JPH0849951A - Equipment and method of controlling air conditioner - Google Patents

Abstract

PURPOSE: To prevent overheating of a compressor as caused by the failure in sensing the temperature of a delivered refrigerant of a compressor, by receiving a control signal to be outputted from a control means to display the abnormality of a thermistor according to the temperature of the delivered refrigerant sensed by a refrigerant sensed by a refrigerant temperature sensing means. CONSTITUTION: The temperature of a delivered refrigerant of a compressor 55 driven by an inverter means 50 is sensed by a refrigerant temperature sensing means 60, and the abnormality of a thermistor is judged according to the sensed temperature of the delivered refrigerant to control the total operation of an air conditioner by a control means 40. Then, a control signal outputted from the control means 40 is received to display the abnormality of the thermistor on a display means 70. This constitution can prevent overheating of the compressor 55 as caused by the failure in sensing the temperature of the delivered refrigerant of the compressor 55, thereby enabling the accurate sensing and controlling of temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inverter air conditioner in which a compressor is driven by changing a frequency, and in particular, the temperature of a refrigerant discharged from the compressor is accurately sensed to prevent the compressor from overheating. Air conditioner control device, and
It is about the method.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 1, a refrigerant temperature sensing device for an air conditioner detects a refrigerant temperature sensing means when a temperature of a refrigerant discharged through a discharge port of a compressor (hereinafter referred to as a discharged refrigerant temperature) changes. While the resistance value Rth of the thermistor 61, which is a temperature sensor of 60, is changed, the voltage Vcc applied from the DC power supply means (not shown) is divided by the current limiting resistance R1 and the resistance value Rth of the thermistor 61 to control the means. 40 is input to the input terminal A / D.

At this time, the voltage V input from the refrigerant temperature sensing means 60 to the input terminal A / D of the control means 40 is

[Equation 1] (Here, Rth is the resistance value Vcc of the thermistor is the high level voltage value of the DC power supply means.) Therefore, in the control means 40, the input analog voltage is converted into a digital value and the abnormality of the thermistor 61 is detected. Determine the condition.

If the voltage across the thermistor 61 input to the control means 40 approaches the voltage Vcc applied from the DC power supply means, it is determined that the thermistor 61 is open.

The voltage across the thermistor 61 is zero.
When it approaches (zero), it is determined that the thermistor 61 is short-circuited, the operation of the air conditioner is stopped, and "operation error" is displayed via a display means (not shown).

[0006]

By the way, such a conventional refrigerant temperature sensing device for an air conditioner senses only the anomaly of the thermistor due to an open or a short circuit of the thermistor, so that the thermistor can detect from a measurement site. If the temperature of the refrigerant discharged from the compressor cannot be sensed normally due to deviation, the thermistor cannot sense this even when the compressor is overheated due to overload, which not only damages the equipment, but also accurately senses the temperature, and There is a problem that temperature control is difficult.

Therefore, the present invention has been made to solve the above-mentioned various problems, and an object of the present invention is to prevent deviation from a measurement portion of a thermistor that senses the refrigerant discharge refrigerant temperature. Provided are a control device for an air conditioner, which prevents overheating of a compressor due to undetected discharge refrigerant temperature of the compressor, and enables accurate temperature detection and temperature control, and a method thereof. To do.

[0008]

In order to achieve the above object, a control device for an air conditioner according to the present invention comprises a rectifying means for full-wave rectifying a commercial AC voltage input from an AC power supply input terminal into a DC voltage. An air conditioner configured to receive the DC voltage from the rectifying means and convert the operating frequency of the compressor so as to drive the compressor, the compression driven by the inverter means. Refrigerant temperature sensing means for sensing the discharge refrigerant temperature of the machine, and control means for determining the abnormal state of the thermistor according to the discharge refrigerant temperature sensed by the refrigerant temperature sensing means and controlling the overall operation of the air conditioner. Receiving the control signal output from the control means according to the discharge refrigerant temperature sensed by the coolant temperature sensing means and displaying the abnormal state of the thermistor And having a display means that.

The air conditioner control method according to the present invention further comprises a compressor operating step of driving the compressor by converting the operating frequency of the compressor under the control of the control means.
Refrigerant temperature sensing step of sensing a discharge refrigerant temperature of the compressor which changes when the compressor is driven in the compressor operating step, deviation of the thermistor according to the discharge refrigerant temperature sensed from the refrigerant temperature sensing step, and characteristics. An abnormal state determining step of determining an abnormal state of change; an abnormal state displaying step of displaying an abnormal state of the thermistor via display means when the thermistor is determined to be in an abnormal state in the abnormal state determining step; When it is determined that the thermistor is in an abnormal state in the determination step, an operation stop step of stopping the drive of the compressor according to the control of the control unit so as to prevent overheating of the compressor due to an overload is included. Characterize.

[0010]

An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. As shown in FIG. 2, the rectifying means 10 full-wave rectifies the power supply voltage of the commercial AC power supply supplied from the AC power supply input terminal 1 into a DC voltage and outputs the DC voltage.
The current detecting means 20 detects a changing input current of the commercial AC power source supplied from the AC power source input terminal 1, that is, a current change amount input to the compressor 55. Then, the DC power supply means 30 converts the power supply voltage of the commercial AC power supply supplied from the AC power supply input terminal 1 into a predetermined DC voltage Vcc necessary for driving the air conditioner and outputs it.

Further, the control means 40 inputs the DC voltage output from the DC power supply means 30 to initialize the air conditioner and, of course, the input current data detected by the current detection means 20. Enter the compressor 55
Is a microcomputer that determines whether or not the current input to the air conditioner is an overcurrent and controls the overall operation of the air conditioner.

In addition, the inverter means 50 controls the DC voltage output from the rectifying means 10 so as to drive the compressor 55 in accordance with the control signal output from the control means 40. The operating frequency of the compressor 55 is converted by reverse conversion into phase alternating current.

Further, in the figure, the refrigerant temperature sensing means 60
Is for detecting a refrigerant discharge temperature Tp changing in the compressor 55 driven by the inverter means 50 and outputting the refrigerant discharge temperature Tp to the control means 40. The refrigerant temperature sensing means 60 discharges the compressor 55. It is fixed to the outlet pipe and the circuit is constructed as shown in FIG.

The display means 70 is the control means 40.
In addition to displaying the operating conditions input by the user in accordance with the control of 1., it relates to the overcurrent and overheat of the compressor 55 and whether the thermistor 61 of the refrigerant temperature sensing means 60 deviates from the measurement position. Display operating status and operation errors. Hereinafter, the operation and effect of the control device for the air conditioner configured as described above and the method thereof will be described.

3 and 4 are flow charts showing operation control operation steps of the air conditioner according to the present invention. In FIGS. 3 and 4, S indicates a step.

First, when the power source is connected to the air conditioner,
The power supply voltage of the commercial AC power supply supplied from the AC power supply input terminal 1 is input to the rectifying means 10, and full-wave rectified into a DC voltage and output to the inverter means 50. Then, in the DC power supply means 30, the power supply voltage of the commercial AC power supply supplied from the AC power supply input terminal 1 is converted into a predetermined DC voltage necessary for driving the air conditioner, and each drive circuit and control means. Output to 40.

Therefore, in step S1, the DC voltage output from the DC power supply means 30 is input from the control means 40 to initialize the air conditioner, and in step S2 the operation for starting the operation of the air conditioner. Determine if the switch is on.

From the determination result in step S2, if the operation switch is not turned on (when NO),
When the air conditioner is kept in the operation standby state until the operation switch is turned on and the operation in and after step S2 is repeated, and the operation switch is turned on (when YES)
In order to perform the air conditioning operation of the air conditioner, step S
Then, the routine proceeds to step 3 to judge whether the compressor 55 is in the operating condition.

When the compressor 55 is in the operating condition,
The operating frequency of the compressor 55 is determined by the control means 40 according to the temperature difference between the temperature Ts set by the user and the indoor temperature Tr sensed by the indoor temperature sensing means (not shown), and the compressor 55 is driven. .

From the determination result in step S3, if the compressor 55 is not in the operating condition (NO), it is not necessary to operate the air conditioner.
If the compressor 55 is in the operating condition (YES), the control means 40 controls the indoor temperature Tr and the set temperature Ts to return to step S4. Compressor 5 according to the difference of
A control signal for driving the compressor 55 by deciding the operating frequency of No. 5 is output to the inverter means 50.

As a result, in the inverter means 50, the DC voltage input from the rectifying means 10 is changed to a variable voltage in accordance with the operating frequency determined by the control means 40.
Also, the compressor 55 is converted to a three-phase alternating current with a variable frequency.
The operating frequency is converted to drive the compressor 55.

At this time, in step S5, the varying input current of the commercial AC power source supplied from the AC power source input terminal 1 is detected from the current detecting means 20 and output to the control means 40. Therefore, the control means 40 converts the analog voltage value corresponding to the change amount of the input current of the AC power source input terminal 1 detected by the current detection means 20 into a digital value and compares it with the preset reference current data. .

Next, in step S6, the input current change amount of the AC power supply input terminal 1 is input to the compressor 55 in accordance with the result of comparison with the reference current data preset in the control means 40. Determine if the current is overcurrent.

From the determination result in step S6, if the current input to the compressor 55 is not an overcurrent (NO), the process proceeds to step S7 and the refrigerant temperature sensing means 60.
As a result, the refrigerant discharge temperature Tp that changes when the compressor 55 is driven is sensed by the thermistor 61, which is a temperature sensing sensor.

In the thermistor 61, the refrigerant discharge temperature T
The resistance value Rth changes according to the change of p. At this time, the DC voltage Vc output from the DC power supply means 30.
c is divided by the current limiting resistor R1 and the changed resistance value Rth of the thermistor 61 and input to the input terminal A / D of the control means 40, and the control means 40 converts this into digital data.

Therefore, in step S8, the thermistor 61 input to the input terminal A / D of the control means 40 is used.
It is determined whether or not the voltage across both ends is close to the DC voltage Vcc output from the DC power supply means 30, and it is determined whether or not the thermistor 61 is open.

If the thermistor 61 is not open (NO in step S8), the process proceeds to step S9, in which the control means 40 determines whether the voltage across the thermistor 61 approaches 0. Is determined to determine whether the thermistor 61 is short-circuited.

If the thermistor 61 is not short-circuited (NO in step S9) from the determination result in step S9, it is necessary to check whether the thermistor 61 deviates from the measurement position. Then, the compressor 55 driven by the inverter means 50
It is determined whether or not the operating time of has passed the predetermined time t.

From the judgment result in the step S10, when the operating time of the compressor 55 exceeds a predetermined time t (YE
(When S), the process proceeds to step S11, and it is determined whether the operating frequency of the compressor 55 driven by the inverter means 50 is a predetermined frequency F or higher.

From the determination result in step S11, when the operating frequency of the compressor 55 is equal to or higher than the predetermined frequency F (YE
(In the case of S), the process proceeds to step S12, and it is determined whether or not the current consumption of the compressor 55 driven by the inverter means 50 is equal to or more than the predetermined current A.

If the current consumption of the compressor 55 is greater than or equal to the predetermined current A (YES) from the determination result in step S12, the process proceeds to step S13, and the refrigerant discharge detected by the refrigerant temperature sensing means 60 is detected. It is determined whether the temperature Tp is equal to or lower than the predetermined temperature T.

From the determination result in step S13, if the refrigerant discharge temperature Tp is equal to or lower than the predetermined temperature T (YES), the thermistor 61 has deviated from the measurement position. Therefore, in step S14. Under the control of the control means 40, the "thermistor abnormality" indicating that an abnormality has occurred in the thermistor 61 is displayed via the display means 70.

The criterion for judging the state in which the thermistor 61 deviates from the measurement position is that if the current consumption is equal to or more than the predetermined current A after the lapse of a predetermined time t from the start of the operation of the compressor 55, This is based on the experimental result that the refrigerant discharge temperature Tp of the compressor 55 is always equal to or higher than the predetermined temperature T, and the data corresponding to the condition that the thermistor 61 deviates from the measurement position is set in the control means 40. There is.

Therefore, since it is impossible to detect whether or not the compressor 55 is overheated due to overload, the control means 40 drives the compressor 55 to prevent the compressor 55 from being overheated in step S15. The control signal for stopping is output to the inverter means 50.

In the inverter means 50, the control means 4
By stopping the DC voltage input from the rectifying means 10 according to the control signal output from 0 to stop the driving of the compressor 55, the operation of the air conditioner is stopped and the operation is ended.

On the other hand, from the result of the determination in step S13, if the refrigerant discharge temperature Tp is not lower than the predetermined temperature T (N
(When it is O), the air conditioner is in a normal state, so that in step S20, the inverter unit 50 changes the DC voltage input from the rectifying unit 10 to a variable voltage and a variable frequency according to the control of the control unit 40. The operation frequency of the compressor 55 is converted by reverse conversion into three-phase alternating current, and the compressor 55 is driven to perform the normal operation of the air conditioner, and the operation is finished.

From the determination result in step S6, if the current input to the compressor 55 is an overcurrent (YE
(When S), the process proceeds to step S21, and the display means 7
When "0" is displayed, "overcurrent" indicating the occurrence of overcurrent is displayed according to the control of the control means 40, and the process proceeds to step S15 to repeat the operations of step S15 and thereafter.

If the thermistor 61 is open (YES) from the determination result in step S8, it means that the anomaly has occurred in the thermistor 61. Therefore, the process proceeds to step S14 and steps S14 and thereafter. Repeat the operation of. If the thermistor 61 is short-circuited according to the determination result in step S9 (Y
In the case of ES), since the anomaly has occurred in the thermistor 61, the process proceeds to step S14 and step S1.
The operations of 4 and below are repeated.

On the other hand, if it is determined from the determination result in step S10 that the operating time of the compressor 55 has not passed the predetermined time t (NO), the process proceeds to step S20 and the operations in step S20 and subsequent steps are performed. If the operation frequency of the compressor 55 is not equal to or higher than the predetermined frequency F (NO) based on the determination result in step S11, the process proceeds to step S20 and the operations in step S20 and subsequent steps are repeated.

If the current consumption of the compressor 55 is not equal to or higher than the predetermined current A (NO) from the determination result in step S12, the process proceeds to step S20 and the operations in and after step S20 are repeated.

As described above, the embodiment of the present invention has been described by exemplifying the thermistor for detecting the temperature of the refrigerant discharged from the compressor. However, the present invention is not limited to this, and heat exchange in the room is performed. According to the present invention, the control means is set with a reference for judging a malfunction due to a deviation of a temperature sensor for detecting a pipe temperature of a container, a pressure sensor for detecting a pressure, a current sensor for detecting a current, or a characteristic change. The same purpose and effect as can be achieved.

[0042]

As described above, according to the control device for an air conditioner and the method thereof according to the present invention, it is determined whether the thermistor for sensing the temperature of the refrigerant discharged from the compressor has deviated from the measurement site, and Accurate temperature sensing as well as preventing compressor overheating due to unsensed refrigerant discharge refrigerant temperature,
Also, an excellent effect that the temperature can be controlled can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing a refrigerant temperature sensing circuit of a normal air conditioner.

FIG. 2 is a block diagram showing control of a control device for an air conditioner according to an embodiment of the present invention.

FIG. 3 is a flowchart showing operation control operation steps of the air conditioner according to the present invention.

FIG. 4 is a flowchart showing operation control operation steps of the air conditioner according to the present invention.

[Explanation of symbols]

 10 Rectification Means 20 Current Detection Means 30 DC Power Supply Means 55 Compressors 60 Refrigerant Temperature Sensing Means 70 Display Means

Claims (2)

[Claims] 1. A rectifying means for full-wave rectifying a commercial AC voltage input from an AC power source input terminal into a DC voltage, and an operation of the compressor so that the DC voltage from the rectifying means is input to drive the compressor. In an air conditioner having inverter means for converting frequency, a refrigerant temperature sensing means for sensing a discharge refrigerant temperature of a compressor driven by the inverter means, and a refrigerant temperature sensing means for sensing the refrigerant temperature. The abnormal state of the thermistor is determined according to the discharged refrigerant temperature, the control means for controlling the entire operation, and the control signal output from the control means according to the discharged refrigerant temperature sensed by the refrigerant temperature sensing means are received. A control device for an air conditioner, comprising: a display unit that displays an abnormal state of the thermistor. 2. A compressor operating step for converting the operating frequency of the compressor to drive the compressor under the control of the control means, and a discharge of the compressor which changes when the compressor is driven in the compressor operating step. A refrigerant temperature sensing step of sensing the refrigerant temperature, a deviation of the thermistor according to the discharged refrigerant temperature sensed from the refrigerant temperature sensing step, and an abnormality determination step of determining an abnormal state of characteristic change, and the abnormality determination step When it is determined that the thermistor is in an abnormal state, an abnormality display step of displaying the abnormal state of the thermistor via the display means, and when the thermistor is determined to be in the abnormal state in the abnormality determination step, an overload An operation stop step of stopping the driving of the compressor according to the control of the control means so as to prevent the compressor from being overheated. A method for controlling an air conditioner, which comprises: