Air conditioning system and control method thereof

Abstract

The invention relates to the technical field of air conditioners, in particular to an air conditioning system and a control method thereof.The air conditioning system comprises a refrigerant circulation loop, a compressor, a condenser and an evaporator are arranged on the refrigerant circulation loop, the air conditioning system further comprises a bypass auxiliary path and a flash evaporator, and the flash evaporator is arranged on the refrigerant circulation loop and located between the condenser and the evaporator; one end of the bypass auxiliary path is connected with an air outlet of the flash evaporator, and the other end is connected with a pipeline between the evaporator and an air suction port of the compressor; and the gas refrigerant subjected to flash evaporation can enter the bypass auxiliary path and then is mixed with the refrigerant at the outlet of the evaporator to enter an air suction port of the compressor. The gaseous refrigerant after flash evaporation enters the bypass auxiliary path and is mixed with the refrigerant at the outlet of the evaporator to enter the air suction port of the compressor, it is guaranteed that the air suction temperature and the air suction pressure of the compressor are close to the non-frosting condition, the separated liquid refrigerant enters the evaporator to fully absorb heat and evaporate, and the frosting risk of the evaporator is reduced.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and specifically provides an air conditioning system and its control method. Background Technology

[0002] In heat pump air conditioning systems, the outdoor evaporator is prone to frosting under low-temperature heating conditions. The frost layer increases the thermal resistance on the air side, reduces the air volume, and results in insufficient heat exchange in the evaporator, thereby reducing the system's heating capacity and affecting the user experience. Currently, the commonly used principle for delaying frosting is to ensure that the saturation temperature at the evaporator outlet suction pressure is higher than 0℃. Therefore, the methods for delaying frosting include (1) reducing the compressor frequency and decreasing the compression ratio (lower high pressure and higher low pressure) to increase the suction pressure and suction temperature. However, the system's heating capacity will be significantly reduced, affecting the user experience; (2) increasing the main valve opening while keeping the frequency constant, which can directly increase the suction pressure and suction temperature. However, this increases the refrigerant flow on the evaporator side, causing the refrigerant to not completely evaporate on the evaporator side. This requires setting up a large-volume gas-liquid separator on the suction side. The gas-liquid separator is used to separate liquid refrigerant. Due to space constraints, it is impossible to implement a large-volume gas-liquid separator. Therefore, if the main valve is opened too high under the condition that the frequency remains unchanged, the compressor will suck up liquid. Long-term operation with a large opening may affect the stability of the compressor operation. (3) Increase the speed of the outdoor fan or replace it with a large-size fan blade. The increased air volume of the outdoor unit will enhance the heat exchange capacity of the evaporator side, thereby increasing the system suction pressure and suction temperature. At the same time, due to the increased air volume, the flow rate of water vapor flowing through the fins will also increase, which will accelerate the frosting speed. Therefore, increasing the air volume cannot achieve the effect of delaying frosting in all operating conditions.

[0003] Accordingly, there is a need in the field for a new air conditioning system to address the problem that existing air conditioning systems, while delaying evaporator frosting, can easily lead to reduced heating capacity and system operational stability. Summary of the Invention

[0004] The present invention aims to solve the above-mentioned technical problems, namely, to solve the problem that existing air conditioning systems, while delaying evaporator frosting, easily lead to a decrease in heating capacity and system operational stability.

[0005] This invention provides an air conditioning system comprising a refrigerant circulation loop, on which a compressor, a condenser, and an evaporator are disposed. The system also includes a bypass path and a flash evaporator. The flash evaporator is disposed on the refrigerant circulation loop and located between the condenser and the evaporator. One end of the bypass path is connected to the outlet of the flash evaporator, and the other end is connected to a pipeline between the evaporator and the compressor suction port. This allows the refrigerant from the condenser outlet to enter the flash evaporator and flash. The flashed gaseous refrigerant enters the bypass path, while the liquid refrigerant enters the evaporator to absorb heat. The refrigerant from the bypass path and the evaporator outlet mix and enter the compressor suction port.

[0006] When the above technical solution is adopted, the refrigerant circulation loop compresses the low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant. The high-temperature, high-pressure gaseous refrigerant releases heat and condenses into a high-temperature, high-pressure liquid refrigerant in the condenser. The liquid refrigerant enters the evaporator, absorbs heat, and evaporates into a low-temperature, low-pressure gaseous refrigerant. The gaseous refrigerant is then drawn into the compressor and compressed to enter the next cycle. Throughout the process, the refrigerant releases heat in the condenser and absorbs heat in the evaporator to achieve the purpose of heating. The air conditioning system of this invention adds a bypass auxiliary path to assist the evaporator in increasing the suction temperature. The refrigerant from the condenser outlet enters the flash evaporator and is separated into gaseous and liquid refrigerant. The flashed gaseous refrigerant can enter the bypass auxiliary path and mix with the low-temperature, low-pressure gaseous refrigerant at the evaporator outlet before entering the compressor suction port. This ensures that the compressor suction temperature and suction pressure are close to those under non-frosting conditions, thereby ensuring stable heating capacity. The separated liquid refrigerant enters the evaporator and, due to the mixing of the refrigerant at the evaporator outlet with the refrigerant in the bypass auxiliary path, returns to the compressor, reducing the amount of refrigerant entering the evaporator and thus reducing the heat load on the evaporator. The refrigerant can fully absorb heat and evaporate in the evaporator to increase the suction temperature and suction pressure, thereby reducing the risk of evaporator frosting. In this way, the air conditioning system can reduce the risk of evaporator frosting while ensuring stable heating capacity and not reducing user thermal comfort.

[0007] In the optional technical solutions of the above-mentioned air conditioning system, the air conditioning system further includes a first throttling device, which is disposed on the pipeline between the flash evaporator and the condenser.

[0008] When the above technical solution is adopted, the refrigerant before entering the flash evaporator is throttled and depressurized to a state suitable for flash evaporation by adjusting the opening of the first throttling device, thereby providing the flash evaporation effect.

[0009] In the optional technical solutions of the above-mentioned air conditioning system, a second throttling device is provided on the refrigerant circulation loop, and the second throttling device is located between the flash evaporator and the evaporator.

[0010] By adopting the above technical solution, the refrigerant before entering the evaporator is throttled and depressurized by adjusting the second throttling device, thereby improving the evaporation effect of the refrigerant in the evaporator.

[0011] In the optional technical solutions of the above-mentioned air conditioning system, the air conditioning system further includes a valve body, which is disposed on the bypass auxiliary road.

[0012] When the above technical solution is adopted, the valve body is used to control the connection between the bypass auxiliary circuit and the compressor.

[0013] In the optional technical solutions of the above-mentioned air conditioning system, the air conditioning system further includes a four-way valve, which is installed on the refrigerant circulation loop.

[0014] By adopting the above technical solution, the flow direction of refrigerant in the air conditioning system is controlled by the reversing of the four-way valve, thereby realizing the switching of the air conditioning system's cooling or heating functions. The controllability and reliability of the pipeline are improved by multi-path diversion.

[0015] In the optional technical solutions of the above-mentioned air conditioning system, the first throttling device is an expansion valve or a capillary tube.

[0016] With the above technical solution, either the expansion valve or the capillary tube can throttle the refrigerant before it enters the flash evaporator to achieve a state suitable for flashing.

[0017] This invention also provides a control method for an air conditioning system. The air conditioning system includes a refrigerant circulation loop, on which a compressor, a condenser, and an evaporator are disposed. The air conditioning system further includes a bypass auxiliary path and a flash evaporator. The flash evaporator is disposed in the refrigerant circulation loop and located between the condenser and the evaporator. One end of the bypass auxiliary path is connected to the outlet of the flash evaporator, and the other end is connected to a pipeline between the evaporator and the compressor suction port. This allows the refrigerant from the condenser outlet to enter the flash evaporator and flash. The flashed gaseous refrigerant enters the bypass auxiliary path, while the liquid refrigerant enters the evaporator to absorb heat. The refrigerant from the bypass auxiliary path and the outlet refrigerant of the evaporator mix and enter the compressor suction port. The air conditioning system also includes a valve body disposed on the bypass auxiliary path.

[0018] The control method includes:

[0019] Received instruction to run delayed frosting heating mode;

[0020] Control the valve body to open.

[0021] When the above technical solution is adopted, after receiving the instruction to operate the delayed frosting heating mode, the valve body is opened to connect the bypass auxiliary circuit and the compressor suction port, so that the gaseous refrigerant in the bypass auxiliary circuit and the gaseous refrigerant at the evaporator outlet are mixed and enter the compressor suction port, thereby making the heating capacity close to that when it is not frosted, while reducing the heat load of the evaporator. The refrigerant can fully evaporate and absorb heat in the evaporator, thus delaying frosting without reducing the heating capacity.

[0022] In the optional technical solutions of the control method for the above-mentioned air conditioning system, the control method further includes:

[0023] Received instruction to operate in normal heating mode;

[0024] The valve body and the first throttling device are closed.

[0025] When the above technical solution is adopted, after receiving the instruction to operate in the conventional heating mode, the valve body is closed so that all the refrigerant at the condenser outlet enters the evaporator to absorb heat and evaporate, and operates in the conventional heating mode.

[0026] In the optional technical solutions of the control method for the above-mentioned air conditioning system, the control method further includes:

[0027] Obtain the evaporator temperature;

[0028] When the evaporator temperature is lower than the preset temperature, a command is sent to control the air conditioning system to operate in a delayed frosting heating mode.

[0029] When the above technical solution is adopted, the evaporator is prone to frost when the evaporator temperature is relatively low. Therefore, the delayed frost heating mode is operated to prevent frost formation.

[0030] In the optional technical solutions of the control method for the above-mentioned air conditioning system, after the step of "obtaining the evaporator temperature", the control method further includes:

[0031] When the evaporator temperature is greater than or equal to the preset temperature, a command is sent to control the air conditioning system to operate in normal heating mode.

[0032] When the above technical solution is adopted, when the evaporator temperature is relatively high, it means that the evaporator is not easy to frost, so the conventional heating mode is run to reduce energy consumption.

[0033] Those skilled in the art will understand that the present invention provides an air conditioning system, which includes a refrigerant circulation loop (main loop), on which a compressor, a condenser, and an evaporator are disposed. Further, the air conditioning system also includes a bypass auxiliary loop and a flash evaporator. The flash evaporator 3 is disposed on the refrigerant circulation loop and located between the condenser and the evaporator. One end of the bypass auxiliary loop is connected to the outlet of the flash evaporator, and the other end is connected to a pipeline between the evaporator and the compressor suction port. This allows the refrigerant from the condenser outlet to flash inside the flash evaporator. The flashed gaseous refrigerant enters the bypass auxiliary loop, while the liquid refrigerant enters the evaporator to absorb heat. The refrigerant from the bypass auxiliary loop and the outlet of the evaporator mix and enter the compressor suction port.

[0034] When the above technical solution is adopted, the refrigerant circulation loop compresses the low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant. The high-temperature, high-pressure gaseous refrigerant releases heat and condenses into a high-temperature, high-pressure liquid refrigerant in the condenser. The liquid refrigerant enters the evaporator, absorbs heat, and evaporates into a low-temperature, low-pressure gaseous refrigerant. The gaseous refrigerant is then drawn into the compressor and compressed to enter the next cycle. Throughout the process, the refrigerant releases heat in the condenser and absorbs heat in the evaporator to achieve the purpose of heating. The air conditioning system of this invention adds a bypass auxiliary path to assist the evaporator in increasing the suction temperature. The refrigerant from the condenser outlet enters the flash evaporator and is separated into gaseous and liquid refrigerant. The flashed gaseous refrigerant can enter the bypass auxiliary path and mix with the low-temperature, low-pressure gaseous refrigerant at the evaporator outlet before entering the compressor suction port. This ensures that the compressor suction temperature and suction pressure are close to those under non-frosting conditions, thereby ensuring stable heating capacity. The separated liquid refrigerant enters the evaporator and, due to the mixing with the refrigerant at the evaporator outlet through the bypass auxiliary path, returns to the compressor, reducing the amount of refrigerant entering the evaporator and thus reducing the heat load on the evaporator. The refrigerant can fully absorb heat and evaporate in the evaporator to increase the suction temperature and suction pressure, thereby reducing the risk of evaporator frosting. This allows the air conditioning system to maintain stable heating capacity without reducing user thermal comfort, while also reducing the risk of evaporator frosting and preventing heating capacity reduction caused by frequent frosting during operation. Attached Figure Description

[0035] The preferred embodiments of the present invention are described below with reference to the accompanying drawings, in which:

[0036] Figure 1 This is a schematic diagram of the refrigerant flow direction of the air conditioning system of the present invention when operating in the delayed frosting heating mode;

[0037] Figure 2 This is a flowchart of the main steps of the control method for the air conditioning system of the present invention;

[0038] Figure 3 This is a flowchart illustrating the specific steps of the control method for the air conditioning system of the present invention.

[0039] List of reference numerals in the attached diagram:

[0040] 1. Refrigerant circulation loop; 12. Compressor; 13. Condenser; 14. Evaporator; 15. Second throttling device; 16. Four-way valve; 2. Bypass auxiliary circuit; 3. Flash evaporator; 4. First throttling device; 5. Valve body. Detailed Implementation

[0041] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art can make adjustments as needed to adapt to specific applications. For example, the air conditioning system of the present invention can be applied to central air conditioning, multi-split air conditioning, cabinet air conditioning, or wall-mounted air conditioning, etc. Those skilled in the art can define the application of the air conditioning system as needed, and all such applications fall within the scope of protection of the present invention.

[0042] It should be noted that in the description of this invention, terms such as "inner" and "outer" indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. This is merely for ease of description and does not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0043] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0044] Reference Figure 1 , Figure 1The middle arrow indicates the refrigerant flow direction when operating in delayed frosting heating mode. To address the problem that existing air conditioning systems, while delaying frosting, easily lead to reduced heating capacity and system operational stability, this invention provides an air conditioning system. The air conditioning system includes a refrigerant circulation loop 1 (main loop), on which a compressor 12, a condenser 13, and an evaporator 14 are installed. During normal heating operation, the refrigerant circulation loop 1 compresses the low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant. The high-temperature, high-pressure gaseous refrigerant releases heat and condenses into a high-temperature, high-pressure liquid refrigerant in the condenser 13. The liquid refrigerant enters the evaporator 14, absorbs heat, and evaporates back into a low-temperature, low-pressure gaseous refrigerant. The gaseous refrigerant is then drawn into the compressor 12 and compressed to enter the next cycle. Throughout this process, the refrigerant releases heat in the condenser 13 and absorbs heat in the evaporator 14, achieving the purpose of heating.

[0045] Furthermore, the air conditioning system also includes a bypass auxiliary line 2 and a flash evaporator 3. The flash evaporator 3 utilizes the principle that the boiling point of the refrigerant changes with pressure. Due to a sudden drop in pressure, some of the fluid evaporates instantaneously, forming steam. Gas-liquid separation is achieved through the flash evaporator 3. The flash evaporator 3 is located on the refrigerant circulation loop 1 and between the condenser 13 and the evaporator 14. One end of the bypass auxiliary line 2 is connected to the outlet of the flash evaporator 3, and the other end is connected to the pipeline between the evaporator 14 and the suction port of the compressor 12. This allows the refrigerant from the condenser outlet to enter the flash evaporator 3 for flashing. The flashed gaseous refrigerant enters the bypass auxiliary line 2, while the liquid refrigerant enters the evaporator 14 to absorb heat. The refrigerant from the bypass auxiliary line 2 and the outlet of the evaporator 14 mix and return to the compressor suction port.

[0046] The advantages of the above configuration are as follows: The air conditioning system of the present invention adds a bypass auxiliary path 2 to assist the evaporator 14 in increasing the suction temperature. The refrigerant at the outlet of the condenser 13 enters the flash evaporator 3 and is separated into gaseous refrigerant and liquid refrigerant. The gaseous refrigerant after flashing can enter the bypass auxiliary path 2 and mix with the low-temperature and low-pressure gaseous refrigerant at the outlet of the evaporator 14 before entering the compressor suction port, ensuring that the compressor suction temperature and suction pressure are close to those under non-frosting conditions, thereby ensuring stable heating capacity. The separated liquid refrigerant enters the evaporator 14, and because the bypass auxiliary path 2 mixes with the refrigerant at the outlet of the evaporator 14, it returns to the compressor 12, resulting in a reduction in the amount of refrigerant entering the evaporator 14, thereby reducing the heat load of the evaporator 14. The refrigerant can fully absorb heat and evaporate in the evaporator 14 to increase the suction temperature and suction pressure, thereby reducing the risk of frost formation on the evaporator 14. Thus, the air conditioning system can reduce the risk of evaporator frost while ensuring stable heating capacity and not reducing user thermal comfort.

[0047] The specific implementation method of the air conditioning system is described below:

[0048] Reference Figure 1The air conditioning system includes a refrigerant circulation loop 1, on which a compressor 12, a four-way valve 16, a condenser 13, a second throttling device 15, and an evaporator 14 are sequentially installed. The refrigerant circulation loop 1 compresses low-temperature, low-pressure gaseous refrigerant into high-temperature, high-pressure gaseous refrigerant. This high-temperature, high-pressure gaseous refrigerant releases heat and condenses into high-temperature, high-pressure liquid refrigerant in the condenser 13. The second throttling device 15 throttles the liquid refrigerant, which then enters the evaporator 14, absorbs heat, and evaporates into low-temperature, low-pressure gaseous refrigerant. The gaseous refrigerant is then drawn into the compressor 12 and compressed to enter the next cycle. Throughout this process, the refrigerant releases heat in the condenser 13 and absorbs heat in the evaporator 14, achieving the purpose of heating.

[0049] The flow direction of refrigerant in the air conditioning system is controlled by the four-way valve 16, thereby realizing the switching of the air conditioning system's cooling or heating functions. The controllability and reliability of the pipeline are improved by multi-path diversion.

[0050] Furthermore, the air conditioning system also includes a bypass auxiliary line 2, a first throttling device 4, and a flash evaporator 3. The first throttling device 4 and the flash evaporator 3 are both installed on the refrigerant circulation loop 1 and located between the condenser 13 and the evaporator 14. The first throttling device 4 is located between the outlet of the condenser 13 and the inlet of the flash evaporator 3, so that the first throttling device 4 can throttle and reduce the pressure of the refrigerant before the inlet of the flash evaporator 3 to a state suitable for flashing. One end of the bypass auxiliary line 2 is connected to the outlet of the flash evaporator 3, and the other end of the bypass auxiliary line 2 is connected to the pipeline between the evaporator 14 and the compressor 12. A valve body 5 is installed on the bypass auxiliary line 2, and the valve body 5 is used to control the connection between the bypass auxiliary line 2 and the compressor suction port.

[0051] Optionally, the valve body 5 is a solenoid valve. However, it should be noted that the present invention does not impose any restrictions on the specific type of the valve body 5. It can also be a manual valve, a pneumatic valve, an electric valve, or a regulating valve, etc. Those skilled in the art can set the type of the valve body 5 as needed, and all such settings fall within the protection scope of the present invention.

[0052] When the air conditioning system needs to delay the frosting of the evaporator 14, the valve body 5 is opened so that the refrigerant at the outlet of the condenser 13 is throttled and depressurized by the first throttling device 4 and then enters the flash evaporator 3 for flashing. The gaseous refrigerant after flashing mixes with the gaseous refrigerant at the outlet of the evaporator 14 and enters the compressor suction port, ensuring that the compressor suction temperature and suction pressure are close to those under the non-frosting condition. The liquid refrigerant in the flash evaporator enters the evaporator 14 to absorb heat and vaporize. By reducing the amount of refrigerant entering the evaporator 14 and reducing the heat load of the evaporator 14, the refrigerant in the evaporator 14 is ensured to absorb enough heat, thereby increasing the suction temperature and suction pressure and delaying frosting. In other words, the frosting of the evaporator 14 is delayed while ensuring the heating capacity of the air conditioning system.

[0053] When the evaporator 14 is in a state where it is not easy to frost, the valve body 5 can be closed and the opening of the first throttling device 4 can be opened to the maximum, so that the refrigerant at the outlet of the condenser 13, after being throttled and depressurized at the second throttling device 15 by the flash evaporator 3, can all enter the evaporator 14 to absorb heat, so that the air conditioning system can operate in normal heating mode. Therefore, the air conditioning system of the present invention can operate in the corresponding mode according to the change of the external ambient temperature to ensure user experience and air conditioning operating efficiency.

[0054] It should be noted that the specific types of the first throttling device 4 and the second throttling device 15 can be electronic expansion valves, thermal expansion valves, capillary tubes, etc. Those skilled in the art can set the specific types of the first throttling device 4 and the second throttling device 15 as needed, as long as they can achieve the throttling effect, and all of them fall within the protection scope of this invention.

[0055] In summary, this invention uses a flash evaporator 3 to separate the refrigerant from the condenser 13 into gaseous and liquid states. The gaseous refrigerant enters the bypass auxiliary path 2, while the liquid refrigerant enters the evaporator 14 to absorb heat and vaporize. The medium-temperature, medium-pressure gaseous refrigerant from the bypass auxiliary path 2 mixes with the low-temperature, low-pressure gaseous refrigerant from the evaporator 14 outlet and enters the compressor suction port. This ensures that the compressor suction temperature and suction pressure are close to those under non-frosting conditions. Furthermore, because the amount of refrigerant entering the evaporator 14 is reduced, the refrigerant in the evaporator 14 fully absorbs heat and evaporates. Therefore, the suction pressure and suction temperature of the refrigerant in the evaporator 14 are increased compared to the past, thus delaying frost formation in the evaporator 14. Consequently, the air conditioning system can maintain stable heating capacity while delaying frost formation.

[0056] As described in the first paragraph of this section, the above embodiments are merely used to illustrate the principles of the present invention and are not intended to limit the scope of protection of the present invention. Without departing from the principles of the present invention, those skilled in the art can adjust the above structure so that the present invention can be applied to more specific application scenarios.

[0057] In addition, the present invention also provides a control method for an air conditioning system, referring to... Figure 1 The air conditioning system includes a refrigerant circulation loop 1, on which a compressor 12, a four-way valve 16, a condenser 13, a second throttling device 15, and an evaporator 14 are sequentially arranged. Further, the air conditioning system also includes a bypass auxiliary line 2 and a flash evaporator 3. The flash evaporator 3 is arranged on the refrigerant circulation loop 1 and located between the condenser 13 and the evaporator 14. One end of the bypass auxiliary line 2 is connected to the outlet of the flash evaporator 3, and the other end of the bypass auxiliary line 2 is connected to the pipeline between the evaporator 14 and the suction port of the compressor 12. A valve body 5 is arranged on the bypass auxiliary line 2, which is used to control the connection between the bypass auxiliary line 2 and the suction port of the compressor.

[0058] Furthermore, the air conditioning system also includes a temperature sensor and a controller. The temperature sensor is disposed on the outer surface of the evaporator 14 to detect the temperature of the evaporator 14. However, this invention does not impose any restrictions on the location of the temperature detection on the evaporator 14. For example, the temperature sensor can also be disposed at the evaporator outlet to detect the refrigerant temperature at the outlet of the evaporator 14. The outlet refrigerant temperature can indicate the temperature of the evaporator 14. Those skilled in the art can set the placement of the temperature sensor as needed, as long as it can reflect the temperature of the evaporator 14, and all such settings fall within the protection scope of this invention. The controller can acquire the evaporator temperature and can also control the operating status of the outdoor unit, such as controlling the start and stop of the compressor 12. Those skilled in the art will understand that this invention does not impose any restrictions on the specific structure and model of the controller. Those skilled in the art can set the structure and model of the controller according to actual usage requirements.

[0059] Reference Figure 2 The main steps of the control method include:

[0060] Step S10: Received instruction to run delayed frosting heating mode;

[0061] Step S20: Control valve body to open.

[0062] Upon receiving the instruction to operate the delayed frosting heating mode, valve 5 is opened to connect the bypass auxiliary circuit 2 and the refrigerant circulation circuit 2. The gaseous refrigerant after flashing in the flash evaporator 3 enters the compressor suction port through the bypass auxiliary circuit 2. The flashed gaseous refrigerant mixes with the gaseous refrigerant at the outlet of the evaporator 14 and enters the compressor suction port together, ensuring that the compressor suction temperature and suction pressure are close to the non-frosting condition (i.e., not easy to frost). The liquid refrigerant in the flash evaporator enters the evaporator 14 to absorb heat and vaporize. By reducing the heat load of the evaporator 14, the refrigerant in the evaporator 14 is ensured to fully absorb heat, increasing the suction temperature and suction pressure, thus delaying frosting. In other words, the frosting of the evaporator 14 is delayed while ensuring the heating capacity of the air conditioning system.

[0063] Taking the first throttling device 4 and the second throttling device 15 as electronic expansion valves as an example, refer to Figure 3 The specific steps of the control method include:

[0064] Step S11: Obtain the evaporator temperature;

[0065] Step S12: When the evaporator temperature is lower than the set temperature, send a command to run the delayed frosting heating mode;

[0066] Step S13: Received instruction to run delayed frosting heating mode;

[0067] Step S14: Control valve body to open;

[0068] Step S15: When the evaporator temperature is greater than or equal to the set temperature, send a command to run the normal heating mode;

[0069] Step S16: Received instruction to run the normal heating mode;

[0070] Step S17: Close the control valve body.

[0071] The evaporator temperature is monitored to determine whether evaporator 14 is prone to frosting. For example, if the set temperature is 0°C, and the evaporator temperature is below 0°C, it indicates that evaporator 14 is prone to frosting during air conditioning operation. In this case, the air conditioning system is controlled to operate in a delayed frosting heating mode to delay frosting of evaporator 14. If the evaporator temperature is above 0°C, it indicates that evaporator 14 is not prone to frosting, and the air conditioning system is controlled to operate in normal heating mode. In normal heating mode, the high-temperature, high-pressure refrigerant at the compressor outlet enters the condenser 13 through refrigerant circulation loop 1. The refrigerant releases heat at the condenser 13, raising the indoor temperature. Then, the refrigerant passes through the second electronic expansion valve and enters the evaporator 14 to absorb heat and vaporize, returning to the compressor suction port to continue the next refrigerant cycle. Those skilled in the art can set the specific value of the set temperature as needed. This invention does not impose any restrictions on the specific value of the set temperature, and all such values ​​fall within the protection scope of this invention.

[0072] Those skilled in the art will understand that the above-described air conditioning system also includes other known structures, including but not limited to random access memory, flash memory, read-only memory, programmable read-only memory, volatile memory, non-volatile memory, serial memory, parallel memory, or registers, etc., and processors including but not limited to CPLD / FPGA, DSP, ARM processor, MIPS processor, etc. To avoid unnecessarily obscuring the embodiments of this disclosure, these known structures are not shown in the accompanying drawings.

[0073] Although the steps in the above embodiments are described in the aforementioned order, those skilled in the art will understand that, in order to achieve the desired effect, different steps need not be executed in this order; they can be executed simultaneously (in parallel) or in a reverse order. For example, those skilled in the art can set the order of the steps as needed, and all such settings fall within the scope of protection of this invention.

[0074] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. An air conditioning system, characterized in that, The air conditioning system includes a refrigerant circulation loop, on which a compressor, condenser, and evaporator are installed. The system also includes a bypass auxiliary path and a flash evaporator. The flash evaporator is located in the refrigerant circulation loop between the condenser and the evaporator. One end of the bypass auxiliary path is connected to the outlet of the flash evaporator, and the other end is connected to a pipeline between the evaporator and the compressor suction port. This allows the refrigerant from the condenser outlet to enter the flash evaporator and flash. The flashed gaseous refrigerant enters the bypass auxiliary path, while the liquid refrigerant enters the evaporator to absorb heat. The refrigerant from the bypass auxiliary path and the evaporator outlet mix and enter the compressor suction port.

2. The air conditioning system according to claim 1, characterized in that, The air conditioning system also includes a first throttling device, which is disposed on the pipeline between the flash evaporator and the condenser.

3. The air conditioning system according to claim 1, characterized in that, A second throttling device is provided on the refrigerant circulation loop, and the second throttling device is located between the flash evaporator and the evaporator.

4. The air conditioning system according to claim 1, characterized in that, The air conditioning system also includes a valve body, which is disposed on the bypass auxiliary road.

5. The air conditioning system according to any one of claims 1-4, characterized in that, The air conditioning system also includes a four-way valve, which is installed on the refrigerant circulation loop.

6. The air conditioning system according to claim 2, characterized in that, The first throttling device is an expansion valve or a capillary tube.

7. A control method for an air conditioning system, characterized in that, The air conditioning system includes a refrigerant circulation loop, on which a compressor, condenser, and evaporator are installed. The system also includes a bypass auxiliary path and a flash evaporator. The flash evaporator is located in the refrigerant circulation loop between the condenser and the evaporator. One end of the bypass auxiliary path is connected to the outlet of the flash evaporator, and the other end is connected to a pipeline between the evaporator and the compressor suction port. This allows the refrigerant from the condenser outlet to enter the flash evaporator and flash. The flashed gaseous refrigerant enters the bypass auxiliary path, while the liquid refrigerant enters the evaporator to absorb heat. The refrigerant from the bypass auxiliary path and the evaporator outlet mix and enter the compressor suction port. The air conditioning system also includes a valve body located on the bypass auxiliary path. The control method includes: Received instruction to run delayed frosting heating mode; Control the valve body to open.

8. The control method for an air conditioning system according to claim 7, characterized in that, The control method further includes: Received instruction to operate in normal heating mode; Control the valve body to close.

9. The control method for an air conditioning system according to claim 7, characterized in that, The control method further includes: Obtain the evaporator temperature; When the evaporator temperature is lower than the preset temperature, a command is sent to control the air conditioning system to operate in a delayed frosting heating mode.

10. The control method for an air conditioning system according to claim 9, characterized in that, After the step of "obtaining the evaporator temperature", the control method further includes: When the evaporator temperature is greater than or equal to the preset temperature, a command is sent to control the air conditioning system to operate in normal heating mode.

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