JPH0754770Y2 - Air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an air conditioner capable of reducing pressure equalizing noise during pressure equalizing operation at the time of operation stop due to thermo-off.

<Prior Art> Conventionally, there is an air conditioner that uses an electric valve as an expansion valve for reducing the pressure of high-pressure refrigerant from a compressor. However, the cost of the electrically operated valve is high, and the circuit for controlling by the microcomputer or the like becomes complicated. Therefore,
As shown in FIG. 3, in order to configure an air conditioner more easily, there is one using a mechanical expansion valve as an expansion valve (Japanese Patent Laid-Open No. 64-075868).

In such an air conditioner, for example, the high-temperature high-pressure gas refrigerant discharged from the compressor 1 during heating operation is condensed in the indoor heat exchanger 2, decompressed by the mechanical expansion valve 3, and evaporated by the outdoor heat exchanger 4. , And returns to the compressor 1 via the accumulator 5. At that time, the indoor heat exchanger 2
The room is heated by the heat of condensation generated when the refrigerant is condensed in.

In this way, when the indoor temperature reaches the set temperature as a result of the heating operation being performed, the compressor 1 is stopped by thermo-off and the operation is stopped. In that case, in order to reduce the load on the compressor 1 when the compressor 1 is restarted when the operation is restarted by the thermo-on, the pressure on the high pressure side and the pressure on the low pressure side of the refrigerant are equalized. In such a pressure equalizing operation, the solenoid valve 6 is opened for a predetermined time, and the high pressure side refrigerant is released to the low pressure side through the bypass pipe 7, the heat storage heat exchanger 8, the bypass pipe 9 and the check valve 10. Carried out by.

<Problems to be Solved by the Invention> As described above, in the air conditioner, when the operation is stopped, the solenoid valve 6 is opened to perform the pressure equalizing operation. Therefore, when the solenoid valve 6 is opened, the refrigerant on the high pressure side suddenly flows to the low pressure side to rapidly equalize the pressure, and a violent pressure equalizing noise is generated.

Such pressure equalizing noise is not so serious in a noisy place such as a factory, but is a serious problem in a quiet place where an air conditioner is installed.

Therefore, an object of the present invention is to provide an air conditioner capable of performing a pressure equalizing operation with less pressure equalizing noise when the operation is stopped.

<Means for Solving the Problems> In order to achieve the above object, the first invention is, as illustrated in FIG. 1, a compressor 11, a condenser means 13, 15, a mechanical expansion valve 14, an evaporator means 15, With a refrigerant circuit in which 13 are sequentially interposed,
In an air conditioner that performs a pressure equalizing operation by connecting the high-pressure side refrigerant pipe and the low-pressure side refrigerant pipe without the mechanical expansion valve 14 when the operation is stopped, an operation to determine whether or not the operation is stopped The stop determination means and the operation stop determination means, when it is determined that the operation is stopped, while rotating the condenser fan 25 at a predetermined rotation speed prior to the pressure equalizing operation, the pressure equalizing operation has been started. In this case, the fan control means for stopping the fan 25, the temperature detection means 23 for detecting the temperature of the high pressure side of the refrigerant, and the temperature of the high pressure side of the refrigerant detected by the temperature detection means 23 is intense during the pressure equalizing operation. It is characterized in that it is provided with a pressure equalizing operation control means for starting the pressure equalizing operation when the temperature becomes equal to or lower than a predetermined temperature at which no pressure equalizing noise is generated.

The second invention is, as illustrated in FIG. 1, a compressor.
11, a condensing means 13,15, a mechanical expansion valve 14, has a refrigerant circuit in which the evaporation means 15, 13 are sequentially interposed, the high-pressure side refrigerant pipe and the low-pressure side refrigerant pipe when the operation is stopped the mechanical expansion valve 14 In an air conditioner that performs a pressure equalizing operation by connecting without interposing, an operation stop determination unit that determines whether or not the operation is stopped,
The fan 25 for the condenser is rotated at a predetermined rotation speed prior to the pressure equalizing operation when it is determined by the operation stop determination means that the fan 25 is operated when the pressure equalizing operation is started. Fan control means for stopping the operation, time measuring means for measuring the elapsed time after the operation stop determining means determines that the operation is stopped, and the result of the time measurement by the time measuring means is the pressure equalization operation of the high-pressure side refrigerant. It is characterized in that it is provided with a pressure equalizing operation control means for starting the time pressure equalizing operation when a predetermined time is reached until the pressure becomes a pressure that does not sometimes generate a violent pressure equalizing sound.

<Operation> In the first invention, when the operation stop determination unit determines that the air conditioner is in the operation stop state, the fan control unit rotates the condenser fan 25 at a predetermined rotation speed. Then, when the temperature of the high pressure side refrigerant detected by the temperature detecting means 23 becomes equal to or lower than a predetermined temperature that does not cause a severe pressure equalizing sound during the pressure equalizing operation, the pressure equalizing operation control means The refrigerant pipe and the low-pressure side refrigerant pipe are connected without a mechanical expansion valve, and the pressure equalizing operation is started. Thus, when the pressure equalizing operation is started, the fan 25 is stopped by the fan control means.

Further, in the second invention, when the operation stop determination means determines that the operation is stopped, the fan control means rotates the condenser fan 25 at a predetermined rotation speed.
Further, the elapsed time after the operation is determined to be stopped is measured by the time measuring means. Then, when the time measured by the above-mentioned time measuring means reaches a predetermined time until the pressure of the high-pressure side refrigerant becomes a pressure that does not generate a severe pressure equalizing sound during the pressure equalizing operation, the pressure equalizing operation control is performed. The pressure equalizing operation is started by the means, and the fan 25 is stopped by the fan control means.

That is, in each of the above-mentioned inventions, before the pressure equalizing operation in the operation stop state is started, the condenser fan 25 is previously rotated at a predetermined rotation speed to accelerate the condensation of the high pressure side refrigerant to some extent, and the pressure of the high pressure side refrigerant is increased. When the pressure equalizing operation is performed, the pressure is reduced to a pressure that does not generate a severe pressure equalizing sound, and then the pressure equalizing operation is started.

<Embodiment> Hereinafter, the present invention will be described in detail with reference to an illustrated embodiment.

This invention controls the rotation speed of the condenser fan in advance to reduce the refrigerant pressure on the high-pressure side to a pressure that does not generate a severe pressure equalizing sound during the pressure equalizing operation when the air conditioner is stopped. After that, the pressure equalizing operation is carried out to reduce the pressure equalizing sound during the pressure equalizing operation.

FIG. 1 is a refrigerant circuit diagram relating to heating operation in the air conditioner of the present invention. This refrigerant circuit consists of a compressor 11 and a four-way valve 1.
2, an indoor heat exchanger 13, a mechanical expansion valve 14, an outdoor heat exchanger 15, a four-way valve 12 and an accumulator 16 are sequentially connected to each other. The opening degree of the mechanical expansion valve 14 is controlled according to the low-pressure side refrigerant temperature by the temperature sensitive cylinder 30 attached to the low-pressure side refrigerant pipe.

On the outer peripheral surface of the compressor 11, a heat storage device composed of a heat storage heat exchanger 17 and a heat storage material is provided. However, the heat storage material is omitted in FIG. Then, the one end 17a of the refrigerant pipe provided in the heat storage heat exchanger 17 so as to spirally rotate around the compressor 11 and the space between the indoor heat exchanger 13 and the mechanical expansion valve 14 are electromagnetically connected. It is connected by a bypass pipe 18 via a valve 21.
On the other hand, the other end 17b of the refrigerant pipe and the outdoor heat exchanger 15
And between the mechanical expansion valve 14 and the bypass pipe 19 via the check valve 22.
Connect by.

Here, in this embodiment, the bypass pipe as described above is used.
The defrosting operation and the pressure equalizing operation are executed by using the path formed by the heat storage heat exchanger 17 and the bypass pipe 19.

A thermistor 23 that detects the condensation temperature Tc of the indoor heat exchanger 13 is installed near the indoor heat exchanger 13. Then, the detection signal from the thermistor 23 is input to the indoor microcomputer 24. On the other hand, in the vicinity of the outdoor heat exchanger 15, the outdoor heat exchanger is
A thermistor 27 that detects the evaporation temperature Te of 15 is installed. Then, the detection signal from the thermistor 27 is sent to the outdoor microcomputer.
Enter in 28. Further, the indoor microcomputer 24 outputs a fan control signal for controlling the rotation speed of the indoor fan 25 to the fan motor 26, while the outdoor microcomputer 28 controls the opening / closing of the solenoid valve 21 with respect to the solenoid valve 21. A solenoid valve control signal for outputting is output.

The outdoor microcomputer 28 and the indoor microcomputer 24 carry out the defrosting operation and the pressure equalizing operation while exchanging information with each other.
That is, when the outdoor microcomputer 28 detects the start of the defrosting operation based on the detection signal from the thermistor 27, the electromagnetic valve
Open 21 to start defrosting operation. Then, according to the information from the indoor microcomputer 24, the condensation temperature Tc of the indoor heat exchanger 13
Has reached the peak cut control temperature, the inverter 29 is controlled, for example, to reduce the drive power supply frequency of the compressor 11.

When the outdoor microcomputer 28 detects that the indoor temperature has reached the set temperature based on the information from the indoor microcomputer 24, the outdoor microcomputer 28 stops the compressor 11 and puts it into an operation stop state, and at the same time, opens the solenoid valve 21 to make the temperature uniform. Start pressure operation. On the other hand, the indoor microcomputer 24, based on the information from the outdoor microcomputer 28,
When it is known that the compressor 11 has stopped operating, a fan control signal is output to the fan motor 26 and the rotation speed of the indoor fan 25, which is a condenser fan, prior to the start of the pressure equalizing operation by the outdoor microcomputer 28. To control.

That is, the indoor microcomputer 24 and the outdoor microcomputer 28 constitute the operation stop judging means, the fan controlling means, the time measuring means and the pressure equalizing operation controlling means.

In the air conditioner configured as above, the four-way valve is used during heating operation.
Switch 12 as shown in FIG. Then, the high-temperature and high-pressure gas refrigerant discharged from the compressor 11 becomes the indoor heat exchanger 13
The interior of the room is heated by the condensation heat released by the condensation heat. The high-pressure liquid refrigerant condensed by the indoor heat exchanger 13 is decompressed by the mechanical expansion valve 14, and further evaporated by the outdoor heat exchanger 15 to become a low-pressure gas refrigerant and return to the compressor 11. At that time, the heat radiated from the compressor 11 is accumulated in the heat storage material.

In this state, the outdoor microcomputer 28 uses the detection signal sent from the thermistor 27 (for example, the difference between the evaporation temperature Te of the outdoor heat exchanger 15 and the outside air temperature becomes a predetermined value).
When it is determined that the defrosting operation should be started, the solenoid valve 21 is opened and the defrosting operation is started. Then, as shown by the arrow in FIG. 1, the high-pressure liquid refrigerant after being condensed by the indoor heat exchanger 13 and heating the room by the heat of condensation passes through the solenoid valve 21 and reaches the heat storage heat exchanger 17. Then, heat is exchanged in the heat storage heat exchanger 17 to recover the heat stored in the heat storage material.

On the other hand, the hot gas refrigerant from the heat storage heat exchanger 17 is a check valve.
It is supplied to the outdoor heat exchanger 15 via 22. Then, the high temperature gas refrigerant supplied to the outdoor heat exchanger 15 is the outdoor heat exchanger 15.
Is defrosted by the condensation heat generated at that time. The partially liquefied refrigerant thus returns to the compressor 11 via the four-way valve 12 and the accumulator 16.

In this way, the indoor microcomputer 24 indicates that the room temperature has reached the set temperature during the heating operation while defrosting.
When it is detected, the indoor microcomputer 24 outputs a thermo-off signal to the outdoor microcomputer 28. Then, the outdoor microcomputer 28 stops the compressor 11 based on the thermo-off signal from the indoor microcomputer 24, and enters the operation stop state. In that case,
Since the mechanical expansion valve 14 is in the closing direction under the control of the temperature-sensitive cylinder 30, the pressure of the high-pressure side refrigerant and the pressure of the low-pressure side refrigerant are not easily uniform as they are. Therefore,
The outdoor microcomputer 28 and the indoor microcomputer 24 carry out the pressure equalization control operation.

FIG. 2 is a flowchart of the pressure equalizing control operation relating to the indoor microcomputer 24, among the pressure equalizing control operations performed by the outdoor microcomputer 28 and the indoor microcomputer 24. The pressure equalization control operation procedure will be described below with reference to FIG.

The four-way valve 12 is set on the heating operation side and the heating operation is started. At the same time, the pressure equalization control operation starts.

In step S1, based on the information from the outdoor microcomputer 28,
It is determined whether or not the current operation mode is heating. As a result, if it is determined to be heating, the process proceeds to step S2, and if not, the pressure equalization control operation ends.

In step S2, based on the information from the outdoor microcomputer 28,
It is determined whether or not the operation is stopped. As a result, if it is determined that the operation is stopped, the process proceeds to step S3, and if not, the operation waits until the operation is stopped.

In step S3, the set time of the timer is set to t (about 150 seconds), and time counting is started.

In step S4, the fan motor 26 is driven by the fan control signal.
Is controlled, and the number of rotations of the indoor fan 25 is set to the number of rotations N rpm that does not give the user a feeling of cool air.

By doing so, heat exchange in the indoor heat exchanger 13 is promoted to some extent, and the high-pressure side refrigerant releases condensation heat. As a result, the pressure of the high pressure side refrigerant is reduced.

In step S5, it is determined whether or not the condensing temperature Tc of the indoor heat exchanger 13 is equal to or lower than the temperature T at which a severe pressure equalizing noise does not occur even when the pressure equalizing operation is started. As a result, if the temperature is equal to or lower than the temperature T, the process proceeds to step S7, and if not, the step
Go to S6.

In step S6, it is determined whether or not the time counting operation started in step S3 has timed up. As a result, if the time is up, the process proceeds to step S7, and if not, the process returns to step S5.

Here, the set time t of the timer is an elapsed time until the pressure of the high-pressure side refrigerant becomes a pressure at which a severe pressure equalizing noise is not generated during the pressure equalizing operation when the indoor fan 25 is rotated at the rotation speed Nrpm. Is set to.

In step S7, the pressure equalizing operation instruction signal for instructing the outdoor microcomputer 28 to open the solenoid valve 21 and start the pressure equalizing operation is output.

Then, the outdoor microcomputer 28 receives the pressure equalizing operation instruction signal from the indoor microcomputer 24 and opens the solenoid valve 21 to start the pressure equalizing operation. As a result, the high-pressure side refrigerant passes through the opened solenoid valve 21, the heat storage heat exchanger 17, and the check valve 22 to flow to the low-pressure side to equalize the pressure. At that time, the above step S4
In the above, since the high pressure side refrigerant releases the condensation heat in advance and the pressure is reduced, no violent pressure equalizing noise is generated.

That is, after the number of rotations of the indoor fan 25 is set to N rpm, the condensing temperature Tc in the indoor heat exchanger 13 becomes equal to or lower than the temperature T, or waits for the measurement time to elapse for the time t before performing the pressure equalizing operation. I will enter.

In step S8, the fan motor 26 is driven by the fan control signal.
And the indoor fan 25 is stopped, and the pressure equalization control operation ends.

As described above, in this embodiment, when the indoor microcomputer 24 detects that the operation is stopped based on the information from the outdoor microcomputer 28 during the heating operation, the indoor microcomputer 24 rotates the rotation speed of the indoor fan 25. Set to a number N. After that, the indoor microcomputer 24 determines whether the condensation temperature Tc in the indoor heat exchanger 13 has reached the temperature T or lower, or the rotation speed of the indoor fan 25 is N rpm.
Wait until the time elapsed from setting to
A pressure equalizing operation instruction signal is output to the outdoor microcomputer 28.
After that, the indoor fan 25 is stopped.

Then, the outdoor microcomputer 28, based on the pressure equalizing operation instruction signal from the indoor microcomputer 24, the solenoid valve 21 for releasing the high pressure side refrigerant flowing out from the indoor heat exchanger 13 to the low pressure side.
Is opened to start the pressure equalizing operation.

By doing so, in the operation stopped state, before the pressure equalizing operation is started by the control of the outdoor microcomputer 28, the heat exchange in the indoor heat exchanger 13 is promoted to some extent, and the refrigerant on the high pressure side is in the indoor heat exchanger 13. It releases the heat of condensation and reduces the pressure.

At this time, the temperature T is set to a temperature at which the pressure of the high-pressure side refrigerant does not generate a severe pressure equalizing sound during the pressure equalizing operation, while the set time t causes the indoor fan 25 to rotate at the rotation speed N. The elapsed time after that is set to the time until the pressure of the high-pressure side refrigerant reaches a pressure at which a severe pressure equalizing noise is not generated during the pressure equalizing operation. Therefore, before the pressure equalization operation is started, the pressure of the high-pressure side refrigerant is reduced to a pressure at which a severe pressure equalization noise is not generated during the pressure equalization operation. That is, according to this embodiment, it is possible to reduce the pressure equalizing noise during the pressure equalizing operation when the operation is stopped.

Further, the indoor microcomputer 24 and the outdoor microcomputer 28 used at that time use the microcomputer for defrosting operation control. Therefore, it is not necessary to specially install a microcomputer for controlling the pressure equalizing operation, and the pressure equalizing operation can be performed without increasing the cost.

In the above embodiment, the heating operation is described as an example for simplification of description, but the invention is not limited to the heating operation.

In the above embodiment, the bypass pipe 18 heat storage heat exchanger
A pressure equalizing operation is performed using a path formed by 17 and the bypass pipe 19. However, the present invention is not limited to this, as long as the high-pressure side refrigerant pipe and the low-pressure side refrigerant pipe in the refrigerant circuit are connected without a mechanical expansion valve to perform a pressure equalizing operation. .

The thermistor 23 in the above embodiment is installed near the indoor heat exchanger 13 and detects the condensation temperature Tc.
However, the present invention is not limited to this. The point is that the temperature of the high pressure side of the refrigerant can be detected to detect that the pressure of the high pressure side refrigerant has dropped.

Further, the algorithm of the pressure equalizing control operation in this invention is not limited to the above embodiment.

In the above embodiment, the pressure equalizing operation is performed when the condensing temperature Tc in the indoor heat exchanger 13 reaches the temperature T or lower, or when the time elapsed from setting the rotation speed of the indoor fan 25 to N rpm is time t. I'm trying to enter. However, in the present invention, the above two conditions are not necessarily required as the conditions for starting the pressure equalizing operation, and the start of the pressure equalizing operation may be determined based on only one of the conditions.

<Effect of Device> As is clear from the above, the air conditioner of the first device is
It has an operation stop determination means, a fan control means, a temperature detection means, and a pressure equalization operation control means, and when the operation is stopped, the rotation speed of the condenser fan is set to a predetermined rotation speed, and the temperature of the high pressure side of the refrigerant is Is equal to or lower than a predetermined temperature that does not produce a severe pressure equalization noise during pressure equalization operation, the high pressure side refrigerant pipe and the low pressure side refrigerant pipe are connected without a mechanical expansion valve to equalize pressure. Since the fan is stopped at the same time as starting the operation, prior to the start of the pressure equalizing operation when the operation is stopped,
The pressure of the high-pressure side refrigerant can be shifted to the pressure equalizing operation after being reduced to a pressure at which a severe pressure equalizing noise does not occur during the pressure equalizing operation.

The air conditioner according to the second aspect of the invention is an operation stop determination means,
Having a fan control means, a time measuring means and a pressure equalizing operation control means, when the operation is stopped, the rotation speed of the condenser fan is set to a predetermined rotation speed and at the same time the elapsed time after the operation is stopped is measured. However, when the above-mentioned timing result reaches a predetermined time until the pressure of the high pressure side refrigerant becomes a pressure that does not cause a severe pressure equalizing sound during the pressure equalizing operation, the high pressure side refrigerant pipe and the low pressure side refrigerant pipe And the fan are stopped by connecting and without a mechanical expansion valve, so that the pressure of the high-pressure side refrigerant is equalized before starting the pressure equalization operation when the operation is stopped. At times, the pressure can be shifted to a pressure equalizing operation after the pressure is reduced to a level that does not cause a violent pressure equalizing noise.

Therefore, according to each of the above inventions, it is possible to perform the pressure equalizing operation with less pressure equalizing noise when the operation is stopped.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a refrigerant circuit in an air conditioner of the present invention, FIG. 2 is a flow chart of pressure equalizing control operation, and FIG. 3 is an explanatory view of an air conditioner capable of performing conventional pressure equalizing operation. Is. 11 ... Compressor, 13 ... Indoor heat exchanger, 15 ... Outdoor heat exchanger, 17
… Heat storage heat exchanger, 21… Solenoid valve, 23, 27… Thermistor, 24
… Indoor microcomputer, 25… Indoor fan, 26… Fan motor,
28 ... Outdoor microcomputer.

Claims (2)

[Scope of utility model registration request] 1. A refrigerant circuit having a compressor (11), a condensing means (13,15), a mechanical expansion valve (14), and an evaporating means (15,13) arranged in sequence, and having a high pressure side at the time of stoppage of operation. In an air conditioner that performs a pressure equalizing operation by connecting a refrigerant pipe and a low-pressure side refrigerant pipe without the mechanical expansion valve (14), an operation stop determining means for determining whether or not the operation is in an stopped state. When the operation stop determination means determines that the operation is in the stopped state, the condenser fan (25) is rotated at a predetermined rotation speed prior to the pressure equalization operation, while the pressure equalization operation is started. The fan control means for stopping the fan (25), the temperature detection means (23) for detecting the temperature of the high pressure side of the refrigerant, and the temperature of the high pressure side of the refrigerant detected by the temperature detection means (23) are even. When the temperature is below the specified temperature, which does not cause a severe pressure equalization An air conditioner comprising a pressure equalizing operation control means for starting the pressure equalizing operation in the case of occurrence. 2. A refrigerant circuit having a compressor (11), a condensing means (13,15), a mechanical expansion valve (14), and an evaporating means (15,13) sequentially provided, and having a high pressure side when the operation is stopped. In an air conditioner that performs a pressure equalizing operation by connecting a refrigerant pipe and a low-pressure side refrigerant pipe without the mechanical expansion valve (14), an operation stop determining means for determining whether or not the operation is in an stopped state. When the operation stop determination means determines that the operation is in the stopped state, the condenser fan (25) is rotated at a predetermined rotation speed prior to the pressure equalization operation, while the pressure equalization operation is started. The fan control means for stopping the fan (25), the time measuring means for measuring the elapsed time after the operation stop determining means determines that the operation is in the stopped state, and the result of the time counting by the time measuring means is that of the high pressure side refrigerant. The pressure does not generate a violent pressure equalizing sound during pressure equalizing operation. An air conditioner characterized by comprising equalizing pressure operation control means for starting the equalizing pressure operation when reaching a predetermined time up to a pressure such.