Heat pump system

Abstract

The utility model relates to the technical field of heat pumps, and discloses a heat pump system which comprises a first circulation loop and a second circulation loop which are respectively connected with a compressor and respectively form a loop, and a condenser, a first throttling device and a first heat exchanger are sequentially arranged on the first circulation loop in the refrigerant flow direction. A second heat exchanger and a second throttling device are sequentially arranged on the second circulation loop, the second heat exchanger is connected with an outlet of the compressor, and the second throttling device is connected with an air return opening of the compressor; the first heat exchanger and the second heat exchanger are suitable for mutual heat exchange. The heat pump can operate at low environment temperature, for example, the heat pump can normally operate in cold regions or winter, the evaporation temperature and the energy efficiency ratio of the heat pump in the low-temperature environment can be increased, and the reliability and the stability of the system are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to heat pump technical field, concretely relates to heat pump system. BACKGROUND

[0002] With the development of science and technology and the improvement of people's living standards, heat pump technology is increasingly widely used in the fields of family and industry. The heating principle of heat pump system is based on Reverse Carnot Cycle, and its basic working process includes four main steps: compression, condensation, expansion and evaporation. As a kind of efficient and environmentally friendly energy conversion device, heat pump can extract heat from low-temperature heat source and transfer it to high-temperature heat source, and is widely used in the fields of heating, refrigeration, hot water supply, etc.

[0003] However, the efficiency of traditional heat pump system will decrease significantly when it runs at low ambient temperature, such as in cold regions or winter, and even cannot run normally. Because of the low temperature environment, the evaporation temperature of heat pump decreases, which leads to the increase of compressor load and the decrease of energy efficiency ratio, seriously affecting the reliability and stability of the system. UTILITY MODEL CONTENTS

[0004] The technical problem solved by the utility model is to provide a heat pump system, which effectively solves the problems of low system reliability and low energy efficiency ratio of existing heat pump system when heating at low ambient temperature.

[0005] The above technical problem is solved by the following technical scheme:

[0006] A heat pump system, comprising a first circulation loop and a second circulation loop connected with a compressor respectively and forming a loop, a condenser, a first throttling device and a first heat exchanger are arranged on the first circulation loop in turn along the flow direction of refrigerant, a second heat exchanger and a second throttling device are arranged on the second circulation loop, the second heat exchanger is connected with the outlet of the compressor, and the second throttling device is connected with the return gas port of the compressor; the first heat exchanger and the second heat exchanger are adapted to heat each other.

[0007] The heat pump system has the beneficial effects that: due to the low ambient temperature, the evaporation capacity of the unit is weakened, the evaporator may be frosted in the low temperature environment, if the water temperature is high and the ambient temperature is low, the ordinary heating cycle can generate a large compression ratio, the unit power rises and the product energy efficiency decreases, therefore, the heat pump system divides the refrigerant of the unit into two parts, one part goes through the first circulation loop, that is, part of the refrigerant enters the first throttling device, the throttled refrigerant enters the first heat exchanger for evaporation, and finally returns to the compressor to complete the ordinary heating cycle; meanwhile, the second throttling device is opened, and part of the refrigerant goes through the second circulation loop, that is, part of the refrigerant enters the second heat exchanger, because the refrigerant directly enters the second heat exchanger from the compressor exhaust, and then expands back to the compressor through the second throttling device, therefore, the surface temperature of the second heat exchanger is high, the second heat exchanger exchanges heat with the first heat exchanger, the temperature of the first heat exchanger is improved, the system evaporation environment is improved, the system efficiency can be improved, and the compression ratio of the system is reduced.

[0008] In one of the embodiments, the heat pump system further comprises a connecting pipeline, a first control valve and a second control valve, the first control valve is arranged on the connecting pipeline, the second control valve is arranged on the pipeline between the second throttling device and the gas return port of the compressor, one end of the connecting pipeline is connected to the pipeline between the first throttling device and the first heat exchanger, and the other end of the connecting pipeline is connected to the pipeline between the second throttling device and the second control valve.

[0009] In one of the embodiments, the heat pump system further comprises a four-way reversing valve, two ports of the four-way reversing valve are connected to the pipeline between the outlet of the compressor and the second heat exchanger, and the other two ports of the four-way reversing valve are connected to the pipeline between the gas return port of the compressor and the second throttling device.

[0010] In one of the embodiments, the first throttling device and / or the second throttling device is an expansion valve.

[0011] In one of the embodiments, the first throttling device and / or the second throttling device is a combination structure of an expansion valve and a solenoid valve.

[0012] In one of the embodiments, the heat pump system further comprises a first temperature sensor, a second temperature sensor and a controller, the first temperature sensor is used to collect the ambient temperature, the second temperature sensor is used to collect the water inlet temperature of the condenser, and the controller is electrically connected to the first temperature sensor and the second temperature sensor.

[0013] In one of the embodiments, the four-way reversing valve, the first control valve and the second control valve are solenoid valves.

[0014] In one of the embodiments, the four-way reversing valve and the controller are electrically connected, and the controller controls the reversing of the four-way reversing valve; the first control valve and the controller are electrically connected, and the controller controls the opening degree of the first control valve; and the second control valve and the controller are electrically connected, and the controller controls the opening degree of the second control valve.

[0015] In one of the embodiments, the condenser is a plate heat exchanger, the condenser has a first channel for flowing refrigerant and a second channel for flowing water, and the first channel is connected to the first circulation loop.

[0016] In one of the embodiments, the negative pressure fan and the second heat exchanger are respectively arranged on opposite sides of the first heat exchanger; and the second heat exchanger is located on the air inlet side. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the following specific embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0018] Figure 1 FIG. 1 is a structural schematic diagram of a heat pump system according to an embodiment of the present application;

[0019] Figure 2 FIG. 2 is another structural schematic diagram of a heat pump system according to an embodiment of the present application;

[0020] Figure 3 FIG. 3 is a running schematic diagram of the heat pump system shown in FIG. 1 in a normal heating mode; Figure 2

[0021] FIG. 4 is a running schematic diagram of the heat pump system shown in FIG. 1 in a low ambient temperature heating mode; Figure 4 Figure 2 FIG. 5 is a running schematic diagram of the heat pump system shown in FIG. 1 in a low water temperature heating mode;

[0022] Figure 5 Figure 2 FIG. 6 is a running schematic diagram of the heat pump system shown in FIG. 1 in a high water temperature heating mode;

[0023] Figure 6 FIG. 7 is a control flowchart of the heat pump system shown in FIG. 1; Figure 2

[0024] FIG. 8 is a control flowchart of the heat pump system shown in FIG. 2; Figure 7 Figure 1 FIG. 9 is a control flowchart of the heat pump system shown in FIG. 3;

[0025] Figure 8 ​​​The utility model discloses a control flow chart of the heat pump system shown in the embodiment of the utility model Figure 2

[0026] Mark explanation:

[0027] 1, compressor;2, condenser;3, first throttling device;4, second throtting device;5, combined heat exchange device;51, first heat exchanger;52, second heat exchanger;53, fan;6, four-way reversing valve;7, first control valve;8, second control valve;9, connecting pipeline;10, first branch;20, second branch;30, third branch;40, fourth branch. Specific implementation

[0028] In order to make the purpose, technical scheme and advantage of the embodiment of the utility model more clear, the technical scheme in the embodiment of the utility model will be described clearly and completely below with the drawings in the embodiment of the utility model, obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiment. Based on the embodiment in the utility model, all other embodiments obtained by the skilled in the art without making creative labor are within the protection scope of the utility model.

[0029] Traditional heat pump system often shows obvious deficiency when facing high requirement of outlet water temperature and low ambient temperature operation, mainly reflected in the following aspects:

[0030] 1, low ambient temperature operation: in cold regions or winter, the efficiency of traditional heat pump system will decrease significantly, even unable to operate normally. In low temperature environment, the evaporation temperature of heat pump decreases, leading to the increase of compressor load and the decrease of energy efficiency ratio, seriously affecting the reliability and stability of the system.

[0031] 2, system operation reliability: traditional heat pump system is single in design, lacks flexibility, and cannot dynamically adjust system parameters according to actual operation. This leads to large fluctuation of system performance under different working conditions, easy to cause fault, affecting the normal use of users.

[0032] 3, energy efficiency ratio: although the heat pump system has higher energy efficiency ratio compared with traditional heating mode, but under certain conditions, such as high load operation or extreme ambient temperature, the energy efficiency ratio still needs to be further improved. Improving the energy efficiency ratio of heat pump system can not only save energy, but also reduce operating cost and improve the economic benefit of users.

[0033] 4, single operation mode, under different working conditions, the system performance fluctuates greatly, easy to cause fault, the system reliability is low, affects the normal use of users.

[0034] ​5. High water temperature requirement: The design of traditional heat pump systems usually cannot meet the user's demand for high-temperature hot water. In some application scenarios, such as industrial hot water supply, high-temperature heating, etc., the user needs the heat pump system to provide hot water with a higher temperature, while the outlet water temperature of the traditional heat pump system is usually low, which cannot reach the required temperature level.

[0035] To solve the above problems, the utility model provides a kind of heat pump system, by introducing combination heat exchanger structure, can be dynamically adjusted the role of each sub heat exchanger according to actual situation in the system operation process, to maximize the operating conditions of heat pump, improve the reliability and stability of system. At the same time, the heat pump system improves the outlet water temperature and energy efficiency ratio of heat pump system to a certain extent, meets the demand of user to high-performance heat pump system.

[0036] The embodiments of the utility model are described below in conjunction with Figures 1 to 8

[0037] According to the embodiments of the utility model, a kind of heat pump system is provided, first circulation loop and second circulation loop are connected with compressor 1 respectively and form loop respectively, first circulation loop is provided with condenser 2, first throttling device 3 and first heat exchanger 51 in sequence along the flow direction of refrigerant, second circulation loop is provided with second heat exchanger 52 and second throttling device 4, second heat exchanger 52 is connected with the outlet of compressor 1, and second throttling device 4 is connected with the back gas port of compressor 1;First heat exchanger 51 and second heat exchanger 52 are adapted to heat exchange with each other.

[0038] Referring to Figures 1 to 4 , the arrow in the figure represents the flow direction of refrigerant.

[0039] The heat pump system provided by the embodiments of the utility model can operate in ordinary heating mode and low ambient temperature heating mode.

[0040] Specifically, when only first circulation loop operates, it is ordinary heating mode. The circulating flow direction of refrigerant in compressor 1 is: compressor 1, condenser 2, first throttling device 3, first heat exchanger 51, compressor 1.

[0041] The specific working principle is as follows:

[0042] ​The compressor 1 compresses the low-pressure and low-temperature refrigerant gas into high-pressure and high-temperature gas, and the high-pressure and high-temperature refrigerant gas enters the condenser 2 to exchange heat with the medium (such as indoor air or water) that needs to be heated, so that the heat is transferred to the indoor air or water to achieve the heating effect. The refrigerant after heat exchange is lowered in temperature and pressure and becomes high-pressure and low-temperature liquid. The high-pressure and low-temperature refrigerant liquid is rapidly expanded through the first throttling device 3, and the pressure and temperature are sharply lowered, becoming low-pressure and low-temperature liquid. The first heat exchanger 51 serves as an evaporator, and then the low-pressure and low-temperature refrigerant liquid absorbs heat from the surrounding environment in the first heat exchanger 51, and is evaporated into low-pressure and low-temperature gas, and then returns to the compressor 1 to continue the cycle. Thus, a normal heating cycle is completed.

[0043] Specifically, the low ambient temperature heating mode is when the first circulation loop and the second circulation loop are operated at the same time. Part of the refrigerant in the compressor 1 goes through the first circulation loop, and the circulation flow direction is: compressor 1, condenser 2, first throttling device 3, first heat exchanger 51, compressor 1. The other part goes through the second circulation loop, and the circulation flow direction is: compressor 1, second heat exchanger 52, second throttling device 4, compressor 1.

[0044] The specific working principle is as follows:

[0045] The working principle of the first circulation loop is the same as that of the normal heating mode described above.

[0046] The working principle of the second circulation loop is as follows: because the ambient temperature is low, the evaporating capacity of the unit is weakened, so the first heat exchanger 51 may frost in a low-temperature environment. At the same time, if the water temperature is high and the ambient temperature is low, the normal heating cycle will produce a large compression ratio, resulting in an increase in the power of the unit and a decrease in the energy efficiency of the product. Therefore, the refrigerant of the unit is divided into two parts, one part goes through the first circulation loop, that is, part of the refrigerant enters the first throttling device 3 from the condenser 2, and the throttled refrigerant enters the first heat exchanger 51 to evaporate, and finally returns to the compressor 1 to complete the normal heating cycle; at the same time, the second throttling device 4 is opened, and the other part goes through the second circulation loop, that is, part of the refrigerant directly enters the second heat exchanger 52 and the second throttling device 4 from the compressor 1 and then returns to the compressor 1. Here, the second heat exchanger 52 is used as a condenser to achieve the effect of condensation. The surface temperature of the second heat exchanger 52 is high, and the high-temperature and high-pressure refrigerant gas exchanges heat with the first heat exchanger 51 in the second heat exchanger 52 to supplement the heat to the first heat exchanger 51, improve the temperature of the first heat exchanger 51, improve the evaporation environment of the system, improve the efficiency of the system, and reduce the compression ratio of the system.

[0047] The heat pump system provided by the embodiment of the utility model, through setting second circulation loop, and setting second heat exchanger 52 which is arranged side by side with first heat exchanger 51 and can exchange heat mutually on second circulation loop, when selecting low ambient temperature heating mode, first circulation loop and second circulation loop operate simultaneously, rely on the heat exchange of second heat exchanger 52 and first heat exchanger 51, can supplement the heat required for the evaporation of first heat exchanger 51, improve the evaporation environment of system, reduce the compression ratio of system, improve system efficiency.

[0048] Further, if the water temperature is higher and the evaporation temperature is lower, the opening of the second throttling device 4 can be adjusted as needed to control the injection amount of the refrigerant return gas, improve the system pressure ratio, and improve the system operation reliability, capacity and energy efficiency.

[0049] The utility model can operate at low ambient temperature, such as normal operation in cold regions or winter, and can improve the evaporation temperature and energy efficiency ratio of the heat pump at low temperature environment, improve the reliability and stability of the system. In addition, the utility model can switch between ordinary heating mode and low ambient temperature heating mode according to different ambient temperature, the system has high reliability, and the user can use normally.

[0050] Specifically, in some embodiments, the condenser 2 is a plate heat exchanger. The condenser 2 has a first channel for flowing refrigerant and a second channel for flowing water, and the first channel is connected to the first circulation loop.

[0051] The control process of the heat pump system provided by the above embodiment is as follows:

[0052] Collect the ambient temperature Ta, compare the collected ambient temperature Ta with the preset ambient temperature threshold M, and obtain the first determination result;

[0053] Collect the inlet water temperature Tw of the condenser 2, compare the collected inlet water temperature Tw of the condenser 2 with the preset minimum water temperature threshold A and the preset maximum water temperature threshold B, and obtain the second determination result;

[0054] Based on the first determination result and the second determination result, the first throttling device 3 and the second throttling device 4 are controlled to act to switch between the ordinary heating mode and the low ambient temperature heating mode.

[0055] The control flow chart of the heat pump system is as shown in Figure 7 .

[0056] According to the comparison result of the collected ambient temperature Ta and the preset ring temperature threshold M, combined with the comparison result of the collected water inlet temperature Tw of the condenser 2 and the preset minimum water temperature threshold A and the preset maximum water temperature threshold B, the opening and closing or reversing of each valve and the start and stop of each device are controlled, the two modes of ordinary heating mode and low ring temperature heating mode are switched, and different heating modes can be selected according to different working conditions, so that the system can operate at low ambient temperature, and the reliability and energy efficiency ratio of the system operation are improved.

[0057] Specifically, when the first determination result is Ta>M and the second determination result is A≤Tw≤B, the first throttling device 3 is controlled to be opened, and the second throttling device 4 is controlled to be closed, so as to switch to the ordinary heating mode; when the first determination result is Ta≤M, the first throttling device 3 and the second throttling device 4 are controlled to be opened, so as to switch to the low ring temperature heating mode.

[0058] The first determination result is Ta>M, which indicates that the ring temperature of the working condition is normal. Taking A=30°C and B=45°C as an example, when the water inlet temperature Tw of the condenser 2 is in the temperature interval of 30°C to 45°C, the ordinary heating mode is run, and at this time, only the first circulation loop is connected, and the remaining loops are disconnected.

[0059] Specifically, the first determination result is Ta≤M, which indicates that the ambient temperature of the working condition is low. Taking M as -10°C as an example, the collected ambient temperature Ta≤-10°C, at this time, the low ring temperature heating mode is run, that is, the first circulation loop and the second circulation loop are connected and run.

[0060] The above is some embodiments of the heat pump system and the control mode of its operation. The following provides another embodiment of the heat pump system and the control mode of its operation, which can realize the four modes of ordinary heating mode, low ring temperature heating mode, low water temperature heating mode and high water temperature heating mode, and can switch between the four modes according to different working conditions. For details, refer to Figures 2 to 6 , and Figure 8 .

[0061] In some embodiments, a four-way reversing valve 6 is further included, two ports of the four-way reversing valve 6 are connected with the pipeline between the outlet of the compressor 1 and the second heat exchanger 52, and the other two ports of the four-way reversing valve 6 are connected with the pipeline between the back gas port of the compressor 1 and the second throttling device 4.

[0062] By setting the four-way reversing valve 6, the reversing of the pipeline can be realized. In the low ring temperature heating mode, the second circulation loop is run, and the circulating flow direction of the refrigerant is: compressor 1, four-way reversing valve 6, second heat exchanger 52, second throttling device 4, four-way reversing valve 6, compressor 1.

[0063] Further, refer to Figure 2, the second circulation loop comprises a first branch 10, a second branch 20, a third branch 30 and a fourth branch 40 connected in sequence, one end of the first branch 10 is connected with the outlet of the compressor 1, the other end is connected with the first port of the four-way reversing valve 6, one end of the second branch 20 is connected with the second port of the four-way reversing valve 6, the other end is connected with one end of the third branch 30, the other end of the third branch 30 is connected with the third port of the four-way reversing valve 6, one end of the fourth branch 40 is connected with the fourth port of the four-way reversing valve 6, the other end is connected with the back gas port of the compressor 1.

[0064] Specifically, in the embodiment, the second heat exchanger 52 and the second throttling device 4 are both arranged in the second branch 20, and the second control valve 8 is arranged on the third branch 30. Figure 4 As shown in the low ambient temperature heating mode, the second throttling device 4 is located downstream of the second heat exchanger 52 in the second circulation loop.

[0065] The four-way reversing valve 6 can connect the first branch 10 and the second branch 20, and connect the third branch 30 and the fourth branch 40, at this time, the second circulation loop is connected. It can also realize the connection of the second branch 20 and the fourth branch 40 to realize the low water temperature heating mode, and the specific working principle will be described later.

[0066] In some embodiments, a connecting pipeline 9, a first control valve 7 and a second control valve 8 are further included, the first control valve 7 is arranged on the connecting pipeline 9, the second control valve 8 is arranged on the pipeline between the second throttling device 4 and the back gas port of the compressor 1, one end of the connecting pipeline 9 is connected to the pipeline between the first throttling device 3 and the first heat exchanger 51, and the other end is connected to the pipeline between the second throttling device 4 and the second control valve 8.

[0067] Specifically, in the embodiment, when the low ambient temperature heating mode is running, the first throttling device 3, the second throttling device 4 and the second control valve 8 are all opened, the first control valve 7 is closed, and the four-way reversing valve 6 connects the outlet of the compressor 1 with the second heat exchanger 52 and connects the second control valve 8 with the back gas port of the compressor 1, that is, the first branch 10 and the second branch 20 are connected, and the third branch 30 and the fourth branch 40 are connected.

[0068] The heat pump system is connected between the first circulation loop and the second circulation loop through the connecting pipeline 9, and the first control valve 7 is arranged on the connecting pipeline 9. In addition, the heat pump system further comprises a second control valve 8. By controlling the opening and closing of the first control valve 7 and the second control valve 8 and the reversing of the four-way reversing valve 6, the low water temperature heating mode and the high water temperature heating mode can be realized.

[0069] The specific control and working principle of the low water temperature heating mode are as follows:

[0070] The first throttling device 3, the second throttling device 4 and the first control valve 7 are all opened, the second control valve 8 is closed, and the four-way reversing valve 6 guides the outlet of the compressor 1 to the second heat exchanger 52, that is, the first branch 10 and the second branch 20 are communicated, so that the third circulation loop is formed, and the second circulation loop is disconnected. The circulation flow direction of the refrigerant in the fourth circulation loop is: the compressor 1, the four-way reversing valve 6, the second heat exchanger 52, the second throttling device 4, the first control valve 7, the first heat exchanger 51, and the compressor 1. When the first circulation loop and the fourth circulation loop operate simultaneously, it is the high water temperature heating mode.

[0071] Specifically, the refrigerant expanded from the first throttling device 3 is divided into two parts, one part flows to the condenser 2 along the first circulation loop, and the other part flows into the second throttling device 4 through the first control valve 7 to become low-temperature and low-pressure refrigerant liquid, and then evaporates into low-temperature and low-pressure gas in the second heat exchanger 52, and returns to the compressor 1 through the four-way reversing valve 6, to complete a cycle.

[0072] Specifically, when the inlet water temperature of the condenser 2 is low, the low water temperature heating mode is operated. At this time, the condensing capacity of the heat pump system is large, so the heat pump system needs large evaporation capacity, so part of the refrigerant flows to the first heat exchanger 51 after passing through the first throttling device 3, and the other part flows to the second heat exchanger 52 through the first control valve 7. At this time, the first heat exchanger 51 and the second heat exchanger 52 are both evaporators, and the system evaporation capacity is greatly enhanced, which can match the high condensing capacity of the heat pump system, and improve the heating capacity and efficiency of the system.

[0073] The high water temperature heating mode is specifically controlled and works as follows:

[0074] The first throttling device 3, the second throttling device 4 and the first control valve 7 are all opened, the second control valve 8 is closed, and the four-way reversing valve 6 guides the outlet of the compressor 1 to the second heat exchanger 52, that is, the first branch 10 and the second branch 20 are communicated, so that the third circulation loop is formed, and the second circulation loop is disconnected. The circulation flow direction of the refrigerant in the fourth circulation loop is: the compressor 1, the four-way reversing valve 6, the second heat exchanger 52, the second throttling device 4, the first control valve 7, the first heat exchanger 51, and the compressor 1. When the first circulation loop and the fourth circulation loop operate simultaneously, it is the high water temperature heating mode.

[0075] Specifically, the high-temperature and high-pressure refrigerant gas flowing out of the compressor 1 is divided into two parts, one part flows to the condenser 2 along the first circulation loop, and the other part flows into the second heat exchanger 52 through the four-way reversing valve 6. At this time, the heat exchanger is used as the condenser 2, and the heat-exchanged refrigerant becomes low-temperature and high-pressure liquid, which is then expanded into low-temperature and low-pressure liquid in the second throttling device 4, and then flows into the first heat exchanger 51 through the first control valve 7 to evaporate into low-temperature and low-pressure gas, and finally returns to the compressor 1, to complete a cycle.

[0076] Specifically, when the water inlet temperature of the condenser 2 is high, a high water temperature heating mode is run, at this time, the condensing capacity of the heat pump system is small, so the heat pump system needs a more appropriate evaporation capacity, therefore, part of the refrigerant is exchanged through the condenser 2 and throttled through the first throttling device 3, and then flows to the first heat exchanger 51, at this time, the first heat exchanger 51 is an evaporator, because the condensing capacity and the evaporation capacity of the product do not match, it is easy to cause the system to be abnormal, at this time, the second throttling device 4 is opened, and the first control valve 7 is opened, part of the refrigerant flows out from the compressor 1 and enters the second heat exchanger 52, at this time, the second heat exchanger 52 is a condenser 2, which condenses the refrigerant, and then mixes with the refrigerant throttled through the condenser 2 and enters the first heat exchanger 51 for evaporation, to supplement the evaporation demand of the system evaporator and ensure the normal operation of the system, and the refrigerant flows out of the first heat exchanger 51 and returns to the compressor 1.

[0077] The heat pump system provided by the embodiment can maximize the high-temperature outlet water temperature of the system while ensuring the normal operation of the system when the heat pump system is run in the high water temperature heating mode.

[0078] In some embodiments, a first temperature sensor, a second temperature sensor and a controller are further included. The first temperature sensor is used to collect the ambient temperature, the second temperature sensor is used to collect the water inlet temperature of the condenser 2, and the controller is electrically connected with the first temperature sensor and the second temperature sensor respectively.

[0079] In some embodiments, the four-way reversing valve 6, the first control valve 7 and the second control valve 8 are all solenoid valves.

[0080] In some embodiments, the four-way reversing valve 6 is electrically connected with the controller and controlled by the controller to reverse, the first control valve 7 is electrically connected with the controller and controlled by the controller to control the opening degree of the first control valve 7, and the second control valve 8 is electrically connected with the controller and controlled by the controller to control the opening degree of the second control valve 8.

[0081] Specifically, the controller compares the ambient temperature collected by the first temperature sensor with a preset ambient temperature threshold M in the controller, and when the collected ambient temperature is lower than M, the low ambient temperature heating mode is executed.

[0082] The controller compares the water inlet temperature of the condenser 2 collected by the second temperature sensor with a preset water inlet temperature threshold, and executes any one of the normal heating mode, the low water temperature heating mode or the high water temperature heating mode according to the comparison result. Specifically, the four-way reversing valve 6 can be controlled to reverse to achieve different conduction states, and the first control valve 7 and the second control valve 8 can be controlled to open and close to execute a certain heating mode according to different working conditions.

[0083] In some embodiments, the first throttling device 3 and / or the second throttling device 4 is an expansion valve.

[0084] In other embodiments, the first throttling device 3 and / or the second throttling device 4 is a combination of an expansion valve and a solenoid valve.

[0085] When the first throttling device 3 and the second throttling device 4 are both combinations of an expansion valve and a solenoid valve, the first throttling device 3 and the second throttling device 4 are respectively electrically connected with the controller, the controller controls the start-stop of the first throttling device 3 and the second throttling device 4, and controls the opening of the first throttling device 3 and the second throttling device 4 according to the operation requirements of different working conditions, so as to control the flow of the refrigerant.

[0086] In some embodiments, the heat pump system further comprises a negative pressure fan 53, and the negative pressure fan 53 and the second heat exchanger 52 are respectively arranged on opposite sides of the first heat exchanger 51; the second heat exchanger 52 is located on the air inlet side.

[0087] Specifically, the first heat exchanger 51, the second heat exchanger 52 and the negative pressure fan 53 constitute a combined heat exchange device 5.

[0088] For the control process of the heat pump system of the above-mentioned embodiments, the following is provided:

[0089] The ambient temperature Ta is collected, and the collected ambient temperature Ta is compared with the preset ambient temperature threshold M to obtain a first determination result;

[0090] The inlet water temperature Tw of the condenser 2 is collected, and the collected inlet water temperature Tw of the condenser 2 is compared with the preset minimum water temperature threshold A and the preset maximum water temperature threshold B to obtain a second determination result;

[0091] Based on the first determination result and the second determination result, the first throttling device 3, the second throttling device 4, the four-way reversing valve 6, the first control valve 7 and the second control valve 8 are controlled to act, so as to switch between the ordinary heating mode, the low ambient temperature heating mode, the low water temperature heating mode and the high water temperature heating mode.

[0092] The control flow chart of the heat pump system is shown in Figure 8 .

[0093] According to the comparison result of the collected ambient temperature Ta and the preset ring temperature threshold M, combined with the comparison result of the collected water inlet temperature Tw of the condenser 2 and the preset minimum water temperature threshold A and the preset maximum water temperature threshold B, the opening and closing or reversing of each valve and the start and stop of each device are controlled, and the four modes of ordinary heating mode, low ambient temperature heating mode, low water temperature heating mode and high water temperature heating mode are switched, so that different heating modes can be selected according to different working conditions, so that the system can run at low ambient temperature, and meet the low water temperature and high water temperature heating demand, and at the same time, the reliability and energy efficiency ratio of the system operation are improved.

[0094] Ordinary heating mode: when the first determination result is Ta>M and the second determination result is A≤Tw≤B, the first throttling device 3 is controlled to be opened, the second throttling device 4, the first control valve 7 and the second control valve 8 are all closed, so as to switch to the ordinary heating mode.

[0095] Low ambient temperature heating mode: when the first determination result is Ta≤M, the first throttling device 3, the second throttling device 4 and the second control valve 8 are all opened, the four-way reversing valve 6 is connected to the outlet of the compressor 1 and the second heat exchanger 52, and the second control valve 8 is connected to the return air port of the compressor 1, and the first control valve 7 is closed, so as to switch to the low ambient temperature heating mode.

[0096] Ordinary heating mode and low ambient temperature heating mode are the same as the above control mode, which will not be repeated here.

[0097] Low water temperature heating mode: when the first determination result is Ta>M and the second determination result is Tw

[0098] Specifically, the first determination result is Ta>M, which indicates that the ambient temperature of the working condition is normal. Taking A=30℃ as an example, when the water inlet temperature Tw of the condenser 2 is less than 30℃, the low water temperature heating mode is run, at this time, the first circulating loop and the third circulating loop are connected and run.

[0099] High water temperature heating mode: when the first determination result is Ta>M and the second determination result is Tw>B, the first throttling device 3, the second throttling device 4 and the first control valve 7 are all opened, the four-way reversing valve 6 is connected to the outlet of the compressor 1 and the second heat exchanger 52, and the second control valve 8 is closed, so as to switch to the high water temperature heating mode.

[0100] Specifically, the first determination result is Ta>M, which indicates that the ambient temperature of the working condition is normal. Taking B=45℃ as an example, when the water inlet temperature Tw of the condenser 2 is greater than 45℃, the high water temperature heating mode is run, at this time, the first circulation loop and the fourth circulation loop are communicated and run.

[0101] The control of the heat pump system provided in the embodiment of the utility model can formulate four heating modes according to the ambient temperature and the water inlet temperature of the condenser, so as to further improve the reliability and energy efficiency ratio of the heat pump system.

[0102] In the specific contents of the above specific embodiments, each technical feature can be combined arbitrarily without contradiction, and in order to make the description simple, all possible combinations of the above technical features are not described, however, as long as the combination of the technical features does not exist contradiction, it should be considered as the scope of the description.

[0103] The specific contents of the above specific embodiments only express several implementation modes of the utility model, the description is more specific and detailed, but it should not be understood as the limitation of the patent scope of the utility model. It should be pointed out that for ordinary skilled persons in the art, on the premise of not departing from the concept of the utility model, a number of modifications and improvements can be made, which belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent should be subject to the appended claims.

Claims

1. A heat pump system, characterized by, The compressor (1) is connected with a first circulation loop and a second circulation loop respectively, the first circulation loop is provided with a condenser (2), a first throttling device (3) and a first heat exchanger (51) in sequence along the refrigerant flow direction, the second circulation loop is provided with a second heat exchanger (52) and a second throttling device (4), the second heat exchanger (52) is connected with the outlet of the compressor (1), the second throttling device (4) is connected with the back gas port of the compressor (1), and the first heat exchanger (51) and the second heat exchanger (52) are adapted to heat exchange with each other.

2. The heat pump system of claim 1, wherein, The connecting pipeline (9), the first control valve (7) and the second control valve (8) are further included, the first control valve (7) is arranged on the connecting pipeline (9), the second control valve (8) is arranged on the pipeline between the second throttling device (4) and the back gas port of the compressor (1), one end of the connecting pipeline (9) is connected with the pipeline between the first throttling device (3) and the first heat exchanger (51), and the other end of the connecting pipeline (9) is connected with the pipeline between the second throttling device (4) and the second control valve (8).

3. The heat pump system of claim 2, wherein, The four-way reversing valve (6) is further included, two ports of the four-way reversing valve (6) are connected with the pipeline between the outlet of the compressor (1) and the second heat exchanger (52), and the other two ports of the four-way reversing valve (6) are connected with the pipeline between the back gas port of the compressor (1) and the second throttling device (4).

4. The heat pump system according to any one of claims 1 to 3, characterized in that, The first throttling device (3) and / or the second throttling device (4) is an expansion valve.

5. The heat pump system according to any one of claims 1 to 3, characterized in that, The first throttling device (3) and / or the second throttling device (4) is a combination structure of an expansion valve and a solenoid valve.

6. The heat pump system of claim 3, wherein, Further comprising: A first temperature sensor for collecting ambient temperature; A second temperature sensor for collecting the water inlet temperature of the condenser (2); A controller electrically connected with the first temperature sensor and the second temperature sensor respectively.

7. The heat pump system of claim 6, wherein, The four-way reversing valve (6), the first control valve (7) and the second control valve (8) are all solenoid valves.

8. The heat pump system of claim 7, wherein, The four-way reversing valve (6) is electrically connected with the controller and controlled by the controller; The first control valve (7) is electrically connected with the controller and controlled by the controller; The second control valve (8) is electrically connected with the controller and controlled by the controller.

9. The heat pump system according to any one of claims 1 to 3, characterized in that, The condenser (2) is a plate heat exchanger, the condenser (2) has a first channel for flowing refrigerant and a second channel for flowing water, and the first channel is connected with the first circulation loop.

10. The heat pump system according to any one of claims 1 to 3, characterized in that, Further comprising a negative pressure fan (53), the negative pressure fan (53) and the second heat exchanger (52) are arranged on opposite sides of the first heat exchanger (51) respectively, and the second heat exchanger (52) is located on the air inlet side.

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