Non-azeotropic mixed working medium heat pump system

Abstract

The utility model relates to the technical field of heat pumps, and discloses a non-azeotropic mixed working medium heat pump system which comprises a compressor and a refrigerant circulation loop which is connected with the compressor and forms a loop with the compressor, and a condenser, a first throttling device, a liquid storage device and an evaporator are sequentially arranged on the refrigerant circulation loop in the refrigerant flow direction. The liquid storage device is provided with a refrigerant inlet, a first refrigerant outlet and a second refrigerant outlet, the refrigerant inlet is connected with the first throttling device, the first refrigerant outlet is connected with an inlet of the evaporator, the second refrigerant outlet is connected with the inlet of the evaporator through a bypass pipeline, and an electric control valve is arranged on the bypass pipeline. According to the heat pump system, low-boiling-point components in gaseous working media account for a large amount, namely, refrigerant components actually participating in the whole defrosting circulation account for a large amount, so that high pressure in the defrosting circulation is improved, mass flow is increased, finally, acting of a compressor is larger, namely, condensation heat dissipating capacity of defrosting of an evaporator is larger, and energy consumption is reduced. Therefore, the defrosting effect of the non-azeotropic mixed working medium heat pump system is improved.

Description

Technical Field

[0001] This utility model relates to the field of heat pump technology, and in particular to a non-azeotropic mixed working fluid heat pump system. Background Technology

[0002] With the development of science and technology and the improvement of people's living standards, heat pump technology is increasingly widely used in residential and industrial fields. Because the temperature range between the heat source and heat sink in a heat pump system is large, traditional single working fluids are no longer sufficient to meet the requirements, such as ultra-low ambient temperature heating in buildings and ultra-high water temperature heating in industry. Non-azeotropic mixtures can flexibly select the components and proportions of the working fluid according to the application, increasing the temperature difference between the heat source and heat sink, thereby adapting to the large temperature span requirements of specific applications.

[0003] However, when non-azeotropic working fluids are used in traditional heat pump systems, reverse defrosting is usually required using a four-way valve, which results in a complex flow path and low defrosting efficiency in the heat pump system. Utility Model Content

[0004] The technical problem solved by this utility model is to provide a non-azeotropic mixed working fluid heat pump system, which effectively solves the technical problem of low defrosting efficiency when non-azeotropic mixed working fluids are used in heat pumps.

[0005] The above-mentioned technical problems are solved by the following technical solutions:

[0006] A non-azeotropic mixed working fluid heat pump system, comprising:

[0007] A compressor and a refrigerant circulation loop connected to the compressor and forming a loop respectively, wherein a condenser, a first throttling device, a liquid receiver and an evaporator are sequentially provided along the refrigerant flow direction in the refrigerant circulation loop;

[0008] The liquid receiver is provided with a refrigerant inlet, a first refrigerant outlet and a second refrigerant outlet. The refrigerant inlet is connected to the first throttling device, the first refrigerant outlet is connected to the inlet of the evaporator, and the second refrigerant outlet is connected to the inlet of the evaporator through a bypass pipe. An electrically controlled valve is provided on the bypass pipe.

[0009] Compared with the prior art, the non-azeotropic mixed working fluid heat pump system of this utility model has the following advantages: When the non-azeotropic mixed working fluid heat pump system defrosts, the electronic control valve is opened and the opening degree of the first throttling device is maximized. After the non-azeotropic mixed working fluid is discharged from the compressor, it enters the condenser for cooling. The cooled non-azeotropic mixed working fluid enters the first throttling device for throttling, and the throttled non-azeotropic mixed working fluid enters the liquid receiver. In the liquid receiver, most of the gaseous working fluid is discharged from the second refrigerant outlet and enters the bypass pipeline. It is then transported to the evaporator for condensation through the electronic control valve and then returns to the compressor to complete the defrosting cycle. During the defrosting cycle, because the opening of the first throttling device is adjusted to the maximum, the throttling effect is poor. Therefore, the temperature and pressure of the non-azeotropic working fluid remain high after flowing through the first throttling device. Moreover, most of the low-boiling-point working fluid is in a gaseous state. When the gaseous working fluid condenses in the evaporator, it releases a large amount of heat for defrosting. According to the characteristics of the non-azeotropic working fluid, the proportion of low-boiling-point components in the gaseous working fluid is relatively large. That is, the proportion of low-boiling-point components in the refrigerant components actually participating in the entire defrosting cycle is larger than that in the heating cycle. Furthermore, since the density of the low-boiling-point working fluid is greater than that of the high-boiling-point working fluid, the high pressure and mass flow rate of the working fluid in the defrosting cycle are increased. Ultimately, the compressor does more work, that is, the condensation heat dissipation of the evaporator during defrosting is greater, thus effectively improving the defrosting effect of the non-azeotropic working fluid heat pump system. In addition, there is no need to use a four-way valve for reverse heat exchange defrosting, which simplifies the flow path of the non-azeotropic working fluid heat pump system and reduces costs.

[0010] In one embodiment, it further includes:

[0011] The regenerator has a first heat exchange channel and a second heat exchange channel that exchange heat with each other. The first heat exchange channel is connected between the first refrigerant outlet and the inlet of the evaporator, and the second heat exchange channel is connected between the outlet of the evaporator and the return gas port of the compressor.

[0012] A second throttling device is connected between the outlet of the first heat exchange channel and the inlet of the evaporator.

[0013] In one embodiment, both the first throttling device and the second throttling device are expansion valves.

[0014] In one embodiment, both the first throttling device and the second throttling device are combinations of an expansion valve and a solenoid valve.

[0015] In one embodiment, a gas-liquid separator is also provided on the refrigerant circulation loop, and the gas-liquid separator is located near the return port of the compressor.

[0016] In one embodiment, an evaporator fan is also included, which drives air to flow through the evaporator.

[0017] In one embodiment, the first refrigerant outlet is located at the bottom of the liquid reservoir, and the second refrigerant outlet is located at the top of the liquid reservoir.

[0018] In one embodiment, the condenser is a plate heat exchanger having a first channel for circulating refrigerant and a second channel for circulating water. The first channel is connected to the refrigerant circulation loop, and the two ends of the second channel are used to connect water-using devices.

[0019] In one embodiment, it further includes:

[0020] The first temperature sensor is used to collect ambient temperature;

[0021] The second temperature sensor is used to collect the outlet temperature of the evaporator;

[0022] The controller is electrically connected to the first temperature sensor and the second temperature sensor, respectively.

[0023] In one embodiment, the controller is also electrically connected to the electrically controlled valve and the first throttling device, respectively. The controller is used to control the on / off state of the electrically controlled valve and the opening degree of the first throttling device based on a comparison between the ambient temperature and the outlet temperature of the evaporator. Attached Figure Description

[0024] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of a non-azeotropic mixed working fluid heat pump system according to an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of the control flow of a non-azeotropic mixed working fluid heat pump system according to an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the control flow of a non-azeotropic mixed working fluid heat pump system according to another embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of the control flow of a non-azeotropic mixed working fluid heat pump system according to another embodiment of the present invention;

[0029] Figure 5This is a schematic diagram of the control flow of a non-azeotropic mixed working fluid heat pump system according to another embodiment of the present invention;

[0030] Figure 6 This is a schematic diagram of the control flow of a non-azeotropic mixed working fluid heat pump system according to another embodiment of the present invention.

[0031] Explanation of reference numerals in the attached figures:

[0032] 1. Compressor; 2. Condenser; 3. First throttling device; 4. Liquid receiver; 41. Bypass line; 42. Refrigerant inlet; 43. First refrigerant outlet; 44. Second refrigerant outlet; 5. Electrically controlled valve; 6. Regenerator; 61. First heat exchange passage; 62. Second heat exchange passage; 7. Second throttling device; 8. Evaporator; 9. Gas-liquid separator; 10. Evaporator fan. Detailed Implementation

[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0034] In the description of this utility model, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0035] According to embodiments of the present invention, such as Figure 1 As shown, a non-azeotropic mixed working fluid heat pump system is provided, including: a compressor 1 and a refrigerant circulation loop connected to the compressor 1 and forming a circuit. A condenser 2, a first throttling device 3, a liquid receiver 4 and an evaporator 8 are arranged sequentially along the refrigerant flow direction on the refrigerant circulation loop. The liquid receiver 4 is provided with a refrigerant inlet 42, a first refrigerant outlet 43 and a second refrigerant outlet 44. The refrigerant inlet 42 is connected to the first throttling device 3, the first refrigerant outlet 43 is connected to the inlet of the evaporator 8, and the second refrigerant outlet 44 is connected to the inlet of the evaporator 8 through a bypass pipe 41. An electric control valve 5 is provided on the bypass pipe 41.

[0036] In this embodiment, the arrows in the figure indicate the refrigerant flow direction. The refrigerant can specifically be a non-azeotropic mixture. The non-azeotropic mixture heat pump system provided in this embodiment can operate in heating mode and defrosting mode. When the non-azeotropic mixture heat pump system is in heating mode, the refrigerant flow direction within the compressor 1 is: condenser 2, first throttling device 3, liquid receiver 4, evaporator 8, compressor 1.

[0037] The specific heating principle is as follows: Compressor 1 compresses low-pressure, low-temperature refrigerant gas into high-pressure, high-temperature gas. This high-pressure, high-temperature refrigerant gas enters condenser 2, where it exchanges heat with the medium to be heated (such as indoor air or water), transferring heat to the indoor air or water to achieve the heating effect. After heat exchange, the refrigerant's temperature and pressure decrease, becoming a high-pressure, low-temperature gas-liquid mixture. This high-pressure, low-temperature gas-liquid mixture expands rapidly after being throttled by the first throttling device 3, causing a sharp drop in pressure and temperature, transforming into a low-pressure, low-temperature gas-liquid mixture. Then, this low-pressure, low-temperature gas-liquid mixture enters the liquid receiver 4 through refrigerant inlet 42, where it is separated into gaseous and liquid working fluids. The liquid working fluid flows out from the first refrigerant outlet 43 and along the connecting pipe to the evaporator 8 connected to the liquid receiver 4. In the evaporator 8, the liquid working fluid absorbs heat from the air and evaporates into a low-temperature, low-pressure gas, which is then drawn into compressor 1 and continues to circulate through compressor 1. This completes one heating cycle.

[0038] Due to the low ambient temperature, the unit's evaporation capacity is reduced, therefore, evaporator 8 may frost up in low-temperature environments. When the non-azeotropic mixed refrigerant heat pump system is in defrost mode, the gaseous refrigerant in the system is discharged through the second refrigerant outlet 44 and enters the bypass pipe 41. In the refrigerant circulation loop, the refrigerant flow direction within compressor 1 is: condenser 2, first throttling device 3, liquid receiver 4, electronic control valve 5, evaporator 8, compressor 1.

[0039] The specific defrosting principle is as follows: Compressor 1 compresses the low-pressure, low-temperature refrigerant gas into a high-pressure, high-temperature gas. This high-pressure, high-temperature refrigerant gas enters condenser 2, where it exchanges heat with the medium requiring heating (such as indoor air or water), transferring heat to the indoor air or water to achieve a heating effect. After heat exchange, the refrigerant's temperature and pressure decrease, becoming a high-pressure, low-temperature gas-liquid mixture. This high-pressure, low-temperature gas-liquid mixture expands rapidly after being throttled by the first throttling device 3, causing a sharp drop in pressure and temperature, transforming into a low-pressure, low-temperature gas-liquid mixture. This low-pressure, low-temperature gas-liquid mixture then enters the liquid receiver 4 through refrigerant inlet 42, where it is separated into gaseous and liquid refrigerant. In the liquid receiver 4, most of the gaseous refrigerant is discharged from the second refrigerant outlet 44 into the bypass pipe 41, and then transported to the evaporator 8 for condensation via the electronically controlled valve 5. It is then drawn into compressor 1 and continues to circulate through compressor 1. This completes one defrosting cycle.

[0040] During the defrosting cycle, because the opening of the first throttling device 3 is adjusted to the maximum, the throttling effect is poor. Therefore, the temperature and pressure of the non-azeotropic working fluid remain high after flowing through the first throttling device 3. Moreover, most of the low-boiling-point working fluid is in a gaseous state. When the gaseous refrigerant condenses in the evaporator 8, it releases a large amount of heat for defrosting. According to the characteristics of the non-azeotropic working fluid, the proportion of low-boiling-point components in the gaseous working fluid is relatively large. That is, the proportion of low-boiling-point components in the refrigerant actually participating in the entire defrosting cycle is larger than that in the heating cycle. Furthermore, since the density of the low-boiling-point working fluid is greater than that of the high-boiling-point working fluid, the working fluid pressure increases and the mass flow rate increases during the defrosting cycle. Ultimately, the compressor 1 does more work, that is, the condensation heat dissipation of the evaporator 8 during defrosting is greater, thereby effectively improving the defrosting effect of the non-azeotropic working fluid heat pump system.

[0041] In one embodiment, the system further includes a first temperature sensor, a second temperature sensor, and a controller. The first temperature sensor is used to acquire the ambient temperature; the second temperature sensor is used to acquire the outlet temperature of the evaporator 8; and the controller is electrically connected to both the first and second temperature sensors.

[0042] In one embodiment, the controller is also electrically connected to the solenoid valve 5 and the first throttling device 3 respectively. The controller is used to control the opening and closing of the solenoid valve 5 and the opening degree of the first throttling device 3 based on the comparison result of the ambient temperature and the outlet temperature of the evaporator 8.

[0043] Specifically, the controller compares the ambient temperature Ta collected by the first temperature sensor with the preset first target temperature Ts1 in the controller, then calculates the difference between the evaporator 8 outlet temperature Te collected by the second temperature sensor and the ambient temperature Ta, and compares the difference with the target temperature difference ds. When Te ≤ Ts1 and (Ta-Te) ≥ ds, the non-azeotropic refrigerant heat pump system is controlled to execute defrost mode. At this time, the controller controls the electronically controlled valve 5 in the refrigerant circulation loop to open, and simultaneously controls the opening degree of the first throttling device 3 to the maximum.

[0044] In one embodiment, the condenser 2 is a plate heat exchanger. The condenser 2 has a first channel for circulating refrigerant and a second channel for circulating water. The first channel is connected to the refrigerant circulation loop, and the two ends of the second channel are used to connect water-using devices.

[0045] Because the boiling points of the mixed working fluids differ significantly, the components cannot be completely condensed in condenser 2 or completely evaporated in evaporator 8, resulting in poor heating performance of the heat pump system.

[0046] In one embodiment, the heat pump system further includes a regenerator 6 having a first heat exchange channel 61 and a second heat exchange channel 62 that exchange heat with each other. The first heat exchange channel 61 is connected between the first refrigerant outlet 43 and the inlet of the evaporator 8, and the second heat exchange channel 62 is connected between the outlet of the evaporator 8 and the return port of the compressor 1. A second throttling device 7 is connected between the outlet of the first heat exchange channel 61 and the inlet of the evaporator 8.

[0047] In this embodiment, the specific heating principle is as follows: Compressor 1 compresses low-pressure, low-temperature refrigerant gas into high-pressure, high-temperature gas. The high-pressure, high-temperature refrigerant gas enters condenser 2, where it exchanges heat with the medium to be heated (such as indoor air or water), transferring heat to the indoor air or water to achieve the heating effect. After heat exchange, the refrigerant's temperature and pressure decrease, becoming a high-pressure, low-temperature gas-liquid mixture. This high-pressure, low-temperature gas-liquid mixture expands rapidly after being throttled by the first throttling device 3, causing its pressure and temperature to drop sharply, transforming into a low-pressure, low-temperature gas-liquid mixture. Then, the low-pressure, low-temperature gas-liquid mixture enters the liquid receiver 4 through the refrigerant inlet 42, and the liquid receiver 4 separates the gas-liquid mixture into gaseous working fluid and liquid working fluid. The liquid working fluid continues to be discharged from the first refrigerant outlet 43 and flows along the connecting pipeline to the first heat exchange channel 61 connected to the liquid receiver 4, so as to enter the regenerator 6 to further cool the low-temperature liquid working fluid. Then, it flows out from the first heat exchange channel 61 and flows through the second throttling device 7 for throttling again, further reducing the pressure and temperature of the refrigerant, and preparing for heat exchange in the evaporator 8. The non-azeotropic working fluid, after passing through the second throttling device 7, flows into the evaporator 8 along the connecting pipe. In the evaporator 8, the liquid working fluid absorbs heat from the air and evaporates into a low-temperature, low-pressure gas. It then flows out of the evaporator 8 outlet and into the second heat exchange channel 62 along the connecting pipe, flowing towards the regenerator 6 where it exchanges heat again with the liquid working fluid. The gaseous working fluid, after exchanging heat with the regenerator 6, flows out of the second heat exchange channel 62 and is drawn into the compressor 1, continuing its circulation through the compressor 1. This completes one heating cycle.

[0048] During the heating cycle, the evaporator 8 absorbs heat from the air, and the compressor 1 performs work, causing both parts of energy to release heat in the condenser 2, raising the water temperature for heating. The non-azeotropic working fluid undergoes throttling and reheating successively from the outlet of the condenser 2 to the inlet of the evaporator 8, which greatly reduces the throttling temperature difference between the condenser 2 and the evaporator 8 compared to traditional heat pump systems, ultimately significantly reducing throttling losses and improving heating performance.

[0049] Specifically, taking a condenser 2 outlet temperature of 45℃ and an evaporator 8 inlet temperature of -35℃ as an example, the throttling temperature difference of a traditional heat pump system reaches 80℃. However, the non-azeotropic mixed working fluid heat pump system provided in this embodiment typically has a temperature of around 20℃ after the first-stage throttling and around -30℃ after the regenerator 6. That is, the first-stage throttling temperature difference is 45℃ - 20℃ = 25℃, the second-stage throttling temperature difference is -30℃ - (-35℃) = 5℃, and the total throttling temperature difference is 25℃ + 5℃ = 30℃. Therefore, the total throttling temperature difference of the non-azeotropic mixed working fluid heat pump system provided in this embodiment is reduced by 80℃ - 30℃ = 50℃ compared to the traditional system, thereby significantly reducing the throttling temperature difference from condenser 2 to evaporator 8, greatly reducing throttling losses, and thus improving the heating performance of the mixed working fluid heat pump system.

[0050] Furthermore, the specific defrosting working principle is as follows: Compressor 1 compresses the low-pressure, low-temperature refrigerant gas into a high-pressure, high-temperature gas. The high-pressure, high-temperature refrigerant gas enters condenser 2, where it exchanges heat with the medium that needs to be heated, transferring heat to the indoor air or water to achieve a heating effect. After heat exchange, the refrigerant's own temperature and pressure decrease, becoming a high-pressure, low-temperature gas-liquid mixture. This high-pressure, low-temperature gas-liquid mixture rapidly expands after being throttled by the first throttling device 3, causing its pressure and temperature to drop sharply, transforming it into a low-pressure, low-temperature gas-liquid mixture. Then, the low-pressure, low-temperature gas-liquid mixture enters the liquid receiver 4 through the refrigerant inlet 42, and the gas-liquid mixture is separated by the liquid receiver 4 to obtain gaseous refrigerant and liquid refrigerant. In the liquid receiver 4, most of the gaseous refrigerant is discharged from the second refrigerant outlet 44 of the liquid receiver 4 into the bypass pipeline 41, and is delivered to the evaporator 8 for condensation through the electronic control valve 5. Subsequently, it flows out from the outlet of the evaporator 8 and flows into the second heat exchange channel 62 along the connecting pipeline, so as to flow to the regenerator 6 for heat absorption and evaporation. The evaporated gaseous working fluid flows out from the second heat exchange channel 62 and is sucked into the compressor 1, and continues to circulate through the compressor 1.

[0051] In one embodiment, both the first throttling device 3 and the second throttling device 7 are expansion valves. Furthermore, both the first throttling device 3 and the second throttling device 7 are combinations of expansion valves and solenoid valves.

[0052] When both the first throttling device 3 and the second throttling device 7 are a combination of an expansion valve and a solenoid valve, the first throttling device 3 and the second throttling device 7 are electrically connected to the controller. The controller controls the start and stop of the first throttling device 3 and the second throttling device 7, and controls the opening degree of the first throttling device 3 and the second throttling device 7 according to the operating requirements of different working conditions, so as to control the flow rate of refrigerant.

[0053] In one embodiment, a gas-liquid separator 9 is also provided on the refrigerant circulation loop, and the gas-liquid separator 9 is located near the return port of the compressor 1.

[0054] In this embodiment, the gas-liquid separator 9 can separate the liquid refrigerant from the non-azeotropic working fluid returned from the regenerator 6, preventing the liquid working fluid from directly entering the compressor 1. Liquid working fluid entering the compressor 1 may cause liquid slugging, meaning that when the liquid is compressed inside the compressor 1, because the liquid is incompressible, it will exert a huge impact force on the compressor 1's components, potentially damaging valves, pistons, and other parts, and in severe cases, even rendering the compressor 1 unusable. Furthermore, by separating the gas and liquid, the flow rate of the gaseous working fluid entering the compressor 1 becomes more stable and uniform, helping the compressor 1 to operate more efficiently, thereby improving the performance and energy efficiency ratio of the entire heat pump system.

[0055] In one embodiment, an evaporator fan 10 is also included, which drives air to flow through the evaporator 8.

[0056] In this embodiment, the evaporator fan 10 is used to drive airflow, so that air flows continuously and evenly across the surface of the evaporator 8, accelerating the heat transfer between the air and the evaporator 8. Moreover, by uniformly delivering air, the evaporator fan 10 helps to maintain a uniform surface temperature of the evaporator 8, reducing the possibility of frosting or making the frosting more uniform, thereby extending the effective working time of the evaporator 8, reducing the defrosting frequency, and improving the overall operating efficiency of the non-azeotropic working fluid heat pump system.

[0057] In one embodiment, a first refrigerant outlet 43 is located at the bottom of the liquid receiver 4, and a second refrigerant outlet 44 is located at the top of the liquid receiver 4. By placing the first refrigerant outlet 43 at the bottom of the liquid receiver 4, the liquid working fluid in the liquid receiver 4 can easily flow out from the first refrigerant outlet 43, allowing the liquid working fluid to be quickly transferred to the regenerator 6 for heat exchange. Due to the characteristics of the non-azeotropic mixture working fluid, the low-boiling-point working fluid is mostly in a gaseous state. By placing the second refrigerant outlet 44 at the top of the liquid receiver 4, the low-boiling-point working fluid can be easily discharged from the second refrigerant outlet of the liquid receiver 4, allowing the low-boiling-point working fluid to be quickly transferred to the evaporator 8 for condensation and heat release.

[0058] like Figure 2 As shown, the control flow of the non-azeotropic mixed working fluid heat pump system provided in the above embodiments is as follows:

[0059] Step S100: Obtain the outlet temperature Te of evaporator 8, compare the outlet temperature Te of evaporator 8 with the first target temperature Ts1, and obtain the first determination result;

[0060] Step S200: Obtain the ambient temperature Ta, calculate the difference between the ambient temperature Ta and the outlet temperature Te of the evaporator 8, compare the difference with the target temperature difference ds, and obtain the second judgment result.

[0061] Step S300: Based on the first determination result and the second determination result, control the first throttling device 3 and the electric control valve 5 to operate.

[0062] In this embodiment, the non-azeotropic mixed refrigerant heat pump system includes a heating mode and a defrosting mode. When the non-azeotropic mixed refrigerant heat pump system is started, the compressor 1 is turned on, the first throttling device 3 is turned on according to the target adjustment step, and the electronically controlled valve 5 is in the closed state. Based on the first determination result of the evaporator 8 outlet temperature Te and the first target temperature Ts1 obtained by the temperature sensor, combined with the obtained ambient temperature Ta, the difference between the ambient temperature Ta and the evaporator 8 outlet temperature Te is calculated, and a second determination result of the difference and the target temperature difference ds is obtained. The opening and closing of each valve and the start and stop of each device are controlled by the first determination result and the second determination result to switch between the heating mode and the defrosting mode. Different operating modes can be selected according to different operating conditions, which can effectively improve the heating performance of the non-azeotropic mixed refrigerant heat pump system, and at the same time, it can also make the non-azeotropic mixed refrigerant heat pump system have a high defrosting effect.

[0063] like Figure 3 As shown, in one embodiment, step S300 includes the following steps:

[0064] Step S310: In response to the first determination result being Te≤Ts1 and the second determination result being (Ta-Te)≥ds, control the electronic control valve 5 and the first throttling device 3 to be in the open state, and control the first throttling device 3 to open to the maximum degree;

[0065] Step S320: In response to the first determination result being Te > Ts1 and the second determination result being (Ta-Te) < ds, the first throttling device 3 is in the open state and the electric control valve 5 is in the closed state.

[0066] In this embodiment, if the first determination result is Te≤Ts1 and the second determination result is (Ta-Te)≥ds, it indicates that the difference between the ambient temperature Ta and the outlet temperature Te of the evaporator 8 is large, and frost forms on the surface of the evaporator 8. At this time, the electrically controlled valve 5 on the pipeline between the liquid receiver 4 and the evaporator 8 is opened to connect the liquid receiver 4 and the evaporator 8. At this time, most of the gaseous working fluid in the liquid receiver 4 enters the bypass pipeline 41 from the second refrigerant outlet 44 and is transferred to the evaporator 8 for condensation, and then flows from the evaporator 8 to the compressor 1 for circulation. When the gaseous working fluid condenses in the evaporator 8, it releases a large amount of heat to defrost. At the same time, the first throttling device 3 is opened to its maximum opening to allow more refrigerant to evaporate and absorb heat in the evaporator 8, thereby increasing the temperature of the evaporator 8 and accelerating the melting speed of the frost layer. If the first determination result is Te > Ts1 and the second determination result is (Ta-Te) < ds, it indicates that the difference between the ambient temperature Ta and the outlet temperature Te of the evaporator 8 is in a normal state; the first throttling device 3 is in a normal open state and the electric control valve 5 is in a closed state to prevent the gaseous working fluid from flowing from the liquid receiver 4 into the evaporator 8, thereby allowing the non-azeotropic mixed working fluid heat pump system to operate in heating mode.

[0067] In one embodiment, such as Figure 4 As shown, step S300 further includes the following steps:

[0068] Step S330: In response to the first determination result being Te≤Ts1 and the second determination result being (Ta-Te)≥ds, control the evaporator fan 10 and the second throttling device 7 to be in the closed state, control the electric control valve 5 and the first throttling device 3 to be in the open state, and control the first throttling device 3 to be opened to the maximum opening degree.

[0069] Step S340: In response to the first determination result being Te > Ts1 and the second determination result being (Ta-Te) < ds, the evaporator fan 10, the first throttling device 3 and the second throttling device 7 are all in the open state, and the electric control valve 5 is in the closed state.

[0070] In this embodiment, when the non-azeotropic working fluid heat pump system is started, the evaporator fan 10 and the second throttling device 7 are simultaneously turned on to the target adjustment step number. If the first determination result is Te≤Ts1 and the second determination result is (Ta-Te)≥ds, it indicates that the difference between the ambient temperature Ta and the outlet temperature Te of the evaporator 8 is large, and frost forms on the surface of the evaporator 8. At this time, it is necessary to control the evaporator fan 10 and the second throttling device 7 to shut down, and to control the electrically controlled valve 5 on the pipeline between the liquid receiver 4 and the evaporator 8 to connect the liquid receiver 4 and the evaporator 8. At this time, most of the gaseous working fluid in the liquid receiver 4 enters the bypass pipeline 41 from the second refrigerant outlet 44 and is transferred to the evaporator 8 for condensation. Then, it flows from the evaporator 8 to the second heat exchange channel 62 in the regenerator 6 for heat absorption and evaporation. When the gaseous working fluid condenses in the evaporator 8, it releases a large amount of heat for defrosting. At the same time, the first throttling device 3 is controlled to open to the maximum degree so that more refrigerant evaporates and absorbs heat in the evaporator 8, thereby increasing the temperature of the evaporator 8 and accelerating the melting speed of the frost layer.

[0071] If the first determination result is Te > Ts1 and the second determination result is (Ta-Te) < ds, it indicates that the difference between the ambient temperature Ta and the outlet temperature Te of the evaporator 8 is in a normal state. The evaporator fan 10, the first throttling device 3 and the second throttling device 7 are all in the open state, and the electric control valve 5 is kept in the closed state to prevent the gaseous working fluid from flowing from the liquid receiver 4 into the evaporator 8, so that the non-azeotropic mixed working fluid heat pump system can operate in heating mode.

[0072] like Figure 5 As shown, in one embodiment, step S340 includes the following steps:

[0073] Step S341: In response to the heat pump system being in heating mode, obtain the target adjustment steps of the first throttling device 3 and the second throttling device 7;

[0074] Step S342: Adjust the opening degree of the first throttling device 3 and the second throttling device 7 based on the target adjustment step number;

[0075] Step S343: Control the first throttling device 3 and the second throttling device 7 to operate at the adjusted opening.

[0076] In this embodiment, when the non-azeotropic heat pump system is in heating mode, it operates in heating mode. At this time, based on the current operating status of the non-azeotropic heat pump system, such as temperature, pressure, working fluid flow rate, and the preset target heating temperature, the opening degree of the first throttling device 3 and the second throttling device 7 needs to be determined to achieve precise adjustment of the operating status of the non-azeotropic heat pump system. For example, if the current heating effect is poor, it may be necessary to increase the working fluid flow rate. Therefore, the corresponding target adjustment steps will be calculated to increase the opening degree of the throttling devices to increase the working fluid flow rate and enhance the heating effect.

[0077] Then, based on the calculated target adjustment steps, the opening degrees of the first throttling device 3 and the second throttling device 7 are actually adjusted using a stepper motor. After adjusting the opening degrees of the first throttling device 3 and the second throttling device 7 to the target values, the non-azeotropic heat pump system controls both throttling devices to maintain stable operation at the adjusted opening degrees, achieving stable and efficient heating operation. Simultaneously, the non-azeotropic heat pump system continuously monitors relevant operating parameters to readjust the opening degrees of the throttling devices according to actual conditions, ensuring that the non-azeotropic heat pump system is always in optimal heating operation.

[0078] like Figure 6 As shown, in one embodiment, after step S330, the following steps are included:

[0079] Step S331: In response to the heat pump system being in defrost mode, detect the outlet temperature Te of evaporator 8, compare the outlet temperature Te of evaporator 8 with the second target temperature Ts2, and obtain the third judgment result.

[0080] Step S332: In response to the third determination result that Te≥Ts2, control the evaporator fan 10, the first throttling device 3 and the second throttling device 7 to open, and control the electric control valve 5 to close, so as to switch to the heating mode.

[0081] Step S333: In response to the third determination result being Te < Ts2, the evaporator fan 10 and the second throttling device 7 remain closed, while the electric control valve 5 and the first throttling device 3 remain open to maintain the defrosting mode.

[0082] In this embodiment, when the operating mode of the non-azeotropic heat pump system switches to defrost mode, the outlet temperature Te of the evaporator 8 is continuously monitored by a temperature sensor and compared with the second target temperature Ts2. Then, based on the comparison result, the first throttling device 3, the second throttling device 7, the electronically controlled valve 5, and the evaporator fan 10 are controlled to switch to heating mode or maintain defrost mode. If the third determination result is Te≥Ts2, it indicates that the operating condition of the non-azeotropic heat pump system has returned to normal. At this time, the evaporator fan 10, the first throttling device 3, and the second throttling device 7 are turned on, restoring the heating circuit of the non-azeotropic heat pump system to normal operating status. Simultaneously, the electronically controlled valve 5 is closed, switching the operating mode of the non-azeotropic heat pump system to heating mode. It is understood that the opening degrees of the first throttling device 3 and the second throttling device 7 are restored to their pre-defrost opening degrees.

[0083] If the third determination result is Te < Ts2, it means that the frost layer on the surface of the evaporator 8 has not been completely removed. At this time, the evaporator fan 10 and the second throttling device 7 remain in the closed state, and the electric control valve 5 and the first throttling device 3 remain in the open state to maintain the defrosting mode until the frost layer on the surface of the evaporator 8 is completely removed.

[0084] It is understood that the first target temperature Ts1, the target temperature difference ds, and the second target temperature Ts2 in this invention can all be set according to actual needs, and no specific restrictions are imposed here.

[0085] In the specific implementation of the above embodiments, the technical features can be combined in any non-contradictory way. For the sake of brevity, not all possible combinations of the above technical features are described. However, as long as the combination of these technical features is not contradictory, it should be considered to be within the scope of this specification.

[0086] The specific embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A non-azeotropic mixed working fluid heat pump system, characterized in that, include: A compressor (1) and a refrigerant circulation loop connected to the compressor (1) to form a loop, wherein a condenser (2), a first throttling device (3), a liquid receiver (4) and an evaporator (8) are sequentially arranged along the refrigerant flow direction on the refrigerant circulation loop; The liquid receiver (4) is provided with a refrigerant inlet (42), a first refrigerant outlet (43) and a second refrigerant outlet (44). The refrigerant inlet (42) is connected to the first throttling device (3), the first refrigerant outlet (43) is connected to the inlet of the evaporator (8), and the second refrigerant outlet (44) is connected to the inlet of the evaporator (8) through a bypass pipe (41). An electric control valve (5) is provided on the bypass pipe (41).

2. The non-azeotropic mixed working fluid heat pump system according to claim 1, characterized in that, Also includes: The regenerator (6) has a first heat exchange channel (61) and a second heat exchange channel (62) for mutual heat exchange. The first heat exchange channel (61) is connected between the first refrigerant outlet (43) and the inlet of the evaporator (8), and the second heat exchange channel (62) is connected between the outlet of the evaporator (8) and the return port of the compressor (1). The second throttling device (7) is connected between the outlet of the first heat exchange channel (61) and the inlet of the evaporator (8).

3. The non-azeotropic mixed working fluid heat pump system according to claim 2, characterized in that, Both the first throttling device (3) and the second throttling device (7) are expansion valves.

4. The non-azeotropic mixed working fluid heat pump system according to claim 2, characterized in that, Both the first throttling device (3) and the second throttling device (7) are combinations of expansion valves and solenoid valves.

5. The non-azeotropic mixed working fluid heat pump system according to any one of claims 1-4, characterized in that, The refrigerant circulation loop is also equipped with a gas-liquid separator (9), which is located near the return port of the compressor (1).

6. The non-azeotropic mixed working fluid heat pump system according to any one of claims 1-4, characterized in that, It also includes an evaporator fan (10) for driving air through the evaporator (8).

7. The non-azeotropic mixed working fluid heat pump system according to claim 1, characterized in that, The first refrigerant outlet (43) is located at the bottom of the liquid reservoir (4), and the second refrigerant outlet (44) is located at the top of the liquid reservoir (4).

8. The non-azeotropic mixed working fluid heat pump system according to claim 1, characterized in that, The condenser (2) is a plate heat exchanger. The condenser (2) has a first channel for circulating refrigerant and a second channel for circulating water. The first channel is connected to the refrigerant circulation loop, and the two ends of the second channel are used to connect water-using devices.

9. The non-azeotropic mixed working fluid heat pump system according to claim 1, characterized in that, Also includes: The first temperature sensor is used to collect ambient temperature; The second temperature sensor is used to collect the outlet temperature of the evaporator (8); The controller is electrically connected to the first temperature sensor and the second temperature sensor, respectively.

10. The non-azeotropic mixed working fluid heat pump system according to claim 9, characterized in that, The controller is also electrically connected to the electric control valve (5) and the first throttling device (3) respectively. The controller is used to control the opening and closing of the electric control valve (5) and the opening degree of the first throttling device (3) based on the comparison result between the ambient temperature and the outlet temperature of the evaporator (8).

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