JP2889762B2 - Air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called remote condenser type air conditioner in which an indoor unit is provided with a compressor, an evaporator, an accumulator and a pressure reducing mechanism, and an outdoor unit is provided only with a condenser. The present invention relates to an air conditioner having a heat exchanger for heating for raising the room temperature when the temperature is low in an indoor unit.

[0002]

2. Description of the Related Art An air conditioner of this type is used for air conditioning of a room in which, for example, an electronic computer or a communication device is installed. Electronic computers and communication devices generate heat during operation, and the air conditioner performs a cooling operation to cool them. However, if the room temperature is still low after the start of the computer or the communication device in winter or the like, the cooling operation of the air conditioner causes cold air having a temperature lower than the temperature suitable for the operation of the computer or the communication device to be air-conditioned. When sent to the air-conditioning target, the air-conditioning target adversely affects the air-conditioning target. To prevent this, when the room temperature falls below a predetermined temperature, the air-conditioning apparatus is turned on by a heating heat exchanger (a type of condensation). Heating operation to raise the temperature of the air blown from the air conditioner.

Generally, a four-way valve is used as a refrigerant flow switching valve for switching between the cooling operation and the heating operation, and the switching operation of the four-way valve uses a differential pressure between a high-pressure refrigerant and a low-pressure refrigerant. Is common.

Conventionally, this type of air conditioner is disclosed in
As described in Japanese Patent No. 29269, the refrigerant outlet high pressure pipe of the heating heat exchanger is connected to the suction side connection port of the four-way valve for switching the heating operation, and the refrigerant is supplied to the outdoor unit even during the heating operation by switching the valve. It is supposed to be sent.

[0005]

In the above prior art, since the suction side connection port of the four-way valve also becomes high in pressure, the differential pressure for returning the four-way valve to the cooling operation state when the compressor is stopped or the like. However, there was a problem that the four-way valve was stopped at an intermediate position.

An object of the present invention is to provide an air conditioner of this type which can obtain a stable refrigerant cycle without the switching valve being stopped at an intermediate position in both the cooling operation and the heating operation in consideration of the above problems. To be.

[0007]

In order to achieve the above object, an air conditioner according to the present invention is characterized by what is described in each claim.

[0008]

In the air conditioner of the present invention, the state of the refrigerant flow switching valve is ensured in both the cooling operation and the heating operation, and a stable refrigeration cycle can be formed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, first, second and third embodiments of the present invention will be described with reference to FIGS. 1, 2 and 3, respectively.

First Embodiment As shown in FIG. 1, an air conditioner according to the present embodiment is of a remote condenser type, and an indoor unit A includes a compressor 1, an expansion valve (decompression device) 5, an evaporator 6, and a heating unit. It is composed of the main components of a heat exchanger 7, an accumulator 8, blocking valves 3 and 4, and a four-way valve 2, solenoid valves 9 and 10 for controlling a refrigerant flow direction.
Non-return valves 11, 12 and 13 are provided, while outdoor unit B comprises the main components of condenser 14, blocking valves 15 and 16, each connected by piping as shown. The compressor discharge side connection part 17 of the four-way valve 2 is connected to a discharge pipe of the compressor 1, the condenser side connection part 20 is connected to a pipe for sending refrigerant to an outdoor unit,
The evaporator side connection 19 is connected to a pipe for sending the refrigerant to the heating heat exchanger 7, and the compressor suction side connection 18 is connected to a low pressure pipe between the evaporator 6 and the compressor 1.

During the cooling operation, the four-way valve 2 is in the switching state shown by the solid line, the solenoid valves 9 and 10 are both closed, and the refrigerant discharged from the compressor 1 is supplied to the four-way valve 2 and the check valve 11 The condenser 14 of the outdoor unit passes through the stop valve 3 and the stop valve 15.
To be condensed, and the check valve 16, the check valve 4, the check valve 1
3. A refrigeration cycle is constituted by entering the evaporator 6 through the expansion valve 5 and evaporating and returning to the compressor 1 through the accumulator 8.

On the other hand, during the heating operation, the four-way valve 2 is switched as shown by a broken line, and the refrigerant discharged from the compressor 1 is switched in the flow direction by the four-way valve 2 and is transferred to the heating heat exchanger 7. The condensed refrigerant is sent and condensed, and the condensed refrigerant is sent to the outdoor unit via the solenoid valve 10 and the check valve 12, or is sent to the outdoor unit via the solenoid valve 10 and the check valve 12 and the electromagnetic valve. It is controlled so as to be diverted to the one sent to the upstream side of the expansion valve 5 through 9 or to be sent to the upstream of the expansion valve 5 through the solenoid valve 9.

The flow of the refrigerant during the heating operation will be described in more detail. The refrigerant condensed in the heating heat exchanger 7 from the compressor 1 via the four-way valve 2 is an electromagnetic valve in the initial stage when the operation is switched to the heating operation. 9 and the solenoid valve 10 are opened, the compressor 1 is passed through the check valve 12, the outdoor heat exchanger 14, the check valve 13, the expansion valve 5, the evaporator 6, and the accumulator 8.
The refrigerant condensed in the heating heat exchanger 7 at a stage after a lapse of a short time has passed through the solenoid valves 9 and 10
Are opened, a part passes through the solenoid valve 10, the check valve 12, the outdoor heat exchanger 14, and the check valve 13, the other part passes through the solenoid valve 9, and both of them extend through the expansion valve 5. Expansion valve 5, evaporator 6 and accumulator 8 after merging upstream of
The refrigerant condensed in the heating heat exchanger 7 flows through the path returning to the compressor 1 through the passage and passing through the above-mentioned transient steps, and completes the transition to the heating operation. When the solenoid valve 9 is closed and the solenoid valve 9 is opened, all the gas flows through the path returning to the compressor 1 through the solenoid valve 9, the expansion valve 5, the evaporator 6, and the accumulator 8.

The liquid refrigerant accumulated in the heating heat exchanger 7 during the heating operation is then transferred to the cooling refrigeration cycle via the evaporator-side connection 19 and the suction-side connection 18 of the four-way valve 2 when switching to the cooling operation. It is to be collected.

By configuring the refrigeration cycle as described above, the four-way valve 2 is configured such that the compressor suction-side connection portion 18 is always at a low pressure and the compressor discharge-side connection portion 17 is always at a high pressure. When the four-way valve 2 is switched using the differential pressure, the differential pressure required for switching the four-way valve 2 is sufficiently ensured.

Second Embodiment As shown in FIG. 2, this embodiment is a remote condenser type air conditioner similar to the first embodiment.
It is composed of the main components of a compressor 1, an expansion valve 5, an evaporator 6, a heating heat exchanger 7, an accumulator 8, blocking valves 3 and 4, and a three-way valve 21, an electromagnetic valve 9,
10, 22 and check valves 11, 12, 13 are provided. On the other hand, the outdoor unit B is composed of main components of a condenser 14, blocking valves 15 and 16, and is connected by piping. The three connection portions of the three-way valve 21 are connected to the discharge pipe of the compressor 1, the pipe for sending the refrigerant to the outdoor unit, and the pipe for sending the refrigerant to the heat exchanger 7 for heating, respectively, as shown in the figure. A refrigerant recovery pipe is connected from an inlet pipe of the heating heat exchanger to a low-pressure pipe between the evaporator 6 and the accumulator 8 via an electromagnetic valve 22.

During the cooling operation, the three-way valve 21 is in the switching state indicated by the solid line, the solenoid valves 9 and 10 are closed, and the solenoid valve 22
Is opened, and the refrigerant discharged from the compressor 1 is supplied to the three-way valve 2
1, sent to the condenser 14 of the outdoor unit via the check valve 11, the check valves 3 and 15, and the check valves 16 and 4, the check valve 13,
A refrigerating cycle is formed through the expansion valve 5, the evaporator 6, and the return to the compressor 1 via the accumulator 8.

On the other hand, during the heating operation, the three-way valve 21
Are switched as indicated by the broken line, the solenoid valve 22 is closed, and the refrigerant discharged from the compressor 1 is switched in the flow direction by the three-way valve 21 and sent to the heat exchanger 7 for heating to condense. The condensed refrigerant is sent to the outdoor unit via the solenoid valve 10 and the check valve 12, or the refrigerant is supplied to the outdoor unit via the solenoid valve 10 and the check valve 12.
Through the solenoid valve 9 and the expansion valve 5 through the solenoid valve 9.
It is controlled so as to be diverted to the one sent to the upstream of the expansion valve 5 or sent to the upstream of the expansion valve 5 via the solenoid valve 9, the details of which are the same as those described in the first embodiment. .

The liquid refrigerant accumulated in the heating heat exchanger 7 during the heating operation is then returned to the low-pressure pipe between the evaporator 6 and the accumulator 8 by opening the solenoid valve 22 when switching to the cooling operation. And is collected in a cooling refrigeration cycle.

In the present embodiment, the switching operation of the three-way valve 21 is performed not by using the differential pressure of the refrigerant but by electromagnetic force. Therefore, the three-way valve 21 can be reliably switched irrespective of the problem that the differential pressure for switching disappears as in the prior art described above.

Third Embodiment As shown in FIG. 3, this embodiment is a remote condenser type air conditioner like the first embodiment. Indoor unit A
It is composed of the main components of a compressor 1, expansion valves 5 and 23, an evaporator 6, a heating heat exchanger 7, an accumulator 8, blocking valves 3 and 4, and a four-way valve 2, an electromagnetic valve 9, 10, 24 and 25, check valves 11, 12 and 13 are provided, and the outdoor unit B includes a condenser 14, a check valve 15
And 16 main components, and each is connected by piping as shown.

During the cooling operation, the four-way valve 2 is in the switching state shown by the solid line, and the solenoid valves 9, 10, 24 and 25 are all closed, and the refrigerant discharged from the compressor 1 receives the four-way valve 2. It is sent to the condenser 14 of the outdoor unit through the check valve 11, the check valve 3, and the check valve 15, and enters the evaporator 6 through the check valve 16, the check valve 4, the check valve 13, and the expansion valve 5, and A refrigeration cycle that returns to the compressor 1 via the accumulator 8 is configured.

On the other hand, during the heating operation, the four-way valve 2 is switched as shown by a broken line, and the refrigerant discharged from the compressor 1 is switched in the flow direction by the four-way valve 2 and the heat exchanger 7 is heated. Then, the flow of the refrigerant condensed and condensed in the heating heat exchanger 7 is completely transferred to the heating operation through the same transitional stage after the switching of the heating operation as described in the first embodiment ( However, until then, the solenoid valves 24 and 25 are closed.) However, in the third embodiment, after completely shifting to the heating operation, the solenoid valves 24 and 25 are opened and the compression is performed. The refrigerant condensed in the heat exchanger 7 for heating through the four-way valve 2 from the machine 1 is sent to the upstream of the expansion valve 5 through the solenoid valve 9, where it is diverted, and partly expanded. And returns to the compressor 1 via the accumulator 8, and the other part is
The heat is sent to the heat exchanger 14 of the outdoor unit via the expansion valve 23, the solenoid valve 24, the blocking valve 4 and the blocking valve 16 to evaporate (at this time, the outdoor heat exchanger 14 acts as an evaporator), and the blocking valve 15 , The blocking valve 3, the solenoid valve 25, the outdoor heat exchanger side connection 20 of the four-way valve 2, and the compressor suction side connection 18 through the low-pressure pipe between the evaporator 6 and the accumulator 8.
Return to Here, by adjusting the degree of opening of the expansion valve 5 and the expansion valve 23, the evaporating capacity of the evaporator 6 is controlled, and the balance with the condensing capacity of the heating heat exchanger 7 is changed. Thus, a heating operation cycle capable of changing the indoor heating capacity can be obtained.

[0024]

According to the present invention, the switching valve does not stop at the intermediate position in both the cooling operation and the heating operation.
A stable refrigeration cycle can be obtained.

[Brief description of the drawings]

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

FIG. 2 is a refrigeration cycle system diagram of an air conditioner according to a second embodiment of the present invention.

FIG. 3 is a refrigeration cycle system diagram of an air conditioner according to a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Compressor 2 ... Four-way valve 3, 4 ... Blocking valve 5 ... Expansion valve 6 ... Evaporator 7 ... Heat exchanger for heating 8 ... Accumulator 9, 10 ... Solenoid valve 11, 12, 13 ... Check valve 14 ... Condensation Units 15 and 16 Block valve 17 Compressor discharge connection of four-way valve 18 Compressor suction connection of four-way valve 19 Evaporator connection of four-way valve 20 Condenser-side connection of four-way valve 21 ... three-way valve 22 ... solenoid valve 23 ... expansion valve 24, 25 ... solenoid valve

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F25B 6/02 F25B 29/00 F25B 13/00

Claims (3)

(57) [Claims] 1. An air conditioner comprising an indoor unit having a compressor, an evaporator and a decompression device, and an outdoor unit having a condenser connected by refrigerant piping to constitute a cooling refrigeration cycle, A heat exchanger for a heater is provided, and a refrigerant flow switching valve for switching between a cooling operation and a heating operation is provided on the discharge side of the compressor, and when the refrigerant flow switching valve is switched to the heating operation, the compressor is turned off. Performing a heating operation cycle in which the discharged refrigerant is sent to the heat exchanger for the heater, condensed, and returned to the compressor via the decompression device and the evaporator, thereby heating the indoor air passing through the heat exchanger for heating. In the air conditioner, a four-way valve is provided as the refrigerant flow switching valve, and the four-way valve has a compressor discharge side connection part, a condenser side connection part, an evaporator side connection part, and a compressor suction side connection. The parts are each pressure An air conditioner connected to a discharge pipe of a compressor, a pipe for sending a refrigerant to an outdoor unit, a pipe for sending a refrigerant to a heat exchanger for heating, and a low-pressure pipe between an evaporator and a compressor. 2. An air conditioner comprising an indoor unit having a compressor, an evaporator, and a decompression device, and an outdoor unit having a condenser connected by refrigerant piping to form a cooling refrigeration cycle, A heat exchanger for a heater is provided, and a refrigerant flow switching valve for switching between a cooling operation and a heating operation is provided on the discharge side of the compressor, and when the refrigerant flow switching valve is switched to the heating operation, the compressor is turned off. Performing a heating operation cycle in which the discharged refrigerant is sent to the heat exchanger for the heater, condensed, and returned to the compressor through the decompression device and the evaporator, thereby heating the indoor air passing through the heat exchanger for heating. In the air conditioner, a three-way valve is provided as the refrigerant flow switching valve, and three connection parts of the three-way valve are respectively a discharge pipe of a compressor, a pipe for sending refrigerant to an outdoor unit, and a pipe for heating. Cool to heat exchanger The piping connected to the pipe that sends the medium and the solenoid valve for recovering the refrigerant from the heating heat exchanger to the refrigeration cycle during the cooling operation are connected to the evaporator and the compression pipe through the inlet pipe of the heating heat exchanger. An air conditioner, which is connected to a low-pressure pipe between the air conditioner and the air conditioner. 3. A part of the refrigerant condensed by the heating heat exchanger during the heating operation is decompressed by a decompression device different from the decompression device and sent to a condenser provided in an outdoor unit. 2. The air conditioner according to claim 1, wherein the evaporator is used as an evaporator, and is returned to the compressor via the four-way valve after being evaporated.