At this time, the refrigerant medium flows from the stopped hot water heat exchanger 200 to the circulating pipeline assembly for heat exchange. When A1≤A≤A2, the switching valve b821 and the switching valve a621 are controlled to be closed. At this time, the connection between the stopped hot water heat exchanger 200 and the circulating pipeline assembly is closed, so that the refrigerant medium can fully participate in the heat exchange work in the circulating pipeline assembly.

[0054] In the cooling mode, this solution accurately controls the flow direction of the refrigerant according to the supercooling degree of the refrigerant, thereby avoiding the situation where excess refrigerant is retained in the external air heat exchanger 300, resulting in excessive supercooling of the refrigerant and an increase in the condensation temperature of the refrigerant, thereby further improving the heat exchange effect of the heat pump device in the cooling mode.

[0055] Furthermore, Figures 6 to 8As shown, when the user sets the mode to heating mode, the switching valve d432, the first expansion valve 612 and the switching valve f641 are all in the open state, and the switching valve a621, the switching valve b821, the switching valve e910, the switching valve g421, the switching valve h613 and the switching valve i711 are all in the closed state; the circulation pipeline is regulated according to the supercooling degree, including: When A<A3, the second expansion valve 721 is controlled to be closed, and the switching valve c822 is controlled to be opened; When A>A4, the second expansion valve 721 is controlled to open, and the switching valve c822 is controlled to close; When A3≤A≤A4, the second expansion valve 721 and the switching valve c822 are controlled to be closed; Wherein, A is the degree of supercooling, A3 and A4 are preset values, and A3<A4.

[0056] It should be noted that, when A>A4, the second expansion valve 721 is controlled to open, and the switching valve c822 is controlled to close. At this time, the refrigerant medium flows from the circulation pipeline assembly to the stopped cold water heat exchanger 400 for temporary storage. When A<A3, the second expansion valve 721 is controlled to close, and the switching valve c822 is controlled to open. At this time, the refrigerant medium flows from the stopped cold water heat exchanger 400 to the circulation pipeline assembly for heat exchange. When A3≤A≤A4, the second expansion valve 721 and the switching valve c822 are controlled to close. At this time, the connection between the stopped hot water heat exchanger 400 and the circulation pipeline assembly is closed, so that all the refrigerant medium can participate in the heat exchange work in the circulation pipeline assembly.

[0057] In the heating mode, this solution precisely controls the flow direction of the refrigerant according to the supercooling degree of the refrigerant, thereby avoiding excess refrigerant from being retained in the hot water heat exchanger 200, thereby further improving the heat exchange effect of the heat pump device in the heating mode.

[0058] Furthermore, Fig. 9 and Fig.10 As shown, when the user sets the mode to the heating main mode, the first expansion valve 612, the second expansion valve 721, the switching valve d432, the switching valve f641, the switching valve g421 and the switching valve i711 are all in the open state, and the switching valve a621, the switching valve c822, the switching valve e910 and the switching valve h613 are all in the closed state; the circulation pipeline is regulated according to the supercooling degree, including: When A<A5, the switching valve b821 is controlled to be closed; When A>A6, the control switching valve b821 is opened; Wherein, A is the degree of supercooling, A5 and A6 are preset values, and A5<A6.

[0059] It should be noted that when A>A6, the switching valve b821 is controlled to be opened, and the refrigerant medium flows from the circulation pipeline assembly to the gas-liquid separator 500 for temporary storage. When A<A5, the switching valve b821 is controlled to be closed, and the refrigerant medium flows from the gas-liquid separator 500 to the circulation pipeline assembly for heat exchange.

[0060] In the heating main mode, this solution accurately controls the flow direction of the refrigerant according to the supercooling degree of the refrigerant, thereby avoiding excess refrigerant from being retained in the hot water heat exchanger 200, thereby further improving the heat exchange effect of the heat pump device in the heating main mode.

[0061] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A heat pump system, characterized in that: The heat pump system comprises a compressor (100), a hot water heat exchanger (200), an outside air heat exchanger (300), a cold water heat exchanger (400), and a gas-liquid separator (500) which are connected by a circulation pipeline assembly through which a cooling medium circulates. The circulation pipeline assembly comprises: an output pipe (710), the output pipe (710) being arranged on a discharge side of the hot water heat exchanger (200); a first input pipe (720), the first input pipe (720) being arranged at the first connection end (410) of the cold water heat exchanger (400), and the first input pipe (720) being in communication with the output pipe (710); A second input pipe (810), the second input pipe (810) being arranged at a second connection end (210) of the hot water heat exchanger (200); a third input pipe (820), one end of the third input pipe (820) being connected to the first input pipe (720), and the other end of the third input pipe (820) being connected to the second input pipe (810); The first pipeline assembly (600) arranged on the liquid side of the external air heat exchanger (300) is connected to the second pipeline assembly (700) composed of the first input pipe (720) and the output pipe (710), the third pipeline assembly (800) composed of the second input pipe (810) and the third input pipe (820), and the first connecting pipe (420) arranged between the cold water heat exchanger (400) and the gas-liquid separator (500).

2. The heat pump system according to claim 1, characterized in that: The first pipeline assembly (600) comprises a first branch pipe (610) arranged between the external air heat exchanger (300) and the second pipeline assembly (700), and a second branch pipe (620) arranged between the second pipeline assembly (700) and the third pipeline assembly (800). The heat pump system further comprises: a three-way pipe a (611), the three-way pipe a (611) being arranged at the connection between the third pipeline assembly (800) and the second pipeline assembly (700) so as to connect the second branch pipe (620), the second input pipe (810) and the third input pipe (820); a switching valve a (621), wherein the switching valve a (621) is arranged on the second branch pipe (620); When the switching valve a (621) is in an open state, the third pipeline assembly (800) is connected to the second pipeline assembly (700); when the switching valve a (621) is in a closed state, the connection between the third pipeline assembly (800) and the second pipeline assembly (700) is closed.

3. The heat pump system according to claim 2, characterized in that: The first pipeline assembly (600) further includes a third branch pipe (630), and the heat pump system further includes: a switching valve b (821), the switching valve b (821) being arranged at one end of the second input pipe (810) close to the three-way pipe a (611); a switching valve c (822), the switching valve c (822) being arranged at one end of the second input pipe (810) close to the first input pipe (720); The third branch pipe (630) is arranged between the switching valve b (821) and the switching valve c (822), and when the switching valve b (821) is in the open state and the switching valve c (822) is in the closed state, the third branch pipe (630) is used to connect the first connecting pipe (420) and the second input pipe (810); when the switching valve b (821) is in the closed state and the switching valve c (822) is in the open state, the third branch pipe (630) is used to connect the first connecting pipe (420) and the third input pipe (820).

4. The heat pump system according to claim 3, characterized in that: The circulation pipeline also includes: a second connecting pipe (430), the second connecting pipe (430) being used to connect the exhaust end of the compressor (100) and the hot water heat exchanger (200); a fourth pipeline assembly (900), the fourth pipeline assembly (900) being arranged on the gas side of the external air heat exchanger (300), and the fourth pipeline assembly (900) being in communication with the second connecting pipe (430) via a three-way pipe b (431); a switching valve d (432), the switching valve d (432) being arranged between the second connecting pipe (430) and the three-way pipe b (431); a switching valve e (910), the switching valve e (910) being arranged between the external air heat exchanger (300) and the three-way pipe b (431); When the switching valve d (432) is in the open state and the switching valve e (910) is in the closed state, the compressor (100) is connected to the hot water heat exchanger (200); when the switching valve d (432) is in the closed state and the switching valve e (910) is in the open state, the compressor (100) is connected to the external air heat exchanger (300); when the switching valve d (432) and the switching valve e (910) are both in the open state, the compressor (100) is connected to the hot water heat exchanger (200) and the external air heat exchanger (300), respectively.

5. The heat pump system according to claim 4, characterized in that: The first pipeline assembly (600) further comprises a fourth branch pipe (640), one end of the fourth branch pipe (640) being connected between the switching valve e (910) and the external air heat exchanger (300), and the other end of the fourth branch pipe (640) being connected to the third branch pipe (630) and the first connecting pipe (420) via a four-way valve b (660); the circulation pipeline further comprises: a switching valve f (641), the switching valve f (641) being arranged on the fourth branch pipe (640); a switching valve g (421), the switching valve g (421) being arranged at one end of the first connecting pipe (420) close to the cold water heat exchanger (400); When the switching valve f (641) is in the open state, the external air heat exchanger (300) is connected to the gas-liquid separator (500); when the switching valve f (641) is in the closed state, the connection between the external air heat exchanger (300) and the gas-liquid separator (500) is closed; when the switching valve g (421) is in the open state, the cold water heat exchanger (400) is connected to the gas-liquid separator (500); when the switching valve g (421) is in the closed state, the connection between the cold water heat exchanger (400) and the gas-liquid separator (500) is closed.

6. The heat pump system according to claim 3, characterized in that: The first pipeline assembly (600) and the second pipeline assembly (700) are connected via a four-way valve a (650), and the heat pump system further comprises: a first expansion valve (612), the first expansion valve (612) being arranged on the first branch pipe (610); a switching valve h (613), the switching valve h (613) being arranged on the first branch pipe (610), and the switching valve h (613) being connected in parallel with the first expansion valve (612); a second expansion valve (721), the second expansion valve (721) being arranged at one end of the first input pipe (720) close to the four-way valve a (650); a switching valve i (711), the switching valve i (711) being arranged at one end of the output pipe (710) close to the four-way valve a (650); When either the first expansion valve (612) or the switching valve h (613) is in an open state, the liquid side of the external air heat exchanger (300) is connected to the first pipeline assembly (600).

7. A control method for a heat pump system, characterized in that: The control method is used to control the heat pump system according to any one of claims 1 to 6, and the control method comprises: During the operation of the heat pump system according to the user-set mode, obtaining refrigerant parameters of the refrigerant medium; According to the refrigerant parameters, determining whether the refrigerant medium is in a supercooled state; If the refrigerant is in the supercooled state, controlling the heat pump system to enter a refrigerant recovery mode; The user setting modes include heating mode, heating main mode and cooling mode.

8. The control method according to claim 7, characterized in that: The refrigerant parameters include a first temperature of the refrigerant when it flows through the four-way valve a (650) and a first pressure on the exhaust side of the compressor (100); judging whether the refrigerant is in a supercooled state based on the refrigerant parameters includes: Obtaining the saturation temperature of the cold medium at the first pressure; Obtaining a degree of supercooling of the refrigerant medium according to the first temperature and the saturation temperature; The circulation pipeline is regulated according to the supercooling degree so that the heat pump system enters the refrigerant recovery mode.

9. The control method according to claim 8, characterized in that: When the user setting mode is the cooling mode, the first expansion valve (612), the switching valve c (822), the switching valve d (432), the switching valve f (641) and the switching valve i (711) are all in the closed state, and the second expansion valve (721), the switching valve e (910), the switching valve g (421) and the switching valve h (613) are all in the open state; and regulating the circulation pipeline according to the supercooling degree includes: When A<A1, the switching valve b (821) is controlled to be opened, and the switching valve a (621) is controlled to be closed; When A>A2, the switching valve b (821) is controlled to be closed, and the switching valve a (621) is controlled to be opened; When A1≤A≤A2, the switching valve b (821) and the switching valve a (621) are controlled to be closed; Wherein, A is the supercooling degree, A1 and A2 are preset values, and A1<A2.

10. The control method according to claim 8, characterized in that: When the user setting mode is the heating mode, the switching valve d (432), the first expansion valve (612) and the switching valve f (641) are all in the open state, and the switching valve a (621), the switching valve b (821), the switching valve e (910), the switching valve g (421), the switching valve h (613) and the switching valve i (711) are all in the closed state; the regulating the circulation pipeline according to the supercooling degree includes: When A<A3, the second expansion valve (721) is controlled to be closed, and the switching valve c (822) is controlled to be opened; When A>A4, the second expansion valve (721) is controlled to be opened, and the switching valve c (822) is controlled to be closed; When A3≤A≤A4, the second expansion valve (721) and the switching valve c (822) are controlled to be closed; Wherein, A is the supercooling degree, A3 and A4 are preset values, and A3<A4.

11. The control method according to claim 8, characterized in that: When the user setting mode is the heating main mode, the first expansion valve (612), the second expansion valve (721), the switching valve d (432), the switching valve f (641), the switching valve g (421) and the switching valve i (711) are all in the open state, and the switching valve a (621), the switching valve c (822), the switching valve e (910) and the switching valve h (613) are all in the closed state; the regulating the circulation pipeline according to the supercooling degree includes: When A<A5, the switching valve b (821) is controlled to be closed; When A>A6, the switching valve b (821) is controlled to open; Wherein, A is the supercooling degree, A5 and A6 are preset values, and A5<A6.

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