JP2002107000A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner, permitting the capacity control operation and a re-heating and dehumidifying operation of an indoor heat exchanger upon the dehumidifying operation in accordance with a temperature difference between a set temperature and a room temperature. SOLUTION: In the air conditioner constituted of a refrigerating cycle wherein a compressor 1, a four-way valve 2, an outdoor heat exchanger 5, an expansion valve 4 and an indoor heat exchanger through a refrigerant pipeline, the indoor heat exchanger is constituted of the series connection of a first indoor heat exchanger 3a and a second indoor heat exchanger 3b through an opening degree regulating valve 6 and a bypass passage 8 is provided between the first indoor heat exchanger 3a and the opening degree regulating valve 6 and between the second indoor heat exchanger 3b and the expansion valve 4 to permit the re-heating and dehumidifying operation by a method wherein the opening degree regulating valve 6 is opened and the opening and closing valve 7 is closed upon normal heating and cooling operation while the opening and closing of the opening and closing valve 7 as well as the opening degree of the opening degree regulating valve 6 and the expansion valve 4 are controlled in accordance with a temperature difference between a set temperature and the room temperature upon the dehumidifying operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner capable of performing a capacity control operation and a reheat dehumidification operation of an indoor heat exchanger according to a temperature difference between a set temperature and a room temperature during a dehumidification operation.

[0002]

2. Description of the Related Art A conventional air conditioner of this kind, for example, FIG.
, A compressor 21, a four-way valve 22, and two passes 23a, 23
An indoor heat exchanger 23 having a b structure, an expansion valve 24, and an outdoor heat exchanger 25 are sequentially connected to form a refrigeration cycle, and one of the indoor heat exchangers 23 at the time of cooling operation on one side 23b side. An on-off valve 26 is provided on the inlet side. In the cooling operation, the on-off valve 26 is opened, and the refrigerant circulates in the direction of the solid arrow. Compressor
The high-temperature and high-pressure gaseous refrigerant discharged from 21 is a four-way valve 22
Flows through the outdoor heat exchanger 25, and releases heat to the outside by heat exchange.
While passing through the indoor heat exchanger 23, it exchanges heat with the indoor air, cools the indoor air, absorbs heat and evaporates, becomes a low-temperature low-pressure gas, and returns to the compressor 1 via the four-way valve 2.

In the dehumidifying operation, the on-off valve 26 is closed,
It circulates in the direction of the dashed solid arrow. The flow of the refrigerant is the same as that in the above cooling operation, but the indoor heat exchanger 23 is of a capacity control system in which the heat exchange capacity of the refrigerant flowing through only one path 23a is halved. This makes it possible to increase the dehumidifying capacity even though the blowing temperature is higher than that of the normal cooling. However, in the case of the capacity control method as described above, when the set temperature is high, the room temperature is lowered by the dehumidifying operation, the temperature immediately reaches the set temperature, the compressor stops, and the humidity cannot be reduced sufficiently. Occurs.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has a capacity control operation and a reheat dehumidification operation for an indoor heat exchanger during a dehumidification operation according to a temperature difference between a set temperature and a room temperature. The purpose of the present invention is to provide an air conditioner that enables the above.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and comprises a compressor, a four-way valve, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger. In an air conditioner connected by piping to form a refrigeration cycle, the indoor heat exchanger is configured by connecting a first indoor heat exchanger and a second indoor heat exchanger in series via an opening adjustment valve. A bypass path is provided between the first indoor heat exchanger and the opening degree adjustment valve and between the second indoor heat exchanger and the expansion valve via an on-off valve, so that normal heating is performed. During the cooling operation, the opening control valve is opened and the opening / closing valve is closed.During the dehumidifying operation, the opening / closing valve is opened / closed according to a temperature difference between a set temperature and room temperature, and the opening control valve and the expansion valve are operated. , And the reheat dehumidification operation is enabled.

If the temperature difference between the set temperature and the room temperature is equal to or larger than the predetermined temperature difference during the dehumidifying operation, the on-off valve is closed, the opening adjustment valve is fully opened, and the expansion valve is opened by opening the normal throttle. It is configured to control each time.

When the temperature difference between the set temperature and the room temperature is between 0 and a predetermined temperature difference during the dehumidifying operation, the on-off valve is opened, the opening adjustment valve is closed, and the expansion valve is operated normally. It is configured to control the opening degree of the throttle.

In the dehumidifying operation, when the temperature difference between the set temperature and the room temperature is 0 or less, the on-off valve is closed, the opening adjustment valve is reduced to a predetermined opening, and the expansion valve is controlled to be fully opened. It has become.

Further, an electronic expansion valve is used as the opening adjustment valve, and a solenoid valve is used as the opening / closing valve.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described based on embodiments with reference to the drawings. FIG. 1 is a view showing one embodiment of a refrigeration cycle of an air conditioner according to the present invention. In the figure, 1 is a compressor, 2 is a four-way valve for switching the flow of refrigerant discharged from the compressor 1 in accordance with a heating operation, a cooling operation or a dehumidifying operation, 3a is a first indoor heat exchanger, and 3b is a second indoor heat exchanger. An exchanger 4 is an expansion valve, 5 is an outdoor heat exchanger, and 6 is an opening adjustment valve, which is connected in a ring shape by a refrigerant pipe to constitute a refrigeration cycle. The first indoor heat exchanger 3a and the opening adjustment valve 6
, And a bypass 8 between the second indoor heat exchanger 3b and the expansion valve 4 via an on-off valve 7.

In the above configuration, during normal cooling, the on-off valve 7 is closed, the opening adjustment valve 6 is fully opened, and the refrigerant circulates in the direction of the solid arrow. That is, the high-temperature high-pressure gaseous refrigerant discharged from the compressor 1 flows through the outdoor heat exchanger 5 through the four-way valve 2, releases heat to the outside by heat exchange, is condensed and liquefied, and decompressed by the expansion valve 4. It becomes a low-temperature, low-pressure liquid,
2nd indoor heat exchanger 3b, opening adjustment valve 6, 1st indoor heat exchanger
3a, heat exchange with indoor air while passing through the first and second indoor heat exchangers 3a, 3b, cools the indoor air, absorbs heat and evaporates, turns into low-temperature low-pressure gas, It returns to the compressor 1 via the valve 2. During the heating operation, the direction of circulation of the refrigerant is reversed,
The operation is the same as in the cooling operation except that the operation of the outdoor heat exchanger 5, the first indoor heat exchanger 3a, and the operation of the second indoor heat exchanger 3b are opposite to those in the cooling operation.

During the dehumidifying operation, the opening and closing of the on-off valve 7 and the opening of the opening adjustment valve 6 and the expansion valve 4 are controlled in accordance with the temperature difference between a preset room temperature and room temperature. The reheat dehumidifying operation is enabled. Temperature difference between set temperature (for example, 25 ° C) and room temperature (for example, 31 ° C)
When T0 (6 ° C.) is equal to or greater than the predetermined temperature difference T1 (for example, 5 ° C.), the on-off valve 7 is closed, and the opening adjustment valve 6 is fully opened,
The expansion valve 4 is controlled to a normal throttle opening. That is, the same operation as the normal cooling operation is performed.

A temperature difference T0 (1 ° C.) between a set temperature (eg, 25 ° C.) and a room temperature (eg, 26 ° C.) is 0 and a predetermined temperature difference T1.
When the temperature is between (for example, 5 ° C.), the open / close valve 7 is opened, the opening adjustment valve 6 is closed, and the expansion valve 4 is controlled to the normal throttle opening, as indicated by the dashed arrow. That is,
It is configured to perform capacity control for operating only the first indoor heat exchanger 3a.

When the temperature difference T0 (−3 ° C.) between the set temperature (eg, 25 ° C.) and the room temperature (eg, 22 ° C.) is 0 or less, the on-off valve 7 is closed as indicated by a double arrow, The opening adjustment valve 6 is throttled to a predetermined opening, and the expansion valve 4 is controlled to fully open. That is, the second indoor heat exchanger 3b is operated as a reheater using a condenser to heat the room, and the first indoor heat exchanger 3a is heated.
Is operated as an evaporator to perform a dehumidifying operation in a heating mode.

As described above, the indoor heat exchanger is connected to the opening adjustment valve 6.
, The first indoor heat exchanger 3a and the second indoor heat exchanger 3b are connected in series, and the second indoor heat exchange between the first indoor heat exchanger 3a and the opening adjustment valve 6 is performed. Between the vessel 3b and the expansion valve 4,
A bypass passage 8 is provided via an on-off valve 7. During normal heating and cooling operations, the opening degree adjustment valve 6 is opened, and the on-off valve 7 is closed. By controlling the opening and closing of the on-off valve 7 and the opening of the opening adjustment valve 6 and the expansion valve 4 to enable the reheat dehumidifying operation, the temperature between the set temperature and the room temperature during the dehumidifying operation is controlled. According to the difference, the air conditioner enables the indoor heat exchangers 3a and 3b to perform full-pass cooling operation, capacity control operation, and reheat dehumidification operation.

[0016]

As described above, the indoor heat exchanger is constructed by connecting the first indoor heat exchanger and the second indoor heat exchanger in series via the opening adjustment valve, and the first indoor heat exchanger is connected to the first indoor heat exchanger. A bypass path is provided between the exchanger and the opening adjustment valve and between the second indoor heat exchanger and the expansion valve via an on-off valve. During normal heating and cooling operations, the opening adjustment valve is provided. , Close the on-off valve,
During the dehumidifying operation, the opening and closing of the on-off valve and the opening of the opening adjustment valve and the expansion valve are controlled in accordance with the temperature difference between the set temperature and the room temperature. According to the temperature difference of the air conditioner, the indoor heat exchanger is capable of performing the full-pass cooling operation, the capacity control operation, and the reheat dehumidification operation.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of a refrigeration cycle of an air conditioner according to the present invention.

FIG. 2 is a diagram illustrating the operation of each valve and the indoor heat exchanger according to the present invention.

FIG. 3 is a diagram showing an example of a refrigeration cycle of a conventional air conditioner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3a 1st indoor heat exchanger 3b 2nd indoor heat exchanger 4 Expansion valve 5 Outdoor heat exchanger 6 Opening control valve 7 On-off valve 8 Bypass path

Claims (6)

[Claims] 1. A compressor, a four-way valve, an outdoor heat exchanger,
In an air conditioner configured by connecting an expansion valve and an indoor heat exchanger with a refrigerant pipe to form a refrigeration cycle, the indoor heat exchanger is connected to a first indoor heat exchanger and a second indoor heat exchanger through an opening adjustment valve. A heat exchanger is connected in series, and between the first indoor heat exchanger and the opening adjustment valve, and between the second indoor heat exchanger and the expansion valve via an on-off valve. In normal heating and cooling operations, the opening degree adjustment valve is opened and the on-off valve is closed, and in dehumidifying operation, the on-off valve is opened and closed according to a temperature difference between a set temperature and room temperature. And an opening degree of the opening degree adjustment valve and the expansion valve, thereby enabling a reheat dehumidification operation. 2. During the dehumidifying operation, if the temperature difference between the set temperature and the room temperature is equal to or greater than a predetermined temperature difference, the on-off valve is closed, the opening degree adjustment valve is fully opened, and the expansion valve is opened normally. 2. The air conditioner according to claim 1, wherein the air conditioner is controlled every time. 3. During the dehumidifying operation, when the temperature difference between the set temperature and room temperature is between 0 and a predetermined temperature difference, the on-off valve is opened, the opening degree adjustment valve is closed, and the expansion valve is moved to a normal state. The air conditioner according to claim 1, wherein the degree of opening of the throttle is controlled. 4. During the dehumidifying operation, if the temperature difference between the set temperature and room temperature is 0 or less, the on-off valve is closed, the opening adjustment valve is throttled to a predetermined opening, and the expansion valve is controlled to fully open. The air conditioner according to claim 1, wherein: 5. The air conditioner according to claim 1, wherein an electronic expansion valve is used as the opening adjustment valve. 6. The air conditioner according to claim 1, wherein an electromagnetic valve is used as the on-off valve.