JPH11304222A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provider an air conditioner which enables a curtailing of heat radiation loss and a shortening of defrosting time during the defrosting of an outdoor unit. SOLUTION: In an outdoor heat exchanger 5, separate paths thereof are set the same in the length from the side of a four way valve 3 almost at the intermediate point thereof and linked together to provide a link part 5b. A branching is made between the four-way valve 3 and the outdoor heat exchanger 5 and a second solenoid valve 4b is arranged to connect the link part 5b almost at the intermediate point of the paths of the outdoor heat exchanger 5 with a bypass while a first solenoid valve 4a is arranged to connect the branch of the link part 5b and one end 5a of the outdoor heat exchanger 5 and a temperature sensor 9 is provided near an outlet on the side of a restrictor 6 of the outdoor heat exchanger 5. A control is performed as follows: At the start of dehumidification, the second solenoid valve 4b is operated to be opened while the first solenoid valve 4a is closed and when the detected temperature Tc of the temperature sensor 9 exceeds a set temperature T1, the second solenoid valve 4b is operated to be opened while the first solenoid valve 4a is closed. When the detected temperature Tc of the temperature sensor 9 exceeds a defrosting end temperature T2, the second solenoid 4b and the first solenoid valve 4a are operated to be closed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner and, more particularly, to a configuration and control of a refrigerant circuit of an outdoor unit.

[0002]

2. Description of the Related Art FIG. 3 (a) is a refrigerant circuit diagram of an air conditioner showing an example of the related art, and FIG. 3 (b) is an explanatory view of a main part. FIG.
(A) is a refrigerant circuit diagram of an air conditioner showing another conventional example, and (b) is an explanatory view of a main part. As shown in the figure, a refrigerant circuit of a conventional air conditioner includes a compressor 2 housed in an outdoor unit 1, a four-way valve 3, an outdoor heat exchanger 5, an indoor unit 10
And a indoor heat exchanger 11, which are sequentially connected to form a refrigerant circuit.

In the above configuration, during the cooling operation, the refrigerant flow in the outdoor unit 1 passes through the compressor 2 and the four-way valve 3 to the two-pass outdoor heat exchanger 5 as indicated by a broken line arrow. The refrigerant flows from the outdoor heat exchanger 3 via the expansion device 6 into the indoor heat exchanger 11 of the indoor unit 10. And
The refrigerant returns to the compressor 2 via the four-way valve 3 of the outdoor unit 1. Further, during the heating operation, the refrigerant flow path returns to the compressor 2 via the expansion device 6 along a path opposite to that during the cooling as indicated by a solid arrow.

In order to defrost the outdoor unit 1 during heating, the four-way valve 3 is switched as shown in FIG.
As shown in FIG. 4, a reverse method performed by using a cooling cycle, and a discharge gas from the compressor 2 is supplied to the outdoor heat exchanger 5 via the bypass pipe 7 and the solenoid valve 8 a on the side of the throttle device 6 of the outdoor heat exchanger 5. There is a hot gas bypass system in which one end 5a is injected. However, in any of the above methods,
High-temperature discharge gas is injected from the same point from the start to the end of the defrost regardless of the degree of frost melting. There has been a problem that the discharge gas must be continuously injected into the injection port, and there is a possibility that a loss due to heat radiation increases and a defrosting time becomes longer.

[0005]

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide an air conditioner in which the loss of heat radiation is reduced and the defrosting time is reduced when the outdoor unit is defrosted. I have.

[0006]

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, a throttle device, and an indoor heat exchanger. ,
These are sequentially connected by a refrigerant pipe to form a refrigerant circuit, and in the air conditioner performing defrosting of the outdoor unit by switching the four-way valve, a branch is made between the four-way valve and the outdoor heat exchanger. A second solenoid valve that connects a substantially middle portion of the outdoor heat exchanger by a bypass, and a first solenoid valve that connects the branch and the outdoor heat exchanger are disposed, and the first heat valve of the outdoor heat exchanger is provided. A temperature sensor is provided in the vicinity of the expansion device side outlet, at the start of dehumidification, the second solenoid valve is closed, the first solenoid valve is opened, and when the temperature detected by the temperature sensor exceeds a set temperature, the second (2) Opening the solenoid valve, closing the first solenoid valve, and when the temperature detected by the temperature sensor exceeds the defrost end temperature, controls the second solenoid valve and the first solenoid valve to a closed state. So that

[0007] Alternatively, the compressor comprises a compressor, a four-way valve, an outdoor heat exchanger, an expansion device, and an indoor heat exchanger. These are sequentially connected by refrigerant piping to form a refrigerant circuit. In the air conditioner performing defrosting of the outdoor unit by switching a valve, a second electromagnetic device that branches off from between the four-way valve and the outdoor heat exchanger and connects substantially the middle of the outdoor heat exchanger by a side path. A valve, a first electromagnetic valve connecting the branch and the outdoor heat exchanger is provided, a timer is provided in the outdoor unit, at the start of dehumidification, the second electromagnetic valve is in a closed state, the first electromagnetic valve is provided. When the defrosting elapsed time of the timer exceeds the switching set time, the second solenoid valve is opened, the first solenoid valve is closed, and the timer has been defrosted. When the frost end time is exceeded, the second solenoid valve and the first The set to be controlled in a closed state solenoid valve. And, when the outdoor heat exchanger has a plurality of paths, a substantially middle part of each path of the outdoor heat exchanger is connected to each other with the same length from the four-way valve side. .

Alternatively, the compressor comprises a compressor, a four-way valve, an outdoor heat exchanger, an expansion device, and an indoor heat exchanger, and these are sequentially connected by refrigerant piping to form a refrigerant circuit. In an air conditioner that performs defrosting of the outdoor unit by injecting a discharge gas from the unit through a bypass pipe into the expansion device side of the outdoor heat exchanger,
A second solenoid valve that branches off from between the discharge side of the compressor and the outdoor heat exchanger and connects substantially the middle of the outdoor heat exchanger by a side path; and connects the branch and the outdoor heat exchanger. A first solenoid valve is provided, a temperature sensor is provided near the four-way valve side outlet of the outdoor heat exchanger, at the start of dehumidification, the second solenoid valve is closed, the first solenoid valve is opened, When the detected temperature of the temperature sensor exceeds the set temperature, the second solenoid valve is opened, the first solenoid valve is closed, and when the detected temperature of the temperature sensor exceeds the defrost end temperature, The second solenoid valve and the first solenoid valve are controlled to be closed.

Alternatively, the compressor comprises a compressor, a four-way valve, an outdoor heat exchanger, an expansion device, and an indoor heat exchanger, and these are sequentially connected by refrigerant pipes to form a refrigerant circuit. In an air conditioner that performs defrosting of the outdoor unit by injecting a discharge gas from the unit through a bypass pipe into the expansion device side of the outdoor heat exchanger,
A second solenoid valve that branches off from between the discharge side of the compressor and the outdoor heat exchanger and connects substantially the middle of the outdoor heat exchanger by a side path; and connects the branch and the outdoor heat exchanger. A first solenoid valve is provided, a timer is provided in the outdoor unit, at the start of dehumidification, the second solenoid valve is closed, the first solenoid valve is opened, and the defrosting elapsed time of the timer is set by switching. When the time exceeds, the second solenoid valve is opened, the first solenoid valve is closed, and the defrosting elapsed time of the timer exceeds the defrost end time, the second solenoid valve and The first solenoid valve is controlled to be closed. When the outdoor heat exchanger has a plurality of paths, a substantially middle portion of each path of the outdoor heat exchanger is connected to each other with the same length from the throttle device side. .

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail based on embodiments with reference to the accompanying drawings. FIG.
(A) is a refrigerant circuit diagram of an air conditioner showing one embodiment of the present invention, (b) is an explanatory view of a main part, and (c) is a flowchart. 1 is a refrigerant circuit diagram of an air conditioner showing one embodiment of the present invention. The same numbers are used for the same components. In the figure, 1 is an outdoor unit, 2 is a compressor, 3 is a four-way valve, 4a is a first solenoid valve, 4b is a second solenoid valve,
5 is an outdoor heat exchanger, 6 is a throttle device, 10 is an indoor unit, 11
Is an indoor heat exchanger.

In this embodiment, an expansion valve is used for the outdoor heat exchanger 5 having two passes and the expansion device 6.
These are sequentially connected by a refrigerant pipe to form a refrigerant circuit. At the same time, an air conditioner that defrosts the outdoor unit 1 by switching the four-way valve 3 is configured.
Here, approximately the middle of each path of the outdoor heat exchanger 5 is:
The same length from the four-way valve 3 side is connected to each other,
A connecting portion 5b is provided. A second solenoid valve 4b that branches off from between the four-way valve 3 and the outdoor heat exchanger 5 and connects a substantially middle connecting portion 5b of the outdoor heat exchanger 5 by a bypass.
And a first solenoid valve 4a for connecting the branch to one end 5a of the outdoor heat exchanger 5.

On the other hand, a temperature sensor 9 is provided near the outlet of the outdoor heat exchanger 5 on the throttle device 6 side. Further, an input unit 12 for the output of the sensor 9, a control unit 13 for controlling the solenoid valve 4 b and the solenoid valve 4 a based on a signal from the input unit 12, and a storage unit 14 for storing a set temperature and a set time for control Is provided in the outdoor unit 1. At the start of dehumidification, the input unit 12, the control unit 13, and the storage unit 14 are used to close the second solenoid valve 4b, open the first solenoid valve 4a, and detect the detected temperature Tc of the temperature sensor 9. When the temperature exceeds the set temperature T1, the second solenoid valve 4b is opened and the first solenoid valve 4a is closed, and when the temperature Tc detected by the temperature sensor 9 exceeds the defrost end temperature T2, The second solenoid valve 4b;
The first solenoid valve 4a is controlled to be closed. In this embodiment, only one connecting portion 5b is provided. However, a plurality of connecting portions 5b may be provided, and the set temperature may be set to a plurality of values corresponding thereto.

Next, the operation of the present invention having the above configuration will be described. First, when the defrosting starts, the first solenoid valve 4
a is in an open state, and the second solenoid valve 4b is in an open state.
(ST1) Then, since high-temperature discharge gas is injected into the entirety of the outdoor heat exchanger 5, defrosting is performed entirely, but defrosting in the vicinity of the first solenoid valve 4a is mainly performed. Next, the detected temperature Tc of the temperature sensor 9 disposed in the pipe of the outdoor heat exchanger 5
It is determined whether the temperature exceeds the set temperature T1. If not, the determination is No at Tc <T1, and this determination is repeated.
T2) While the first solenoid valve 4a is closed, the second solenoid valve 4b is opened. (ST3)

At this time, defrosting in the vicinity of the first solenoid valve 4a is completed, and defrosting is performed on the portion of the outdoor heat exchanger 5 from the second solenoid valve 4b. Further, it is determined whether or not the detected temperature Tc of the temperature sensor 9 exceeds the defrost end temperature T2. If not, Tc <T2 and No, and this determination is repeated.
> T2, Yes (ST4), the second solenoid valve 4b
Is closed to complete defrosting. (ST5)

FIG. 2A is a refrigerant circuit diagram of an air conditioner showing another embodiment of the present invention, FIG. 2B is an explanatory view of a main part, and FIG.
Is a flowchart. In the case of this embodiment, the outdoor unit 1
, A four-way valve 3, an outdoor heat exchanger 5 having a plurality of paths, a throttling device 6b, and an indoor unit 10 having an indoor heat exchanger 11. These are connected by refrigerant piping. A refrigerant circuit is formed by sequentially connecting pipes.

At the same time, the discharge gas from the compressor 2 is injected into one end 5a of the outdoor heat exchanger 5 on the side of the expansion device 6 through a bypass pipe 7, thereby defrosting the outdoor unit 1. Do. Here, when the outdoor heat exchanger 5 has a plurality of paths, substantially the middle of each path of the outdoor heat exchanger 5 is connected to each other with the same length from the throttle device 6 side, A connecting portion 5b is provided. And it branches off from between the discharge side of the compressor 2 and the outdoor heat exchanger 5,
A second electromagnetic valve 8b for connecting the connecting portion 5b substantially at the middle of the outdoor heat exchanger 5 by a bypass, and a first electromagnetic valve 8a for connecting the branch to one end 5a of the outdoor exchanger 5 are provided. doing.

At the same time, the outdoor unit 1 has a timer 1
5 is provided. Further, a control unit 13 for controlling the solenoid valve 4b and the solenoid valve 4a, and a storage unit 14 for storing a set temperature and a set time for control are provided in the outdoor unit 1. At the start of dehumidification, the input unit 12, the control unit 13, the storage unit 14
The second solenoid valve 8b is closed using the first solenoid valve 8
a to the open state, and the defrosting elapsed time t of the timer 15
When the switching set time t1 is exceeded, the second solenoid valve 8b is opened and the first solenoid valve 8a is closed, and the defrosting elapsed time t of the timer 15 exceeds the defrost end time t2. Then, the second solenoid valve 8a and the first solenoid valve 8b are controlled to be closed. Next, the operation of the present invention in the above configuration will be described. First, when defrosting starts, the first solenoid valve 4a is opened and the second solenoid valve 4b is opened. (ST1) Then, since the high-temperature discharge gas is injected into the entirety of the outdoor heat exchanger 5, defrosting is performed entirely.
Defrosting in the vicinity of a is mainly performed. Next, it is determined whether or not the elapsed time t from the start of the defrosting does not exceed the switching set time t1, and if not, t <t1 is No, and this determination is repeated. If the switching setting time t1 is exceeded, t> Y at t1
es (ST2), the first solenoid valve 4a is closed, while the second solenoid valve 4b is open.
(ST3)

At this time, defrosting in the vicinity of the first solenoid valve 4a is completed, and defrosting is performed on the portion of the outdoor heat exchanger 5 from the second solenoid valve 4b. Further, it is determined whether or not the elapsed time t exceeds the defrost end time t2. If not, No is determined at t <t2, and this determination is repeated. If the elapsed time t exceeds the defrost end time t2, Yes is determined at t> t2. (ST4), the first solenoid valve 4b is closed, and defrosting is completed. (ST5) Although not shown in the drawing because it is the same, the temperature Tc of the temperature sensor 9 shown in the above-mentioned one embodiment is different from that of the above-mentioned other embodiment.
The opening / closing control of the first solenoid valve 8a and the second solenoid valve 8b may be performed by the following. Also, although not shown in the figure because it is the same,
In this embodiment, the opening and closing control of the first solenoid valve 8a and the second solenoid valve 8b may be performed based on the elapsed time t of the timer 15 shown in the other embodiment.

[0019]

As described above, according to the present invention, the compressor, the four-way valve, the outdoor heat exchanger, the expansion device, and the indoor heat exchanger are sequentially connected by refrigerant piping. In the air conditioner that performs defrosting of the outdoor unit by switching the four-way valve, a branch is made from between the four-way valve and the outdoor heat exchanger, and an abbreviation of the outdoor heat exchanger. A second solenoid valve connecting the middle by a side path, and a first solenoid valve connecting the branch and the outdoor exchanger are provided, and a temperature sensor is provided near an outlet of the outdoor heat exchanger on the throttle device side. At the start of dehumidification, the second solenoid valve is closed, the first solenoid valve is opened, and when the temperature detected by the temperature sensor exceeds a set temperature, the second solenoid valve is opened, and the first solenoid valve is opened. The valve is closed, and the temperature detected by the temperature sensor is the defrost end temperature. When it exceeds, the second solenoid valve and was the first solenoid valve to be controlled in a closed state.

As a result, it is possible to provide an outdoor unit of an air conditioner in which heat loss is reduced and defrosting time is reduced.

[Brief description of the drawings]

FIG. 1A is a refrigerant circuit diagram of an air conditioner showing one embodiment of the present invention, FIG. 1B is an explanatory diagram of a main part, and FIG. 1C is a flowchart.

FIG. 2A is a refrigerant circuit diagram of an air conditioner showing another embodiment of the present invention, FIG. 2B is an explanatory diagram of a main part, and FIG. 2C is a flowchart.

FIG. 3A is a refrigerant circuit diagram of an air conditioner showing an example of the related art, and FIG. 3B is an explanatory diagram of a main part.

FIG. 4A is a refrigerant circuit diagram of an air conditioner showing another example of the related art, and FIG. 4B is an explanatory diagram of a main part.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outdoor unit 2 Compressor 3 Four-way valve 4a First solenoid valve 4b Second solenoid valve 5 Outdoor heat exchanger 5a One end of outdoor heat exchanger 5b Connection part 6 Throttling device 7 Bypass pipe 8a First solenoid valve 8b Second solenoid valve 9 temperature sensor 10 indoor unit 11 indoor heat exchanger 12 input unit 13 control unit 14 storage unit 15 timer

Claims (6)

[Claims] 1. A compressor, a four-way valve, an outdoor heat exchanger,
An air conditioner comprising a throttle device and an indoor heat exchanger, which are sequentially connected by a refrigerant pipe to form a refrigerant circuit, and which switches the four-way valve to defrost the outdoor unit. A second solenoid valve that branches off from between the four-way valve and the outdoor heat exchanger and connects a substantially intermediate portion of the outdoor heat exchanger by a bypass.
A first solenoid valve for connecting the branch and the outdoor heat exchanger is provided, and a temperature sensor is provided near an outlet of the outdoor heat exchanger on the expansion device side, and when the dehumidification starts, the second solenoid valve is closed. State, open the first solenoid valve, when the temperature detected by the temperature sensor exceeds a set temperature,
The second solenoid valve is opened, the first solenoid valve is closed, and when the temperature detected by the temperature sensor exceeds the defrost end temperature, the second solenoid valve and the first solenoid valve are closed. An air conditioner characterized by being controlled. 2. A compressor, a four-way valve, an outdoor heat exchanger,
An air conditioner comprising a throttle device and an indoor heat exchanger, which are sequentially connected by a refrigerant pipe to form a refrigerant circuit, and which switches the four-way valve to defrost the outdoor unit. A second solenoid valve that branches off from between the four-way valve and the outdoor heat exchanger and connects a substantially intermediate portion of the outdoor heat exchanger by a bypass.
Disposing a first solenoid valve connecting the branch and the outdoor heat exchanger, providing a timer in the outdoor unit, at the start of dehumidification, closing the second solenoid valve, opening the first solenoid valve. When the defrosting elapsed time of the timer exceeds the switching set time, the second solenoid valve is opened, the first solenoid valve is closed, and the defrosting elapsed time of the timer is a defrost end time. An air conditioner characterized by controlling the second solenoid valve and the first solenoid valve to be in a closed state when the pressure exceeds the limit. 3. When the outdoor heat exchanger has a plurality of paths, substantially the middle of each path of the outdoor heat exchanger is connected to each other with the same length from the four-way valve side. The air conditioner according to claim 1 or 2, wherein: 4. A compressor, a four-way valve, an outdoor heat exchanger,
A throttle device and an indoor heat exchanger, which are sequentially connected by a refrigerant pipe to form a refrigerant circuit, and discharge gas from the compressor is passed through a bypass pipe.
In the air conditioner which performs defrosting of the outdoor unit by injecting the outdoor heat exchanger into the expansion device side, the air conditioner branches from the discharge side of the compressor and the outdoor heat exchanger, and the outdoor heat exchanger A second solenoid valve that connects a substantially middle of the vessel by a side path, and a first solenoid valve that connects the branch and the outdoor heat exchanger are disposed, and near the four-way valve-side outlet of the outdoor heat exchanger. A temperature sensor is provided, at the start of dehumidification, the second solenoid valve is closed, the first solenoid valve is opened, and when the temperature detected by the temperature sensor exceeds a set temperature,
The second solenoid valve is opened, the first solenoid valve is closed, and when the temperature detected by the temperature sensor exceeds the defrost end temperature, the second solenoid valve and the first solenoid valve are closed. An air conditioner characterized by being controlled. 5. A compressor, a four-way valve, an outdoor heat exchanger,
A throttle device and an indoor heat exchanger, which are sequentially connected by a refrigerant pipe to form a refrigerant circuit, and discharge gas from the compressor is passed through a bypass pipe.
In the air conditioner which performs defrosting of the outdoor unit by injecting the outdoor heat exchanger into the expansion device side, the air conditioner branches from the discharge side of the compressor and the outdoor heat exchanger, and the outdoor heat exchanger A second solenoid valve that connects a substantially middle of the vessel by a side path, and a first solenoid valve that connects the branch and the outdoor heat exchanger are provided, and a timer is provided in the outdoor unit, and at the start of dehumidification, The second solenoid valve is closed, the first solenoid valve is opened, and when the defrosting elapsed time of the timer exceeds the switching set time, the second solenoid valve is opened, and the first solenoid valve is closed. An air conditioner wherein the second solenoid valve and the first solenoid valve are controlled to be in a closed state when a defrosting elapsed time of the timer exceeds a defrost end time. 6. When the outdoor heat exchanger has a plurality of paths, substantially the middle of each path of the outdoor heat exchanger is connected to each other with the same length from the throttle device side. The air conditioner according to claim 4 or 5, wherein: