TW587144B - System for controlling degree of superheat of air conditioner and control method thereof - Google Patents

Abstract

Disclosed herein is a system and method for controlling the degree of superheat of an air conditioner. The air conditioner includes a compressor controlled in a pulse width modulation manner according to duty control signals, a condenser, an electronic expansion valve and an evaporator so as to form a refrigeration cycle. An entrance temperature sensor situated at the entrance of the evaporator and an exit temperature sensor situated at the exit of the evaporator are connected to a control unit. The control unit calculates the degree of superheat of the evaporator using the difference between mean entrance and exit temperatures of the evaporator sensed by the entrance temperature sensor and the exit temperature sensor for a period of time corresponding to a duty cycle period of the compressor, and regulates the opening of the electronic expansion valve according to the calculated degree of superheat.

Description

587144

The present invention relates to an air conditioner, and more particularly to a system and a method for controlling the air conditioner by using a pulse width modulation compressor to overheat the air conditioner. '' T

[Knowledge technology]

Ik's building is getting larger and larger, and consumer demand for multi-air conditioners is increasing. With this multi-air conditioner system, multiple indoor units (in (j0〇r unit) Connected to a single out door unit. In this multi-air conditioner, the amount of refrigeration required by each unit in the house is changed according to the environmental characteristics of the location where it is located, and by the heat exchanger installed on the inside of the house The opening of the electronic expansion valve of the indorr side heat exchangers or evaporators can be adjusted to achieve the above-mentioned requirements. More specifically, because of the internal and external units in the multi-air conditioner, The lengths of the refrigerant conduits are not exactly equal, so the refrigerant in each refrigerant conduit will be subjected to different flow resistance, which will cause the degree of overheating between its evaporators (the degree of overheating of each evaporator = The outlet temperature of the evaporator-the inlet temperature of the evaporator) are different. In theory, the superheating range

Degree refers to the difference between the temperature of the superheated steam at saturation temperature (saturation temperatuiO) and the saturation temperature relative to its saturation pressure. In practical applications, the outlet and inlet of the evaporator are generally used. The difference between the temperatures is regarded as the degree of superheating, and the degree of superheating of the evaporator is controlled by controlling the outlet and inlet temperatures. When the refrigerant flowing out of the evaporator has a high degree of superheating, this will

587144

Causes its compressor to overheat and reduce its efficiency. When the level of the cold remedy exceeds two degrees, a safety device will be activated. All operations of medium and earth-side air conditioners. On the other hand, when the superheating degree of the cold bundle agent is too low, the refrigerant entering the compressor will be increased accordingly. Therefore, the above-mentioned indoor heat exchanger (evaporator) will be overheated. It is necessary to carry out appropriate control, so as to make the binary in the house # reach the maximum performance, reduce the early difference between the performance of the units in the house, improve the performance of the compressor and the overall system and Its stability. In addition, since the compressor type of a general multi-air conditioner uses a constant speed type or a variable rotation number, the flow rate of the refrigerant will not be affected during the operation of the compressor. It's changed a lot. As can be seen from Figure 8, since the inlet and outlet temperatures of the evaporator show a fairly stable change, the inlet and outlet temperatures of the evaporator can be easily measured in some cases, and can be borrowed. The difference between the inlet and outlet temperatures of the evaporator is used to appropriately control the degree of overheating.

The pulse width modulated compressor disclosed in U.S. Patent No. 6047557 and Japanese Unexamined Patent Publication No. Hei 8-334094 is a variable load compressor belonging to other types. The compressors used in these refrigeration systems include a plurality of freezing compartments or refrigerating compartments, and the above design is used to shorten the piping in the cold bundle system. Among them, the refrigerant conduits between the compressor and the evaporator

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: j distance. Due to their uniformity in the building's air-conditioning system and the control between these air-conditioning systems and the refrigeration system, these compressors cannot be used in these built-up systems. Furthermore, in addition to the control system and control of the air-pulse width modulation compressor in the conventional technology, the conventional technology does not propose a control method related to the long-air == ..., length. When the flow of the refrigerant used in an air conditioner is set at weekly loading time and non-loading time (u η 1 oading), these actions will also be in the line. Therefore, the pulse width hair is used The existence and non-existence of the state above the inlet and outlet temperature of the compressor determines the time period of the compressor in the air conditioner of the compressor. ) Compressor degree modulation up and down. Therefore, the degree of evaporation will start with phase-independent modulation and the compressor will be operated under the refrigerant. The drop of the compressor will be based on the calculation of the input and the line with Is, and the suspension will be the same as that of the zero. The cold wave agent of the machine-cooled agent is warm when the pulse wave exits, that is, when the agent is discharged, and the agent is fed in, the steamed width modulation degree of the agent cannot be related to or prior to this. The object of the present invention is Aiming at the above-mentioned conventional technology, an improvement is proposed. In the air conditioner overheating degree control system and control method of the present invention, a pulse width modulation compressor is used, and the compressor is calculated based on the inlet and outlet temperatures of the evaporator. The degree of overheating, so that the temperature fluctuation Phenomenon can be compensated, and the air conditioner has the best effect.

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587144

5. Description of the invention (4) Yes. The purpose of the present invention is to improve the conventional technology. In the air conditioner overheating degree control system and control method of the present invention, a pulse width modulation compressor is used. Temperature to calculate the degree of overheating, so that the temperature fluctuations can be compensated, and the air conditioner has the best effect.

To achieve the above object, the present invention proposes a system for controlling the overheating privacy of an air conditioner. The overheating degree control system of an air conditioner includes a compressor, a condenser, an electronic expansion valve, and an evaporator. The compressor is controlled by a pulse width modulation method according to the work control signal, so it can form a cold-bamboo cycle together. An inlet temperature sensor is provided at the inlet of the evaporator, and an outlet temperature sensor is provided at the outlet of the evaporator. Under a time period relative to one duty cycle of the compressor, it can be detected that the degree of overheating is the average input of the evaporator detected by the inlet temperature sensor and the outlet temperature sensor. Difference between outlet temperatures. A control unit calculates the degree of overheating of the hair dryer based on the difference, and adjusts the opening of the electronic expansion valve by the control unit based on the calculated degree of overheating. ,

In the method for controlling the degree of overheating of the air conditioner provided by the present invention, the air conditioner includes a compressor, an electronic expansion valve, and an evaporator, and the compressor is controlled by a pulse wave according to a work control signal Width modulation method. The method for controlling the overheating degree of the air conditioner includes the following steps: detecting an inlet temperature and an outlet temperature of the evaporator; and based on the detected inlet temperature

587144 V. Description of the invention (5) Degree, the outlet temperature to calculate the degree of superheat; based on the calculated degree of superheat to calculate the target opening value of the electronic expansion valve; and adjust the electronic expansion valve to the calculated Target opening value. Examples

In order to make the above-mentioned objects, features, and advantages of the present invention more comprehensible, a preferred embodiment is given below in conjunction with the accompanying drawings for detailed description as follows. FIG. 1 is a system cycle diagram for controlling the degree of overheating of an air conditioner 1. The air conditioner 1 of the present invention includes a compressor 2, a condenser 3, a plurality of electronic expansion valves 4 and a plurality of evaporators 5; before, after The devices are connected by a plurality of refrigerating conduits to form a closed refrigerating circuit. Among these refrigerant pipes, one of the refrigerant bundle pipes used to connect the out flow side of the compressor 2 to the inf 1 owside of the electronic expansion valve is a high pressure pipe. conduit 6), through which the high-pressure refrigerant discharged by the compressor 2 can be guided; used to connect the outflow side of the electronic expansion valve 4 to one of the inflow sides of the compressor 2 The east agent conduit is a low pressure conduit 7 through which the low-pressure refrigerant expanded through the electronic expansion valve 4 is guided. The condenser 3 is located above the high-pressure duct 6 'and the evaporator 5 is. When the compressor 2 is in the operating state, the cold; east agent flows in the direction of the solid arrow (sol id arrow direct ions).

5050-4483-PF (N) .ptd Page 10 587144 V. Description of the invention (6) In addition, the air conditioner 1 series includes an outdoor unit 8 and a plurality of indoor units 9, among which, the The outdoor unit 8 is mainly composed of the compressor 2 and the condenser 3. In addition, the outdoor unit 8 further includes an accumulator 10 and a receiver 11, wherein the accumulator 10 is disposed upstream of the low-pressure pipe 7 of the compressor 2, and the The collector 11 is disposed downstream of the high-pressure duct 6 of the condenser 3. The function of the pressure accumulator 10 is to collect and evaporate the liquid refrigerant that has not been evaporated, and to allow the evaporated refrigerant to flow to the compressor 2. If the refrigerant in the evaporator 5 has not completely evaporated, the refrigerant entering the pressure accumulator 10 is a liquid-gas refrigerant · refrigerant. After the liquid refrigerant is evaporated by the accumulator 10, the gaseous cold / east agent (cold; east agent gas (r e f r i g e r a n t g a s)) is allowed to enter the compressor 2. In order to achieve the above purpose, the inlet and outlet ends of the refrigerant pipe located inside the pressure accumulator i 0 are preferably placed on the upper portion of the pressure accumulator 1 0. If the refrigerant in the condenser 3 is not completely condensed, the refrigerant entering the collector 11 is a liquid-gas refrigerant. The purpose of this collector is to separate liquid refrigerant from gaseous refrigerant 'so that only liquid refrigerant in liquid-gas mixed refrigerant can be discharged. In order to achieve this, the inlet and outlet ends of the refrigerant tube located inside the collector Π are preferably extended to the lower portion of the collector 11. A vent bypass conduit 12 connects the collector 11 upstream of the low-pressure conduit 7 of the pressure accumulator 10, so that

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V. Description of the invention (7) The gaseous cold collected in the collector 11 can be cooled; the east agent can perform bypass flow. The inlet of the ventilation bypass conduit 12 is located at the top of the closing 5 | 11 so that only the gaseous refrigerant can enter the ventilation bypass conduit 12. A vent valve (vent & valve) 13 is provided on the vent bypass tube 12, and the vent valve 13 is used to control the flow rate of the gaseous refrigerant that is bypassed and drained. In FIG. 1, the double-dotted arrows (double dotted v / arrows) are used to indicate the flow direction of the gaseous refrigerant. 0 The portion of the high-pressure duct 6 extending from the collector 11 passes through the pressure accumulator 10. The relatively high-temperature coldness can be passed through the high-pressure duct 6; the east agent can be used to vaporize the low-temperature liquid cold bundle agent in the pressure accumulator 10. In order to effectively evaporate the liquid refrigerant, a part of the structure of the low-pressure pipe 7 in the accumulator 10 has a u-shaped portion and will pass through the high-pressure pipe of the accumulator 10. The partial structure of 6 is positioned inside the U-shaped portion passing through the low-pressure duct 7. ° In addition, the outdoor unit 8 includes a hot gas bypass conduit 14 and a liquid bypass conduit U (jud bypass conduit) 15, wherein the hot gas bypass conduit 14 is used to connect the high-pressure pipe 6 part between the compressor 2 and the condenser 3 to the pressure storage H 1 0, and the liquid bypass f 5 is used to connect to the = set Downstream of the accumulator 11 and upstream of the accumulator 10. A hot gas valve (hot gas valve) 16 is provided on the hot gas bypass pipe 14, and the hot gas valve 16 is used to control the bypass. The flow rate of the hot gas, and a liquid valve 17 is provided on the gas bypass 14 to control the flow rate of the liquid refrigerant to be bypassed by the liquid valve 17

587144 V. Description of Invention (8) Rate. Therefore, when the hot gas valve 6 is open, a part of the hot gas discharged from the compressor 2 is bypassed along the hot gas in accordance with the direction of the dotted arrow in FIG. 1. 1 4 to move; when the liquid compartment 17 is open, the part of the liquid cold / east agent discharged by the collector 丨 丨 is bypassed along the liquid according to the direction of the double-pointed arrow in Fig. 1 The catheter 15 is moved. The above-mentioned plural indoor units 9 are arranged in parallel, and each of the indoor units 9 includes an electronic expansion valve 4 and an evaporator 5. Therefore, the plurality of indoor units 9 are connected to the outdoor unit 8, and the capacity and shape of each indoor unit 9 can be completely the same or can be performed by other methods. Evaporator entrance temperature sensors H (evaporator entrance temperature sensors) 30 are provided at the positions of the inlets of the evaporator 5, respectively. These evaporator inlet temperature sensors 30 are provided for entering the evaporator. The temperature of the refrigerant in the evaporator 5 is detected, and a plurality of evaporator exit temperature sensors 31 are provided at the positions of the outlets of the evaporator 5, respectively. The detector 31 detects the temperature of the refrigerant leaving the evaporator 5. The above temperature sensor is a property sensing means for detecting the degree of superheat of the evaporator, and for example, a pressure sensor or other sensing devices may be used for the Check the pressure or other characteristics of the refrigerant. Each compressor 2 shown in Figs. 2a and 2b is a variable that can be controlled by a pulse width modulation manner.

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V. Description of the invention (9)

Variable capacity compressors. Each compressor 2 includes a casing 20, a motor 21, a rotatable scroll 22, and a static scroll 24. Among them, The casing 20 is formed with an inlet 18 and an outlet 19. The motor 21 is disposed in the casing 20, and the rotatable scroll 22 is rotated by the rotational force of the motor 21. A compression chamber 23 is defined by the stationary scroll 24 and the rotatable scroll 22 at the same time. A bypass conduit 25 is attached to the housing 20, and a position (position) above the stationary scroll 24 is connected to the inlet 18 'by the bypass conduit 25 and a PWM Valve (pulse width modulation valve, puise width

A Modulated Valve 26 is mounted on the bypass conduit 25. The PWM valve 26 is a solenoid valve. In Figure 2a,

The PWM valve 26 is in an OFF state, the bypass duct 25 is closed by the PWM valve 26, and the refrigerant is discharged by the compressor 2 system. This state is referred to as a "load state (1 〇adingsfate)" where "the compressor 2 is operated with a load of 100%. In Figure 2b, the PWM valve 26 series shows In the on state, the bypass duct 25 is opened by the pWM valve 26. At this time, the compressor 2 does not discharge the refrigerant. This state is called "unloading state" state) ", in which the compressor 2 is operated with a load of 0%. Whether in a loaded state or in a non-loaded state, power is supplied to the compressor 2 and the motor 21 is first-class The speed is reversed. When the power supply to the compressor 2 is stopped, the motor 21 is stopped.

5050-4483-PF (N) .ptd Page 14 587144 V. Description of the invention (10) Stop operation 'and the compressor 2 also stops operating in the third figure The compressor 2 is under load, non-periodic The operation is carried out in a mode, in which load, 1 negative = week, and the load time is changed according to the required cooling capacity. In the state, because the compressor 2 discharges the refrigerant, 'so the temperature of the evaporator 5 will continue to drop during the load time; in a non-negative state, because the compressor 2 does not discharge the refrigerant In this way, the temperature of the evaporator 5 will continue to increase during the load time. In Figure 3 / hatched port ions, the amount of refrigerated discharge is indicated, and the signals used to control the load and non-load time are called duty control signals. In the preferred implementation of the present invention, it can be known that, because the load and non-load time are changed according to the total cooling capacity required by the compressor 2, the load of the compressor 2 is changed according to this method, for example, · -Each cycle is kept at 20 minutes. FIG. 4 is a block diagram showing a system for controlling the degree of overheating of an air conditioner according to the present invention. The outdoor unit 8 in the figure includes an outdoor control unit (outd〇〇〇〇 ntr〇i unit) 27, where the outdoor control unit 27 is connected to the compressor 2, the pWM valve 26, and the outdoor control unit 27 can be used to transmit and receive related signals. In addition, the outdoor control unit 27 is connected to an outdoor communication circuit unit 28, so the outdoor communication circuit unit 28 is used to transmit and receive related signals. Each indoor unit 9 series includes an indoor communication circuit unit (indoor

587144 V. Description of the invention (11) communication circuit unit) 32, wherein the indoor communication circuit unit 32 is connected to an indoor control unit (ind〇〇r cQntl * Ql 11 heart 〇29 and the outdoor unit 8), so that The indoor communication circuit unit 32 transmits and receives related signals. The functions of the outdoor communication circuit unit 28 and the indoor communication circuit unit 32 are used in wired or wireless mode. The data is transmitted and received. The evaporator inlet temperature sensor 30 and the evaporator outlet temperature sensor 31 are connected to the input port of the control unit 29 in the house. And the electronic expansion valve 4 is connected to the house. The output unit 2 of the control unit 29 (output P0rt). When it is cold; the agent passes through the electronic expansion valve 4 and the inlet temperature sensor 30 is the temperature of the evaporator 5 and the outlet temperature of the evaporator The sensor 31 checks the temperature of the refrigerant passing through the μ evaporator 5 to the control unit 29 in the room. The temperature of the inlet and outlet of the evaporation state 5 in the room ^ ^ is calculated to overheat and bite again. The opening of the electronic expansion valve 4 is controlled. The manufacturer's figure 5 'the following will control the overheating degree of the air conditioner first' The cycle or the cycle of the compressor 2 is from ^ ^ (). The work of the money shrinking machine 2 The indoor communication power ^-^ Where 8 is transmitted to the indoor control unit 29 via the outdoor communication circuit unit 28, in the embodiment: 32 and 'on the evaporator 5th day of the evaporator > The preset value is 20 seconds. Then, for this (si〇2 °). The test temperature is periodically or continuously detected ... The inlet temperature of send 5 can be determined by the evaporator inlet temperature 587144.

The temperature is obtained by the detection of the temperature sensor 30, and the evaporation is measured by the evaporator outlet temperature sensor 3, and the outlet temperature is deductible by the element 29 in addition to the detected transmission of the evaporator 5. The control cycle and the detection period of the house are accumulated, and the outlet temperature and detection frequency (s103) are also calculated. Demonstration-detection frequency. Then, by the control unit 29 in each room, which of the cycles is the same as the work of the compressor 2. The accumulated test will be performed if the § dressing cycle determined by the control unit 29 in the room (S1 〇4). During the working cycle of the compressor 2, it is more and more exhaustive. If the control unit 29 in the house judges] the procedure of ^ \ will be repeated 丄 ^ When the cumulative detection cycle judged is the same as the duty cycle of the compressor 2, the

The coverage of the entrance and exit ′ and the detection frequency obtained through calculation can be used to calculate the mean entrance and exit temperatures (mean entrance and exU temperatures). In short, when the degree of overheating is started to be controlled, the indoor control unit 29 confirms the duty cycle, and the indoor control unit 29 is used to calculate the average inlet and outlet temperature. In other embodiments, the load time of the compressor 2 can be used to replace the duty cycle of the compressor, and the outdoor unit 8 can send out relevant information on the load time. Then, 'the degree of overheating of the air conditioner 1 can be calculated (S1 06). The superheating degree value used in this embodiment is obtained by subtracting the average inlet temperature from the average outlet temperature in the evaporator 5. When the overheating degree of the air conditioner 1 is calculated, based on this value, a preset target opening value of the electronic expansion valve 4 can be obtained.

5050-4483-PF (N) .ptd Page 17 587144 V. Description of the invention (13) And adjust the opening size of the electronic expansion valve 4 to the calculated target opening value (S1 08). In addition, when the air conditioner 1 has a high degree of overheating, the electronic expansion valve 4 is set to a small target opening value; and when the air conditioner 1 has a low degree of overheating, the electronic expansion valve 4 is set to Large target openings. Because the intermittent discharge of refrigerant occurs during the operation of the pulse width modulation compressor, it is necessary to calculate the degree of overheating according to the inlet / outlet / jnL degree of the evaporation 5, so that it can be targeted Compensate for temperature fluctuations. It can be seen from Figures 6 and 7 that during the operation, the temperature difference between the inlet and outlet of the evaporator of the pulse width modulation compressor will often change, so the inlet and outlet temperature of the evaporator is used to calculate the overheating. In some examples of the degree, the degree of overheating of the air conditioner obtained by it may deviate from the actual degree of superheating. Even when the average temperature is used, when one of the accumulated time (accumulated different from the cycle of the PWM valve or the duty cycle of the compressor 2) used to perform the average degree detection, The temperature difference between the two will change with time. The working time of compressor 2 is one of the average temperature detection. When the cumulative time is the same as the cycle time of the machine, the average temperature is different from the actual temperature. The degree of pulse is controlled; the number of cranes is 'and the appropriate degree of overheating is compared with the actual degree of overheating.' The calculated degree of overheating is likely to be equal to industrial applicability The way to control the inlet and outlet of the evaporator is to compensate for the operation under this period. Therefore, the value of the degree and the opening of the expansion valve are well known. This is performed to the extent that the above-mentioned method is used to adjust the period of the superheating interval and based on this small system can make the system expose its control side evaporator. Equivalent to the temperature of the life, a value can be calculated for the air conditioner for a method, the method of which averages the inlet and outlet control ', and the fluctuation of the compressor's working phenomenon is calculated with respect to the adjusted air conditioner with the best efficiency Based on the use of each temperature, the electron energy that can be actually superheated can be obtained by a suitable cycle.

5050-4483-PF (N) .ptd Page 19 587144 The diagram is briefly explained. The first diagram is based on a system cycle diagram for controlling the degree of overheating of an air conditioner. The second diagram is shown in Figure 2a. J 丨 Plane of a pulse width modulated compressor under a loading position; Figure 2b shows the pulse width modulated compressor at an unloading position Section view

Fig. 3 is a graph showing the relationship between a loading time, an unloading time, and a refrigerant discharge amount during the operation period of the compressor in Figs. 2a and 2b. Fig. 4 is a block diagram showing a system for controlling the degree of overheating of an air conditioner according to the present invention; and Fig. 5 is a diagram for controlling the degree of heat of an air conditioner according to the present invention The flow chart of the system; k FIG. 6 is shown in the air conditioner of the present invention,

The cycle time and the working hours of the two machines used to calculate the average temperature γ of the evaporator. The change in the inlet and outlet temperature of the evaporator is equal to the period. Figure 7 shows the air conditioner of the present invention. In the machine, the rounding cycle is used to calculate the average temperature field production time of the evaporator. ^ The change of the inlet and outlet temperature of the evaporator: the state diagram J is the same. Figure 8 shows that Air conditioner M and Con U10ner) change state diagram of inlet and outlet temperature.

587144 Brief description of the drawing 1 ~ air conditioner; 11 ~ collector; 1 ~ 3 vent valve; 1 ~ 5 ~ liquid bypass conduit; 17 ~ liquid valve; 19 ~ outlet; 20 ~ shell; 2 ~ rotating scroll Object 2 4 ~ stationary scroll; 26 ~ PWM valve; 28 ~ outdoor communication circuit 2 9 ~ indoor control unit 3 ~ condenser; 3 0 ~ evaporator inlet temperature 3b evaporator outlet temperature 32 ~ indoor communication circuit 4 ~ Electronic expansion valve; 6 ~ high pressure conduit; 8 ~ outdoor unit; 10 ~ pressure accumulator; 12 ~ ventilation bypass conduit; 14 ~ hot gas bypass conduit; 16 ~ hot gas valve; 18 ~ inlet; 2 ~ Compressor; 2 1 ~ motor; 2 3 ~ compression chamber; 2 5 ~ bypass duct; 2 7 ~ outdoor control unit; unit; degree sensor; degree sensor; unit; 5 ~ evaporator; 7 ~ low pressure Conduit; 9 ~ house unit.

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Claims (1)

587144 VI. Application for patents A variety of air conditioner overheating degree control systems, including the method of making; a condensate also constitutes a characteristic sensor and a control sub-expansion valve 2. Rushen system, one of which is the inlet temperature of the outlet. A timer and the difference between the outlet degrees. Working cycle week 3 · Rushen system, in which the measured temperature flat cycle. 4 · Rushen system, in which an outlet temperature inlet, the compressor is controlled by a pulse width regulator, an electric refrigeration cycle test device, unit, root opening according to the work control signal. Characteristic sensor, determined by temperature sensing under the outlet temperature period. The patented standard, the average mean value, the sub-expansion valve and an evaporator are in common with the compressor to calculate the degree of superheating of the evaporation; and the electric regulation according to the degree of superheating of the evaporator. The air conditioner overheating degree control sensing device described in item 1 includes an inlet temperature sensor and the inlet temperature sensor is disposed at the evaporator sensor and is disposed at an outlet of the evaporator, and the The degree of overheating is the average inlet and outlet temperature of the evaporator detected by the inlet temperature sensor, and the time period is controlled relative to the degree of inlet and outlet temperature of the air conditioner overheating as described in item 2 of the compressor. The time period detected under the time period is the same as one of the compressors. Please operate the air conditioner overheating degree control described in item 1 of the patent scope. The characteristic sensing device includes an inlet temperature sensor and a detector. The inlet temperature sensor is arranged at the outlet of the evaporator, and the temperature sensor is arranged at the outlet of the evaporator, and 5050-4483-PF (N) .ptd Page 22 587144 Scope of patent application One load! = Down 'The degree of overheating is determined by the difference between the average inlet and outlet temperature of the base piano and the outlet temperature sensor detected by the shirt temperature sensor and the outlet temperature sensor. , Σ related system broadcasting, the patent scope? In the air conditioner superheat control, the compressor and the condenser system together constitute an outdoor unit, and the electronic expansion valve and the evaporator system together constitute an indoor unit, and The air conditioner overheating degree control system includes a plurality of indoor units parallel to each other. 6. An air-conditioner overheating degree control method. The air conditioner includes a compressor, an electronic expansion valve, and an evaporator. The compressor is controlled by a pulse width modulation method according to a work control signal. The air conditioner The method for controlling the degree of superheating includes the following steps: detecting the inlet temperature and the outlet temperature of the evaporator; calculating the degree of superheating based on the detected inlet temperature and the outlet temperature; ^ calculating based on the calculated degree of superheating A target opening value of the electronic expansion valve; and adjusting the electronic expansion valve to the calculated target opening value. 7. The method for controlling the overheating degree of an air conditioner according to item 6 of the scope of patent application, wherein the overheating degree is via the inlet temperature sensor, The difference between the inlet temperature and the outlet temperature of the evaporator's zheng detected by the outlet temperature sensor. 8 · Control of overheating of air conditioner as described in item 6 of the scope of patent application 5050-4483-PF (N) .ptd Page 23 587144 6. Method for applying for a patent, wherein, under a load time of the compressor, the degree of overheating is through the inlet temperature sensor, the outlet temperature sense The difference between the average inlet and outlet temperature of the evaporator detected by the detector is determined. Ι · 5050-4483-PF (N) .ptd Page 24