JP2006078089A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely protect a compressor while reducing a device cost in addition to simplification of circuit structure and control thereof. <P>SOLUTION: In the air conditioner 100 including the compressor 7, the compressor 7 comprises a compressor body, a motor driving the compressor body, a casing storing the compressor body and the motor, and a thermistor (temperature sensor) for detecting the temperature of the casing, provided in an upper portion of the casing. A control device 200 performs, based on the detected temperature of the casing, drive-control of the compressor 7 including forced stopping control of the compressor 7 in abnormal temperature rise of discharged refrigerant and control in pressure abnormal reduction to low-pressure side. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an air conditioner, and more particularly to a compressor control technique.

Conventionally, an outdoor unit provided with a compressor, an outdoor heat exchanger as a use side heat exchanger, and an outdoor fan that blows outside air to the outdoor unit, and an indoor unit connected to the outdoor unit via a refrigerant pipe, There is known an air conditioner including the above.
JP-A-5-149631

In the conventional air conditioner, when the compressor is controlled, control is performed using a low-pressure switch or a thermistor in order to control the operation state of the compressor so as not to deviate from a predetermined use condition. Those are known (for example, see Patent Document 1).
In such an air conditioner, a thermistor that prevents a compressor failure due to an abnormal increase in the discharge temperature of the compressor, a thermostat that forcibly stops the compressor by closing the refrigerant circuit when the temperature exceeds a set temperature, There has also been proposed a low-pressure switch that prevents an abnormal rise in the discharge temperature of the compressor when the low-pressure pressure becomes lower than the set pressure.

However, when a plurality of sensors (thermistor, thermostat, low-pressure switch) are provided as described above, there is a problem in that the circuit configuration and control become complicated and the apparatus cost also increases.
SUMMARY OF THE INVENTION An object of the present invention is to provide an air conditioner that can reliably protect a compressor while simplifying the circuit configuration and control and reducing the apparatus cost.

  In order to solve the above-described problems, the compressor, the heat source side heat exchanger, the use side heat exchanger, and the refrigerant pipe connecting the heat source side heat exchanger and the use side heat exchanger are provided, and the heat source side And an expansion valve that controls an amount of refrigerant flowing into the heat exchanger, wherein the compressor includes a compressor body, a motor that drives the compressor body, the compressor body, and the motor. A temperature sensor that detects the temperature of the casing at the top of the casing, and a forced stop control and a low pressure of the compressor when the temperature of the discharged refrigerant rises abnormally based on the detected temperature of the casing And a control unit that performs drive control of the compressor including control when the side pressure is abnormally reduced.

According to the above configuration, the temperature sensor detects the temperature of the casing.
Thereby, based on the detected temperature of the casing, the control unit performs the drive control of the compressor including the forced stop control of the compressor when the abnormal temperature of the discharged refrigerant rises and the control when the low pressure side pressure abnormally decreases.

In this case, an outside air temperature detection sensor for detecting an outside air temperature is provided, and the control unit detects the outside temperature of the temperature sensor for a predetermined time when the detected temperature difference between the outside air temperature and the casing is equal to or higher than a predetermined temperature. You may make it perform drive control of the said compressor based on correction | amendment temperature which correct | amended detection temperature.
Moreover, the said motor may be arrange | positioned at the upper part side of the said compressor main body, and the said temperature sensor may be made to attach to the upper part rather than the arrangement position of the said motor of the said casing.

  Furthermore, at least two of the temperature sensors are provided, and the control unit detects the casing detected by the plurality of temperature sensors when the temperature of the casing detected by the plurality of temperature sensors is within a predetermined temperature range. The drive control of the compressor is performed based on the temperature.

  Furthermore, the control unit forcibly stops the compressor when the temperature of the casing exceeds a predetermined forced stop temperature, and when the temperature of the casing reaches a predetermined drive horsepower maintenance temperature, The compressor may be restarted.

  According to the present invention, it is possible to reliably control the drive of the compressor with a small number of temperature sensors.

Next, a preferred embodiment of the present invention will be described with reference to the drawings.
Drawing 1 is a figure showing the refrigerant circuit composition of the air harmony device of an embodiment.
The air conditioner 100 is configured by connecting the outdoor unit 1 and the indoor unit 2 with a refrigerant pipe including inter-unit pipes 9 and 10, and an operation unit (remote controller) for remotely controlling the air conditioner. 20 is provided.

  The outdoor unit 1 is installed outside and includes a compressor (DC inverter compressor) 7 that compresses the refrigerant, a four-way valve 8 that is connected to the compressor 7 via the discharge pipe 7A and reverses the circulation direction of the refrigerant, Through an outdoor heat exchanger 11 that functions as a heat source side heat exchanger that exchanges heat with the outside air, an outdoor expansion valve 13 that depressurizes the refrigerant according to the opening, a compressor 7 and a suction pipe 7B. The accumulator 5 that performs gas-liquid separation of the refrigerant that is connected and sucked into the compressor 7 is connected and accommodated by a refrigerant pipe. Moreover, the outdoor unit 1 includes a control device 200 that controls the entire air conditioner 100. Further, an outdoor fan 33 is disposed adjacent to the outdoor heat exchanger 11, and the air blown from the outdoor fan 33 is supplied to the outdoor heat exchanger 11.

In the vicinity of the outdoor heat exchanger 11, an outside air temperature sensor 34 for detecting the outside air temperature is provided.
The indoor unit 2 is installed in a conditioned room, functions as a use-side heat exchanger, and exchanges heat between the indoor air and the refrigerant, and a refrigerant refrigerant that flows into the indoor unit 2 during the cooling operation. The indoor expansion valve 23 for controlling the amount is connected and accommodated by a refrigerant pipe. Further, an indoor fan 22 for sending air to these indoor heat exchangers 21 is disposed adjacent to the indoor heat exchanger 21.

FIG. 2 is a block diagram illustrating a functional configuration of the control device.
The control device 200 includes an EEPROM (storage means) 40 that stores a control program, control data, and the like, a CPU 41 that controls the entire air conditioner 1 based on the control program in the EEPROM 40, and various data temporarily. RAM 42 for storing data, a transmission / reception unit 43 for communicating with the operation unit 20, and an interface (I / F) 44 for transmitting and receiving signals to and from each unit of the compressor drive module 103 and the air conditioner 1. Yes.

The control device 200 is connected to the outside air temperature sensor 34 and the indoor temperature sensor 50 via the I / F 44, and is configured to be able to acquire temperature data at each location.
And if the operation part 20 is operated, the control apparatus 100 will control the four-way valve 8, the compressor 7, the outdoor expansion valve 13, the indoor expansion valve 23, the outdoor fan 33, and the indoor fan 22, respectively.

Specifically, in the automatic operation mode, the control device 200 switches the four-way valve 8 based on the difference between the measured temperatures of the outside air temperature sensor 34 and the indoor temperature sensor 50 at the start of operation, so that the air conditioner 1 is set to cooling operation or heating operation. In the case of the manual operation mode, the operation is performed in the instructed operation mode.
Here, when the cooling operation is set, the control device 200 switches the four-way valve 8 to the cooling side, and as shown in FIG. 1, the refrigerant flows as indicated by the solid line arrow, and the outdoor heat exchanger 11 becomes the condenser. The indoor heat exchanger 21 functions as an evaporator and enters a cooling operation state, and the indoor heat exchanger 21 cools the room.

  On the other hand, when the heating operation is set, the control device switches the four-way valve 8 to the heating side, the refrigerant flows as indicated by the wavy arrow, the indoor heat exchanger 21 is the condenser, and the outdoor heat exchanger 11 is It functions as an evaporator and enters a heating operation state, and the indoor heat exchanger 21 heats the room.

At this time, the control device 200 controls the degree of superheat using temperature sensors (not shown) provided in each of the outdoor heat exchanger 11 and the indoor heat exchanger 21, and opens the openings of the outdoor expansion valve 13 and the indoor expansion valve 23. To control. In addition, the control device 200 variably controls the rotation speed of the indoor fan 22 based on the setting of the operation unit 20 or the like.
In parallel with these, the control device 200 calculates the driving horsepower (operating frequency) of the compressor 7 based on the difference between the set temperature set by the operation unit 20 and the indoor temperature acquired by the indoor temperature sensor 50. Variable control will be performed.

  By the way, in this embodiment, in the control of the driving horsepower (operating frequency) of the compressor, the control is performed based on the temperature obtained by one thermistor provided in the compressor 7.

First, the configuration of the compressor 7 will be described.
FIG. 3 is a diagram illustrating the configuration of the compressor.
The compressor 7 includes a compressor body 7C for compressing the refrigerant, a motor 7D for driving the compressor body 7C, and a casing 7E for housing the compressor body 7C and the motor 7D.
A power supply box 7F is provided on the upper surface of the casing 7E, and power is supplied to the motor 7D through the power supply box 7F.
Inside the power supply box 7F, a thermistor 7G as a temperature sensor for measuring the temperature of the casing 7E is disposed so as to be in close contact with the upper surface of the casing 7E.

FIG. 4 is an external perspective view of the compressor. FIG. 5 is an enlarged perspective view of the power supply box portion.
As shown in FIGS. 4 and 5, a power supply box 7F provided on the upper surface of the compressor 7 supplies power to the sensor output line 7H for transmitting the output signal of the thermistor 7G and to the motor 7D from the outside. A power line 7I is drawn out.
The power supply box 7F includes an upper casing 7J and a lower casing 7K, and the upper casing 7J and the lower casing 7K are not easily separated by the fixing bracket 7L.
A packing portion 7M is provided on the side surface of the power supply box 7F, and the sensor output line 7H and the power supply line 7I are drawn out from the packing portion 7M.

FIG. 6 is a perspective view of the power supply box when the fixing bracket and the upper casing are removed.
Inside the power supply box 7F, a thermistor 7G is pressed and attached to the upper surface of the casing 7E by a fixing metal 7N.

Next, control of the compressor of the embodiment will be described.
FIG. 7 is a processing flowchart of the embodiment. FIG. 8 is an explanatory diagram of the operation state.
First, the CPU 41 of the control device 200 detects the outside air temperature TA via the interface 44 and the outside air temperature sensor 34 (step S1).
Subsequently, the CPU 41 detects the thermistor temperature TTH, which is the surface temperature of the casing 7E, via the interface 44 and the thermistor 7G (step S2).

The CPU 41 determines whether or not the difference between the outside air temperature TA and the thermistor temperature TTH is within a predetermined temperature range, that is, whether or not the compressor 7 has just been started (step S3).
If the temperature difference between the outside air temperature TA and the thermistor temperature TTH is within the predetermined temperature range in the determination in step S3 (step S3; Yes), a period for correcting the thermistor temperature TTH detected by the thermistor 7G (from the start of startup). It is determined whether or not a timer for specifying a period until the predetermined time β elapses (step S5).

If it is determined in step S5 that the timer has already been started (step S5; Yes), the process proceeds to step S7.
If it is determined in step S5 that the timer is not activated (step S5; No), the CPU 41 corrects the thermistor temperature TTH at the time of activation based on the temperature difference between the outside air temperature TA and the thermistor temperature TTH. The correction temperature α is set, the control temperature TTH1 is set as in the following equation, a timer for determining a correction period is started, and the process proceeds to step S6 (step S6).
TTH1 = TTH + α

The correction temperature α is determined in consideration of the heat capacity of the casing 7E, and corrects a deviation between the surface temperature of the casing 7E at the time of startup and the actual refrigerant temperature detected through the casing 7E. .
In step S3, when the temperature difference between the outside air temperature TA and the thermistor temperature TTH is outside the predetermined temperature range (step S3; No), the CPU 41 sets the control temperature TTH1 as shown in the following formula ( Step S4), the process proceeds to step S7.
TTH1 = TTH

The CPU 41 compares the control temperature TTH1 with a temperature T1 that defines an area for increasing the driving horsepower of the compressor 7 shown in FIG.
TTH1 <T1
It is discriminate | determined whether it is (step S7).

In the determination in step S7, for example, as in the state up to time t1 in FIG.
TTH1 <T1
Is determined (step S7; Yes), since the driving horsepower of the compressor 7 is low with respect to the required capacity, the driving horsepower increasing process, that is, the rotation speed of the compressor 7 is set. The process to raise is performed (step S10).

Next, the CPU 41 determines whether or not the timer measurement time has passed the predetermined time β (including the case where the timer is not operating) (step S16).
If it is determined in step S16 that the measured time of the timer has exceeded the predetermined time β (step S16; Yes), the CPU 41 sets the control temperature TTH1 as in the following equation (step S17), and processing To step S1 again.
TTH1 = TTH

If it is determined in step S16 that the measured time of the timer has not exceeded the predetermined time β (step S16; No), the process returns to step S1.
In the determination of step S7,
TTH1 ≧ T1
Is determined (step S7; No), the CPU 41 compares the control temperature TTH1 with the temperature T2 that defines the region for maintaining the driving horsepower of the compressor 7 shown in FIG.
TTH1 <T2
It is discriminate | determined whether it is (step S8).

In the determination of step S8, for example, as in the state from time t1 to time t2 in FIG.
TTH1 <T2
When it is determined that it is (step S8; Yes), the CPU 41 further determines whether or not the outdoor unit is being forcibly stopped (step S11).
In the determination of step S11, when the outdoor unit is not forcibly stopped (step S11; No), the driving horsepower of the compressor 7 is almost equal to the required capacity, That is, a process for maintaining the rotational speed of the compressor 7 is performed, and it is determined whether or not the measurement time of the timer has passed the predetermined time β (including the case where the timer is not operating) (step S16).

If it is determined in step S16 that the measured time of the timer has exceeded the predetermined time β (step S16; Yes), the CPU 41 sets the control temperature TTH1 as in the following equation (step S17), and processing To step S1 again.
TTH1 = TTH
If it is determined in step S16 that the measured time of the timer has not exceeded the predetermined time β (step S16; No), the process returns to step S1.

In the determination of step S11, when the outdoor unit is forcibly stopped (step S11; Yes), for example, because the temperature is in a state of lowering due to the forced stop of the compressor 7 shown at time t4 in FIG. The restart process of the compressor 7 is performed (step S13).
Subsequently, the CPU 41 determines whether or not the measurement time of the timer has passed the predetermined time β (including the case where the timer is not operating) (step S16).

If it is determined in step S16 that the measured time of the timer has exceeded the predetermined time β (step S16; Yes), the CPU 41 sets the control temperature TTH1 as in the following equation (step S17), and processing To step S1 again.
TTH1 = TTH
If it is determined in step S16 that the measured time of the timer has not exceeded the predetermined time β (step S16; No), the process returns to step S1.

In the determination of step S8, for example, as in the state after time t2 in FIG.
TTH1 ≧ T2
(Step S8; No), the CPU 41 further compares the control temperature TTH1 with the temperature T3 that defines the region where the drive horsepower of the compressor 7 shown in FIG.
TTH1 <T3
It is determined whether or not (step S9).

In the determination in step S9, for example, in the state from time t2 to time t3 in FIG.
TTH1 <T3
Is determined (step S9; Yes), since the driving horsepower of the compressor 7 is high with respect to the required capacity, the driving horsepower down process, that is, the rotational speed of the compressor 7 is set. The lowering process is performed (step S10).

Next, the CPU 41 determines whether or not the timer measurement time has passed the predetermined time β (including the case where the timer is not operating) (step S16).
If it is determined in step S16 that the measured time of the timer has exceeded the predetermined time β (step S16; Yes), the CPU 41 sets the control temperature TTH1 as in the following equation (step S17), and processing To step S1 again.
TTH1 = TTH

If it is determined in step S16 that the measured time of the timer has not exceeded the predetermined time β (step S16; No), the process returns to step S1.
In the determination of step S9, for example, as in the state after time t3 in FIG.
TTH1 <T3
If it is determined that it is (step S9; Yes), since the driving horsepower of the compressor 7 is too high for the required capacity, the outdoor unit for forcibly stopping the compressor 7 is used. Stop processing is performed (step S15).

Next, the CPU 41 determines whether or not the timer measurement time has passed the predetermined time β (including the case where the timer is not operating) (step S16).
If it is determined in step S16 that the measured time of the timer has exceeded the predetermined time β (step S16; Yes), the CPU 41 sets the control temperature TTH1 as in the following equation (step S17), and processing To step S1 again.
TTH1 = TTH

If it is determined in step S16 that the measured time of the timer has not exceeded the predetermined time β (step S16; No), the process returns to step S1.
As described above, according to the present embodiment, only by providing one thermistor 7G, the forced stop control of the compressor and the low-pressure side abnormal pressure drop control are reliably performed when the abnormal temperature rise of the discharged refrigerant is performed. The machine can be protected, the circuit configuration and control can be simplified, and the apparatus cost can be reduced.

Although one embodiment of the present invention has been described above, the present invention is not limited to this. For example, each set value and piping configuration shown in the above embodiment is not limited to this, and can be appropriately changed without departing from the spirit of the present invention.
In the said embodiment, although the thermistor was provided in the upper surface side of the casing 7E of the compressor 7,
It can be configured to be disposed anywhere as long as it is above the motor 7D.

  In the above embodiment, only one thermistor as a temperature sensor is provided, but when at least two temperature sensors are provided and the temperature of the casing detected by the plurality of temperature sensors is within a predetermined temperature range, It is also possible to perform a drive control of the compressor based on the casing temperatures detected by a plurality of temperature sensors. Thereby, reliability is further improved.

In the above embodiment, the thermistor is used as the temperature sensor, but other temperature sensors can be similarly applied.
In the above embodiment, the case where the present invention is applied to an air conditioner including one outdoor unit and one indoor unit is illustrated, but the present invention is also widely applicable to an air conditioner including an arbitrary number of outdoor units and indoor units. Applicable.

It is a figure which shows the circuit structure of the air conditioning apparatus of embodiment. It is a figure which shows the function structure of a control apparatus. It is a structure explanatory view of a compressor. It is an external appearance perspective view of a compressor. It is an expansion perspective view of a power supply box part. It is a perspective view of a power supply box at the time of removing a fixing metal fitting and an upper casing. It is a processing flowchart of an embodiment. It is explanatory drawing of an operation state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Air conditioning apparatus 1 Outdoor unit 2 Indoor unit 5 Accumulator 7 Compressor 7A Power supply box 7C Compressor body 7D Motor 7E Casing 7G Thermistor (temperature sensor)
DESCRIPTION OF SYMBOLS 11 Outdoor heat exchanger 13 Outdoor expansion valve 20 Operation part 21 Indoor heat exchanger 22 Indoor fan 23 Indoor expansion valve 33 Outdoor fan 34 Outdoor temperature sensor 50 Indoor temperature sensor 200 Control apparatus (control part)

Claims (5)

Refrigerant amount flowing into the heat source side heat exchanger provided in a compressor, a heat source side heat exchanger, a use side heat exchanger, and a refrigerant pipe connecting the heat source side heat exchanger and the use side heat exchanger An air conditioner comprising an expansion valve for controlling
The compressor includes a compressor body, a motor that drives the compressor body, and a casing that houses the compressor body and the motor,
A temperature sensor for detecting the temperature of the casing at the top of the casing;
Based on the detected temperature of the casing, a control unit that performs drive control of the compressor, including forced stop control of the compressor at the time of abnormal temperature rise of the discharged refrigerant and control at the time of low pressure side pressure abnormal decrease,
An air conditioner comprising: The air conditioner according to claim 1, wherein
It has an outside air temperature detection sensor that detects outside air temperature,
The controller controls driving of the compressor based on a corrected temperature obtained by correcting the temperature detected by the temperature sensor for a predetermined time when the detected temperature difference between the outside air temperature and the casing is equal to or higher than a predetermined temperature. An air conditioner characterized by The air conditioner according to claim 1 or 2,
In the compressor, the motor is arranged on the upper side of the compressor body,
The air conditioner is characterized in that the temperature sensor is attached to an upper side of the casing relative to a position where the motor is arranged. The air conditioner according to any one of claims 1 to 3,
At least two temperature sensors are provided,
The control unit performs drive control of the compressor based on the temperature of the casing detected by the plurality of temperature sensors when the temperature of the casing detected by the plurality of temperature sensors is within a predetermined temperature range.
An air conditioner characterized by that. The air conditioner according to any one of claims 1 to 4,
The control unit forcibly stops the compressor when the temperature of the casing exceeds a predetermined forced stop temperature,
The air conditioner characterized by restarting the compressor when the temperature of the casing reaches a predetermined driving horsepower maintenance temperature.

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