JPH0526520A - Air conditioner - Google Patents

Abstract

PURPOSE:To provide an air conditioner that uses electricity efficiently and is capable of accumulating heat into a heat accumulating type heat exchanger. CONSTITUTION:In an air conditioner 1 provided with a refrigerating circuit 2, hot gas bypass circuit 3, and controller 4, a compressor 5 the capability of which can be changed according to the operation frequency is used. Since the controller 4 is provided with a control means 28 which sets the operation frequency of the compressor 5 to a rated frequency when the difference of the temperature in the room and a set temperature is within a specified value in the operation of space heating and opens a control valve 20, the compressor 5 can be operated at maximum efficiency, and it is possible to store the heat of the hot gas from the compressor 5 in a heat accumulating type heat exchanger 22. With this arrangement it is possible to use the electricity efficiently and suppress the use of electricity in vain as much as possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner which utilizes the heat of a heat storage heat exchanger provided in a hot gas bypass circuit during defrosting.

[0002]

2. Description of the Related Art A compressor, an indoor heat exchanger, a pressure reducing device, and an outdoor heat exchanger are connected in a ring shape to form a refrigerating circuit, a control valve and a heat storage heat exchanger, and one end of the compressor An air conditioner equipped with a hot gas bypass circuit connected to the discharge side of the machine and the other end of which is connected between the pressure reducing device and the outdoor heat exchanger is disclosed in Japanese Utility Model Publication No. 63-7811. There is.

In this air conditioner, the heat of the heat storage heat exchanger is dissipated to the outdoor heat exchanger by opening the control valve during defrosting, and the frost is melted.

[0004]

In the above-mentioned air conditioner, a so-called rated compressor that operates at a predetermined frequency is used as the compressor.

Therefore, there is a drawback in that the heating of the room is controlled to be turned on and off, which is not comfortable.

In order to solve this drawback, it is conceivable to use a compressor whose capacity can be changed by the operating frequency in place of the compressor. However, in this compressor, the efficiency of the compressor changes depending on the operating frequency. Therefore, when the heat is stored in the heat storage heat exchanger, the efficiency of the compressor is not always the best, and there is a possibility that electricity cannot be used efficiently.

In particular, the heat stored in the heat storage heat exchanger is used for defrosting and does not warm the room.
It is necessary to efficiently use electricity to store heat in the heat storage tank.

The present invention provides an air conditioner which can efficiently store electricity in a heat storage heat exchanger.

[0009]

The present invention has a refrigeration circuit formed by annularly connecting a compressor, an indoor heat exchanger, a pressure reducing device, and an outdoor heat exchanger, a control valve, and a heat storage heat exchanger. And a hot gas bypass circuit, one end of which is connected to the discharge side of the compressor and the other end of which is connected between the pressure reducing device and the outdoor heat exchanger, and a control device which controls the compressor and the control valve. In the air conditioner equipped with, a compressor whose capacity is changed by the operating frequency is used for the compressor, and the control device compresses the compressor when the difference between the set temperature and the room temperature is within a predetermined value during heating operation. The operating frequency of the machine is set to approximately the rated frequency, and the control means for opening the control valve is provided.

[0010]

In this air conditioner, the control means provided in the control device sets the operating frequency of the compressor to approximately the rated frequency and opens the control valve when the difference between the set temperature and the room temperature is within a predetermined range. ..

When the compressor is operated at about its rated frequency, it operates at about maximum efficiency.

When the control valve of the bypass circuit is opened, hot gas from the compressor passes through the heat storage heat exchanger, and the heat of the hot gas is stored in this heat storage heat exchanger.

[0013]

Embodiments of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 is an air conditioner for performing refrigerant and heating in a room, which mainly comprises a refrigeration circuit 2, a hot gas bypass circuit 3 and a control device 4.

Reference numeral 5 is a variable capacity compressor whose operating frequency can be changed between 30 and 180 Hz and whose rated frequency is 100 Hz.
Is a four-way valve for switching the flow path of the refrigerant in the cooling operation or the heating operation, 7 is an outdoor heat exchanger, 8 is a decompression device, 9 is an indoor heat exchanger, and 10 is an accumulator.

The compressor 5, the four-way valve 6, the outdoor heat exchanger 7, the pressure reducing device 8, the indoor heat exchanger 9, and the accumulator 10 are arranged in the order of refrigerant pipes 11, 12, 13, 14, 1.
The refrigerating circuit 2 is configured by connecting 5 and 16 in a ring shape.

Reference numeral 17 denotes a refrigerant pipe 1 whose one end has a discharge side of the compressor 5.
1, a hot gas bypass pipe having the other end connected to the suction side of the heat exchanger 18, one end of the hot gas bypass pipe 19 connected to the discharge side of the heat exchanger 18, and the other end of the decompression device 8
Is a hot gas bypass pipe connected to a refrigerant pipe 13 that connects the heat exchanger 7 and the outdoor heat exchanger 7, and 20 is a control valve provided in the middle of the hot gas bypass pipe.

An electromagnetic valve is used as the control valve 20.

The heat exchanger 18 is arranged in a heat storage tank 21 containing a heat storage agent such as paraffin, and the heat storage tank and the heat exchanger constitute a heat storage heat exchanger 22. There is.

Then, the heat storage heat exchanger 22 and the control valve 2
0 and the hot gas bypass pipes 17 and 19 form a hot gas bypass circuit 3.

The control device 4 controls the operating frequency of the compressor 5 and controls the opening / closing of the control valve 20.

Reference numeral 23 is a temperature detector for detecting the temperature of the outdoor heat exchanger 7, 24 is a temperature detector for detecting the outside air temperature, 25 is a temperature detector for detecting the temperature of the heat storage agent in the heat storage tank 21, 2
6 is a temperature detector for detecting the indoor temperature.

The control device 4 includes temperature detectors 23, 2
An input circuit 27 for inputting signals from 4, 25 and 26;
A signal from this input circuit is input to control the operating frequency of the compressor 5 and the opening / closing of the control valve 20, a control means 28 including a microcomputer, an inverter circuit 29 for changing the operating frequency, and a control valve. And an output circuit 30 that outputs a signal for opening and closing 20.

When the difference between the room temperature and the set temperature is within a predetermined value during the heating operation, for example, when the room temperature reaches the set temperature [the room temperature is 0.5 of the set temperature].
Even when the temperature reaches within ℃, the operating frequency to the compressor 5 is set to the rated frequency to operate the compressor 5 at the highest efficiency, and the control valve 20 is opened to store the heat of the hot gas in the heat storage tank. Store in the heat storage agent in 21.

When heat is stored in the heat storage tank 21 and the temperature of the heat storage agent rises to, for example, 90 ° C., the control means 28 closes the control valve 20.

Further, the control means 28 opens the control valve 20 at the time of defrosting or at the start of the heating operation to allow hot gas to flow to the heat exchanger 18 and the outdoor heat exchanger 7 so that the heat in the heat storage tank 21 is removed. The heat is dissipated to the outdoor heat exchanger 7.

When the heat in the heat storage tank 21 has been dissipated to the outdoor heat exchanger 7, the control means 28 closes the control valve 20.

A blower fan for passing the indoor air through the indoor heat exchanger 9 and a fan for passing the outdoor air through the outdoor heat exchanger 7 are not shown.

In the air conditioner 1 thus constructed,
During the heating operation, the four-way valve 6 is switched as shown in the figure, the indoor heat exchanger 9 functions as a condenser, and the outdoor heat exchanger 7 functions as an evaporator, and the heating operation is performed.

When the heating operation is continued, the outdoor heat exchanger 7 is gradually frosted.

When the heating operation is continued, the room temperature approaches the set temperature.

In the conventional air conditioner, when the room temperature is far from the set temperature, the variable capacity compressor is operated at the rated frequency, and when the room temperature approaches the set temperature, the compressor is operated. The frequency is lowered and the heat quantity of condensation in the indoor heat exchanger is lowered.

When the operating frequency of the variable capacity type compressor is lowered from the rated frequency, the efficiency of the compressor is reduced, so electricity is not used efficiently.

However, in this air conditioner 1, the frequency temporarily higher than the rated frequency [eg 180
Hz] to operate the compressor 5, and thereafter operate the compressor 5 at the rated frequency.

When the room temperature reaches the set temperature,
The control means 28 sets the operating frequency to the rated frequency so that the compressor 5 is operated at the highest efficiency, and the control valve 20 is opened to allow hot gas to flow through the heat exchanger 18 to store heat in the heat storage tank 21. ..

That is, when the difference between the indoor temperature and the set temperature is within a predetermined range (that is, when a large amount of heat for heating is not required), the compressor 5 remains at the rated frequency with the highest energy efficiency of the compressor. Is operated to store excess heat not used for heating in the heat storage tank 21.

Therefore, it is possible to efficiently store the heat for use during defrosting or when the heating is started up in the heat storage tank 21 with the least electricity.

At this time, since the refrigerant is flowing also through the indoor heat exchanger 9 and the heating is continued, the indoor temperature does not drop sharply.

The heat is stored in the heat storage tank 21, and this temperature is 90%.
When the temperature reaches ° C, it is determined that the heat storage is completed, and the control means 28 closes the control valve 20.

After the control valve 20 is closed, the compressor 5
The operating frequency is variably controlled from the rated frequency according to the difference between the set temperature and the room temperature [see FIG. 4].

When the heating operation is continued, the outdoor heat exchanger 7 is gradually frosted.

The outdoor air temperature and the temperature of the outdoor heat exchanger 7 are shown in FIG.
When it comes within the range of the hatched line, the control means 28 opens the control valve 20 to start the defrosting operation.

When the control valve 20 is opened, the temperature of the refrigerant discharged from the compressor 5 is lowered, and is about 60 ° C., for example.

The refrigerant of about 60 ° C. is stored in the heat storage tank 21 for 9 times.
Since the frost on the outdoor heat exchanger 7 is heated after passing through the outdoor heat exchanger 7 after being heated to about 0 ° C., the frost is quickly melted.

At the time of defrosting, since the refrigerant is flowing through the indoor heat exchanger 9, heating is continued and the indoor temperature does not drop sharply.

After completion of the defrosting operation, the control valve 20 is controlled by the control means 2.
It is closed by 8 [see FIG. 4].

Since the heat is not stored in the heat storage tank 21 when the control valve 20 is closed, when the room temperature reaches the set temperature again, the control means 20 sets the operating frequency to the compressor 5 to the rated frequency. The control valve 20 is set and the heat of the hot gas is stored in the heat storage tank 21.

When the operation of the air conditioner 1 is stopped while the heat is stored in the heat storage tank 21, the heat in the heat storage tank 21 is used at the start of the heating operation.

At the start of the heating operation of the air conditioner 1,
The control means 20 opens the control valve 20 and sets the operating frequency of the compressor 5 to the maximum frequency.

When the control valve 20 and the compressor 5 are controlled in this way, the heat of the refrigerant warmed in the heat storage tank 21 is dissipated to the outdoor heat exchanger 7, and the heat of the outdoor heat exchanger 7 is released. Since the water is pumped to the indoor heat exchanger 9, the rising time of the heating operation is shortened.

In this embodiment, it is conceivable that the operation of the air conditioner 1 may be stopped when the heat storage in the heat storage tank 21 is not completed, and the heat in the heat storage tank 21 must be kept at the start of the heating operation. Not always available. Therefore, the operation of storing heat in the heat storage agent of the heat storage tank 21 [the control valve 20 is opened, before the operation of the air conditioner 1 is stopped so that the heat of the heat storage tank 21 can be always used at the start of the heating operation, Compressor 5
The operating frequency is the rated frequency. The control means 28 may be configured to perform].

Further, in this embodiment, since the solenoid valve is used as the control valve 20, the control valve 20 is controlled to be opened and closed, and an appropriate amount of refrigerant does not flow to the indoor heat exchanger 9. The heat of condensation in the heat exchanger 9 may not be appropriate.

Therefore, as the control valve 20, an electric valve which can control the flow rate of the refrigerant may be used.

[0054]

According to the present invention, in an air conditioner provided with a refrigeration circuit, a hot gas bypass circuit, and a control device, a compressor whose capacity is changed by the operating frequency is used as the compressor of the refrigeration circuit, and the control device is used. Since the operating frequency of the compressor is set to a substantially rated frequency when the difference between the set temperature and the room temperature during the heating operation is within a predetermined range, and the control means for opening the control valve is provided, The machine can be operated at almost the highest efficiency and the heat of the hot gas from the compressor can be stored in the heat storage heat exchanger.

Therefore, electricity can be efficiently used to store heat in the heat storage tank, and useless use of electricity can be suppressed as much as possible.

[Brief description of drawings]

FIG. 1 is a refrigerant circuit diagram of an air conditioner showing an embodiment of the present invention.

FIG. 2 is a diagram showing the relationship between operating frequency and compressor efficiency.

FIG. 3 is a diagram showing the relationship between the outside air temperature and the temperature of the outdoor heat exchanger.

FIG. 4 is a flowchart showing control of the air conditioner of this embodiment.

[Explanation of symbols]

 1 Air Conditioner 2 Refrigeration Circuit 3 Hot Gas Bypass Circuit 4 Control Device 5 Compressor 7 Outdoor Heat Exchanger 8 Pressure Reduction Device 9 Indoor Heat Exchanger 20 Control Valve 22 Heat Storage Heat Exchanger 28 Control Means

Claims (1)

Claim: What is claimed is: 1. A refrigeration circuit configured by annularly connecting a compressor, an indoor heat exchanger, a pressure reducing device, and an outdoor heat exchanger, a control valve, and a heat storage heat exchanger, And a hot gas bypass circuit having one end connected to the discharge side of the compressor and the other end connected between the pressure reducing device and the outdoor heat exchanger, and a control device for controlling the compressor and the control valve. In the air conditioner, a compressor whose capacity is changed according to the operating frequency is used as the compressor, and the controller uses the compressor of the compressor when the difference between the set temperature and the room temperature is within a predetermined value during heating operation. An air conditioner characterized in that an operating frequency is set to a substantially rated frequency and a control means for opening the control valve is provided.