JPH1019391A - Controller for air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a controller for air conditioner capable of COP(coefficient of performance) control that makes maximum a result coefficient and capability control that makes maximum capability. SOLUTION: The present controller of an air conditioner includes a control board 11, a suction temperature sensor 15 for detecting temperature of suction air of an indoor machine 6, and an exhaust gas temperature sensor 12 and an outlet refrigerant temperature sensor 13. The control board 11 achieves capability control when temperature detected by the suection temperature sensor 15 is higher than a set value by 2 deg.C or more while achieving COP control when a difference between the temperature detected by the suction temperature sensor 15 and a set value is 2 deg.C or less. The foregoing capability control is achieved by controlling an opening of an expansion valve 15 and controlling superheat of discharge gas while the COP control is achieved by controlling the opening of the expansion valve 5 to control superheat of a refrigerant at the outlet of the evaporator 1. The respective capability control and superheat for the COP control are stored in a memory 11b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a coefficient of performance [CO
P (coefficien of performance)
t of performance))] or a control device of an air conditioner for controlling the maximum capacity.

[0002]

2. Description of the Related Art Conventionally, as a control device of an air conditioner,
As shown in FIG. 5, it has a temperature sensor 102 attached to the outlet of the evaporator 101, receives the signal from the temperature sensor 102, adjusts the opening of the expansion valve 103, and adjusts the outlet of the evaporator 101. Control board 10 for maintaining the degree of superheat of the refrigerant flowing in the arrow Z method at a constant value (usually 3 ° C. to 5 ° C.)
Some have five. In addition, 107 is a condenser.
In this conventional example, the degree of superheat of the refrigerant at the outlet of the evaporator 101 is maintained at 3 ° C. to 5 ° C., thereby preventing the inflow of the liquid refrigerant from the evaporator 101 to the compressor 160 and protecting the compressor 160. I'm trying.

[0003]

However, the refrigerant having a superheat degree of about 0 ° C. is in a two-phase flow of liquid and gas and is unstable, so that the temperature cannot be measured accurately and is not suitable for control. . Therefore, as described above, the degree of superheat is set to 3 ° C.
At a temperature of about 5 ° C., the refrigerant is reliably vaporized at the outlet of the evaporator 101.

However, in order to maximize the cooling capacity, the degree of superheating of the refrigerant on the suction side of the compressor 160 (≒ evaporator 101
The degree of superheat of the refrigerant at the outlet) must be around 0 ° C.
Therefore, the above-described conventional control device cannot perform control to maximize the capacity of the air conditioner.

In the above-mentioned conventional control device, the evaporator 1
Since the degree of opening of the expansion valve 103 is adjusted so that the degree of superheat of the refrigerant at the outlet of No. 01 is constant, the optimization control for maximizing the COP cannot be performed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an air conditioner control device capable of performing capacity control for maximizing the performance and COP control for maximizing the coefficient of performance.

[0007]

In order to achieve the above object, a control apparatus for an air conditioner according to the first aspect of the present invention includes a capacity control for controlling the air conditioner to maximize its capacity, and an air conditioner. COP that controls the coefficient of performance to be maximum
It is characterized by including a control means capable of selecting either one of the controls.

According to the first aspect of the present invention, if the above-described capacity control is selected, the capacity of the air conditioner can be maximized. On the other hand, if the COP control is selected, the coefficient of performance of the air conditioner can be maximized.

According to a second aspect of the present invention, in the control device for an air conditioner according to the first aspect, the control means selects one of the capacity control and the COP control in accordance with an external input signal. It is characterized by being adapted to be.

According to the second aspect of the present invention, either one of the above-mentioned capability control and COP control can be selected by an external input signal.

According to a third aspect of the present invention, in the control apparatus for an air conditioner according to the first aspect, the control means includes a suction temperature sensor for detecting a temperature of suction air of the indoor unit, and the suction temperature sensor. When the difference between the detected suction air temperature and the set value is within a predetermined range, the COP control is performed, while the difference between the suction air temperature and the set value exceeds the predetermined range. And a control unit for performing capability control.

According to the third aspect of the invention, when the temperature of the intake air is close to the set value, the COP control is executed,
While maximizing the driving coefficient of performance to save energy,
When the temperature of the intake air deviates from the set value, the capacity control is executed to maximize the operating capacity and quickly bring the temperature of the intake air close to the set value. Therefore, according to the third aspect of the invention, it is possible to selectively use the energy saving and the maximum operation capacity.

According to a fourth aspect of the present invention, in the control device for an air conditioner according to the first aspect, the control means includes a discharge gas temperature sensor for detecting a temperature of a discharge gas of the compressor; A controller that receives a signal representing the temperature of the discharge gas from a temperature sensor, controls expansion means, and sets the degree of superheat of the discharge gas to a value that maximizes the capacity of the air conditioner. It is characterized by:

According to the fourth aspect of the present invention, the expansion means is controlled based on a signal indicating the temperature of the discharge gas from a temperature sensor which detects the temperature of the discharge gas of the compressor, and the discharge gas is superheated. The degree is set to a value that maximizes the performance of the air conditioner.

As described above, if the degree of superheat of the gas discharged from the compressor is controlled to a value that maximizes the capacity of the air conditioner by controlling the expansion means, the non-evaporated liquid is not added to the refrigerant to the compressor. And the compressor can be kept reliable, and the capacity of the air conditioner can be maximized.

According to the fourth aspect of the present invention, the capacity can be controlled by detecting the degree of superheat of the refrigerant at the discharge side of the compressor.
Unlike the conventional case, it is not necessary to detect the degree of superheat of the refrigerant near 0 ° C. on the suction side of the compressor, and the controllability is good.

According to a fifth aspect of the present invention, in the control device for an air conditioner according to the first aspect, the control means includes an outlet refrigerant temperature sensor for detecting a refrigerant temperature at an outlet of the evaporator; In response to a signal representing the refrigerant temperature at the outlet from the refrigerant temperature sensor, the expansion means is controlled to set the degree of superheat of the refrigerant at the outlet to a value that maximizes the coefficient of performance of the air conditioner. And a control unit.

According to the fifth aspect of the present invention, the expansion means is controlled based on a signal representing the refrigerant temperature at the outlet from a temperature sensor which detects the refrigerant temperature at the outlet of the evaporator,
The degree of superheating of the refrigerant at the outlet of the evaporator is set to a value that maximizes the coefficient of performance of the air conditioner.

As described above, if the degree of superheat of the refrigerant at the outlet of the evaporator is controlled to a value at which the coefficient of performance of the air conditioner is maximized by controlling the expansion means, the refrigerant to the compressor is not The reliability of the compressor can be maintained by preventing the evaporation liquid from remaining, and the coefficient of performance of the air conditioner can be maximized.

According to a sixth aspect of the present invention, in the control apparatus for an air conditioner according to the fourth aspect, the control means is adapted to optimally superheat the discharge gas of the compressor so as to maximize the capacity of the air conditioner. Storage unit for storing the temperature for each frequency of a power supply for driving the compressor of the air conditioner, wherein the control unit determines that the degree of superheat of the discharge gas of the compressor corresponds to the drive frequency of the compressor. The expansion means is controlled so as to have the optimum degree of superheat stored in the storage section.

According to the sixth aspect of the present invention, the control unit includes:
The expansion means is controlled so that the degree of superheat of the gas discharged from the compressor becomes the optimum degree of superheat for each frequency stored in the storage unit. Therefore, according to the invention of claim 6, even when the output of the compressor is frequency-controlled by the inverter, the capacity control that can maximize the capacity in accordance with the frequency of the power supply driving the compressor can be performed. .

According to a seventh aspect of the present invention, in the control device for an air conditioner according to the fourth aspect, the control means is configured to optimally heat the discharge gas of the compressor so as to maximize the capacity of the air conditioner. Storage unit that stores the degree of superheat of the refrigerant of the air conditioner for each pipe length of the refrigerant, and the control unit controls the superheat degree of the discharge gas of the compressor according to the combination of the frequency and the pipe length. The expansion means is controlled so as to have the optimum degree of superheat stored in the storage section.

According to the seventh aspect of the present invention, the control unit includes:
The expansion means is controlled so that the degree of superheat of the discharge gas of the compressor becomes the optimum degree of superheat corresponding to the combination of the frequency and the pipe length stored in the storage unit. Therefore, according to the invention of claim 7, when the output of the compressor is frequency-controlled by the inverter, the capacity can be maximized according to the frequency of the power source driving the compressor and the pipe length. Capability control can be performed.

According to an eighth aspect of the present invention, in the control device for an air conditioner according to the fifth aspect, the control means includes a refrigerant at an outlet of the evaporator which maximizes a coefficient of performance of the air conditioner. A storage unit for storing the optimum degree of superheat for each frequency of a power supply for driving the compressor of the air conditioner, wherein the control unit determines that the degree of superheat of the refrigerant at the outlet of the evaporator is equal to the drive frequency. The expansion unit is controlled so that the optimum degree of superheat stored in the storage unit is stored in correspondence with the above.

According to the eighth aspect of the present invention, the control unit includes:
The expansion means is controlled so that the degree of superheating of the refrigerant at the outlet of the evaporator becomes the optimum degree of superheating for each frequency stored in the storage unit. Therefore, according to the invention of claim 8, even when the frequency of the output of the compressor is controlled by the inverter, the COP control that can maximize the coefficient of performance in accordance with the frequency of the power supply driving the compressor is performed. I can do it.

According to a ninth aspect of the present invention, in the control apparatus for an air conditioner according to the fifth aspect, the control means includes a refrigerant at an outlet of the evaporator that maximizes a coefficient of performance of the air conditioner. A storage unit that stores the optimum degree of superheat for each refrigerant pipe length of the air conditioner, wherein the control unit determines that the superheat degree of the refrigerant at the outlet of the evaporator is the frequency and the pipe length. The expansion means is controlled so that the optimum degree of superheat stored in the storage unit corresponds to the combination of

According to the ninth aspect of the present invention, the control unit includes:
The expansion means is controlled such that the degree of superheat of the refrigerant at the outlet of the evaporator becomes an optimum degree of superheat corresponding to the combination of the frequency and the pipe length stored in the storage unit. Therefore, according to the invention of claim 9, when the output of the compressor is frequency-controlled by the inverter, the coefficient of performance is maximized in accordance with the frequency of the power source driving the compressor and the pipe length. Possible COP control.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 1 shows a configuration of an air conditioner having an embodiment of an air conditioner control device according to the present invention. The air conditioner includes an evaporator 1, a compressor 2, a condenser 3, and an electronic expansion valve 5 as expansion means. The evaporator 1 is built in the indoor unit 6. The output of the compressor 2 is controlled by inverter control of the frequency of the drive power supply. In FIG. 1, the arrow X indicates the direction in which the refrigerant flows.

The control device according to this embodiment includes a control board 11 as a control unit, a discharge gas temperature sensor 12
And an outlet refrigerant temperature sensor 13. The discharge gas temperature sensor 12 detects the temperature of the discharge gas of the compressor 2, and the outlet refrigerant temperature sensor 13 detects the refrigerant temperature at the outlet of the evaporator 1.

In this embodiment, a suction temperature sensor 15 for detecting the temperature of the suction air of the indoor unit 6 is provided. The control board 11 and the temperature sensors 12, 13 and 1
5 constitutes a control means. The control board 11 has C
PU (central processing unit) 11a and memory 11 as a storage unit
b.

When the temperature of the suction air detected by the suction temperature sensor 15 is higher than a predetermined set value by 2 ° C. or more, the control board 11 performs the capacity control, while controlling the capacity by the suction temperature sensor 15. When the difference between the temperature of the intake air and the predetermined set value is less than 2 ° C., COP
Perform control.

When performing the capacity control, the control board 1 receives a signal indicating the temperature of the discharge gas from the compressor 2 from the discharge gas temperature sensor 12 and controls the opening of the electronic expansion valve 5. Then, the degree of superheat of the discharge gas is set to a value that maximizes the capacity of the air conditioner. The memory 11b of the control board 11 determines the optimal degree of superheat of the gas discharged from the compressor 2 so as to maximize the performance of the air conditioner, by the frequency of the voltage for driving the compressor 2 and the refrigerant pipe length. Is stored in correspondence with the combination of. And the CPU
Reference numeral 11a controls the electronic expansion valve 5 so that the optimal degree of superheat stored in the memory 11b corresponds to the drive frequency.

According to this embodiment, the capacity can be controlled by detecting the degree of superheat of the refrigerant at the outlet side of the compressor 2.
Unlike the conventional case, it is not necessary to detect the degree of superheat of the refrigerant near 0 ° C. on the suction side of the compressor 2, and the controllability is good.

On the other hand, when performing the COP control, the control board 1 receives a signal indicating the refrigerant temperature at the outlet of the evaporator 1 from the outlet refrigerant temperature sensor 13 and opens the electronic expansion valve 5. Controlling the degree of superheat of the refrigerant at the outlet,
The value is set so as to maximize the coefficient of performance of the air conditioner. The memory 11b of the control board 11 stores the optimum degree of superheat of the refrigerant at the outlet of the evaporator 1 so as to maximize the coefficient of performance of the air conditioner, the frequency of the power source driving the compressor 2 and the refrigerant. It is stored corresponding to the combination with the pipe length. Then, the CPU 11a controls the electronic expansion valve 5 so that the optimal degree of superheat stored in the memory 11b corresponds to the drive frequency.

According to the control device for an air conditioner having the above configuration, when the temperature of the intake air is higher than the set value by 2 ° C. or more, the control board 11 executes the capacity control to output the output of the compressor 2. At the maximum, the temperature of the intake air can be quickly reduced to the set value. When the difference between the temperature of the suction air and the set value is less than 2 ° C., the COP
By executing the control, the coefficient of performance of operation can be maximized to save energy. Therefore, according to this embodiment, the control for energy saving and the control of the maximum air conditioning capacity can be performed when necessary.

Further, according to this embodiment, when performing the performance control, the control board 11 indicates the temperature of the discharge gas from the temperature sensor 12 which has detected the temperature of the discharge gas of the compressor 2. The opening degree of the electronic expansion valve 5 is controlled based on the signal, and as shown in FIG. 2, the degree of superheating of the discharge gas is set to a value that maximizes the capacity of the air conditioner. At this time, the superheat degree of the suction gas of the compressor 2 is close to 0 ° C., but the superheat degree (t) of the discharge gas is set to be equal to or less than the superheat degree td at which the unevaporated liquid does not return to the refrigerant to the compressor 2. Control so that it does not become. Therefore, the capacity of the air conditioner can be maximized while maintaining the reliability of the compressor 2. Also, it is difficult to measure the superheat degree of the compressor suction gas around 0 ° C,
Even in this state, the discharge gas has a certain degree of superheating, and can be accurately measured.

According to this embodiment, when performing the capacity control, as shown in FIGS. 3A and 3B, the control board 11 controls the superheat degree of the gas discharged from the compressor 2 Memory 1 above
1b stores the driving frequencies f ₁ , f ₂ ,
f ₃ and so that the refrigerant pipe length L _1, L optimum superheat t ₁₁ corresponding to the combination of _{2, t 12, t 13,} t 21, t 22, t 23, and controls the electronic expansion valve 5 . Therefore, according to this embodiment, when the output of the compressor 2 is frequency-controlled by the inverter, the frequency (f ₁ , f ₂ , f ₃ ) of the power source driving the compressor 2 and the piping of the refrigerant Capability control capable of maximizing the capability can be performed according to the combination with the length (L ₁ , L ₂ ).

Further, according to this embodiment, when performing the COP control, the control board 11 controls the superheat degree of the refrigerant at the outlet of the evaporator 2 as shown in FIGS. 6 (A) and 6 (B). Are optimal superheat degrees t ₁₀₁ , t ₁₀₂ , t ₁₀₃ , and t ₂₀₁ corresponding to a combination of the drive frequencies f ₁ , f ₂ , f ₃ stored in the memory 11b and the refrigerant pipe lengths L ₁ , L _2. , t ₂₀₂ , t ₂₀₃ , the electronic expansion valve 5 is controlled. Therefore, according to this embodiment, when the frequency of the output of the compressor 2 is controlled by the inverter, the performance is improved in accordance with the combination of the frequency of the power source driving the compressor 2 and the refrigerant pipe length. COP control that can maximize the coefficient can be performed.

In the above embodiment, the control board 11 automatically selects either the capacity control or the COP control according to the difference between the temperature of the intake air of the indoor unit 6 and the set value. As described above, a manual switch for control selection may be provided on the control board 11 and one of the capacity control and the COP control may be selected by switching this switch.

In the above embodiment, the compressor 2 is controlled by the inverter. However, the present invention can be applied to a case where the compressor 2 is driven at a constant frequency.
Further, in the above-described embodiment, the case of the cooling air conditioning that forms the indoor unit with the evaporator 1 has been described. However, the case of the heating and air conditioning that forms the indoor unit with the condenser 3 also has a four-way switching valve. The present invention can be applied to a cooling and heating machine.

[0042]

As is apparent from the above description, the control apparatus for an air conditioner according to the first aspect of the present invention has a capacity control for controlling the capacity of the air conditioner to be maximized and a coefficient of performance of the air conditioner. There is provided control means which can select either one of COP control for controlling to be maximum.

According to the first aspect of the present invention, if the above-described capacity control is selected, the capacity of the air conditioner can be maximized. On the other hand, if the COP control is selected, the coefficient of performance of the air conditioner can be maximized.

According to a second aspect of the present invention, in the control device for an air conditioner according to the first aspect, the control means selects one of the capacity control and the COP control in accordance with an external input signal. It is supposed to be.

According to the second aspect of the present invention, either one of the above-described capability control and COP control can be selected by an external input signal.

According to a third aspect of the present invention, in the control device for an air conditioner according to the first aspect, the control means includes a suction temperature sensor for detecting a temperature of suction air of the indoor unit, and the suction temperature sensor. When the difference between the detected suction air temperature and the set value is within a predetermined range, the COP control is performed, while the difference between the suction air temperature and the set value exceeds the predetermined range. And a control unit for performing efficiency control.

According to the third aspect of the invention, when the temperature of the intake air is close to the set value, the COP control is executed,
While maximizing the driving coefficient of performance to save energy,
When the temperature of the intake air deviates from the set value, the capacity control is executed to maximize the operating capacity and quickly bring the temperature of the intake air close to the set value. Therefore,
According to the third aspect of the invention, the energy saving control and the maximum operation capacity control can be performed when each of them is required.

According to a fourth aspect of the present invention, in the control device for an air conditioner according to the first aspect, the control means includes: a discharge gas temperature sensor for detecting a temperature of a discharge gas of the compressor; A control unit that receives a signal representing the temperature of the discharge gas from a temperature sensor, controls expansion means, and sets the degree of superheat of the discharge gas to a value that maximizes the performance of the air conditioner. ing.

According to the fourth aspect of the present invention, the expansion means is controlled based on a signal indicating the temperature of the discharge gas from the temperature sensor which detects the temperature of the discharge gas of the compressor, and the overheating of the discharge gas is controlled. The degree is set to a value that maximizes the performance of the air conditioner.

As described above, if the degree of superheat of the gas discharged from the compressor is controlled so that the capacity of the air conditioner is maximized by controlling the expansion means, the unevaporated liquid is not added to the refrigerant to the compressor. And the compressor can be kept reliable, and the capacity of the air conditioner can be maximized.

According to the fourth aspect of the present invention, the capacity can be controlled by detecting the degree of superheat of the refrigerant at the outlet side of the compressor.
Unlike the conventional case, there is no need to detect an unstable refrigerant superheat degree near 0 ° C. on the suction side of the compressor, and the controllability is good.

According to a fifth aspect of the present invention, in the control device for an air conditioner according to the first aspect, the control means includes an outlet refrigerant temperature sensor for detecting a refrigerant temperature at an outlet of the evaporator; In response to a signal representing the refrigerant temperature at the outlet from the refrigerant temperature sensor, the expansion means is controlled to set the degree of superheat of the refrigerant at the outlet to a value that maximizes the coefficient of performance of the air conditioner. And a control unit.

According to the fifth aspect of the present invention, the expansion means is controlled based on a signal representing the refrigerant temperature at the outlet from the temperature sensor detecting the refrigerant temperature at the outlet of the evaporator,
The degree of superheating of the refrigerant at the outlet of the evaporator is set to a value that maximizes the coefficient of performance of the air conditioner.

As described above, if the degree of superheat of the refrigerant at the outlet of the evaporator is controlled to a value that maximizes the coefficient of performance of the air conditioner by controlling the expansion means, the refrigerant to the compressor is not The reliability of the compressor can be maintained by preventing the evaporation liquid from remaining, and the coefficient of performance of the air conditioner can be maximized.

According to a sixth aspect of the present invention, in the control apparatus for an air conditioner according to the fourth aspect, the control means is configured to optimize the superheat of the discharge gas of the compressor so as to maximize the capacity of the air conditioner. Storage unit for storing the temperature for each frequency of a power supply for driving the compressor of the air conditioner, wherein the control unit determines that the degree of superheat of the discharge gas of the compressor corresponds to the drive frequency of the compressor. Then, the expansion means is controlled so as to have the optimum degree of superheat stored in the storage unit.

According to the sixth aspect of the present invention, the control unit includes:
The expansion means is controlled so that the degree of superheat of the gas discharged from the compressor becomes the optimum degree of superheat for each frequency stored in the storage unit. Therefore, according to the invention of claim 6, even when the output of the compressor is frequency-controlled by the inverter, the capacity control that can maximize the capacity in accordance with the frequency of the power supply driving the compressor can be performed. .

According to a seventh aspect of the present invention, in the control device for an air conditioner according to the fourth aspect, the control means is configured to optimize the superheat of the discharge gas of the compressor so as to maximize the capacity of the air conditioner. Storage unit that stores the degree of superheat of the refrigerant of the air conditioner for each pipe length of the refrigerant, and the control unit controls the superheat degree of the discharge gas of the compressor according to the combination of the frequency and the pipe length. Then, the expansion means is controlled so as to have the optimum degree of superheat stored in the storage unit.

According to the seventh aspect of the present invention, the control unit includes:
The expansion means is controlled so that the degree of superheat of the discharge gas of the compressor becomes the optimum degree of superheat corresponding to the combination of the frequency and the pipe length stored in the storage unit. Therefore, according to the invention of claim 7, when the output of the compressor is frequency-controlled by the inverter, the capacity can be maximized according to the frequency of the power source driving the compressor and the pipe length. Capability control can be performed.

According to an eighth aspect of the present invention, in the control device for an air conditioner according to the fifth aspect, the control means includes a refrigerant at an outlet of the evaporator which maximizes a coefficient of performance of the air conditioner. A storage unit for storing the optimum degree of superheat for each frequency of a power supply for driving the compressor of the air conditioner, wherein the control unit determines that the degree of superheat of the refrigerant at the outlet of the evaporator is equal to the drive frequency. The expansion means is controlled so as to correspond to the optimum degree of superheat stored in the storage unit.

According to the eighth aspect of the present invention, the control unit includes:
The expansion means is controlled so that the degree of superheating of the refrigerant at the outlet of the evaporator becomes the optimum degree of superheating for each frequency stored in the storage unit. Therefore, according to the invention of claim 8, even when the frequency of the output of the compressor is controlled by the inverter, the COP control that can maximize the coefficient of performance in accordance with the frequency of the power supply driving the compressor is performed. I can do it.

According to a ninth aspect of the present invention, in the control device for an air conditioner according to the fifth aspect, the control means includes a refrigerant at an outlet of the evaporator which maximizes a coefficient of performance of the air conditioner. A storage unit that stores the optimum degree of superheat for each refrigerant pipe length of the air conditioner, wherein the control unit determines that the superheat degree of the refrigerant at the outlet of the evaporator is the frequency and the pipe length. The expansion means is controlled so that the optimum degree of superheat stored in the storage unit is obtained in accordance with the combination of

According to the ninth aspect of the present invention, the control unit includes:
The expansion means is controlled such that the degree of superheat of the refrigerant at the outlet of the evaporator becomes an optimum degree of superheat corresponding to the combination of the frequency and the pipe length stored in the storage unit. Therefore, according to the invention of claim 9, when the output of the compressor is frequency-controlled by the inverter, the coefficient of performance is maximized in accordance with the frequency of the power source driving the compressor and the pipe length. Possible COP control.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of an embodiment of a control device for an air conditioner of the present invention.

FIG. 2 is a characteristic diagram illustrating an operation of controlling the capacity by adjusting the degree of superheat of the discharge gas in the embodiment.

FIG. 3 (A) shows the capacity control by adjusting the discharge gas superheat degree t for each compressor drive frequency f ₁ , f ₂ , f ₃ according to the pipe length L ₁ in the above embodiment. FIG. 3B is a characteristic diagram for explaining an operation of performing the operation shown in FIG.
FIG. 7 is a characteristic diagram illustrating an operation of adjusting the discharge gas superheat degree t for each of the compressor drive frequencies f ₁ , f ₂ , and f ₃ according to the pipe length L ₂ to perform capacity control.

FIG. 4 (A) is a graph showing the adjustment of the superheat degree t of the refrigerant at the evaporator outlet for each of the compressor drive frequencies f ₁ , f ₂ and f ₃ in the above embodiment according to the pipe length L _1. FIG. 4B is a characteristic diagram for explaining an operation of performing the COP control by using the compressor drive frequencies f ₁ , f ₂ , and f ₃ according to the pipe length L ₂ in the embodiment. It is a characteristic view explaining operation which adjusts superheat degree t of a refrigerant at an evaporator outlet, and performs COP control.

FIG. 5 is a schematic diagram showing a configuration of a conventional control device for an air conditioner.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Evaporator, 2 ... Compressor, 3 ... Condenser, 5 ... Electronic expansion valve, 6 ... Indoor unit, 11 ... Control board, 11a ... CPU, 1
1b: memory, 12: discharge gas temperature sensor, 13: outlet refrigerant temperature sensor, 15: suction temperature sensor.

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Takeshi Arai 1304 Kanaokacho, Sakai City, Osaka Daikin Industries Inside the Kanaoka Plant of Sakai Seisakusho Co., Ltd. (72) Shinichi Watanabe 1304 Kanaokacho, Sakai City, Osaka Daikin Industries, Ltd. Inside the Sakai Plant Kanaoka Plant (72) Inventor Toru Kaji 1304 Kanaokacho, Sakai City, Osaka Daikin Industries, Ltd. Inside the Sakai Plant Kanaoka Plant (72) Inventor Daisuke Miyake 1304, Kanaokacho, Sakai City, Osaka Daikin Industries, Ltd. Inside the Kanaoka Plant (72) Masakazu Hara 1304 Kanaokacho, Sakai City, Osaka Prefecture Daikin Industries, Ltd.Sakai Plant Co., Ltd. (72) Inventor Shigekazu Kitano 1304, Kanaokacho, Sakai City, Osaka Daikin Industries Sakai Works Kanaoka in the factory

Claims (9)

[Claims] The present invention can select either one of a capacity control for controlling the air conditioner to maximize its capacity and a COP control for controlling the performance coefficient of the air conditioner to a maximum. A control device for an air conditioner, comprising a control means (11, 13, 15). 2. The control device for an air conditioner according to claim 1, wherein the control means (11, 13, 15) selects one of the capacity control and the COP control according to an external input signal. A control device for an air conditioner, wherein the control device is adapted to be operated. 3. The control device for an air conditioner according to claim 1, wherein the control means (11, 13, 15) detects a temperature of an intake air of the indoor unit (6).
(15), when the difference between the temperature of the suction air detected by the suction temperature sensor (15) and the set value is within a predetermined range, COP
While performing the control, when the difference between the temperature of the suction air and the set value exceeds the predetermined range, the control unit (11) that performs the capacity control is provided. Air conditioner control device. 4. The control device for an air conditioner according to claim 1, wherein said control means (11, 13, 15) includes a discharge gas temperature sensor (12) for detecting a temperature of a discharge gas of the compressor (2). ) And a signal indicating the temperature of the discharge gas from the discharge gas temperature sensor (12), and controls the expansion means (5) to increase the degree of superheat of the discharge gas and to make the capacity of the air conditioner maximum. A control unit for an air conditioner, comprising: a control unit (11) for setting a value such that: 5. The control device for an air conditioner according to claim 1, wherein the control means (11, 13, 15) includes an outlet refrigerant temperature sensor (11) for detecting a refrigerant temperature at an outlet of the evaporator (1). 13) and a signal representing the refrigerant temperature at the outlet from the outlet refrigerant temperature sensor (13), and controls the expansion means (5) to determine the degree of superheat of the refrigerant at the outlet. And a control unit (11) for setting the coefficient of performance to a maximum value. 6. The control device for an air conditioner according to claim 4, wherein the control means (11, 13, 15) discharges gas from the compressor (2) so as to maximize the capacity of the air conditioner. A storage unit (11b) for storing the optimum degree of superheat for each frequency of a power supply for driving the compressor (2) of the air conditioner, wherein the control unit (11) The degree of superheat of the discharge gas is determined by the storage unit corresponding to the drive frequency of the compressor (2).
A control device for an air conditioner, characterized in that the expansion means (5) is controlled so that the optimum degree of superheat stored in (11b) is stored. 7. The control device for an air conditioner according to claim 4, wherein the control means (11, 13, 15) discharges gas from the compressor (2) so as to maximize the capacity of the air conditioner. Storage unit (11b) storing the optimum degree of superheat corresponding to the combination of the frequency of the power supply for driving the compressor (2) of the air conditioner and the piping length of the refrigerant of the air conditioner.
The controller (11) is configured to determine that the degree of superheat of the discharge gas of the compressor (2) corresponds to the optimum superheat stored in the storage unit (11b) corresponding to the combination of the frequency and the pipe length. A control device for an air conditioner, wherein the control means controls an expansion means (2) so that the air conditioner is controlled to a certain degree. 8. The control device for an air conditioner according to claim 5, wherein the control means (11, 13, 15) has an outlet of the evaporator (1) for maximizing a coefficient of performance of the air conditioner. The optimal degree of superheat of the refrigerant in the air conditioner compressor
(2) A storage unit that stores the power for driving each frequency.
(11b), wherein the control unit (11) is configured to determine the degree of superheat of the refrigerant at the outlet of the evaporator (1) in accordance with the drive frequency by the optimal superheat degree stored in the storage unit (11b). A control device for an air conditioner, characterized by controlling an expansion means (5) such that 9. The control device for an air conditioner according to claim 5, wherein the control means (11, 13, 15) comprises an outlet of the evaporator (1) for maximizing a coefficient of performance of the air conditioner. Storage unit (11b) storing the optimum degree of superheat of the refrigerant in the air conditioner in association with the combination of the frequency of the power supply for driving the compressor (2) of the air conditioner and the piping length of the refrigerant of the air conditioner. The control unit (11) stores the superheat degree of the refrigerant at the outlet of the evaporator (1) in the storage unit (11b) corresponding to the combination of the frequency and the pipe length. A control means for an air conditioner, characterized in that the expansion means (5) is controlled so as to obtain an optimum degree of superheat.