A bidirectional adjustable regenerative cycle co2 heat pump module device
Patent Information
- Application Number
- CN202522303876.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-30
- Publication Date
- 2026-09-29
- Estimated Expiration
- 2035-10-30
AI Technical Summary
由于液态冷媒不可压缩，若进入压缩机气缸，会引发液击现象，大幅缩短压缩机的使用寿命，甚至导致系统停机
本实用新型提供的一种具有双向可调回热循环CO2热泵模块装置，通过引入带有多个单向连通接口的换向装置，在仅采用单个回热器的前提下，便可实现夏季与冬季的双向循环；通过设置能根据温度调节流经回热器低压侧的冷媒量以及直接进入压缩机进气端的冷媒量的分流装置，使得CO2热泵模块装置能够根据工况进行动态调整流量，提高了热泵系统的能效、制冷量以及制热量，降低了系统的复杂度与成本，同时减少了维护成本，提升了系统的可靠性。
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Figure CN224815171U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of heat pump system technology, and in particular to a CO2 heat pump module device with bidirectional adjustable heat return cycle. Background Technology
[0002] Hydrofluorocarbons (HFCs), as refrigerants with high global warming potential, pose a significant threat to ozone layer depletion and global warming due to their widespread use. Based on this, the international community adopted the Kigali Amendment, imposing control measures on HFCs. my country has officially joined the amendment, explicitly including HFCs in its key control scope. Against this policy backdrop, exploring the application of natural refrigerants has become a cutting-edge research direction in the field of thermal management.
[0003] Carbon dioxide is considered an ideal alternative due to its zero ozone depletion potential. However, its practical application still faces many technical challenges. Most existing carbon dioxide heat pump systems use a single regenerator design, which makes it difficult to dynamically adapt to the variable flow requirements caused by different environmental and room temperatures. This limits the system's stability under variable flow and temperature conditions, and can easily lead to insufficient air conditioning cooling capacity under high loads due to insufficient heat recovery.
[0004] Meanwhile, in northern my country, winter temperatures often drop below -20°C. When carbon dioxide heat pump systems operate under these low-temperature conditions, the compressor intake is prone to carrying liquid refrigerant. Since liquid refrigerant is incompressible, if it enters the compressor cylinder, it can cause liquid slugging, significantly shortening the compressor's lifespan and even leading to system shutdown. The heating capacity will also decrease due to the refrigerant's thermodynamic properties, resulting in insufficient heating capacity, a sharp drop in energy efficiency ratio, and difficulty in meeting heating demands. While using electric auxiliary heating can compensate for the reduced heating capacity, it significantly increases energy consumption and operating costs. Utility Model Content
[0005] This invention provides a CO2 heat pump module device with bidirectional adjustable recirculation heat cycle to overcome the above-mentioned technical problems.
[0006] To achieve the above objectives, the technical solution of this utility model is as follows: A CO2 heat pump module device with bidirectional adjustable regenerative cycle includes a compressor, a four-way reversing valve, a reversing device, a first throttle valve, a regenerator, an evaporator, and a gas-liquid separator. The first and second ports, the third and first ports, the third and fourth ports, and the fourth and second ports of the reversing device are all unidirectionally connected. The compressor's outlet is connected to port d of the four-way reversing valve, the four-way reversing valve's port c is connected to the first port of the reversing device, and the second port of the reversing device is connected to the high-pressure side inlet of the regenerator. The high-pressure side outlet of the regenerator... The inlet is connected to the third and fourth ports of the reversing device via a first pipeline equipped with a first throttle valve and a temperature sensor. The two ends of the evaporator are connected to the first pipeline and the e port of the four-way reversing valve, respectively. The inlet of the gas-liquid separator is connected to the s port of the four-way reversing valve. The outlet of the gas-liquid separator is connected to the low-pressure side inlet of the regenerator and the air inlet of the compressor via a flow divider. The flow divider can adjust the amount of refrigerant flowing through the low-pressure side of the regenerator and the amount of refrigerant directly entering the air inlet of the compressor according to the temperature data detected by the temperature sensor.
[0007] Furthermore, the flow splitting device includes a second throttle valve and a third throttle valve. The inlet ends of both the second and third throttle valves are connected to the outlet end of the gas-liquid separator. The outlet end of the second throttle valve is connected to the low-pressure side inlet of the regenerator, and the outlet end of the third throttle valve is connected to the air inlet of the compressor.
[0008] Furthermore, the reversing device includes a first check valve, a second check valve, a third check valve, and a fourth check valve; The first interface is located between the outlet end of the first check valve and the inlet end of the fourth check valve; the second interface is located between the outlet end of the third check valve and the outlet end of the fourth check valve; the third interface is located between the inlet end of the first check valve and the inlet end of the second check valve; and the fourth interface is located between the outlet end of the second check valve and the inlet end of the third check valve.
[0009] Furthermore, a condenser is provided between port C of the four-way reversing valve and the first interface of the reversing device.
[0010] Furthermore, the first pipeline includes a main pipeline and two branch pipelines. The first throttle valve and temperature sensor are installed on the main pipeline. One end of the main pipeline is connected to the high-pressure side outlet of the regenerator, and the other end of the main pipeline is connected to one end of the two branch pipelines. The other ends of the two branch pipelines are respectively connected to the third interface and the fourth interface.
[0011] Furthermore, a drying filter is provided between the first throttle valve and the temperature sensor.
[0012] Beneficial effects: This utility model provides a CO2 heat pump module device with bidirectional adjustable regenerative cycle. By introducing a reversing device with multiple unidirectional connection interfaces, bidirectional circulation in summer and winter can be achieved using only a single regenerator. By setting up a flow-diverting device that can adjust the amount of refrigerant flowing through the low-pressure side of the regenerator and the amount of refrigerant directly entering the compressor intake end according to the temperature, the CO2 heat pump module device can dynamically adjust the flow rate according to the operating conditions, improving the energy efficiency, cooling capacity, and heating capacity of the heat pump system, reducing the system complexity and cost, reducing maintenance costs, and improving the system reliability. Attached Figure Description
[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the 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 based on these drawings without creative effort.
[0014] Figure 1 This is a schematic diagram of the structure of a CO2 heat pump module device with bidirectional adjustable recirculation heat cycle disclosed in this utility model; Figure 2 This is a schematic diagram of the refrigerant flow in summer cooling mode within a CO2 heat pump module device with bidirectional adjustable heat cycle disclosed in this utility model. Figure 3 This is a schematic diagram of the refrigerant flow in a low-temperature regenerative mode in winter within a CO2 heat pump module device with bidirectional adjustable regenerative heat cycle disclosed in this utility model. Figure 4 This is a schematic diagram of the structure of an existing CO2 heat pump module device.
[0015] In the picture: 1. Compressor; 2. Four-way directional valve; 3. Condenser; 4. First check valve; 5. Second check valve; 6. Third check valve; 7. Fourth check valve; 8. First throttle valve; 9. Regenerator; 10. Evaporator; 11. Gas-liquid separator; 12. Temperature sensor; 13. Second throttle valve; 14. Third throttle valve; 15. Dryer filter; Ⅰ. First interface; Ⅱ. Second interface; Ⅲ. Third interface; Ⅳ. Fourth interface. Detailed Implementation
[0016] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0017] This embodiment provides a CO2 heat pump module device with bidirectional adjustable heat return cycle, such as... Figure 1 As shown, the device includes a compressor 1, a four-way reversing valve 2, a reversing device, a first throttle valve 8, a regenerator 9, an evaporator 10, and a gas-liquid separator 11. The first port I and second port II, the third port III, the first port I, the third port III, and the fourth port IV, as well as the fourth port IV and the second port II of the reversing device, are all unidirectionally connected. The outlet of the compressor 1 is connected to port d of the four-way reversing valve 2, and port c of the four-way reversing valve 2 is connected to port I of the reversing device. A condenser 3 is located between port c of the four-way reversing valve 2 and port I of the reversing device. The second port II of the reversing device is connected to the high-pressure side inlet of the regenerator 9. The high-pressure side outlet of the regenerator 9 is connected to the third interface III and the fourth interface IV of the reversing device via a first pipeline equipped with a first throttle valve 8 and a temperature sensor 12. The two ends of the evaporator 10 are respectively connected to the first pipeline and the e port of the four-way reversing valve 2. The inlet end of the gas-liquid separator 11 is connected to the s port of the four-way reversing valve 2. The outlet end of the gas-liquid separator 11 is connected to the low-pressure side inlet of the regenerator 9 and the air inlet of the compressor 1 via a flow divider. The flow divider can adjust the amount of refrigerant flowing through the low-pressure side of the regenerator 9 and the amount of refrigerant directly entering the air inlet of the compressor 1 according to the temperature data detected by the temperature sensor 12.
[0018] The method of controlling the flow rate based on temperature regulation is a well-known existing technology and is not the inventive point of this application, so it will not be elaborated further here.
[0019] This utility model provides a CO2 heat pump module device and control method with bidirectional adjustable regenerative cycle. By introducing a reversing device with multiple unidirectional connection interfaces, bidirectional circulation in summer and winter can be achieved using only a single regenerator. By setting up a flow divider that can adjust the amount of refrigerant flowing through the low-pressure side of the regenerator and the amount of refrigerant directly entering the compressor intake end according to the temperature, the CO2 heat pump module device can dynamically adjust the flow rate according to the operating conditions, improving the energy efficiency, cooling capacity, and heating capacity of the heat pump system, reducing the system complexity and cost, reducing maintenance costs, and improving the system reliability.
[0020] Specifically, such as Figure 1 As shown, the flow splitting device includes a second throttle valve 13 and a third throttle valve 14. The inlet ends of the second throttle valve 13 and the third throttle valve 14 are both connected to the outlet end of the gas-liquid separator 11. The outlet end of the second throttle valve 13 is connected to the low-pressure side inlet of the regenerator 9, and the outlet end of the third throttle valve 14 is connected to the air inlet end of the compressor 1.
[0021] Specifically, such as Figure 1 As shown, the reversing device includes a first check valve 4, a second check valve 5, a third check valve 6, and a fourth check valve 7; The first interface I is located between the outlet end of the first one-way valve 4 and the inlet end of the fourth one-way valve 7; the second interface II is located between the outlet end of the third one-way valve 6 and the outlet end of the fourth one-way valve 7; the third interface III is located between the inlet end of the first one-way valve 4 and the inlet end of the second one-way valve 5; and the fourth interface IV is located between the outlet end of the second one-way valve 5 and the inlet end of the third one-way valve 6.
[0022] The reversing device structure ensures that the refrigerant in the pipeline from the second port II to the third port III always flows in one direction, preventing the refrigerant fluid from reversing due to special operating conditions (such as the system defrosting process) and impacting the first throttle valve 8, causing the first throttle valve 8 (electronic expansion valve) to lose synchronization.
[0023] Preferably, such as Figure 1 As shown, a drying filter 15 is provided between the first throttle valve 8 and the temperature sensor 12.
[0024] Normal operation can be achieved with only a one-way electronic expansion valve as the first throttle valve 8 and a one-way filter 15, eliminating the need for a two-way filter and a two-way electronic expansion valve, which greatly reduces the cost of the system.
[0025] Specifically, such as Figure 1As shown, the first pipeline includes a main pipeline and two branch pipelines. The first throttle valve 8 and the temperature sensor 12 are installed on the main pipeline. One end of the main pipeline is connected to the high-pressure side outlet of the regenerator 9, and the other end of the main pipeline is connected to one end of the two branch pipelines. The other ends of the two branch pipelines are respectively connected to the third interface III and the fourth interface IV.
[0026] In practical applications, the aforementioned CO2 heat pump module device with bidirectional adjustable heat recovery cycle is preloaded with a summer cooling mode and a winter low-temperature heat recovery mode. like Figure 2 As shown, the summer cooling mode means that the refrigerant discharged from the compressor 1 enters the d port of the four-way reversing valve 2, and then exits from the c port. After passing through the condenser 3 and the fourth one-way valve 7, it enters the high-pressure side of the regenerator 9, and then enters the evaporator 10 through the first throttle valve 8 and the second one-way valve 5. The refrigerant discharged from the evaporator 10 enters the e port of the four-way reversing valve 2, and then exits from the s port into the gas-liquid separator 11. After the liquid phase components are separated from the gas-liquid separator 11, part of the gaseous refrigerant enters the low-pressure side of the regenerator 9 through the second throttle valve 13, and then enters the inlet end of the compressor 1; the other part enters the inlet end of the compressor 1 directly through the third throttle valve 14. like Figure 3 As shown, the winter low-temperature regeneration mode refers to the following: the refrigerant discharged from the compressor 1 enters the d port of the four-way reversing valve 2, and then exits from the e port. After passing through the evaporator 10 and the third check valve 6, it enters the high-pressure side of the regenerator 9, and then enters the condenser 3 through the first throttle valve 8 and the first check valve 4. The refrigerant discharged from the condenser enters the c port of the four-way reversing valve 2, and then exits from the s port into the gas-liquid separator 11. After the liquid phase components are separated from the gas-liquid separator 11, part of the gaseous refrigerant enters the low-pressure side of the regenerator 9 through the second throttle valve 13, and then enters the intake end of the compressor 1; the other part enters the intake end of the compressor 1 directly through the third throttle valve 14.
[0027] The heat pump module is equipped with a temperature sensor corresponding to the compressor to detect the compressor's suction and discharge temperatures. In this embodiment, the control logic of the second throttle valve 13 in the summer cooling mode is as follows: The transfer function controlling the opening degree of the second throttle valve 13: G(x)=(K1×(Tdis-Tp1)+K2×(Tsu-Ts)+K3×Tva)×K4 wherein, Tdis is the discharge temperature of the compressor, Tp1 is the target discharge temperature in summer, Tsu is the suction temperature of the compressor, Ts is the saturation temperature of evaporation pressure, Tva is the temperature measured by the temperature sensor 12, K1 is the summer discharge coefficient, K2 is the summer superheat coefficient, K3 is the summer regenerative coefficient, and K4 is the summer transfer coefficient; and the opening degree of the second throttle valve 13 is determined by comparing G(x) with a first threshold a1, a second threshold b1, a third threshold c1 and a fourth threshold d1, wherein a1<b1<c1<d1, that is: when G(x)≥d1, the second throttle valve 13 is opened by 10 steps; when c1≤G(x)<d1, the second throttle valve 13 is opened by 5 steps; when b1≤G(x)<c1, the opening degree of the second throttle valve 13 remains unchanged; when a1≤G(x)<b1, the second throttle valve 13 is closed by 5 steps; when G(x)<a1, the second throttle valve 13 is closed by 10 steps; said a1, b1, c1 and d1 are determined through tests; the control logic of the third throttle valve 14 in the summer refrigeration mode is as follows: when Tdis>Tp1, the third throttle valve 14 is fully opened; when Tp1-10<Tdis≤Tp1, the third throttle valve 14 is opened to 50%; when Tdis≤Tp1-10, the third throttle valve 14 is fully closed; the control logic of the second throttle valve 13 in the winter low-temperature regeneration mode is as follows: G(x) = (K5×(Tdis - Tp2) + K6×(Tsu - Ts) + K7×Tva) × K8 wherein, Tp2 is the target discharge temperature in winter, K5 is the winter discharge coefficient, K6 is the winter superheat coefficient, K7 is the winter regenerative coefficient, and K8 is the winter transfer coefficient; and the opening degree of the second throttle valve 13 is determined by comparing G(x) with a fifth threshold a2, a sixth threshold b2, a seventh threshold c2 and an eighth threshold d2, wherein a2<b2<c2<d2, that is: when G(x)≥d2, the second throttle valve 13 is opened by 10 steps; when c2≤G(x)<d2, the second throttle valve 13 is opened by 5 steps; when b2≤G(x)<c2, the opening degree of the second throttle valve 13 remains unchanged; when a2≤G(x)<b2, the second throttle valve 13 is closed by 5 steps; when G(x)<a2, the second throttle valve 13 is closed by 10 steps; a2, b2, c2, and d2 were confirmed by experiments; The control logic of the third throttle valve 14 under the winter low-temperature regeneration mode is as follows: When Tdis > Tp2, the third throttle valve 14 is fully open; When Tp2-10 < Tdis ≤ Tp2, the third throttle valve 14 is open by 50%; When Tdis≤Tp2-10, the third throttle valve 14 is fully closed.
[0028] Preferably, Tp1=110, Tp2=90, K1=10, K2=0.5, K3=2, K4=-5, K5=8, K6=5, K7=15, and K8=-10.
[0029] To better illustrate the beneficial effects of this embodiment, it is compared with the prior art below. Figure 4 An existing CO2 air conditioning system includes a compressor 1, a four-way reversing valve 2, a condenser 3, a first throttle valve 8, a regenerator 9, an evaporator 10, and a gas-liquid separator 11.
[0030] Compared to existing CO2 heat pump module devices, the improvements in heating capacity and energy efficiency under limited operating conditions in this embodiment are shown in the table below: When the heat recovery rate is controlled at 3.5kW, the cooling effect in summer is as follows:
[0031] When the heat recovery rate is controlled at 4.3kW, the cooling effect in summer is as follows:
[0032] When the heat return is controlled at 1kW, the heating effect in winter is as follows:
[0033] When the heat return is controlled at 1.8kW, the heating effect in winter is as follows:
[0034] By controlling the heat recovery, the system's energy efficiency and cooling / heating performance are improved in both summer and winter. This application aims to address the problem of liquid slugging in the compressor due to liquid in the suction air caused by the compressor operating at low temperatures in the frigid winter environments of northern my country. It also solves the problem of insufficient heating performance of heat pump systems in high-altitude and cold regions due to low winter ambient temperatures. Furthermore, this application can increase the heating capacity of heat pumps in high-altitude and cold regions, increase the supply air temperature in low-temperature regenerative mode during winter, enhance user comfort, and, in extreme cases, ensure that the exhaust temperature does not exceed the compressor's exhaust temperature operating limit by dynamically adjusting the heat recovery.
[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.
Claims
1. A CO2 heat pump module device with bidirectional adjustable recirculation heat cycle, characterized in that, The system includes a compressor (1), a four-way reversing valve (2), a reversing device, a first throttle valve (8), a regenerator (9), an evaporator (10), and a gas-liquid separator (11). The first and second ports, the third and first ports, the third and fourth ports, and the fourth and second ports of the reversing device are all unidirectionally connected. The outlet of the compressor (1) is connected to port d of the four-way reversing valve (2), port c of the four-way reversing valve (2) is connected to the first port of the reversing device, the second port of the reversing device is connected to the high-pressure side inlet of the regenerator (9), and the high-pressure side outlet of the regenerator (9) is connected to the first throttle valve (8). The first pipe of the temperature sensor (12) is connected to the third and fourth ports of the reversing device. The two ends of the evaporator (10) are connected to the first pipe and the e port of the four-way reversing valve (2) respectively. The inlet end of the gas-liquid separator (11) is connected to the s port of the four-way reversing valve (2). The outlet end of the gas-liquid separator (11) is connected to the low-pressure side inlet of the regenerator (9) and the air inlet end of the compressor (1) through the diversion device. The diversion device can adjust the amount of refrigerant flowing through the low-pressure side of the regenerator (9) and the amount of refrigerant directly entering the air inlet end of the compressor (1) according to the temperature data detected by the temperature sensor (12).
2. The CO2 heat pump module device with bidirectional adjustable heat return cycle according to claim 1, characterized in that, The flow divider includes a second throttle valve (13) and a third throttle valve (14). The inlet ends of the second throttle valve (13) and the third throttle valve (14) are both connected to the outlet end of the gas-liquid separator (11). The outlet end of the second throttle valve (13) is connected to the low-pressure side inlet of the regenerator (9), and the outlet end of the third throttle valve (14) is connected to the air inlet end of the compressor (1).
3. The CO2 heat pump module device with bidirectional adjustable heat return cycle according to claim 2, characterized in that, The reversing device includes a first check valve (4), a second check valve (5), a third check valve (6), and a fourth check valve (7). The first interface is located between the outlet end of the first check valve (4) and the inlet end of the fourth check valve (7); the second interface is located between the outlet end of the third check valve (6) and the outlet end of the fourth check valve (7); the third interface is located between the inlet end of the first check valve (4) and the inlet end of the second check valve (5); and the fourth interface is located between the outlet end of the second check valve (5) and the inlet end of the third check valve (6).
4. The CO2 heat pump module device with bidirectional adjustable heat return cycle according to claim 3, characterized in that, A condenser (3) is provided between port c of the four-way reversing valve (2) and the first interface of the reversing device.
5. A CO2 heat pump module device with bidirectional adjustable heat return cycle according to claim 4, characterized in that, The first pipeline includes a main pipeline and two branch pipelines. The first throttle valve (8) and temperature sensor (12) are installed on the main pipeline. One end of the main pipeline is connected to the high-pressure side outlet of the regenerator (9), and the other end of the main pipeline is connected to one end of the two branch pipelines. The other ends of the two branch pipelines are respectively connected to the third interface and the fourth interface.
6. A CO2 heat pump module device with bidirectional adjustable heat return cycle according to claim 4, characterized in that, A drying filter (15) is provided between the first throttle valve (8) and the temperature sensor (12).