Refrigerant adjustable heat pump water heater

Abstract

This application relates to the field of heat pump technology, specifically providing a heat pump water heater with adjustable refrigerant. The condenser assembly of the heat pump water heater includes a condenser water supply pipeline and a condenser refrigerant pipeline capable of exchanging heat with each other. The refrigerant circulating in the refrigerant circuit of the heat pump water heater is a mixed refrigerant. The condenser assembly includes a first condenser and a second condenser capable of exchanging heat with each other. The condenser refrigerant pipeline includes first / second condenser refrigerant pipelines connected in series. The heat pump system further includes: a regulating tank, which can be rotated to connect the nodes between the refrigerant pipelines, and the outlet of the regulating tank can be connected to the refrigerant circuit of the heat pump system; and a regenerator, which can be connected to the first / second condenser refrigerant pipelines so as to: use the recovered condensation heat to heat the low-pressure refrigerant in the refrigerant circuit.

Description

Technical Field

[0001] This application relates to the field of heat pump technology, specifically providing a heat pump water heater with adjustable refrigerant. Background Technology

[0002] Traditional heat pump water heaters use a single refrigerant (such as R32 or R290) or a mixed refrigerant with a small boiling point difference (such as R410a). Due to the limitations of the compressor pressure ratio (usually within 15) and exhaust temperature limit (usually within 110℃) in the heat pump system, the supply water temperature of the heat pump water heater is difficult to exceed 70℃, and the heating efficiency is low at this temperature.

[0003] To achieve high temperature rise heating of water supply (e.g., inlet temperature 15℃, outlet temperature >90℃), Chinese invention patent application (CN105157274A) discloses a refrigeration / heating system, including a compressor, a condenser / heater, a preheating regenerator, a subcooling regenerator, a first throttling element, and an evaporator. The high-pressure outlet of the compressor is connected to the refrigerant inlet of the condenser / heater, the refrigerant outlet of the condenser / heater is connected to the high-pressure inlet of the preheating regenerator, the high-pressure outlet of the preheating regenerator is connected to the high-pressure inlet of the subcooling regenerator, the high-pressure outlet of the subcooling regenerator is connected to the inlet of the first throttling element, and the outlet of the first throttling element is connected to the evaporator. The evaporator's inlet and outlet are connected to the low-pressure inlet of the subcooling regenerator, which in turn is connected to the low-pressure inlet of the preheating regenerator. The low-pressure outlet of the preheating regenerator is connected to the compressor inlet, forming a refrigeration cycle loop. The evaporator can output cooling capacity. The condenser / heater also includes a fluid inlet and a fluid outlet. The preheating regenerator also includes a fluid inlet and a fluid outlet. The fluid inlet of the preheating regenerator receives the fluid to be heated, and the fluid outlet of the preheating regenerator is connected to the fluid inlet of the condenser / heater. The fluid outlet of the condenser / heater is a hot fluid outlet, forming a fluid heating pipeline for heating the fluid. It can be seen that in this literature, the system uses multiple regenerators, and the preheating regenerator is a three-flow heat exchanger, making its structure relatively complex. Summary of the Invention

[0004] This application aims to solve at least part of the above-mentioned technical problems and / or at least part of the above-mentioned technical problems, specifically, how to maximize the water supply temperature of a heat pump water heater, and under this premise, simplify the system structure as much as possible.

[0005] In view of this, this application provides a refrigerant-adjustable heat pump water heater, characterized in that the heat pump water heater includes a heat pump system, the heat pump system includes a compressor, a condenser assembly, a throttling element, and an evaporator, the compressor, the condenser assembly, the throttling element, and the evaporator can form a refrigerant circuit, the refrigerant circulating in the refrigerant circuit is a mixed refrigerant, the condenser assembly includes a condenser water supply pipe and a condenser refrigerant pipe that can exchange heat with each other, the condenser water supply pipe can provide hot water, the condenser assembly includes a first condenser and a second condenser, and the condenser refrigerant pipe includes components connected in series to form the first condenser... The heat pump system includes a first condenser refrigerant line and a second condenser refrigerant line constituting the second condenser. It further includes: a regulating tank (such as a storage tank, gas-liquid separator, etc.) with its inlet connected to the node between the first and second condenser refrigerant lines; the outlet of the regulating tank being connectable to the refrigerant circuit of the heat pump system, thereby replenishing the refrigerant circuit; and a regenerator connected to the first and / or second condenser refrigerant lines to heat the low-pressure refrigerant in the refrigerant circuit using the refrigerant flowing through the first and / or second condenser refrigerant lines.

[0006] This configuration allows for several advantages. First, it improves the heating performance of the heat pump water heater by supplementing the low-pressure refrigerant with a regenerator. For example, the refrigerant lines for the first and second condensers can be the same or different, and the specific connection method can be flexibly chosen based on actual needs. Second, compared to single-component refrigerants, a mixed refrigerant containing both high-boiling-point and low-boiling-point refrigerants with a large boiling point difference increases the refrigerant's phase change temperature. Furthermore, by using a regulating tank, the mixed refrigerant can flexibly circulate within the refrigerant circuit, thereby further improving the heating performance of the heat pump water heater.

[0007] It is understood that those skilled in the art can determine the nodes between the inlet / outlet of the regulating tank and the refrigerant lines of the first and second condensers, as well as the specific connection locations and methods in the refrigerant circuit of the heat pump system, according to actual needs. For example, the connection can be switched between connected and disconnected states using one or more control valves, or it can be kept constantly connected. Furthermore, those skilled in the art can determine the specific components of the high-boiling-point and low-boiling-point refrigerants in the mixed refrigerant, their ratio, and the difference in boiling points, etc., according to actual needs.

[0008] In one possible implementation of the above-mentioned heat pump water heater with adjustable refrigerant, the condenser water supply pipeline includes a first condenser water supply pipeline constituting the first condenser and a first condenser water supply pipeline constituting the second condenser, which are connected in series with each other, wherein, when viewed along the water supply path of the heat pump water heater, the first condenser water supply pipeline is located downstream of the second condenser water supply pipeline.

[0009] With this configuration, hot water can be supplied to users downstream of the first condenser water supply line. The first condenser can also be called the high-temperature section condenser, and the second condenser can be called the low-temperature section condenser.

[0010] In one possible implementation of the above-mentioned refrigerant-adjustable heat pump water heater, the heat pump system further includes a control valve assembly comprising: an outgoing control valve capable of switching the connection state between the inlet of the regulating tank and the node between the first condenser refrigerant line and the second condenser refrigerant line; and at least one incoming control valve capable of switching the connection state between the outlet of the regulating tank and the refrigerant circuit.

[0011] This configuration allows for flexible adjustment of the mixed refrigerant circulating in the refrigerant circuit by controlling the on / off state and specific opening degree of the refrigerant discharge / recharge control valve. For example, the refrigerant discharge / recharge control valve can be a solenoid valve.

[0012] In one possible implementation of the above-mentioned heat pump water heater with adjustable refrigerant, the at least one replenishment control valve includes a first replenishment control valve and a second replenishment control valve. The gaseous and liquid portions of the refrigerant in the regulating tank can be replenished to the low-pressure side of the refrigerant circuit via the first and second replenishment control valves, respectively (e.g., they can be replenished to any position in the refrigerant circuit located between the throttling element and the suction port of the compressor).

[0013] This configuration allows for the creation of refrigerant mixtures better suited to current needs and provides possible locations for the refrigerant mixture to be added to the low-pressure side, such as the same or different locations for the gaseous and liquid components.

[0014] Specifically, the mixed refrigerant has a high content of low-boiling-point refrigerant in the gaseous portion and a high content of high-boiling-point refrigerant in the liquid portion. By adjusting the on / off state and specific opening degree of the two injection control valves, it is expected that the mixed refrigerant currently circulating in the heat pump system can be better adapted to the drying requirements of the heat pump system.

[0015] In one possible implementation of the above-mentioned refrigerant-adjustable heat pump water heater, both the gaseous and liquid portions of the refrigerant in the regulating tank can be supplied to the refrigerant circuit at the position corresponding to the compressor's suction port; or both the gaseous and liquid portions of the refrigerant in the regulating tank can be supplied to the refrigerant circuit at the position between the evaporator and the regenerator; or the gaseous portion of the refrigerant in the regulating tank can be supplied to the refrigerant circuit at the position corresponding to the compressor's suction port, and the liquid portion of the refrigerant in the regulating tank can be supplied to the refrigerant circuit at the position between the evaporator and the regenerator; or the gaseous portion of the refrigerant in the regulating tank can be supplied to the refrigerant circuit at the position between the evaporator and the regenerator, and the liquid portion of the refrigerant in the regulating tank can be supplied to the refrigerant circuit at the position between the throttling element and the evaporator.

[0016] This configuration provides a possible way to replenish the refrigerant mixture in the refrigerant circuit of a heat pump system.

[0017] In one possible implementation of the above-mentioned refrigerant-adjustable heat pump water heater, the control valve assembly includes a first control valve, and the regenerator includes a first regenerator pipe and a second regenerator pipe capable of exchanging heat with each other. A first end of the first control valve is connected to a node between the first condenser refrigerant pipe and the second condenser refrigerant pipe, and a second end of the control valve is connected to the first regenerator pipe. The compressor, the first condenser refrigerant pipe, the second condenser refrigerant pipe, the throttling element, the evaporator, the second regenerator pipe, and the compressor can be sequentially connected to form a first refrigerant circuit. Alternatively, the compressor, the first condenser refrigerant pipe, the first control valve, the first regenerator pipe, the throttling element, the evaporator, and the second regenerator pipe can be sequentially connected to form a second refrigerant circuit.

[0018] This configuration allows for the use of the condensation heat recovered from the refrigerant lines of the first condenser to heat the low-pressure refrigerant in the first / second refrigerant circuits, thereby ensuring the heating performance of the heat pump system.

[0019] In one possible implementation of the above-mentioned heat pump water heater with adjustable refrigerant, the control valve assembly includes a second control valve disposed between the first condenser refrigerant line and the second condenser refrigerant line.

[0020] In one possible implementation of the aforementioned refrigerant-adjustable heat pump water heater, the heat pump water heater includes or is equipped with a controller, which is used to: open both the first control valve and the second control valve so that: a portion of the refrigerant circulates through the compressor's exhaust port - the first condenser refrigerant line - the second control valve - the second condenser refrigerant line - the throttling element - the evaporator - the second regenerator line - the compressor's suction port; another portion of the refrigerant circulates through the compressor's exhaust port - the first condenser refrigerant line - the first control valve - the first regenerator line - the throttling element - the evaporator - the second regenerator line - the compressor's suction port, thereby: the condensation heat recovered by the first regenerator line heats the low-pressure refrigerant flowing through the second regenerator line.

[0021] This configuration allows for the preservation of the heat pump system's heating performance through heat recovery treatment.

[0022] It is understood that those skilled in the art can determine the operating parameters of the first / second control valve, such as the opening degree and opening duration, according to actual needs. For example, under the condition that the logic is satisfied, it can be opened at a fixed opening degree, or it can be opened in an adjustable manner, or it can be operated in a way that switches between opening and closing (opening intermittently). For example, the opening degree of the first / second control valve can be dynamically adjusted according to actual needs (such as water supply temperature).

[0023] In one possible implementation of the aforementioned refrigerant-adjustable heat pump water heater, the heat pump water heater includes or is equipped with a controller, which is used to: open the first control valve and close the second control valve, so that: the refrigerant circulates through the compressor's exhaust port - the first condenser refrigerant line - the first control valve - the first regenerator line - the throttling element - the evaporator - the second regenerator line - the compressor's suction port; thereby: the condensation heat recovered by the first regenerator line heats the low-pressure refrigerant flowing through the second regenerator line.

[0024] This configuration allows for ensuring the heating performance of the heat pump system by utilizing only the high-temperature condenser as an effective component of the condenser assembly and subjecting it to regenerative heating. Operating parameters such as the opening degree and duration of the first control valve can be flexibly determined according to actual needs.

[0025] In one possible implementation of the control method for the above-mentioned refrigerant-adjustable heat pump water heater, the heat pump water heater includes or is equipped with a controller, which is used to: close the first control valve and open the second control valve so that: the compressor, the first condenser refrigerant line, the second control valve, the second condenser refrigerant line, the throttling element, the evaporator, the second regenerator line, and the compressor form a refrigerant circuit.

[0026] This configuration allows for the maintenance of the heat pump system's heating capacity while eliminating regeneration and using a mixed refrigerant. In this configuration, the second regenerator piping functions as a non-functional refrigerant passage. Operating parameters such as the opening degree and duration of the second control valve can be flexibly determined based on actual needs.

[0027] In a preferred embodiment of the present invention, the above three control logics can be combined and used in combination according to actual needs during the process of providing hot water to users.

[0028] Based on the preferred embodiment of this application, by configuring the condenser assembly to include two independent condensers and selecting a mixed refrigerant, the low-pressure refrigerant can be heated by recovering condensation heat through the setting of the first / second control valve, thereby ensuring the heating effect. By setting the out / inlet control valve, the amount / component / ratio of refrigerant in the refrigerant circuit can be adjusted, thereby allowing the refrigerant currently circulating in the refrigerant circuit to better adapt to the current heating demand.

[0029] Because the heat pump water heater in this application improves the heating efficiency of the heat pump system, it can significantly increase the hot water temperature. Experiments show that, based on the preferred embodiment of this application, the supply water temperature of the heat pump water heater can exceed 80°C (e.g., even reaching above 90°C). This allows for several advantages: firstly, the increased supply water temperature reduces the volume of the heat pump water heater's tank; secondly, it enables further heating of the water at the current supply temperature to meet the requirements for direct drinking water. Attached Figure Description

[0030] The preferred embodiments of this application will now be described with reference to the accompanying drawings, in which:

[0031] Figure 1 This paper shows a schematic diagram of the structure of a refrigerant-adjustable heat pump water heater according to an embodiment of the present application, and the figure shows the first and second control valves;

[0032] Figure 2 This illustration shows a structural diagram of a heat pump water heater according to an embodiment of the present application, used for adjusting the mixed refrigerant in the heat pump system. Figure 1 ;

[0033] Figure 3 This illustration shows a structural diagram of a heat pump water heater according to an embodiment of the present application, used for adjusting the mixed refrigerant in the heat pump system. Figure 2 ;as well as

[0034] Figure 4 This illustration shows a structural diagram of a heat pump water heater according to an embodiment of the present application, used for adjusting the mixed refrigerant in the heat pump system. Figure 3 ;as well as

[0035] Figure 5 This illustration shows a structural diagram of a heat pump water heater according to an embodiment of the present application, used for adjusting the mixed refrigerant in the heat pump system. Figure 4 .

[0036] List of reference numerals in the attached diagram:

[0037] 100. Heat pump water heater;

[0038] 1. Compressor;

[0039] 2. Condenser assembly;

[0040] 201. First condenser; 202. Second condenser;

[0041] 21. Condenser water supply pipeline;

[0042] 211. Water supply line for the first condenser; 212. Water supply line for the second condenser;

[0043] 22. Condenser refrigerant piping;

[0044] 221. Refrigerant piping for the first condenser; 222. Refrigerant piping for the second condenser;

[0045] 3. Throttling element;

[0046] 4. Evaporator;

[0047] 5. Regenerator;

[0048] 51. First regenerator piping; 52. Second regenerator piping;

[0049] 61. First control valve; 62. Second control valve;

[0050] 7. Regulating tank;

[0051] 71. Turn out control valve;

[0052] 721. First replenishment control valve; 722. Second replenishment control valve. Detailed Implementation

[0053] Preferred embodiments of this application will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of this application and are not intended to limit the scope of protection of this application.

[0054] It should be noted that in the description of this application, terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. These are used merely for ease of description and do not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0055] Furthermore, it should be noted that, in the description of this application, unless otherwise expressly specified and limited, the terms "installation," "setup," and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection, an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0056] Furthermore, to better illustrate this application, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that this application can be implemented even without certain specific details. In some instances, the principles of heat pump systems well-known to those skilled in the art are not described in detail, in order to highlight the main points of this application.

[0057] In this application, on the one hand, the condenser in a traditional heat pump system is adjusted to two independent condensers connected in series, and on this basis, a control valve assembly and a regenerator are added; on the other hand, the single-component refrigerant is replaced with a mixed refrigerant. The following description, in conjunction with the accompanying drawings, illustrates how this application improves the heating performance of the heat pump system.

[0058] Example 1

[0059] Main reference Figure 1 and Figure 2In one possible implementation, the heat pump water heater 100 mainly includes a heat pump system, which mainly includes a compressor 1, a condenser assembly 2, a throttling element (such as an electronic expansion valve) 3, an evaporator 4, and a regenerator 5. The condenser assembly 2 includes a first condenser 201 and a second condenser 202, and has a heat-exchangeable condenser water supply line 21 and a condenser refrigerant line 22. The condenser water supply line 21 includes a first condenser water supply line 211 forming the first condenser and a second condenser water supply line 202 connected in series. The second condenser water supply pipe 212 of the condenser provides hot water to the user from the first condenser water supply pipe 211. Therefore, the first condenser and the second condenser may be referred to as the high-temperature section condenser and the low-temperature section condenser, respectively. The condenser refrigerant pipe 22 includes the first condenser refrigerant pipe 221 and the second condenser refrigerant pipe 222, which are connected in series and constitute the first condenser. The internal pipes of the regenerator 5 include the first regenerator pipe 51 and the second regenerator pipe 52, which can exchange heat. If water at approximately 15°C is introduced into the inlet side of the condenser water supply pipe 21 (first condenser water supply pipe 211), and heat is exchanged with the condenser refrigerant pipes, drinking water at a temperature greater than 90°C can be provided to the user on the supply side. A heat source pipe that can exchange heat with the evaporator refrigerant pipes is configured on the evaporator. The specific structure of the heat pump system is as follows:

[0060] The compressor's discharge port is connected to the first end of the first condenser refrigerant line, the second end of the first condenser refrigerant line is connected to the first end of the second condenser refrigerant line, the second end of the second condenser refrigerant line is connected to the first end of the throttling element, the second end of the throttling element is connected to the first end of the evaporator (of the evaporator refrigerant line), the second end of the evaporator is connected to the first end of the second regenerator line, and the second end of the second regenerator line is connected to the compressor's suction port.

[0061] The first end of the first regenerator pipe is connected to the node between the first condenser refrigerant pipe and the second condenser refrigerant pipe, and the second end of the first regenerator pipe is connected to the first end of the throttling element.

[0062] In one possible implementation, the heat pump system 100 further includes a control valve assembly. In this example, the control valve assembly includes a first control valve 61 and a second control valve 62. A first end of the first control valve 61 is connected to a node between the first condenser refrigerant line 221 and the second condenser refrigerant line 222, and a second end of the first control valve 61 is connected to a first end of the first regenerator line. In other words, the first control valve 61 is located on the refrigerant line between the node between the first and second condenser refrigerant lines and the first regenerator line. The second control valve 62 is located between the first condenser refrigerant line 221 and the second condenser refrigerant line 222. This allows the circulation mode of the mixed refrigerant within the heat pump system to be adjusted by switching the on / off states of the first and second control valves and by adjusting the on / off states and specific opening degrees of the first and second valves. Specifically:

[0063] (1) When both the first and second control valves are open, the compressor's discharge port, after being connected to the first end of the refrigerant pipeline of the first condenser, splits into a first refrigerant branch and a second refrigerant branch. After the first and second refrigerant branches merge, they are sequentially connected to the throttling element, the evaporator, and the compressor's suction port, forming a refrigerant circuit. Wherein:

[0064] The first refrigerant branch includes: the second end of the first condenser refrigerant line is connected to the first end of the first regenerator line via a control valve, and the second end of the first regenerator line is connected to the first end of the throttling element;

[0065] The second refrigerant branch includes: the second end of the first condenser refrigerant line is connected to the first end of the second condenser refrigerant line, and the second end of the second condenser refrigerant line is connected to the first end of the throttling element.

[0066] Based on this, the amount of mixed refrigerant flowing through the first regenerator pipe can be adjusted by regulating the specific opening degree of the control valve in the connected state. On this basis, it is expected that the condensation heat in the first regenerator pipe can be used to fully heat the low-pressure refrigerant entering the second regenerator pipe, thereby ensuring the heating effect of the heat pump system and potentially achieving a significant increase in the water supply temperature of the water heater (the temperature of the drinking water flowing out from the supply side of the condenser water supply pipe).

[0067] (2) When the first control valve 61 is open and the second control valve 62 is closed, the compressor's discharge port is connected to the first end of the refrigerant line of the first condenser, the second end of the refrigerant line of the first condenser is connected to the first end of the refrigerant line of the first regenerator, the second end of the refrigerant line of the first regenerator is connected to the first end of the throttling element, the second end of the throttling element is connected to the first end of the evaporator, the second end of the evaporator is connected to the first end of the refrigerant line of the second regenerator, and the second end of the refrigerant line of the second regenerator is connected to the compressor's suction port. In this case, only the first condenser is in the refrigerant circuit of the heat pump system. Based on this, the heating effect of the heat pump system is improved by synchronously recovering condensation heat.

[0068] (3) When the first control valve 61 is closed and the second control valve 62 is open, the compressor's discharge port is connected to the first end of the first condenser refrigerant line, the second end of the first condenser refrigerant line is connected to the first end of the second condenser refrigerant line, the second end of the second condenser refrigerant line is connected to the first end of the throttling element, the second end of the throttling element is connected to the first end of the evaporator, the second end of the evaporator is connected to the first end of the second regenerator line, and the second end of the second regenerator line is connected to the compressor's suction port. In this case, since there is no recoverable condensation heat in the first regenerator line, the second regenerator line is essentially a closed circuit.

[0069] In addition, this application also introduces mixed refrigerants in order to change the heating effect of the heat pump system by means of refrigerant adjustment and condensation heat recovery.

[0070] In a preferred embodiment of this application, the mixed refrigerant uses a mixed refrigerant with a large boiling point difference. For example, the mixed refrigerant typically includes at least two refrigerants. During condensation and phase change, the phase change temperature of the mixed refrigerant can reach over 70°C, decreasing to 20°C. Specifically, the low-boiling-point refrigerant in the mixed refrigerant can be refrigerants with a normal pressure boiling point ≤-20°C, such as R290 or R1270, while the high-boiling-point refrigerant can be refrigerants with a normal pressure boiling point greater than -20°C, such as R600a or pentane. The molar concentration of the low-boiling-point refrigerant is ≥50%. This large phase change temperature can match the temperature rise during the water supply process of the heat pump water heater; for example, the temperature of the airflow heated by the condenser can rise to over 70°C. In contrast, conventional refrigerants undergo isothermal condensation, resulting in a large heat exchange temperature difference and significant irreversible heat loss. In this application, by using a mixed refrigerant with phase change temperature glide, the changing condensation temperature can be better matched with the temperature rise required in the water supply process, thereby reducing irreversible heat loss due to heat exchange temperature difference and thus improving the heating efficiency of the heat pump system.

[0071] In one possible implementation, the heat pump water heater 100 also includes a regulating tank 7, the inlet of which is connected to a node between the first condenser refrigerant line and the second condenser refrigerant line, thereby recovering / transferring a portion of the mixed refrigerant from the refrigerant circuit. The outlet of the regulating tank 7 can be connected to the low-pressure side of the refrigerant circuit of the heat pump system, thereby replenishing the refrigerant circuit with mixed refrigerant. Accordingly, the control valve assembly also includes a transfer / at least one replenishment control valve for implementing mixed refrigerant regulation.

[0072] In this example, the regulating tank 7 is equipped with a transfer control valve 71 on the pipeline between its inlet and the refrigerant circuit. When it is necessary to recover / transfer the mixed refrigerant, the transfer control valve 71 can be opened. The regulating tank 7 is equipped with a first replenishment control valve 721 and a second replenishment control valve 722 on the pipeline between its outlet and the low-pressure side of the refrigerant circuit. For example, the gaseous portion of the mixed refrigerant in the regulating tank 7 is replenished to the low-pressure side of the refrigerant circuit via the first replenishment control valve 721, and the liquid portion of the mixed refrigerant in the regulating tank 7 is replenished to the low-pressure side of the refrigerant circuit via the second replenishment control valve 722. Thus, when it is necessary to replenish the refrigerant circuit with mixed refrigerant, the first replenishment control valve and / or the second replenishment control valve can be opened. If the gaseous portion contains a high content of low-boiling-point refrigerant and the liquid portion contains a high content of high-boiling-point refrigerant, by adjusting the on / off state and specific opening degree of the two injection control valves, it is hoped that the mixed refrigerant currently circulating in the heat pump system can be better adapted to the water supply needs of the heat pump water heater.

[0073] In this example, the first / second replenishment control valve is located in the refrigerant line between the throttling element 3 and the evaporator 4. In this embodiment, the gaseous and liquid portions of the refrigerant in the regulating tank are replenished into the low-pressure side of the refrigerant circuit, corresponding to the compressor's suction port, via the first / second replenishment control valve. If the gaseous portion of the refrigerant in the regulating tank has a high content of low-boiling-point refrigerant, while the liquid portion has a high content of high-boiling-point refrigerant, the composition ratio of the mixed refrigerant replenished into the refrigerant circuit can be flexibly modulated by adjusting the opening of the two second control valves.

[0074] Example 2

[0075] Main reference Figure 3 In this embodiment, the gaseous and liquid portions of the refrigerant in the regulating tank 7 are respectively supplied to the low-pressure side of the refrigerant circuit, located between the evaporator 4 and the regenerator 5, via the first / second supply control valves. Other parts are largely the same as in Embodiment 1 and will not be described again here.

[0076] Example 3

[0077] Main reference Figure 4 In this embodiment, the gaseous portion of the refrigerant in the regulating tank 7 is supplied to the low-pressure side of the refrigerant circuit via the first supply control valve 721, corresponding to the suction port of the compressor 1. The liquid portion of the refrigerant in the regulating tank 7 is supplied to the low-pressure side of the refrigerant circuit via the second supply control valve 722, located between the evaporator 4 and the regenerator 5. The other parts are largely the same as in Embodiment 1, and will not be described again here.

[0078] Example 4

[0079] Main reference Figure 5 In this embodiment, the gaseous portion of the refrigerant in the regulating tank 7 is supplied to the low-pressure side of the refrigerant circuit, located between the evaporator 4 and the regenerator 5, via the first supply control valve 721. The liquid portion of the refrigerant in the regulating tank 7 is supplied to the low-pressure side of the refrigerant circuit, located between the throttling element 3 and the evaporator 4, via the second supply control valve 722. The other parts are largely the same as in Embodiment 1 and will not be described again here.

[0080] As can be seen, in the preferred embodiment of this application, on the one hand, based on the first / second control valves in the set regenerator and control valve assembly, the condensation heat recovered from this part of the mixed refrigerant can be used to supplement the heating of the low-pressure refrigerant at the evaporator outlet by drawing out a portion of the mixed refrigerant and forming a new circuit, thereby turning the low-pressure refrigerant into a gaseous state and entering the compressor, thus ensuring the heating effect of the heat pump system. On the other hand, based on the mixed refrigerant used in this application (replacing the single-component refrigerant with a mixed refrigerant, increasing the phase change temperature of the refrigerant) and the set out transfer control valve / injection control valve (which can flexibly adjust the quality of the refrigerant by adjustment), it is expected that by adjusting the amount / components / ratio of the refrigerant, the phase change temperature of the refrigerant can be better adapted to the actual water supply demand.

[0081] The technical solutions of this application have been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of this application.

Claims

1. A heat pump water heater with adjustable refrigerant, characterized in that, The heat pump water heater includes a heat pump system, which comprises a compressor, a condenser assembly, a throttling element, and an evaporator. The compressor, the condenser assembly, the throttling element, and the evaporator can form a refrigerant circuit, and the refrigerant circulating in the refrigerant circuit is a mixed refrigerant. The condenser assembly includes condenser water supply lines and condenser refrigerant lines capable of exchanging heat with each other. The condenser water supply lines are capable of providing hot water. The condenser assembly includes a first condenser and a second condenser, and the condenser refrigerant piping includes a first condenser refrigerant piping constituting the first condenser and a second condenser refrigerant piping constituting the second condenser, which are connected in series with each other. The heat pump system also includes: A regulating tank, the inlet of which is connected to the node between the first condenser refrigerant line and the second condenser refrigerant line, and the outlet of which can be connected to the refrigerant circuit of the heat pump system, thereby replenishing the refrigerant circuit; A regenerator, which can be connected to the refrigerant line of the first condenser and / or the refrigerant line of the second condenser, so as to: The low-pressure refrigerant in the refrigerant circuit is heated by the refrigerant flowing through the refrigerant line of the first condenser and / or the refrigerant line of the second condenser.

2. The refrigerant-adjustable heat pump water heater according to claim 1, characterized in that, The condenser water supply pipeline includes a first condenser water supply pipeline constituting the first condenser and a first condenser water supply pipeline constituting the second condenser, which are connected in series. When viewed along the water supply path of the heat pump water heater, the first condenser water supply pipeline is located downstream of the second condenser water supply pipeline.

3. The refrigerant-adjustable heat pump water heater according to claim 1, characterized in that, The heat pump system further includes a control valve assembly, which comprises: The control valve is designed to switch the connection between the inlet of the regulating tank and the nodes between the first condenser refrigerant line and the second condenser refrigerant line; and At least one replenishment control valve, which is capable of switching the connection between the outlet of the regulating tank and the refrigerant circuit.

4. The refrigerant-adjustable heat pump water heater according to claim 3, characterized in that, The at least one replenishment control valve includes a first replenishment control valve and a second replenishment control valve. The gaseous and liquid portions of the refrigerant in the regulating tank can be supplied to the low-pressure side of the refrigerant circuit via the first supply control valve and the second supply control valve, respectively.

5. The refrigerant-adjustable heat pump water heater according to claim 4, characterized in that, Both the gaseous and liquid portions of the refrigerant in the regulating tank can be replenished to the refrigerant circuit at the position corresponding to the compressor's suction port; or Both the gaseous and liquid components of the refrigerant in the regulating tank can be replenished into the refrigerant circuit located between the evaporator and the regenerator; or The gaseous portion of the refrigerant in the regulating tank can be supplied to the refrigerant circuit at the position corresponding to the compressor's suction port, and the liquid portion of the refrigerant in the regulating tank can be supplied to the refrigerant circuit at the position located between the evaporator and the regenerator; or The gaseous portion of the refrigerant in the regulating tank can be replenished in the refrigerant circuit at the position between the evaporator and the regenerator, and the liquid portion of the refrigerant in the regulating tank can be replenished in the refrigerant circuit at the position between the throttling element and the evaporator.

6. The refrigerant-adjustable heat pump water heater according to claim 3, characterized in that, The control valve assembly includes a first control valve. The regenerator includes a first regenerator line and a second regenerator line capable of exchanging heat with each other. A first end of the first control valve is connected to a node between the first condenser refrigerant line and the second condenser refrigerant line, and a second end of the control valve is connected to the first regenerator line. The compressor, the first condenser refrigerant line, the second condenser refrigerant line, the throttling element, the evaporator, the second regenerator line, and the compressor can be connected in sequence to form a first refrigerant circuit; The compressor, the first condenser refrigerant line, the first control valve, the first regenerator line, the throttling element, the evaporator, and the second regenerator line can be connected in sequence to form a second refrigerant circuit.

7. The heat pump water heater according to claim 6, characterized in that, The control valve assembly includes a second control valve, which is disposed between the first condenser refrigerant line and the second condenser refrigerant line.

8. The heat pump water heater according to claim 7, characterized in that, The heat pump water heater includes or is equipped with a controller, the controller being used for: Both the first control valve and the second control valve are opened so that: A portion of the refrigerant circulates through the compressor's discharge port - the first condenser refrigerant line - the second control valve - the second condenser refrigerant line - the throttling element - the evaporator - the second regenerator line - the compressor's suction port; Another portion of the refrigerant circulates through the compressor's discharge port - the first condenser refrigerant line - the first control valve - the first regenerator line - the throttling element - the evaporator - the second regenerator line - the compressor's suction port; thus: This allows the condensation heat recovered by the first regenerator pipe to heat the low-pressure refrigerant flowing through the second regenerator pipe.

9. The heat pump water heater according to claim 7, characterized in that, The heat pump water heater includes or is equipped with a controller, the controller being used for: The first control valve is opened and the second control valve is closed, so that: The refrigerant circulates through the compressor's discharge port - the first condenser refrigerant line - the first control valve - the first regenerator line - the throttling element - the evaporator - the second regenerator line - the compressor's suction port, thereby: This allows the condensation heat recovered by the first regenerator pipe to heat the low-pressure refrigerant flowing through the second regenerator pipe.

10. The heat pump water heater according to claim 7, characterized in that, The heat pump water heater includes or is equipped with a controller, the controller being used for: The first control valve is closed and the second control valve is opened so that: The compressor, the first condenser refrigerant line, the second control valve, the second condenser refrigerant line, the throttling element, the evaporator, the second regenerator line, and the compressor form a refrigerant circuit.

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