Air conditioner defrosting control method and control system
By utilizing a bypass branch and an indoor auxiliary heating device in the air conditioner defrosting mode, and dynamically adjusting the control strategy, the problem of large indoor temperature fluctuations during defrosting is solved, achieving stable indoor temperature control during the defrosting process and improving user comfort.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUANGDONG VANWARD ELECTRIC
- Filing Date
- 2026-03-31
- Publication Date
- 2026-05-29
AI Technical Summary
During the defrosting process of existing air conditioners, the indoor temperature fluctuates greatly, and defrosting and indoor heating cannot be coordinated, resulting in unstable indoor temperature, which affects heating comfort, especially in buildings with poor insulation or in extremely cold weather.
In the defrosting mode of the air conditioner, the indoor heat exchanger is disconnected from the refrigerant circulation loop through the bypass branch, the indoor auxiliary heating device and fan are turned on, and the indoor fan is used to deliver air to supplement heat. At the same time, the control strategy is dynamically adjusted according to the changes in indoor and outdoor temperatures to ensure that the indoor temperature remains stable during the defrosting process.
During the defrosting process, the refrigerant's cold energy is prevented from entering the room and causing a drop in temperature. The indoor heat is replenished in a timely manner to achieve stable control of the indoor temperature during the defrosting process and improve user comfort.
Smart Images
Figure CN122107519A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of air conditioning technology, and more specifically, to an air conditioning defrosting control method and control system. Background Technology
[0002] Air conditioners are an important piece of equipment for energy-saving renovations in northern heating systems. They have the advantages of low installation and operating costs and significant heating effects, and most mainstream models on the market are equipped with both cooling and heating functions. In winter heating mode, the outdoor heat exchanger is prone to frost formation, which affects the heat exchange efficiency and heating capacity of the air conditioner. Therefore, it is necessary to use a four-way valve to switch directions to achieve defrosting operation of the outdoor unit.
[0003] During the defrosting process of existing air conditioners, the indoor unit is usually shut down to prevent cold air from entering the indoor space. However, in scenarios with poor building insulation or in extremely cold weather, there is no heat replenishment during defrosting, causing the indoor temperature to drop rapidly and resulting in large fluctuations in indoor temperature, which seriously affects the comfort of indoor heating. Summary of the Invention
[0004] The first technical problem solved by this invention is to provide an air conditioner defrosting control method and control system, which can solve the problems of large indoor temperature fluctuations and the inability to coordinate defrosting and indoor heating during defrosting in existing air conditioners, and achieve stable control of indoor temperature during the defrosting process.
[0005] The first technical problem solved by this invention is to provide an air conditioning defrosting control system that can solve the problems of large indoor temperature fluctuations and the inability to coordinate defrosting and indoor heating during defrosting in existing air conditioning systems, thereby achieving stable indoor temperature control during the defrosting process. The first technical problem mentioned above is solved by the following technical solution: This invention provides an air conditioner defrosting control method. The air conditioner includes a refrigerant circulation loop, a bypass branch, an indoor auxiliary heating device, and an indoor fan. The two ends of the bypass branch are respectively connected to the two ends of an indoor heat exchanger disposed on the refrigerant circulation loop. The indoor auxiliary heating device is used to heat the indoor heat exchanger, and the indoor fan is used to drive airflow through the indoor heat exchanger. The method includes: The air conditioner is in defrost mode: Obtain the current indoor ambient temperature t and the rate of decrease of indoor temperature r; If the current indoor ambient temperature t is less than the first preset temperature t i1 If the rate of decrease in indoor temperature r is greater than the first preset rate, the indoor heat exchanger is controlled to disconnect from the refrigerant circulation loop and the refrigerant circulation loop is controlled to form a loop through the bypass branch. At the same time, the indoor auxiliary heating device and the indoor fan are turned on, and the indoor fan is rotated in the forward direction to supply air into the room.
[0006] Compared with the prior art, the air conditioning defrosting control method and control system of the present invention have the following advantages: During the defrosting process, if the indoor temperature is lower than the first preset temperature and the rate of temperature decrease is greater than the first preset speed, it indicates that the indoor temperature drops significantly and at a rapid rate. Therefore, it is necessary to disconnect the circuit between the indoor and outdoor heat exchangers. The outdoor heat exchanger forms a circuit through a bypass branch, absorbing indoor heat while ensuring that the defrosting circuit can circulate. At the same time, the indoor auxiliary heating device is turned on and the indoor fan blows heat into the room. This not only prevents the refrigerant from entering the room and exacerbating the temperature drop, but also replenishes the indoor heat in a timely manner, fundamentally solving the problem of no heat supply during defrosting.
[0007] In one embodiment, if the current indoor ambient temperature t is lower than the second preset temperature t i2 Turn on the indoor auxiliary heating device and the indoor fan, and make the indoor fan rotate in the forward direction to supply air into the room; The second preset temperature t i2 Less than the first preset temperature t i1 .
[0008] In one embodiment, The air conditioner also includes an outdoor heat exchanger located in the refrigerant circulation loop, and the method further includes: If the current indoor ambient temperature t is greater than the preset indoor temperature t i1 Or the current indoor ambient temperature t is greater than the second preset temperature t i2 Furthermore, the indoor temperature decrease rate r is less than or equal to the first preset rate, and the inlet and outlet air temperature difference of the outdoor heat exchanger is obtained. T; If the temperature difference between the inlet and outlet air of the outdoor heat exchanger is within a set time period When T rises above the third preset threshold, the bypass branch is disconnected and the circuit between the indoor heat exchanger and the outdoor heat exchanger is connected; at the same time, the indoor auxiliary heating device and the indoor fan are turned on, and the indoor fan is reversed to blow indoor air toward the indoor heat exchanger.
[0009] In one embodiment, if the temperature difference between the inlet and outlet air of the outdoor heat exchanger is within a set time... When T rises to less than or equal to the third set threshold, the indoor auxiliary heating device is shut down, the circuit between the indoor heat exchanger and the outdoor heat exchanger is connected, and the bypass branch is disconnected.
[0010] In one embodiment, when the air conditioner is in defrost mode, the method further includes: acquiring the current outdoor ambient temperature T, and determining the first preset temperature t based on the current outdoor ambient temperature T. i1 and the second preset temperature t i2 .
[0011] In one embodiment, the first preset temperature t is determined based on the current outdoor ambient temperature T. i1 and the second preset temperature t i2 include: The outdoor ambient temperature is divided into multiple preset ambient temperature ranges. The current outdoor ambient temperature T is compared with the multiple preset ambient temperature ranges to determine the preset ambient temperature range in which the current outdoor ambient temperature T is located. Based on the preset ambient temperature range and the first preset temperature t i1 The mapping relationship determines the first preset temperature t i1 The first preset temperature t i1 It is inversely proportional to the preset ambient temperature range; Based on the preset ambient temperature range and the second preset temperature t i2 The mapping relationship determines the second preset temperature t i2 The second preset temperature t i2 Inversely proportional to the preset ambient temperature range The first technical problem mentioned above is solved by the following technical solution: The present invention also provides an air conditioning defrosting control system, including a controller, the controller being used to execute any of the air conditioning defrosting control methods described above, and further comprising: Refrigerant circulation loop; A bypass branch, the two ends of which are respectively connected to the two ends of an indoor heat exchanger installed on the refrigerant circulation loop; The path selection module is connected to the bypass branch and the refrigerant pipeline connected to the indoor heat exchanger, and is used to select whether to connect to the bypass branch or to the indoor heat exchanger. An indoor auxiliary heating device is used to heat the indoor heat exchanger; An indoor fan is used to drive air through the indoor heat exchanger.
[0012] In one embodiment, the bypass selection module includes a first switching valve and a second switching valve; Along the flow direction of the defrosting refrigerant, the first switching valve is located at the inlet of the indoor heat exchanger, one end of the bypass branch is connected to the inlet of the first switching valve, the other end of the bypass branch is connected to the outlet of the indoor heat exchanger, and the second switching valve is located in the bypass branch.
[0013] In one embodiment, the bypass selection module is a three-way valve; The inlet of the three-way valve is connected to the refrigerant circulation loop, and the two outlets of the three-way valve are respectively connected to the inlet of the bypass branch and the inlet of the indoor heat exchanger.
[0014] In one embodiment, the indoor auxiliary heating device is an electric auxiliary heating device. Attached Figure Description
[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0016] Figure 1 A flowchart of an air conditioning defrosting control method provided in an embodiment of the present invention; Figure 2 A schematic diagram of an air conditioning defrosting control system provided in an embodiment of the present invention; Figure 3 and Figure 4 This is a schematic diagram of two refrigerant flow directions in an air conditioning defrosting control system provided in an embodiment of the present invention.
[0017] Icons: 1-Outdoor heat exchanger; 2-Indoor heat exchanger; 3-First solenoid valve; 4-Second solenoid valve; 5-Indoor auxiliary heating device; 6-Indoor fan; 7-Four-way valve; 8-Compressor; 9-Electronic expansion valve; 10-Gas-liquid separator. Detailed Implementation
[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0019] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.
[0020] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0021] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0022] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.
[0023] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they 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 based on the specific circumstances.
[0024] The following is combined with Figures 1-4 The following describes some embodiments of the present invention in detail. Unless otherwise specified, the following embodiments and features can be combined with each other.
[0025] Example 1 This embodiment provides an air conditioner defrosting control method, which can be applied to the air conditioner defrosting control system of the present invention. For example... Figure 1 As shown, the method includes the following steps: Enter defrost mode.
[0026] When the air conditioner is running in heating mode and the defrosting conditions are met, the controller controls the four-way valve 7 to switch, putting the system into defrosting mode. The defrosting conditions can be determined using conventional defrosting logic, such as when the coil temperature of the outdoor heat exchanger 1 is lower than the preset defrosting temperature for a preset time, or when the compressor 8's cumulative running time reaches the preset defrosting cycle, defrosting is deemed necessary. Alternatively, the user can manually initiate the defrosting mode.
[0027] After entering defrost mode, the controller acquires the indoor ambient temperature t, the indoor temperature reduction rate r, and the inlet and outlet air temperature difference of outdoor heat exchanger 1 in real time. Parameters such as T.
[0028] To obtain the current indoor ambient temperature t and the rate of decrease in indoor temperature r, the specific steps are as follows: The controller acquires the current indoor ambient temperature *t* in real time using an indoor temperature sensor located at the indoor unit's return air vent or within the indoor space. Simultaneously, the controller calculates the rate of temperature decrease *r* by continuously collecting the current indoor ambient temperature *t* at multiple time points. Specifically, the controller collects the current indoor ambient temperature *t* at regular intervals (e.g., 10 or 30 seconds), records it in memory, and then calculates the temperature change between adjacent collection points to obtain the rate of temperature decrease *r*. Further, the current indoor ambient temperature *t* is set below a first preset temperature *t0*. i1 The indoor temperature decrease rate *r* is compared with a first preset rate. Specifically, the controller compares the current indoor ambient temperature *t* with a first preset temperature *ti1*. The first preset temperature *ti1* is the first warning line for indoor comfort, usually set slightly lower than the user-set temperature. Specifically, the first preset temperature *t*... i1 Set the temperature t for the user i The temperature after subtracting the first set threshold t1, for example, the user-set temperature t i When the temperature is 20℃, the first preset threshold t1 is 1°C, and the first preset temperature t at this time is... i1 The temperature is 19℃.
[0029] If the current indoor ambient temperature t is less than the first preset temperature t i1 The controller then further determines whether the indoor temperature decrease rate *r* is greater than a first preset rate. Specifically, if the temperature continues to decrease over a continuous period of time and the rate of decrease exceeds a preset threshold, the indoor temperature decrease rate *r* is determined to be greater than the first preset rate. For example, if the temperature decrease rate is greater than 0.5℃ / min for three consecutive minutes, the indoor temperature is determined to be decreasing too rapidly.
[0030] If the current indoor ambient temperature t is less than the first preset temperature t i1 However, r is less than or equal to the first preset speed, or the current indoor ambient temperature t is greater than or equal to the first preset temperature t.i1 If the indoor temperature does not drop significantly, then it can be determined that the temperature drop is not significant.
[0031] When the controller determines that the indoor temperature is dropping too rapidly, it executes the first control strategy, which includes: The indoor heat exchanger 2 is disconnected from the refrigerant circulation loop, and the refrigerant circulation loop is made to form a loop through the bypass branch. At this time, the refrigerant does not flow through the indoor heat exchanger 2, thus avoiding the cooling effect of the refrigerant on the indoor environment.
[0032] Simultaneously, the indoor auxiliary heating device 5 and indoor fan 6 are activated. The indoor auxiliary heating device 5 heats the indoor heat exchanger 2; the indoor fan 6 rotates forward, blowing air into the room. Driven by the indoor fan 6, the air flows through the indoor heat exchanger 2 and is then delivered into the room. Since no refrigerant flows through the indoor heat exchanger 2, its surface temperature is close to the ambient temperature and it does not absorb the heat generated by the indoor auxiliary heating device 5. Therefore, most of the heat generated by the indoor auxiliary heating device 5 is delivered into the room, achieving rapid heat replenishment.
[0033] Optionally, the indoor fan 6 can be controlled to operate at a higher speed to accelerate the air delivery speed and achieve rapid heat replenishment.
[0034] When the indoor temperature drop is determined to be insignificant, the controller further obtains the inlet and outlet air temperature difference of the outdoor heat exchanger 1. The controller uses temperature sensors located on the inlet and outlet sides of the outdoor heat exchanger 1 to determine the frosting status. The inlet air temperature T is measured in real time. in and outlet air temperature T out Calculate the temperature difference between the inlet and outlet air. T = T out - T in .
[0035] In defrosting mode, as the frost gradually melts, the temperature difference between the inlet and outlet air decreases. T will change. If the frost layer is thick, the temperature difference between the inlet and outlet air will increase during the initial defrosting phase. Temperature rises slowly; if the frost layer is thin, the temperature difference between the inlet and outlet air... T rises relatively quickly. In this embodiment, the controller determines the temperature difference between the inlet and outlet air within a preset time. Does the increase in T exceed the third set threshold? For example, if within 5 minutes... If the temperature rises by more than 4°C, the frost layer is considered too thick; if If the temperature rise is less than or equal to 4°C, the frost layer thickness is considered to be within a controllable range.
[0036] When the controller determines that the frost layer thickness is too thick, it executes a second control strategy, which includes: The circuit connecting indoor heat exchanger 2 and outdoor heat exchanger 1 is connected, while the bypass branch is disconnected. At this time, refrigerant flows through indoor heat exchanger 2, which operates as an evaporator. Simultaneously, indoor auxiliary heating device 5 and indoor fan 6 are activated. The indoor fan 6 is reversed, causing it to drive the air to flow in the opposite direction. Driven by the indoor fan 6, the air flows sequentially through the indoor heat exchanger 2. Since the indoor temperature drop is not significant at this time, the refrigerant flowing through the indoor heat exchanger 2 will not have a major impact on indoor comfort. Simultaneously, the outdoor heat exchanger 1 has a thick frost layer. With the above setup, the heat generated by the indoor auxiliary heating device 5 can be blown towards the indoor heat exchanger 2, increasing the evaporation temperature of the indoor heat exchanger 2 and thus improving defrosting efficiency.
[0037] Optionally, the compressor 8 can be controlled to operate at a higher frequency to further improve the refrigerant circulation and defrosting efficiency.
[0038] When the frost layer thickness is determined to be within a controllable range, the controller executes the third control strategy, which specifically includes: The circuit between indoor heat exchanger 2 and outdoor heat exchanger 1 is connected, and the bypass branch is disconnected. At this time, the refrigerant flows through indoor heat exchanger 2, and indoor heat exchanger 2 operates as an evaporator.
[0039] Turn off the indoor auxiliary heating device 5, or keep it off.
[0040] Keep the indoor fan 6 off, or control the indoor fan 6 to run at a very low speed to prevent cold air from blowing out.
[0041] When the temperature difference between the inlet and outlet air of outdoor heat exchanger 1 When T rises to less than or equal to the third preset threshold within the set time, it indicates that the frost layer has been basically melted, and defrosting is complete. At this time, the controller performs the following operations: 5. Turn off the indoor auxiliary heating device.
[0042] The heat exchanger 2 in the control room is connected to the refrigerant circulation loop, and the bypass branch is disconnected.
[0043] Control the four-way valve 7 to switch the system back to heating mode.
[0044] Turn the indoor fan 6 to the forward direction to restore normal air supply.
[0045] Restore the normal operating parameters of compressor 8 and electronic expansion valve 9.
[0046] Example 2 This embodiment adds a second preset temperature t based on embodiment one. i2 The judgment logic. Second preset temperature t i2 This is the second warning line for indoor comfort, and its value is less than the first preset temperature t.i1 When the indoor temperature drops to t i2 The following indicates that indoor comfort has severely declined and reheating needs to be activated unconditionally. Regardless of the rate of temperature decrease, the first control strategy should be executed directly.
[0047] In this embodiment, the second preset temperature t i2 Set the temperature t for the user i The temperature after subtracting the second set threshold t2, for example, the user-set temperature t. i When the temperature is 20°C, the second preset threshold t2 is 2°C, and the second preset temperature t at this time is... i2 18℃ The controller compares the current indoor ambient temperature t with the second preset temperature t i2 Compare the two temperatures. If the current indoor ambient temperature t is lower than the second preset temperature t0... i2 If the temperature drops too quickly, the first control strategy is executed directly, and the rate of temperature decrease is no longer assessed. This multi-level protection mechanism further enhances user comfort under extreme operating conditions.
[0048] Example 3 When the indoor temperature does not drop significantly, the controller obtains the inlet air temperature T of the outdoor heat exchanger 1 in real time. in and outlet air temperature T out Calculate the temperature difference between the inlet and outlet air. T = T out - T in The controller records the initial temperature difference at the start of defrosting. T0, and continuously monitor subsequent temperature difference changes.
[0049] The time window is set to 5 minutes, and the controller calculates the change in the temperature difference between the inlet and outlet air within this time window. If T > the third set threshold (e.g., 4℃), then the frost layer thickness is determined to be too thick, and the second control strategy (assisted defrosting) is executed. If T ≤ the third set threshold, then the frost thickness is determined to be within a controllable range, and the third control strategy is executed to defrost normally.
[0050] It should be noted that the specific values of the setting time and the third setting threshold can be calibrated and optimized according to different product models, outdoor heat exchanger structures, and environmental conditions. For example, for outdoor heat exchangers with a large heat exchange area, the setting time can be appropriately extended or the third setting threshold can be increased; for extremely cold conditions, the setting time can be appropriately shortened or the third setting threshold can be decreased.
[0051] Example 4 This embodiment refines the criteria for determining defrosting completion. During the defrosting process, the controller continuously monitors the temperature difference between the inlet and outlet air of the outdoor heat exchanger 1. T. When When T rises to less than or equal to the third set threshold within the set time, it indicates that the frost layer has basically melted away and the defrosting is complete.
[0052] Specifically, defrosting is considered complete when the following conditions are met: Within two consecutive set time windows (e.g., two 5-minute intervals), the temperature difference between the inlet and outlet air... The increase in T is less than or equal to the third set threshold; or the temperature difference between the inlet and outlet air. The absolute value of T is less than the preset defrosting completion temperature difference threshold.
[0053] After defrosting is completed, the controller performs the recovery operation: shuts off the indoor auxiliary heating device 5, controls the indoor heat exchanger 2 to connect with the refrigerant circulation loop to form a loop and disconnects the bypass branch, controls the four-way valve 7 to switch back to the heating mode, and controls the indoor fan 6 to rotate forward to restore normal air supply.
[0054] Example 5 The controller obtains the outdoor ambient temperature T in real time through an outdoor ambient temperature sensor located near the outdoor unit. Based on the value of the outdoor ambient temperature T, it dynamically adjusts the first preset temperature t. i1 Second preset temperature t i2 The value of is specifically the outdoor ambient temperature T and the first preset temperature t. i1 Second preset temperature t i2 They are all inversely proportional, that is, the lower the outdoor ambient temperature, the higher the first preset temperature t. i1 Second preset temperature t i2 The higher the value, the better.
[0055] Through this adaptive adjustment, the heating activation threshold is automatically raised in extremely cold weather, enabling the system to activate the heating strategy earlier and prepare for the drop in indoor temperature in advance, thereby improving the user experience.
[0056] In this embodiment, the first preset temperature t i1 Second preset temperature t i2 The system automatically sets the temperature without requiring user input, thus achieving automated temperature control.
[0057] More specifically, in this embodiment, a first preset temperature t is determined based on the current outdoor ambient temperature T. i1 Second preset temperature t i2 include: The outdoor ambient temperature is divided into multiple preset ambient temperature ranges. The current outdoor ambient temperature T is compared with these preset ranges to determine the preset ambient temperature range in which the current outdoor ambient temperature T falls. Based on the preset ambient temperature range and a first preset temperature t... i1 The mapping relationship determines the first preset temperature t i1First preset temperature t i1 It is inversely proportional to the preset ambient temperature range; based on the preset ambient temperature range and the second preset temperature t i2 The mapping relationship determines the second preset temperature t i2 Second preset temperature t i2 It is inversely proportional to the preset ambient temperature range.
[0058] The controller internally stores a preset ambient temperature range and a first preset temperature t. i1 The mapping table, and the preset ambient temperature range and the second preset temperature t i2 The mapping relationship table follows these principles: the lower the outdoor ambient temperature corresponding to the preset ambient temperature range, the higher the first preset temperature t. i1 Second preset temperature t i2 The higher the value of t, the better. i1 and t i2 It is inversely proportional to the outdoor ambient temperature.
[0059] More specifically, after the controller obtains the current outdoor ambient temperature T, it performs the following steps: The first step is to compare the current outdoor ambient temperature T with multiple preset ambient temperature ranges to determine the preset ambient temperature range in which the current outdoor ambient temperature T falls.
[0060] The second step involves querying the corresponding first preset temperature ti1 from the mapping table based on the mapping relationship between the preset ambient temperature range and the first preset temperature ti1. The mapping relationship between the preset ambient temperature range and the first preset temperature ti1 can be obtained under simulated operating conditions in a laboratory setting.
[0061] The third step involves querying the corresponding second preset temperature ti2 from the mapping table based on the mapping relationship between the preset ambient temperature range and the second preset temperature ti2. The mapping relationship between the preset ambient temperature range and the second preset temperature ti2 can be obtained under laboratory conditions through simulated operating conditions.
[0062] The fourth step is to use the determined first preset temperature ti1 and second preset temperature ti2 for subsequent control logic judgment.
[0063] Example 6: like Figure 2 As shown, this embodiment provides an air conditioning defrosting control system, which includes a refrigerant circulation loop, a bypass branch, a path selection module, an indoor auxiliary heating device 5, and an indoor fan 6.
[0064] The refrigerant circulation loop includes a compressor 8, an outdoor heat exchanger 1, an indoor heat exchanger 2, a four-way valve 7, an electronic expansion valve 9, and a gas-liquid separator 10. The compressor 8 has an exhaust port and a return port. The exhaust port is connected to the first port of the four-way valve 7, and the return port is connected to the outlet of the gas-liquid separator 10. The inlet of the gas-liquid separator 10 is connected to the second port of the four-way valve 7. The four-way valve 7 also includes a third port and a fourth port. The third port is connected to one end of the outdoor heat exchanger 1, and the fourth port is connected to one end of the electronic expansion valve 9. The other end of the outdoor heat exchanger 1 is connected to the other end of the electronic expansion valve 9 via a pipeline, forming the main refrigerant circulation path. The indoor heat exchanger 2 is located between the electronic expansion valve 9 and the fourth port of the four-way valve 7. Specifically, one end of the indoor heat exchanger 2 is connected to the electronic expansion valve 9 via a path selection module, and the other end of the indoor heat exchanger 2 is connected to the fourth port of the four-way valve 7.
[0065] The four-way valve 7 has two operating states: In heating mode, the first port of the four-way valve 7 is connected to the third port, and the second port is connected to the fourth port. At this time, the high-temperature and high-pressure refrigerant discharged from the compressor 8 enters the indoor heat exchanger 2 through the four-way valve 7. After releasing heat and condensing in the indoor heat exchanger 2, it enters the outdoor heat exchanger 1 through the electronic expansion valve 9 to absorb heat and evaporate, and then returns to the compressor 8 through the four-way valve 7 and the gas-liquid separator 10. In defrosting mode, the four-way valve 7 is reversed, with the first port connected to the fourth port and the second port connected to the third port. At this time, the high-temperature and high-pressure refrigerant discharged from the compressor 8 enters the outdoor heat exchanger 1 through the four-way valve 7. After releasing heat and defrosting in the outdoor heat exchanger 1, it enters the indoor heat exchanger 2 through the electronic expansion valve 9 to absorb heat and evaporate, and then returns to the compressor 8 through the four-way valve 7 and the gas-liquid separator 10.
[0066] The two ends of the bypass branch are respectively connected to the two ends of the indoor heat exchanger 2, which is located in the refrigerant circulation loop. Specifically, one end of the bypass branch is connected to a specific port of the flow selection module, and the other end is connected to the outlet end of the indoor heat exchanger 2, that is, the pipeline between the indoor heat exchanger 2 and the fourth port of the four-way valve 7. The bypass branch is used to selectively bypass the indoor heat exchanger 2 with refrigerant in defrost mode.
[0067] The path selection module connects to the bypass branch and the refrigerant pipeline connected to the indoor heat exchanger 2, and is used to select whether to connect to the bypass branch or the indoor heat exchanger 2. The path selection module can be implemented in various ways, such as using a dual solenoid valve structure or a three-way valve structure, which will be described in detail in subsequent embodiments.
[0068] An indoor auxiliary heating device 5 is provided corresponding to the indoor heat exchanger 2 and is used to heat the indoor heat exchanger 2. In this embodiment, the indoor auxiliary heating device 5 is an electric auxiliary heating device, which uses a PTC electric heating element or an electric heating wire heating element.
[0069] An indoor fan 6 is installed corresponding to the indoor heat exchanger 2 to drive airflow through the indoor heat exchanger 2. The indoor fan 6 uses a reversible DC brushless motor, which can achieve two operating modes: forward and reverse rotation, according to control commands. When the indoor fan 6 rotates forward, air flows through the indoor heat exchanger 2 and is then sent into the room; when the indoor fan 6 rotates in reverse, air is blown towards the indoor heat exchanger 2.
[0070] It also includes a control system, which comprises a controller (not shown in the figure) that is electrically connected to a path selection module, an indoor auxiliary heating device 5, an indoor fan 6, a four-way valve 7, a compressor 8, an electronic expansion valve 9, and multiple temperature sensors. The controller is configured to execute the air conditioning defrosting control method of the present invention.
[0071] The controller can be implemented using a microcontroller, digital signal processor, programmable logic controller or embedded system, etc. It stores a control program and can output control commands according to the preset control logic based on the input sensor signals to drive the actions of each actuator.
[0072] It also features a temperature detection system, which includes multiple temperature sensors, specifically an indoor temperature sensor, an outdoor heat exchanger inlet air temperature sensor, an outdoor heat exchanger outlet air temperature sensor, and an outdoor ambient temperature sensor. The indoor temperature sensor is located at the indoor unit's return air vent or within the indoor space to detect the indoor ambient temperature t. The outdoor heat exchanger inlet air temperature sensor is located on the inlet side of the outdoor heat exchanger 1 to detect the inlet air temperature of the outdoor heat exchanger 1. The outdoor heat exchanger outlet air temperature sensor is located on the outlet side of the outdoor heat exchanger 1 to detect the outlet air temperature of the outdoor heat exchanger 1. The outdoor ambient temperature sensor is located near the outdoor unit to detect the outdoor ambient temperature T.
[0073] All of the above temperature sensors are electrically connected to the controller to provide real-time temperature data to the controller.
[0074] Example 7 This embodiment provides a detailed description of a specific structure of the path selection module. For example... Figure 2 As shown, the path selection module includes a first solenoid valve 3 and a second solenoid valve 4.
[0075] Along the flow direction of the defrosting refrigerant, the first solenoid valve 3 is located at the inlet end of the indoor heat exchanger 2. Specifically, one end of the first solenoid valve 3 is connected to the electronic expansion valve 9, and the other end is connected to the indoor heat exchanger 2. The first solenoid valve 3 is used to control the on / off state of the indoor heat exchanger 2 and the refrigerant circulation loop.
[0076] One end of the bypass branch is connected to the inlet end of the first solenoid valve 3, that is, the end of the first solenoid valve 3 away from the indoor heat exchanger 2; the other end of the bypass branch is connected to the outlet end of the indoor heat exchanger 2, that is, on the pipeline between the indoor heat exchanger 2 and the fourth port S of the four-way valve 7. The second solenoid valve 4 is installed on the bypass branch and is used to control the opening and closing of the bypass branch.
[0077] By controlling the on / off states of the first solenoid valve 3 and the second solenoid valve 4, the refrigerant can be selectively directed to flow through the indoor heat exchanger 2 or the bypass branch. When the first solenoid valve 3 is open and the second solenoid valve 4 is closed, the refrigerant flows through the indoor heat exchanger 2 and does not flow through the bypass branch. When the first solenoid valve 3 is closed and the second solenoid valve 4 is open, the refrigerant flows through the bypass branch and does not flow through the indoor heat exchanger 2.
[0078] It should be noted that the first solenoid valve 3 and the second solenoid valve 4 have opposite opening and closing states, meaning they do not open or close simultaneously to avoid refrigerant flow path conflicts or system blockage. A short delay can be set during the switching process to ensure system pressure balance before switching.
[0079] Example 8 This embodiment provides another specific structure for the path selection module. The path selection module is a three-way valve. The inlet of the three-way valve is connected to the refrigerant circulation loop, specifically to the electronic expansion valve 9. The first outlet of the three-way valve is connected to the inlet of the indoor heat exchanger 2, and the second outlet of the three-way valve is connected to the inlet of the bypass branch.
[0080] The three-way valve can switch between the first and second states: In the first state, the inlet end is connected to the first outlet end and disconnected from the second outlet end. At this time, the refrigerant flows through the indoor heat exchanger 2. In the second state, the inlet is connected to the second outlet and disconnected from the first outlet, at which point the refrigerant flows through the bypass branch.
[0081] Using a three-way valve can reduce the number of solenoid valves, simplify the system structure, and lower costs. The three-way valve can be either an electric three-way valve or a solenoid three-way valve, with the controller outputting a control signal to switch its state.
[0082] Example 9 This embodiment describes in detail the relative positional relationship between the indoor auxiliary heating device 5, the indoor fan 6, and the indoor heat exchanger 2.
[0083] like Figure 2 As shown, the indoor auxiliary heating device 5 is located between the indoor fan 6 and the indoor heat exchanger 2. Specifically, along the airflow direction, the indoor fan 6, the indoor auxiliary heating device 5, and the indoor heat exchanger 2 are arranged in sequence.
[0084] This arrangement has the following advantages: When the indoor fan 6 rotates forward, air flows sequentially through the indoor fan 6, the indoor auxiliary heating device 5, and the indoor heat exchanger 2 before being delivered into the room. At this time, the heat generated by the indoor auxiliary heating device 5 is carried by the air, passing through the indoor heat exchanger 2 before being delivered into the room. Since no refrigerant flows through the indoor heat exchanger 2, its surface temperature is close to the ambient temperature and it does not absorb heat; therefore, almost all the heat is delivered into the room. When refrigerant flows through the indoor heat exchanger 2 and it operates as an evaporator, the heat generated by the indoor auxiliary heating device 5 is absorbed as it flows through the indoor heat exchanger 2, compensating for the heat loss caused by evaporation heat absorption.
[0085] When the indoor fan 6 reverses, air flows sequentially through the indoor heat exchanger 2, the indoor auxiliary heating device 5, and the indoor fan 6. At this time, the heat generated by the indoor auxiliary heating device 5 is blown towards the indoor heat exchanger 2 to heat it, increase its evaporation temperature, and thus improve defrosting efficiency.
[0086] In other embodiments, the indoor auxiliary heating device 5 can also be located on the side of the indoor heat exchanger 2 away from the indoor fan 6, that is, the indoor fan 6, the indoor heat exchanger 2, and the indoor auxiliary heating device 5 are arranged in sequence along the airflow direction. This arrangement can also achieve the above-mentioned functions.
[0087] Example 10 This embodiment defines the type of indoor auxiliary heating device 5. The indoor auxiliary heating device 5 is an electric auxiliary heating device, specifically it can use a PTC electric heating element or an electric heating wire heating element.
[0088] PTC electric heating elements have self-limiting temperature characteristics; as the temperature rises, the resistance increases, the current decreases, and the power decreases, automatically adjusting the heating power. They offer good safety and a long service life. Electric heating wire elements are low-cost and have a fast heating response, making them suitable for cost-sensitive products.
[0089] In other embodiments, the indoor auxiliary heating device 5 may also use other types of heating devices, such as infrared heating devices, hot water heating coils, etc., as long as they can heat the indoor air.
[0090] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A defrosting control method for an air conditioner, characterized in that, The air conditioner includes a refrigerant circulation loop, a bypass branch, an indoor auxiliary heating device, and an indoor fan. The two ends of the bypass branch are respectively connected to the two ends of an indoor heat exchanger disposed on the refrigerant circulation loop. The indoor auxiliary heating device is used to heat the indoor heat exchanger, and the indoor fan is used to drive airflow through the indoor heat exchanger. The method includes: The air conditioner is in defrost mode: Obtain the current indoor ambient temperature t and the rate of decrease of indoor temperature r; If the current indoor ambient temperature t is less than the first preset temperature t i1 If the rate of decrease in indoor temperature r is greater than the first preset rate, the indoor heat exchanger is controlled to disconnect from the refrigerant circulation loop and the refrigerant circulation loop is controlled to form a loop through the bypass branch. At the same time, the indoor auxiliary heating device and the indoor fan are turned on, and the indoor fan is rotated in the forward direction to supply air into the room.
2. The air conditioning defrosting control method according to claim 1, characterized in that, If the current indoor ambient temperature t is lower than the second preset temperature t i2 Turn on the indoor auxiliary heating device and the indoor fan, and make the indoor fan rotate in the forward direction to supply air into the room; The second preset temperature t i2 Less than the first preset temperature t i1 .
3. The air conditioning defrosting control method according to claim 2, characterized in that, The air conditioner also includes an outdoor heat exchanger located in the refrigerant circulation loop, and the method further includes: If the current indoor ambient temperature t is greater than the preset indoor temperature t i1 Or the current indoor ambient temperature t is greater than the second preset temperature t i2 Furthermore, the indoor temperature decrease rate r is less than or equal to the first preset rate, and the inlet and outlet air temperature difference of the outdoor heat exchanger is obtained. T; If the temperature difference between the inlet and outlet air of the outdoor heat exchanger is within a set time period When T rises above the third preset threshold, the bypass branch is disconnected and the circuit between the indoor heat exchanger and the outdoor heat exchanger is connected; at the same time, the indoor auxiliary heating device and the indoor fan are turned on, and the indoor fan is reversed to blow indoor air toward the indoor heat exchanger.
4. The air conditioning defrosting control method according to claim 3, characterized in that, If the temperature difference between the inlet and outlet air of the outdoor heat exchanger is within a set time period When T rises to less than or equal to the third set threshold, the indoor auxiliary heating device is shut down, the circuit between the indoor heat exchanger and the outdoor heat exchanger is connected, and the bypass branch is disconnected.
5. The air conditioning defrosting control method according to claim 2, characterized in that, The air conditioner is in defrost mode, and the method further includes: acquiring the current outdoor ambient temperature T, and determining the first preset temperature t based on the current outdoor ambient temperature T. i1 and the second preset temperature t i2 .
6. The air conditioning defrosting control method according to claim 5, characterized in that, The first preset temperature t is determined based on the current outdoor ambient temperature T. i1 and the second preset temperature t i2 include: The outdoor ambient temperature is divided into multiple preset ambient temperature ranges. The current outdoor ambient temperature T is compared with the multiple preset ambient temperature ranges to determine the preset ambient temperature range in which the current outdoor ambient temperature T is located. Based on the preset ambient temperature range and the first preset temperature t i1 The mapping relationship determines the first preset temperature t i1 The first preset temperature t i1 It is inversely proportional to the preset ambient temperature range; Based on the preset ambient temperature range and the second preset temperature t i2 The mapping relationship determines the second preset temperature t i2 The second preset temperature t i2 It is inversely proportional to the preset ambient temperature range.
7. An air conditioning defrosting control system, comprising a controller, said controller being configured to execute any one of the air conditioning defrosting control methods according to claims 1-6, characterized in that, Also includes: Refrigerant circulation loop; A bypass branch, the two ends of which are respectively connected to the two ends of an indoor heat exchanger installed on the refrigerant circulation loop; The path selection module is connected to the bypass branch and the refrigerant pipeline connected to the indoor heat exchanger, and is used to select whether to connect to the bypass branch or to the indoor heat exchanger. An indoor auxiliary heating device is used to heat the indoor heat exchanger; An indoor fan is used to drive air through the indoor heat exchanger.
8. The air conditioning defrosting control system according to claim 7, characterized in that, The bypass selection module includes a first switching valve and a second switching valve. Along the flow direction of the defrosting refrigerant, the first switching valve is located at the inlet of the indoor heat exchanger, one end of the bypass branch is connected to the inlet of the first switching valve, the other end of the bypass branch is connected to the outlet of the indoor heat exchanger, and the second switching valve is located in the bypass branch.
9. The air conditioning defrosting control system according to claim 7, characterized in that, The bypass selection module is a three-way valve; The inlet of the three-way valve is connected to the refrigerant circulation loop, and the two outlets of the three-way valve are respectively connected to the inlet of the bypass branch and the inlet of the indoor heat exchanger.
10. The air conditioning defrosting control system according to claim 6, characterized in that, The indoor auxiliary heating device is an electric auxiliary heating device.