JP2001082759A - Indoor unit for air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an indoor unit for an air conditioner for holding an air supply efficiency while effectively utilizing an inner space and obtaining sufficient airconditioning capability. SOLUTION: The indoor unit for an air conditioner comprises an indoor side heat exchanger 5 having a first heat exchanger 6 and a second heat exchanger 8 and disposed oppositely to a suction port 22, and an auxiliary pressure reducing unit such as, for example, an auxiliary electronic expansion valve 7 provided at piping for communicating with the exchanger 8 through the exchanger 6. Thus, a drying operation in which the exchanger 6 is used as a reheater and the exchanger 8 is used as a cooler can be conducted by the operation of the valve 7. The exchanger 5 is disposed obliquely to the suction port, and the valve 7 is disposed in a space between the exchanger 5 and the suction port.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an indoor unit of an air conditioner that can be switched to a dry operation, and more particularly to an improvement in a storage structure of an auxiliary pressure reducing device.

[0002]

2. Description of the Related Art At present, an air conditioner frequently used for ordinary households is divided into an indoor unit and an outdoor unit, and each unit is connected by a refrigerant pipe or a power cable. .

An air conditioner generally provided with a heat pump type refrigerating cycle to enable switching between a cooling operation and a heating operation and also to switch to a dry operation to increase the operation rate. Is frequently used.

In this type of apparatus, a compressor, a four-way valve, an outdoor heat exchanger, a pressure reducing device and an indoor heat exchanger are communicated through a refrigerant pipe, and a heat pump type refrigeration system is used. Make up the cycle.

The indoor heat exchanger comprises a first heat exchanger and a second heat exchanger arranged in parallel with each other and communicating with each other via an auxiliary pressure reducing device. During the heating operation, the auxiliary pressure reducing device is fully opened, and the first heat exchanger and the second
The refrigerant in the same state is circulated through the heat exchanger, and both the refrigerants perform an evaporating operation or a condensing operation.

When a dry operation is instructed, the auxiliary pressure reducing device is appropriately throttled to provide a reheater for condensing the refrigerant in the first heat exchanger and a cooler for evaporating the refrigerant in the second heat exchanger. And

On the other hand, the room air, which is the heat exchange air, first exchanges heat with the second heat exchanger located on the windward side to change into dehumidified cool air. Next, heat is exchanged with the first heat exchanger located on the leeward side to perform a reheating action of absorbing heat of condensation, and the temperature returns to room temperature. From the outlet, dehumidified warm air at room temperature is blown out.

[0008]

As described above, dry operation with improved air-conditioning characteristics has been made possible, but the problem lies in the structure for accommodating piping in the indoor unit. That is, Japanese Utility Model Publication No. 61-38035 discloses an improved indoor unit of a separate type air conditioner having a dehumidifying function.
A ventilation passage case forming a ventilation passage is provided with a recess by projecting a part from the outer surface side to the ventilation passage side, and a pipe portion between the first heat exchanger and the second heat exchanger in the recess. Is described.

However, in such a configuration, while a space for accommodating the pipe portion is secured, the ventilation passage itself is reduced, so that the ventilation efficiency is reduced, and the air conditioning capacity is reduced.

During the dry operation, drain water condensed on the pipes may drip into the recesses, flow down the back plate forming the ventilation passage, flow into the room, and give the user discomfort. Was.

In order to prevent such dew condensation, it is necessary to take measures such as enclosing the entire pipe section with a heat insulating material, which increases the number of parts and further complicates assembly work. The problem exists.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and has as its object to provide an air conditioner that maintains the air-blowing efficiency while effectively utilizing the internal space and obtains a sufficient air-conditioning ability. To provide an indoor unit.

[0013]

SUMMARY OF THE INVENTION To achieve the above object, the present invention provides an indoor heat exchanger comprising a first heat exchanger and a second heat exchanger, which are arranged opposite to a suction port. And an auxiliary pressure reducing device provided in a pipe connecting the first heat exchanger and the second heat exchanger. The operation of the auxiliary pressure reducing device reheats the first heat exchanger. In the indoor unit of the air conditioner capable of performing a dry operation in which the second heat exchanger serves as a cooler, the indoor heat exchanger is disposed obliquely with respect to the suction port. The auxiliary pressure reducing device is disposed in a space between the heat exchanger and the suction port.

According to a second aspect, in the indoor unit of the air conditioner according to the first aspect, the auxiliary pressure reducing device is an auxiliary electronic expansion valve or a parallel circuit of a capillary tube and an electromagnetic switching valve.

By adopting the means for solving the above problems, it is possible to maintain the air blowing efficiency while effectively utilizing the internal space of the indoor unit, obtain sufficient air conditioning performance, and simplify the drain water treatment structure. The assembly work becomes easy.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a refrigeration cycle of an air conditioner and its electric control structure.

In the figure, reference numeral 1 denotes a compressor.
The outdoor heat exchanger 3 is connected via the four-way valve 2. The outdoor heat exchanger 3 is connected to a first heat exchanger 6 constituting an indoor heat exchanger 5 via an electronic expansion valve 4 which is a pressure reducing device.

The first heat exchanger 6 is connected to a second heat exchanger 8 via an auxiliary electronic expansion valve 7 constituting an auxiliary pressure reducing device, and these constitute the indoor heat exchanger 5. become. The second heat exchanger 8 is connected to the compressor 1 via the four-way valve 2.
Is connected to the suction side.

The electronic expansion valve 4 and the auxiliary electronic expansion valve 7
Is a pulse motor valve whose opening continuously changes according to the number of input drive pulses. Hereinafter, these pulse motor valves are referred to as PMV4 and sub-PMV7.

The compressor 1 is a variable capacity compressor, and a drive motor is connected to an inverter circuit 9. The inverter circuit 9 rectifies the voltage of the commercial AC power supply 10, converts the rectified voltage to a frequency corresponding to a command from the control unit 11, and outputs the converted frequency. This output is the driving power of the compressor 1 motor.

An outdoor fan 12, which is a blower, is disposed opposite the outdoor heat exchanger 3. For example, a phase control circuit 13 is connected to the drive motor of the outdoor fan 12. The phase control circuit 13 controls the phase of energization of the drive motor from the commercial AC power supply 10 in accordance with a command from the control unit 11. By such a phase control, the rotation speed of the outdoor fan 12 can be changed.

The control section 11 is composed of a microcomputer and its peripheral circuits, and controls the entire air conditioner. The controller 11 has an indoor temperature sensor 14 for detecting the temperature of the indoor air, an outdoor heat exchange temperature sensor 15 for detecting the temperature of the refrigerant in the outdoor heat exchanger 3, and a temperature of the refrigerant at the outlet of the outdoor heat exchanger 3. Outdoor heat exchange outlet temperature sensor 16 for detecting the temperature of the outside air, and the outdoor temperature sensor 1 for detecting the temperature of the outdoor air
7, a four-way valve 2, a PMV4, a sub PMV7, an inverter circuit 9, a phase control circuit 13, a tap switching control circuit for a fan of an indoor blower, a remote control type operation device, and the like.

The control section 11 has the following functional means.

[1] The compressor 1 is operated, and the refrigerant discharged from the compressor is supplied to the four-way valve 2, the outdoor heat exchanger 3, the PMV 4,
A first heat exchanger 6, a sub-PMV 7, a second heat exchanger 8,
Lead to the four-way valve 2 sequentially, and squeeze the PMV4, sub PMV
7 means for fully opening and executing a cooling operation.

[2] The compressor 1 is operated, and the refrigerant discharged from the compressor 1 is supplied to the four-way valve 2, the second heat exchanger 8, the sub PM
V7, the first heat exchanger 6, the PMV4, the outdoor heat exchanger 3, and the four-way valve 2 are sequentially guided, and the PMV4 is throttled.
MV7 is a means for fully opening and performing a heating operation.

[3] The compressor 1 is operated, and the refrigerant discharged from the compressor is supplied to the four-way valve 2, the outdoor heat exchanger 3, the PMV 4,
A first heat exchanger 6, a sub-PMV 7, a second heat exchanger 8,
Lead to the four-way valve 2 sequentially, and fully open PMV4, sub PM
A means for executing a dry operation by squeezing V7.

[4] Means for reducing the condensing temperature of the first heat exchanger 6 by narrowing down the PMV 4 based on the outside air temperature detected by the outdoor temperature sensor 17 during the cold dry operation. In this case, since there is no direct feedback to the control unit 11, the PMV 4 performs pulse control of the absolute value.

As shown in FIG. 2, an indoor unit 20 for housing the indoor heat exchanger 5 is configured. In the figure, reference numeral 21 denotes a unit body provided with a suction port 22 on a front surface and an air outlet 23 on a lower part. The indoor-side heat exchanger 5 is generally formed in a substantially U shape, and is disposed to face the suction port 22. A drain pan 24 is provided at the lower end.

The indoor heat exchanger 5 is composed of a number of fins 25 arranged side by side with a narrow gap therebetween.
5 comprises a heat exchange pipe 26 to be inserted. Here, the heat exchange pipes 26 are arranged in two rows along the longitudinal direction (height direction) of the fins 25. A straight, intermittent slit 27 is interposed along the longitudinal direction (height direction).

With such a slit 27, the fin 25 has a structure substantially divided into two on the windward side directly facing the suction port 22 and the leeward side on the back side. The second heat exchanger 8 is constituted by the fins 25 on the leeward side and the heat exchange pipes 26 for one row, and the fins 25 on the leeward side and the heat exchange pipes 26 are arranged in one row.
Is constituted.

An indoor heat exchanger 5 formed in a V shape
In particular, the sub-PMV 7 is arranged on the upper side that is greatly inclined and near the upper part of the second heat exchanger 8.
That is, since the indoor heat exchanger 5 is formed in a substantially rectangular shape, the upper side thereof is connected to the unit body 21 and the suction port 22.
, There is a blank space. Therefore, by arranging the sub-PMV 7 in this space, an effective arrangement layout can be obtained.

Inside the indoor heat exchanger 5, that is, on the first heat exchanger 6 side, an indoor fan 28 composed of a cross flow fan of the indoor blower is arranged. This indoor fan 28
Needless to say, has an axial length sufficiently opposed to the width direction of the indoor heat exchanger 5.

Next, the air conditioning operation of the air conditioner thus configured will be described. In the cooling operation, the compressor 1 is operated, the four-way valve 2 is not operated (neutral state),
Restriction of PMV4, full opening of sub PMV7, outdoor fan 12
And the operation of the indoor fan 28 are set.

When the refrigerant compressed by the compressor 1 is discharged, it is guided to the outdoor heat exchanger 3 via the four-way valve 2.
In the outdoor heat exchanger 3, the refrigerant condenses and liquefies. The liquid refrigerant that has exited the outdoor heat exchanger 3 is depressurized by the throttling action of the PMV 4, and is guided to the first heat exchanger 6.

The refrigerant having left the first heat exchanger 6 passes through the fully opened sub-PVM 7 and flows into the second heat exchanger 8. In each of the heat exchangers 6 and 8, the refrigerant evaporates and takes latent heat of evaporation from the indoor air to be vaporized. The refrigerant that has passed through these heat exchangers 6 and 8 is sucked into the compressor 1 via the four-way valve 2.

In the heating operation, the operation of the compressor 1 and the four-way valve 2
, The operation of the outdoor fan 12 and the operation of the indoor fan 28 are set. When the refrigerant compressed by the compressor 1 is discharged, the refrigerant is guided to the second heat exchanger 8 via the four-way valve 2. The refrigerant that has exited from the second heat exchanger 8 flows into the first heat exchanger 6 through the fully opened sub-PVM 7. In each of the heat exchangers 8 and 6, the refrigerant condenses and releases heat of condensation to the indoor air to be liquefied. Then, the refrigerant that has passed through the heat exchangers 8 and 6 is depressurized by the throttle action of the PMV 4 and guided to the outdoor heat exchanger 3. The refrigerant is vaporized in the outdoor heat exchanger 3 and is sucked into the compressor 1 through the four-way valve 2.

In the dry operation, operation of the compressor 1, non-operation of the four-way valve 2, full opening of the PMV 4, throttling of the sub PMV 7, and operation of the outdoor fan 12 and the indoor fan 28 are set.

The refrigerant discharged from the compressor 1 is supplied to the four-way valve 2
Through the outdoor heat exchanger 3 and further open P
It is led to the first heat exchanger 6 via the MV 4. The refrigerant is
It condenses and liquefies in the outdoor heat exchanger 3 and the first heat exchanger 6. In particular, the first heat exchanger 6 releases condensation heat to room air.

This liquid refrigerant is decompressed in the sub PMV 7 and guided to the second heat exchanger 8. In the heat exchanger 8, the refrigerant evaporates and takes heat from the indoor air. The refrigerant that has passed through the heat exchanger 8 is sucked into the compressor 1 via the four-way valve 2.

As shown in FIG. 2, the second heat exchanger 8 is located on the windward side and acts as a cooler for dehumidifying and cooling the indoor air guided from the suction port 22, and the first heat exchanger 6 Is on the leeward side and serves as a reheater for heating the dehumidified and cooled indoor air.

From the outlet 23, the air returns to the temperature at the time of suction and is blown out. In other words, the air becomes dry air and is guided into the room to perform this dehumidifying action.

When the room temperature is lower than the temperature set for the remote controller, the warm dry operation is selected. In this warm dry operation, the outdoor fan 12 is operated at a rotation speed of 0 or a very low rotation speed (about 150 rpm).

In this case, since the heat radiation of the refrigerant in the outdoor heat exchanger 3 is small (the sensible heat is small), the amount of heat applied to the first heat exchanger 6 functioning as the reheater increases, and the dehumidification cooling is performed. The dried air is sufficiently warmed and blown into the room.

If the room temperature is close to the temperature set for the remote controller, the isothermal dry operation is selected. At this time, the outdoor fan 12 is operated at an extremely low rotational speed (about 150 rpm), and the heat radiation amount of the first heat exchanger 6 as the reheater is reduced by the heat radiation of the refrigerant in the outdoor heat exchanger 3. The dry air is blown out after being heated to the same temperature as the room temperature.

When the room temperature is higher than the temperature set for the remote controller, the outside air temperature is naturally high. At this time, the cooling capacity tends to be insufficient.

That is, the throttle function of the sub PMV 7 is continued, and the throttle function of the PMV 4 as a pressure reducing device is performed based on the outside air temperature detected by the outdoor temperature sensor 17. The refrigerant is condensed in the outdoor heat exchanger 3, and is further reduced in heat release amount and condensed temperature in a state where the refrigerant is guided to the first heat exchanger 6 by the throttling action of the PMV 4.

In the second heat exchanger 8 as a cooler, the throttle of the sub-PMV 7 is set so as to maintain the maximum cooling capacity, so that the cooling capacity in the cool dry operation at high outside air temperature is maintained. Is done.

Also, as shown in FIG.
7 is disposed on the inclined upper side of the indoor-side heat exchanger 5 formed in a U shape and at a position close to the windward side. On the windward side of the indoor heat exchanger 5, there is a second heat exchanger 8, which serves as a cooler during the dry operation, and a sub PMV 7 is located vertically above the second heat exchanger 8.

During the cooling operation and the dry operation, the second
Condensation occurs in the heat exchanger 8 of the sub-PMV and the piping connected to the sub-PMV 7 also forms condensation. The drain water condensed on the second heat exchanger 8 is blocked by the slits 27 and does not flow into the first heat exchanger 6, but flows down and is treated by the drain pan 24.

The drain water that has condensed on the sub PMV 7 and the like is dropped on the second heat exchanger 8 adjacent to the sub-PMV 7 and is treated in the same manner as the drain water generated in the heat exchanger 8. Therefore, there is no need to provide a drain processing structure dedicated to the sub PMV 7, and effective use of space in the unit main body 21 can be obtained.

In the above embodiment, the first heat exchanger 6
The auxiliary electronic expansion valve 7 is provided as an auxiliary pressure reducing device connected between the first heat exchanger 8 and the second heat exchanger 8, but is not limited thereto.

As shown in FIG. 3, as an auxiliary pressure reducing device,
The electromagnetic on-off valve 30 and the capillary tube 31 may be replaced with a parallel circuit 32 that connects them in parallel. (The other components are the same as those described above with reference to FIG. 1, so the same numbers are given here and a new description is omitted.) During the cooling operation, the electromagnetic on-off valve 30 is opened. Then, the refrigerant guided from the first heat exchanger 6 is passed as it is. During the heating operation, the electromagnetic on-off valve 30 is opened to allow the refrigerant guided from the second heat exchanger 8 to pass through as it is.

In the dry operation including the cool dry operation, the electromagnetic on-off valve 30 is closed to guide the refrigerant guided from the first heat exchanger 6 to the capillary tube 31 to perform the throttling action.

The parallel circuit 32 as the auxiliary pressure reducing device
Is arranged in place of the sub PMV 7 previously described with reference to FIG. That is, it is disposed in a space close to the windward side of the second heat exchanger 8 in the space between the suction port 22 and the inclined upper side of the indoor heat exchanger 5 formed in a U shape. You.

During the cooling operation and the dry operation, the second
Condensation occurs in the heat exchanger 8 of the first embodiment, and condensation also occurs in the parallel circuit 32 and piping connected thereto. The drain water condensed on the second heat exchanger 8 is blocked by the slits 27 and does not flow into the first heat exchanger 6, but flows down and is treated by the drain pan 24.

The drain water condensed on the parallel circuit 32 and the connection piping thereof is dropped into the second heat exchanger 8 adjacent thereto, and is treated in the same manner as the drain water generated in the heat exchanger 8. . Therefore, there is no need to provide a dedicated drain processing structure such as the parallel circuit 32, and the space in the unit body 21 can be effectively used.

[0058]

According to the present invention, a space space is formed between the suction port of the indoor unit and the inclined portion of the indoor heat exchanger, and the auxiliary pressure reducing device is disposed in this case, so that the suction air can flow in the space. The air is guided to the inclined part of the indoor heat exchanger through the auxiliary decompression device, and the air efficiency is maintained and the air efficiency is maintained while effectively utilizing the space in the indoor unit without narrowing the ventilation path as in the past. A small, high-performance indoor unit of an air conditioner can be obtained that can maintain the harmony ability.

The drain water condensed on the auxiliary pressure reducing device drops on the inclined portion of the indoor heat exchanger and is treated in the same manner as the drain water generated in the indoor heat exchanger. There is no need to provide a drain water treatment structure
An indoor unit of an air conditioner having a simple structure and easy to assemble is obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram and an electric control circuit diagram of a refrigeration cycle of an air conditioner, showing an embodiment of the present invention.

FIG. 2 is a schematic vertical sectional view of an indoor unit constituting the air conditioner of the embodiment.

FIG. 3 is a configuration diagram of a refrigeration cycle of an air conditioner according to another embodiment.

[Explanation of symbols]

 6 first heat exchanger, 8 second heat exchanger, 22 inlet, 5 indoor heat exchanger, 7 auxiliary electronic expansion valve (auxiliary pressure reducing device), 31 capillary tube, 30 Electromagnetic on-off valve, 32 ... Parallel circuit (auxiliary pressure reducing device).

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F25B 29/00 391 F24F 1/00 391C (72) Inventor Toshiaki Isugi 336 Tatehara, Fuji City, Shizuoka Prefecture, Ltd. Inside the Toshiba Fuji Plant (72) Inventor Norio Ikaya 336 Tatehara, Fuji City, Shizuoka Prefecture Inside the Fuji Plant Toshiba Corporation (72) Inventor Masaya Yamazaki 336 Tatehara Field, Fuji City, Shizuoka Prefecture Inside the Fuji Plant Toshiba Corporation (72) Inventor Inoue Actual 336 Tatehara, Fuji City, Shizuoka Prefecture Inside the Toshiba Fuji Factory (72) Inventor Hideaki Suzuki 336 Tatehara Fuji City, Shizuoka Prefecture Inside the Fuji Factory Toshiba (72) Inventor Hideaki Motohashi 336 Tatehara, Fuji City, Shizuoka Prefecture Co., Ltd. Toshiba Fuji Factory

Claims (2)

[Claims] 1. An indoor heat exchanger comprising a first heat exchanger and a second heat exchanger and arranged opposite to a suction port, the first heat exchanger and the second heat exchanger. An auxiliary pressure reducing device provided in a pipe communicating with the exchanger, and a dry operation in which the first heat exchanger is a reheater and the second heat exchanger is a cooler by the operation of the auxiliary pressure reducing device. In the indoor unit of the air conditioner, the indoor heat exchanger is disposed obliquely with respect to the suction port, and the auxiliary heat exchanger is provided in a space between the indoor heat exchanger and the suction port. An indoor unit for an air conditioner, wherein a decompression device is disposed. 2. The air conditioner indoor unit according to claim 1, wherein said auxiliary pressure reducing device is an auxiliary electronic expansion valve or a parallel circuit of a capillary tube and an electromagnetic switching valve.