Variable frequency air conditioner expansion valve opening degree control method based on time fuzzy algorithm

Abstract

The application provides a variable frequency air conditioner expansion valve opening degree control method based on a time fuzzy algorithm, and relates to the technical field of air conditioners. After the expansion valve opening degree reaches an initial opening degree, the expansion valve is adjusted by the minimum opening degree each time, and the expansion valve adjustment time is a multiple of a unit time t. The multiple is calculated based on the difference between the target exhaust temperature and the detected exhaust temperature and the change value of the detected exhaust temperature. In this way, the opening or closing of the expansion valve opening degree during the operation of the compressor is adjusted by the minimum unit of 1 step, and only the expansion valve adjustment time interval is changed. The problem of large fluctuation of the expansion valve opening degree of the existing variable frequency air conditioner, which leads to large fluctuation of the exhaust temperature, low stability and low comfort of the air conditioner is solved. The application is suitable for the expansion valve adjustment of the variable frequency air conditioner.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and in particular to a method for controlling the opening degree of an expansion valve in a variable frequency air conditioner based on a time fuzzy algorithm. Background Technology

[0002] Current air conditioners, especially inverter heat pump air conditioners, typically regulate the refrigerant flow of the air conditioning system under different operating conditions through an electronic expansion valve. During the regulation process, flow matching control is usually performed based on temperature parameters as the control target. These temperature parameters include the compressor discharge temperature. When the temperature is higher than the target temperature, the electronic expansion valve needs to be opened to increase the flow, thereby increasing the refrigerant flow and lowering the temperature. Conversely, when the temperature is lower than the target temperature, the electronic expansion valve needs to be opened to decrease the flow, thereby reducing the refrigerant flow and raising the temperature.

[0003] Currently, frequency control schemes for variable frequency air conditioners are all based on the fuzzy control algorithm of the opening degree. Specifically, the control method is based on the difference between the actual exhaust temperature and the target exhaust temperature in a fixed control cycle.

[0004] This fuzzy algorithm-based approach can adapt well to changes in exhaust temperature, but it has two problems: First, controlling the opening at fixed time intervals can lead to untimely control and poor dynamic adaptability of the refrigerant, resulting in the system's heat exchange capacity not being fully utilized. Second, the opening range adjusted by the fuzzy algorithm varies from one step to dozens of steps each time. This irregular opening control may cause the opening to rise or fall too much at once, leading to large fluctuations in exhaust temperature and an excessively long time for the system to converge to stable operation. This results in unstable air conditioning output and large fluctuations in room temperature, adversely affecting the system's control stability and user comfort. At the same time, during low-temperature heating and frosting, the current solution's large-scale closure of the expansion valve can cause rapid and sudden growth of ice crystals. Rapid frosting of the heat exchanger leads to a significant decrease in heating capacity and frequent defrosting actions, resulting in slow heating and large fluctuations in room temperature, causing an uncomfortable experience. Summary of the Invention

[0005] The technical problem solved by this invention is to provide a variable frequency air conditioner expansion valve opening control method based on a time fuzzy algorithm, which solves the problem that the existing variable frequency air conditioner expansion valve opening control has large fluctuations, resulting in large fluctuations in exhaust temperature and causing low air conditioner stability and low comfort.

[0006] The technical solution adopted by this invention to solve the above-mentioned technical problems is: a variable frequency air conditioner expansion valve opening control method based on a time fuzzy algorithm, wherein the expansion valve is adjusted at its minimum opening each time, and the adjustment time of the expansion valve each time is a multiple of the unit time t; the multiple is calculated fuzzily based on the difference between the target exhaust temperature and the detected exhaust temperature and the change value of the detected exhaust temperature, wherein the fuzzy calculation includes:

[0007] When the difference between the target exhaust temperature and the detected exhaust temperature is within a preset range, the multiplier is 0;

[0008] When the difference between the target exhaust temperature and the detected exhaust temperature is not less than the maximum value in the preset range, the multiplier increases as the change in the detected exhaust temperature increases when the change in the detected exhaust temperature is greater than or less than 0, and decreases as the difference between the target exhaust temperature and the detected exhaust temperature increases when the change in the detected exhaust temperature remains unchanged.

[0009] When the difference between the target exhaust temperature and the detected exhaust temperature is not greater than the minimum value in the preset range, the multiplier decreases as the change in the detected exhaust temperature increases, whether the change in the detected exhaust temperature is greater than or less than 0. Conversely, when the change in the detected exhaust temperature remains constant, the multiplier increases as the difference between the target exhaust temperature and the detected exhaust temperature increases.

[0010] Furthermore, the fuzzy calculation is performed by establishing a fuzzy control table to obtain the multiplier by querying the fuzzy control table; the fuzzy control table uses the difference between the target exhaust temperature and the detected exhaust temperature as the X-axis and the detected exhaust temperature change value as the Y-axis.

[0011] Furthermore, the preset range is (-1, 1).

[0012] Furthermore, when the difference between the target exhaust temperature and the detected exhaust temperature is in the range [1, 3), if the change in the detected exhaust temperature is in the range [0, 1), the multiplier is 70; if the change in the detected exhaust temperature is in the range [1, 2), the multiplier is 80; if the change in the detected exhaust temperature is in the range [2, 3), the multiplier is 90; and if the change in the detected exhaust temperature is not less than 3, the multiplier is 100. When the difference between the target exhaust temperature and the detected exhaust temperature is in the range [3, 4), if the change in the detected exhaust temperature is in the range [0, 1), the multiplier is 50; and if the change in the detected exhaust temperature is not less than 3, the multiplier is 100. When the change in temperature is within [1,2), the multiplier is 70; when the change in temperature is within [2,3), the multiplier is 80; when the change in temperature is not less than 3, the multiplier is 90. When the difference between the target exhaust temperature and the detected exhaust temperature is within [4,6), the multiplier is 20 when the change in temperature is within [0,1); 50 when the change in temperature is within [1,2); 70 when the change in temperature is within [2,3); and 70 when the change in temperature is not less than 3. The multiplier is 80; when the difference between the target exhaust temperature and the detected exhaust temperature is in [6,8), if the change in the detected exhaust temperature is in [0,1), the multiplier is 5; if the change in the detected exhaust temperature is in [1,2), the multiplier is 20; if the change in the detected exhaust temperature is in [2,3), the multiplier is 50; if the change in the detected exhaust temperature is not less than 3, the multiplier is 70; when the difference between the target exhaust temperature and the detected exhaust temperature is in [8,10), if the change in the detected exhaust temperature is in [0,1), the multiplier is 3; if the change in the detected exhaust temperature is... When the change value is in [1,2), the multiplier is 5; when the change value of the detected exhaust temperature is in [2,3), the multiplier is 20; when the change value of the detected exhaust temperature is not less than 3, the multiplier is 60. When the difference between the target exhaust temperature and the detected exhaust temperature is not less than 10, when the change value of the detected exhaust temperature is in [0,1), the multiplier is 2; when the change value of the detected exhaust temperature is in [1,2), the multiplier is 3; when the change value of the detected exhaust temperature is in [2,3), the multiplier is 5; when the change value of the detected exhaust temperature is not less than 3, the multiplier is 50.

[0013] Furthermore, when the difference between the target exhaust temperature and the detected exhaust temperature is within (-3, -1], the multiplier is 60 if the change in the detected exhaust temperature is within [0, 1), 40 if the change is within [1, 2), 30 if the change is within [2, 3), and 20 if the change is not less than 3. When the difference between the target exhaust temperature and the detected exhaust temperature is within (-4, -3], the multiplier is 40 if the change is within [0, 1), and 20 if the change is not less than 3. When the change in exhaust temperature is within [1,2), the multiplier is 30; when the change is within [2,3), the multiplier is 20; and when the change is not less than 3, the multiplier is 10. When the difference between the target exhaust temperature and the detected exhaust temperature is within (-6,-4], the multiplier is 7 when the change is within [0,1), 6 when it is within [1,2), 5 when it is within [2,3), and 5 when the change is not less than 3. When the difference between the target exhaust temperature and the detected exhaust temperature is in (-8, -6], the multiplier is 4 if the change in the detected exhaust temperature is in [0, 1), 5 if the change is in [1, 2), 4 if the change is in [2, 3), and 3 if the change is not less than 3. When the difference between the target exhaust temperature and the detected exhaust temperature is in (-10, -8], the multiplier is 5 if the change is in [0, 1), and 6 if the change is in [0, 1). When the temperature change value is in [1,2), the multiplier is 4; when the temperature change value is in [2,3), the multiplier is 3; when the temperature change value is not less than 3, the multiplier is 2. When the difference between the target exhaust temperature and the detected exhaust temperature is not greater than -10, when the temperature change value is in [0,1), the multiplier is 4; when the temperature change value is in [1,2), the multiplier is 3; when the temperature change value is in [2,3), the multiplier is 2; when the temperature change value is not less than 3, the multiplier is 1.

[0014] Furthermore, when the difference between the target exhaust temperature and the detected exhaust temperature is within (-3, -1], the multiplier is 30 if the change in the detected exhaust temperature is within (-1, 0), 35 if the change is within (-2, -1], 40 if the change is within (-3, -2], and 45 if the change is no greater than -3. When the difference between the target exhaust temperature and the detected exhaust temperature is within (-4, -3], the multiplier is 25 if the change is within (-1, 0), and 45 if the change is no greater than -3. When the temperature change is within the range of (-2, -1], the multiplier is 30; when the change is within the range of (-3, -2], the multiplier is 35; and when the change is no greater than -3, the multiplier is 40. When the difference between the target exhaust temperature and the detected exhaust temperature is within the range of (-6, -4], the multiplier is 5 if the change is within the range of (-1, 0), 6 if the change is within the range of (-2, -1], 7 if the change is within the range of (-3, -2], and 7 if the change is no greater than -3. When the difference between the target exhaust temperature and the detected exhaust temperature is in the range of (-8, -6], the multiplier is 8 if the change in the detected exhaust temperature is in the range of (-1, 0), 5 if the change is in the range of (-2, -1], 6 if the change is in the range of (-3, -2], and 7 if the change is not greater than -3. When the difference between the target exhaust temperature and the detected exhaust temperature is in the range of (-10, -8], the multiplier is 3 if the change is in the range of (-1, 0). When the change value is in (-2, -1], the multiplier is 4; when the change value of the detected exhaust temperature is in (-3, -2], the multiplier is 5; when the change value of the detected exhaust temperature is not greater than -3, the multiplier is 6. When the difference between the target exhaust temperature and the detected exhaust temperature is not greater than -10, when the change value of the detected exhaust temperature is in (-1, 0), the multiplier is 2; when the change value of the detected exhaust temperature is in (-2, -1], the multiplier is 3; when the change value of the detected exhaust temperature is in (-3, -2], the multiplier is 4; when the change value of the detected exhaust temperature is not greater than -3, the multiplier is 5.

[0015] Furthermore, when the difference between the target exhaust temperature and the detected exhaust temperature is in the range [1, 3), the multiplier is 50 if the change in the detected exhaust temperature is in the range (-1, 0), 40 if the change is in the range (-2, -1), 30 if the change is in the range (-3, -2), and 20 if the change is not greater than -3. When the difference between the target exhaust temperature and the detected exhaust temperature is in the range [3, 4), the multiplier is 40 if the change in the detected exhaust temperature is in the range (-1, 0), and 40 if the change is not greater than -3. When the change value of the target exhaust temperature is in the range of (-2, -1), the multiplier is 30; when the change value of the detected exhaust temperature is in the range of (-3, -2), the multiplier is 20; and when the change value of the detected exhaust temperature is not greater than -3, the multiplier is 10. When the difference between the target exhaust temperature and the detected exhaust temperature is in the range of [4, 6), when the change value of the detected exhaust temperature is in the range of (-1, 0), the multiplier is 30; when the change value of the detected exhaust temperature is in the range of (-2, -1), the multiplier is 20; when the change value of the detected exhaust temperature is in the range of (-3, -2), the multiplier is 10; and when the change value of the detected exhaust temperature is not greater than -3, the multiplier is 10. When the difference between the target exhaust temperature and the detected exhaust temperature is in the range [6,8), the multiplier is 4 if the change in the detected exhaust temperature is in the range (-1,0), 10 if the change is in the range (-2,-1), 4 if the change is in the range (-3,-2), and 3 if the change is not greater than -3. When the difference between the target exhaust temperature and the detected exhaust temperature is in the range [8,10), the multiplier is 10 if the change is in the range (-1,0), and 3 if the change is not greater than -3. When the change value is in (-2, -1], the multiplier is 4; when the change value of the detected exhaust temperature is in (-3, -2], the multiplier is 3; when the change value of the detected exhaust temperature is not greater than -3, the multiplier is 2. When the difference between the target exhaust temperature and the detected exhaust temperature is not less than 10, when the change value of the detected exhaust temperature is in (-1, 0), the multiplier is 4; when the change value of the detected exhaust temperature is in (-2, -1], the multiplier is 3; when the change value of the detected exhaust temperature is in (-3, -2], the multiplier is 2; when the change value of the detected exhaust temperature is not greater than -3, the multiplier is 1.

[0016] Furthermore, the value of the unit time t ranges from 2 to 10 seconds.

[0017] The beneficial effects of this invention are as follows: This invention provides a variable frequency air conditioner expansion valve opening control method based on a time fuzzy algorithm. After the expansion valve opening reaches the initial opening, the expansion valve is adjusted at its minimum opening each time, and the adjustment time of the expansion valve each time is a multiple of a unit time t. The multiple is calculated fuzzily based on the difference between the target exhaust temperature and the detected exhaust temperature, as well as the change value of the detected exhaust temperature. Thus, the compressor adjusts the opening or closing of the expansion valve in one minimum unit during operation, changing only the adjustment time interval of the expansion valve. This can significantly improve the flow regulation and the operational stability and reliability of the system, enabling the air conditioning system to automatically couple to the optimal refrigerant flow. At the same time, the one-step adjustment of the expansion valve opening can significantly improve the frosting stability of the system during low-temperature heating, avoiding excessive valve closure that could lead to abrupt ice crystal growth and disrupt the stability of the frosting process. This improves the comfort of low-temperature heating and solves the problem of large fluctuations in the opening control of the expansion valve in existing variable frequency air conditioners, which leads to large fluctuations in exhaust temperature and causes low air conditioning stability and low comfort. Attached Figure Description

[0018] Figure 1 This is the fuzzy control table in this invention, where the X-axis represents the difference ΔT between the target exhaust temperature and the detected exhaust temperature, the Y-axis represents the change ΔTp in the detected exhaust temperature, and t represents the unit time. Detailed Implementation

[0019] This invention provides a variable frequency air conditioner expansion valve opening control method based on a time fuzzy algorithm. After the expansion valve reaches its initial opening, it is adjusted to its minimum opening each time, with each adjustment time being a multiple of a unit time t. The multiple is calculated fuzzily based on the difference between the target exhaust temperature and the detected exhaust temperature, as well as the change in the detected exhaust temperature. The fuzzy calculation includes:

[0020] When the difference between the target exhaust temperature and the detected exhaust temperature is within a preset range, the multiplier is 0;

[0021] When the difference between the target exhaust temperature and the detected exhaust temperature is not less than the maximum value in the preset range, the multiplier increases as the change in the detected exhaust temperature increases when the change in the detected exhaust temperature is greater than or less than 0, and decreases as the difference between the target exhaust temperature and the detected exhaust temperature increases when the change in the detected exhaust temperature remains unchanged.

[0022] When the difference between the target exhaust temperature and the detected exhaust temperature is not greater than the minimum value in the preset range, the multiplier decreases as the change in the detected exhaust temperature increases, whether the change in the detected exhaust temperature is greater than or less than 0. Conversely, when the change in the detected exhaust temperature remains constant, the multiplier increases as the difference between the target exhaust temperature and the detected exhaust temperature increases.

[0023] Normally, the minimum opening of the expansion valve is one step, and the value of the unit time t ranges from 2 to 10 seconds, preferably 5 seconds. To ensure that the compressor quickly reaches the initial opening, the initial opening speed is not limited by the one-step adjustment unit and is still controlled according to the original control logic. After the expansion valve reaches the initial opening, the compressor adjusts the opening of the expansion valve in one-step minimum units during operation, only changing the adjustment time interval of the expansion valve. This avoids the situation of large fluctuations in the opening control of the expansion valve of the variable frequency air conditioner, which can greatly improve the flow regulation and the operational stability and reliability of the system. It enables the air conditioning system to automatically couple to the optimal refrigerant flow. At the same time, the expansion valve opening is adjusted in one step each time, which can greatly improve the frosting stability of the system when heating at low temperatures, avoid the sudden change in ice crystal growth caused by excessive valve closure, and prevent the stability of the frosting process from being destroyed, thereby improving the comfort of low-temperature heating.

[0024] Specifically, fuzzy calculation can be performed by establishing a fuzzy control table and querying the fuzzy control table to obtain the multiplier; the fuzzy control table uses the difference between the target exhaust temperature and the detected exhaust temperature as the X-axis and the detected exhaust temperature change value as the Y-axis.

[0025] This invention provides a specific fuzzy control table, such as Figure 1 As shown, the X-axis represents the difference ΔT between the target exhaust temperature and the detected exhaust temperature, the Y-axis represents the change ΔTp in the detected exhaust temperature, and t represents the unit time.

[0026] When the difference ΔT between the target exhaust temperature and the detected exhaust temperature is within the preset range (-1, 1), the multiplier is 0, that is, the opening degree of the expansion valve is not changed.

[0027] When the difference between the target exhaust temperature and the detected exhaust temperature is in the range [1, 3), the multiplier is 70 if the change in the detected exhaust temperature is in the range [0, 1), 80 if the change is in the range [1, 2), 90 if the change is in the range [2, 3), and 100 if the change is not less than 3. When the difference between the target exhaust temperature and the detected exhaust temperature is in the range [3, 4), the multiplier is 50 if the change is in the range [0, 1), and 50 if the change is not less than 3. When the change in exhaust temperature is within [1,2), the multiplier is 70; when the change in exhaust temperature is within [2,3), the multiplier is 80; when the change in exhaust temperature is not less than 3, the multiplier is 90. When the difference between the target exhaust temperature and the detected exhaust temperature is within [4,6), the multiplier is 20 when the change in exhaust temperature is within [0,1); the multiplier is 50 when the change in exhaust temperature is within [1,2); the multiplier is 70 when the change in exhaust temperature is within [2,3); and when the change in exhaust temperature is not less than 3, the multiplier is

[70] . The multiplier is 80; when the difference between the target exhaust temperature and the detected exhaust temperature is in [6,8), if the change in the detected exhaust temperature is in [0,1), the multiplier is 5; if the change in the detected exhaust temperature is in [1,2), the multiplier is 20; if the change in the detected exhaust temperature is in [2,3), the multiplier is 50; if the change in the detected exhaust temperature is not less than 3, the multiplier is 70; when the difference between the target exhaust temperature and the detected exhaust temperature is in [8,10), if the change in the detected exhaust temperature is in [0,1), the multiplier is 3; if the change in the detected exhaust temperature is... When the change value is in [1,2), the multiplier is 5; when the change value of the detected exhaust temperature is in [2,3), the multiplier is 20; when the change value of the detected exhaust temperature is not less than 3, the multiplier is 60. When the difference between the target exhaust temperature and the detected exhaust temperature is not less than 10, when the change value of the detected exhaust temperature is in [0,1), the multiplier is 2; when the change value of the detected exhaust temperature is in [1,2), the multiplier is 3; when the change value of the detected exhaust temperature is in [2,3), the multiplier is 5; when the change value of the detected exhaust temperature is not less than 3, the multiplier is 50.

[0028] When the difference between the target exhaust temperature and the detected exhaust temperature is within (-3, -1], the multiplier is 60 if the change in the detected exhaust temperature is within [0, 1), 40 if the change is within [1, 2), 30 if the change is within [2, 3), and 20 if the change is not less than 3. When the difference between the target exhaust temperature and the detected exhaust temperature is within (-4, -3], the multiplier is 40 if the change is within [0, 1), and 40 if the change is within [2, 3). When the change in temperature is within [1,2), the multiplier is 30; when the change in temperature is within [2,3), the multiplier is 20; and when the change in temperature is not less than 3, the multiplier is 10. When the difference between the target exhaust temperature and the detected exhaust temperature is within (-6,-4], when the change in temperature is within [0,1), the multiplier is 7; when the change in temperature is within [1,2), the multiplier is 6; when the change in temperature is within [2,3), the multiplier is 5; and when the change in temperature is not less than 3, the multiplier is 10. The multiplier is 4; when the difference between the target exhaust temperature and the detected exhaust temperature is in (-8, -6], if the change in the detected exhaust temperature is in [0, 1), the multiplier is 6; if the change in the detected exhaust temperature is in [1, 2), the multiplier is 5; if the change in the detected exhaust temperature is in [2, 3), the multiplier is 4; if the change in the detected exhaust temperature is not less than 3, the multiplier is 3; when the difference between the target exhaust temperature and the detected exhaust temperature is in (-10, -8], if the change in the detected exhaust temperature is in [0, 1), the multiplier is 5; if the change in the detected exhaust temperature is not less than 3, the multiplier is 6; when the difference between the target exhaust temperature and the detected exhaust temperature is in (-10, -8], if the change in the detected exhaust temperature is in [0, 1), the multiplier is 5; if the change in the detected exhaust temperature is less than 3, the multiplier is 6; when the difference between the target exhaust temperature and the detected exhaust temperature is in (-10, -8], if the change in the detected exhaust temperature is in [0, 1), the multiplier is 6; if the change in the detected exhaust temperature is in [1, 2), the multiplier is 6; if the change in the detected exhaust temperature is in [2, 3), the multiplier is 4; if the change in the detected exhaust temperature is not less than 3, the multiplier is 3. When the change in temperature is within [1,2), the multiplier is 4; when the change in temperature is within [2,3), the multiplier is 3; when the change in temperature is not less than 3, the multiplier is 2. When the difference between the target exhaust temperature and the detected exhaust temperature is not greater than -10, when the change in temperature is within [0,1), the multiplier is 4; when the change in temperature is within [1,2), the multiplier is 3; when the change in temperature is within [2,3), the multiplier is 2; when the change in temperature is not less than 3, the multiplier is 1.

[0029] When the difference between the target exhaust temperature and the detected exhaust temperature is within (-3, -1], the multiplier is 30 if the change in the detected exhaust temperature is within (-1, 0), 35 if the change is within (-2, -1], 40 if the change is within (-3, -2], and 45 if the change is no greater than -3. When the difference between the target exhaust temperature and the detected exhaust temperature is within (-4, -3], the multiplier is 25 if the change is within (-1, 0), and 45 if the change is no greater than -3. When the change value is in (-2, -1], the multiplier is 30; when the change value of the detected exhaust temperature is in (-3, -2], the multiplier is 35; when the change value of the detected exhaust temperature is no greater than -3, the multiplier is 40. When the difference between the target exhaust temperature and the detected exhaust temperature is in (-6, -4], when the change value of the detected exhaust temperature is in (-1, 0), the multiplier is 5; when the change value of the detected exhaust temperature is in (-2, -1], the multiplier is 6; when the change value of the detected exhaust temperature is in (-3, -2], the multiplier is 7; when the change value of the detected exhaust temperature is no greater than -3, the multiplier is 40. The multiplier is 8; when the difference between the target exhaust temperature and the detected exhaust temperature is in (-8, -6], if the change in the detected exhaust temperature is in (-1, 0), the multiplier is 4; if the change in the detected exhaust temperature is in (-2, -1], the multiplier is 5; if the change in the detected exhaust temperature is in (-3, -2], the multiplier is 6; if the change in the detected exhaust temperature is not greater than -3, the multiplier is 7; when the difference between the target exhaust temperature and the detected exhaust temperature is in (-10, -8], if the change in the detected exhaust temperature is in (-1, 0), the multiplier is 3; if the change in the detected exhaust temperature is... When the change value is in (-2, -1], the multiplier is 4; when the change value of the detected exhaust temperature is in (-3, -2], the multiplier is 5; when the change value of the detected exhaust temperature is no greater than -3, the multiplier is 6. When the difference between the target exhaust temperature and the detected exhaust temperature is no greater than -10, when the change value of the detected exhaust temperature is in (-1, 0), the multiplier is 2; when the change value of the detected exhaust temperature is in (-2, -1], the multiplier is 3; when the change value of the detected exhaust temperature is in (-3, -2], the multiplier is 4; when the change value of the detected exhaust temperature is no greater than -3, the multiplier is 5.

[0030] When the difference between the target exhaust temperature and the detected exhaust temperature is in the range [1, 3), the multiplier is 50 if the change in the detected exhaust temperature is in the range (-1, 0), 40 if the change is in the range (-2, -1), 30 if the change is in the range (-3, -2), and 20 if the change is not greater than -3. When the difference between the target exhaust temperature and the detected exhaust temperature is in the range [3, 4), the multiplier is 40 if the change in the detected exhaust temperature is in the range (-1, 0), and 30 if the change is not greater than -3. When the difference between the target exhaust temperature and the detected exhaust temperature is in the range of (-2, -1), the multiplier is 30. If the change in the detected exhaust temperature is in the range of (-3, -2), the multiplier is 20. If the change in the detected exhaust temperature is no greater than -3, the multiplier is 10. When the difference between the target exhaust temperature and the detected exhaust temperature is in the range of [4, 6), if the change in the detected exhaust temperature is in the range of (-1, 0), the multiplier is 30. If the change in the detected exhaust temperature is in the range of (-2, -1), the multiplier is 20. If the change in the detected exhaust temperature is in the range of (-3, -2), the multiplier is 10. If the change in the detected exhaust temperature is no greater than -3, the multiplier is 10. The multiplier is 4; when the difference between the target exhaust temperature and the detected exhaust temperature is in [6,8), if the change in the detected exhaust temperature is in (-1,0), the multiplier is 20; if the change in the detected exhaust temperature is in (-2,-1], the multiplier is 10; if the change in the detected exhaust temperature is in (-3,-2], the multiplier is 4; if the change in the detected exhaust temperature is not greater than -3, the multiplier is 3; when the difference between the target exhaust temperature and the detected exhaust temperature is in [8,10), if the change in the detected exhaust temperature is in (-1,0), the multiplier is 10; if the change in the detected exhaust temperature is not greater than -3, the multiplier is 3. When the change value is in (-2, -1], the multiplier is 4; when the change value of the detected exhaust temperature is in (-3, -2], the multiplier is 3; when the change value of the detected exhaust temperature is not greater than -3, the multiplier is 2. When the difference between the target exhaust temperature and the detected exhaust temperature is not less than 10, when the change value of the detected exhaust temperature is in (-1, 0), the multiplier is 4; when the change value of the detected exhaust temperature is in (-2, -1], the multiplier is 3; when the change value of the detected exhaust temperature is in (-3, -2], the multiplier is 2; when the change value of the detected exhaust temperature is not greater than -3, the multiplier is 1.

[0031] In this invention, the larger the multiple of the unit time t, the longer the adjustment time of the expansion valve each time, that is, the slower the change in opening degree. Conversely, the smaller the multiple of the unit time, the shorter the adjustment time of the expansion valve each time, that is, the faster the change in opening degree.

Claims

1. A variable frequency air conditioner expansion valve opening control method based on time fuzzy algorithm, applied after the expansion valve opening reaches the initial opening, characterized in that, The expansion valve is adjusted to its minimum opening each time, and the adjustment time of the expansion valve each time is a multiple of the unit time t; The multiplier is calculated fuzzily based on the difference between the target exhaust temperature and the detected exhaust temperature, as well as the change in the detected exhaust temperature. The fuzzy calculation includes: When the difference between the target exhaust temperature and the detected exhaust temperature is within a preset range, the multiplier is 0; When the difference between the target exhaust temperature and the detected exhaust temperature is not less than the maximum value in the preset range, the multiplier increases as the change in the detected exhaust temperature increases when the change in the detected exhaust temperature is greater than or less than 0, and decreases as the difference between the target exhaust temperature and the detected exhaust temperature increases when the change in the detected exhaust temperature remains unchanged. When the difference between the target exhaust temperature and the detected exhaust temperature is not greater than the minimum value in the preset range, the multiplier decreases as the change in the detected exhaust temperature increases, whether the change in the detected exhaust temperature is greater than or less than 0. Conversely, when the change in the detected exhaust temperature remains constant, the multiplier increases as the difference between the target exhaust temperature and the detected exhaust temperature increases.

2. The variable frequency air conditioner expansion valve opening control method based on time fuzzy algorithm according to claim 1, characterized in that, The fuzzy calculation is performed by establishing a fuzzy control table to obtain the multiplier by querying the fuzzy control table; the fuzzy control table uses the difference between the target exhaust temperature and the detected exhaust temperature as the X-axis and the detected exhaust temperature change value as the Y-axis.

3. The variable frequency air conditioner expansion valve opening control method based on time fuzzy algorithm according to claim 2, characterized in that, The preset range is (-1, 1).

4. The variable frequency air conditioner expansion valve opening control method based on time fuzzy algorithm according to any one of claims 1-3, characterized in that, When the difference between the target exhaust temperature and the detected exhaust temperature is in the range [1, 3), the multiplier is 70 if the change in the detected exhaust temperature is in the range [0, 1), 80 if the change is in the range [1, 2), 90 if the change is in the range [2, 3), and 100 if the change is not less than 3. When the difference between the target exhaust temperature and the detected exhaust temperature is in the range [3, 4), the multiplier is 50 if the change is in the range [0, 1), and 50 if the change is not less than 3. When the change in exhaust temperature is within [1,2), the multiplier is 70; when the change in exhaust temperature is within [2,3), the multiplier is 80; when the change in exhaust temperature is not less than 3, the multiplier is 90. When the difference between the target exhaust temperature and the detected exhaust temperature is within [4,6), the multiplier is 20 when the change in exhaust temperature is within [0,1); the multiplier is 50 when the change in exhaust temperature is within [1,2); the multiplier is 70 when the change in exhaust temperature is within [2,3); and when the change in exhaust temperature is not less than 3, the multiplier is [70]. The multiplier is 80; when the difference between the target exhaust temperature and the detected exhaust temperature is in [6,8), if the change in the detected exhaust temperature is in [0,1), the multiplier is 5; if the change in the detected exhaust temperature is in [1,2), the multiplier is 20; if the change in the detected exhaust temperature is in [2,3), the multiplier is 50; if the change in the detected exhaust temperature is not less than 3, the multiplier is 70; when the difference between the target exhaust temperature and the detected exhaust temperature is in [8,10), if the change in the detected exhaust temperature is in [0,1), the multiplier is 3; if the change in the detected exhaust temperature is... When the change value is in [1,2), the multiplier is 5; when the change value of the detected exhaust temperature is in [2,3), the multiplier is 20; when the change value of the detected exhaust temperature is not less than 3, the multiplier is 60. When the difference between the target exhaust temperature and the detected exhaust temperature is not less than 10, when the change value of the detected exhaust temperature is in [0,1), the multiplier is 2; when the change value of the detected exhaust temperature is in [1,2), the multiplier is 3; when the change value of the detected exhaust temperature is in [2,3), the multiplier is 5; when the change value of the detected exhaust temperature is not less than 3, the multiplier is 50.

5. The variable frequency air conditioner expansion valve opening control method based on time fuzzy algorithm according to any one of claims 1-3, characterized in that, When the difference between the target exhaust temperature and the detected exhaust temperature is within (-3, -1], the multiplier is 60 if the change in the detected exhaust temperature is within [0, 1), 40 if the change is within [1, 2), 30 if the change is within [2, 3), and 20 if the change is not less than 3. When the difference between the target exhaust temperature and the detected exhaust temperature is within (-4, -3], the multiplier is 40 if the change is within [0, 1), and 40 if the change is within [2, 3). When the change in temperature is within [1,2), the multiplier is 30; when the change in temperature is within [2,3), the multiplier is 20; and when the change in temperature is not less than 3, the multiplier is 10. When the difference between the target exhaust temperature and the detected exhaust temperature is within (-6,-4], when the change in temperature is within [0,1), the multiplier is 7; when the change in temperature is within [1,2), the multiplier is 6; when the change in temperature is within [2,3), the multiplier is 5; and when the change in temperature is not less than 3, the multiplier is 10. The multiplier is 4; when the difference between the target exhaust temperature and the detected exhaust temperature is in (-8, -6], if the change in the detected exhaust temperature is in [0, 1), the multiplier is 6; if the change in the detected exhaust temperature is in [1, 2), the multiplier is 5; if the change in the detected exhaust temperature is in [2, 3), the multiplier is 4; if the change in the detected exhaust temperature is not less than 3, the multiplier is 3; when the difference between the target exhaust temperature and the detected exhaust temperature is in (-10, -8], if the change in the detected exhaust temperature is in [0, 1), the multiplier is 5; if the change in the detected exhaust temperature is not less than 3, the multiplier is 6; when the difference between the target exhaust temperature and the detected exhaust temperature is in (-10, -8], if the change in the detected exhaust temperature is in [0, 1), the multiplier is 5; if the change in the detected exhaust temperature is less than 3, the multiplier is 6; when the difference between the target exhaust temperature and the detected exhaust temperature is in (-10, -8], if the change in the detected exhaust temperature is in [0, 1), the multiplier is 6; if the change in the detected exhaust temperature is in [1, 2), the multiplier is 6; if the change in the detected exhaust temperature is in [2, 3), the multiplier is 4; if the change in the detected exhaust temperature is not less than 3, the multiplier is 3. When the change in temperature is within [1,2), the multiplier is 4; when the change in temperature is within [2,3), the multiplier is 3; when the change in temperature is not less than 3, the multiplier is 2. When the difference between the target exhaust temperature and the detected exhaust temperature is not greater than -10, when the change in temperature is within [0,1), the multiplier is 4; when the change in temperature is within [1,2), the multiplier is 3; when the change in temperature is within [2,3), the multiplier is 2; when the change in temperature is not less than 3, the multiplier is 1.

6. The variable frequency air conditioner expansion valve opening control method based on time fuzzy algorithm according to any one of claims 1-3, characterized in that, When the difference between the target exhaust temperature and the detected exhaust temperature is within (-3, -1], the multiplier is 30 if the change in the detected exhaust temperature is within (-1, 0), 35 if the change is within (-2, -1], 40 if the change is within (-3, -2], and 45 if the change is no greater than -3. When the difference between the target exhaust temperature and the detected exhaust temperature is within (-4, -3], the multiplier is 25 if the change is within (-1, 0), and 45 if the change is no greater than -3. When the change value is in (-2, -1], the multiplier is 30; when the change value of the detected exhaust temperature is in (-3, -2], the multiplier is 35; when the change value of the detected exhaust temperature is no greater than -3, the multiplier is 40. When the difference between the target exhaust temperature and the detected exhaust temperature is in (-6, -4], when the change value of the detected exhaust temperature is in (-1, 0), the multiplier is 5; when the change value of the detected exhaust temperature is in (-2, -1], the multiplier is 6; when the change value of the detected exhaust temperature is in (-3, -2], the multiplier is 7; when the change value of the detected exhaust temperature is no greater than -3, the multiplier is 40. The multiplier is 8; when the difference between the target exhaust temperature and the detected exhaust temperature is in (-8, -6], if the change in the detected exhaust temperature is in (-1, 0), the multiplier is 4; if the change in the detected exhaust temperature is in (-2, -1], the multiplier is 5; if the change in the detected exhaust temperature is in (-3, -2], the multiplier is 6; if the change in the detected exhaust temperature is not greater than -3, the multiplier is 7; when the difference between the target exhaust temperature and the detected exhaust temperature is in (-10, -8], if the change in the detected exhaust temperature is in (-1, 0), the multiplier is 3; if the change in the detected exhaust temperature is... When the change value is in (-2, -1], the multiplier is 4; when the change value of the detected exhaust temperature is in (-3, -2], the multiplier is 5; when the change value of the detected exhaust temperature is no greater than -3, the multiplier is 6. When the difference between the target exhaust temperature and the detected exhaust temperature is no greater than -10, when the change value of the detected exhaust temperature is in (-1, 0), the multiplier is 2; when the change value of the detected exhaust temperature is in (-2, -1], the multiplier is 3; when the change value of the detected exhaust temperature is in (-3, -2], the multiplier is 4; when the change value of the detected exhaust temperature is no greater than -3, the multiplier is 5.

7. The variable frequency air conditioner expansion valve opening control method based on time fuzzy algorithm according to any one of claims 1-3, characterized in that, When the difference between the target exhaust temperature and the detected exhaust temperature is in the range [1, 3), the multiplier is 50 if the change in the detected exhaust temperature is in the range (-1, 0), 40 if the change is in the range (-2, -1), 30 if the change is in the range (-3, -2), and 20 if the change is not greater than -3. When the difference between the target exhaust temperature and the detected exhaust temperature is in the range [3, 4), the multiplier is 40 if the change in the detected exhaust temperature is in the range (-1, 0), and 30 if the change is not greater than -3. When the difference between the target exhaust temperature and the detected exhaust temperature is in the range of (-2, -1), the multiplier is 30. If the change in the detected exhaust temperature is in the range of (-3, -2), the multiplier is 20. If the change in the detected exhaust temperature is no greater than -3, the multiplier is 10. When the difference between the target exhaust temperature and the detected exhaust temperature is in the range of [4, 6), if the change in the detected exhaust temperature is in the range of (-1, 0), the multiplier is 30. If the change in the detected exhaust temperature is in the range of (-2, -1), the multiplier is 20. If the change in the detected exhaust temperature is in the range of (-3, -2), the multiplier is 10. If the change in the detected exhaust temperature is no greater than -3, the multiplier is 10. The multiplier is 4; when the difference between the target exhaust temperature and the detected exhaust temperature is in [6,8), if the change in the detected exhaust temperature is in (-1,0), the multiplier is 20; if the change in the detected exhaust temperature is in (-2,-1], the multiplier is 10; if the change in the detected exhaust temperature is in (-3,-2], the multiplier is 4; if the change in the detected exhaust temperature is not greater than -3, the multiplier is 3; when the difference between the target exhaust temperature and the detected exhaust temperature is in [8,10), if the change in the detected exhaust temperature is in (-1,0), the multiplier is 10; if the change in the detected exhaust temperature is not greater than -3, the multiplier is 3. When the change value is in (-2, -1], the multiplier is 4; when the change value of the detected exhaust temperature is in (-3, -2], the multiplier is 3; when the change value of the detected exhaust temperature is not greater than -3, the multiplier is 2. When the difference between the target exhaust temperature and the detected exhaust temperature is not less than 10, when the change value of the detected exhaust temperature is in (-1, 0), the multiplier is 4; when the change value of the detected exhaust temperature is in (-2, -1], the multiplier is 3; when the change value of the detected exhaust temperature is in (-3, -2], the multiplier is 2; when the change value of the detected exhaust temperature is not greater than -3, the multiplier is 1.

8. The variable frequency air conditioner expansion valve opening control method based on time fuzzy algorithm according to any one of claims 1-3, characterized in that, The value of the unit time t ranges from 2 to 10 seconds.

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