JPH02298751A - Air-conditioner - Google Patents

Abstract

PURPOSE:To enable attainment of dehumidification without lowering of a room temperature even when a cooling load is small, by a construction wherein a compressor is operated with a reduced capacity as the room temperature turns equal to a set optimum room temperature in a dehumidifying operation and the flow rate of a refrigerant to an indoor heat exchanger is restricted by a restrictor. CONSTITUTION:When an optimum room temperature is set and an operation mode is set for dehumidification, a controller 11 increases a capacity of a compressor 3 if a difference between the optimum room temperature and an actual room temperature sensed by a room temperature sensor 9 is a prescribed temperature or above, and controls the degree of heating of a refrigerant, so as to cool and dehumidify indoor air. When the room temperature lowers with the cooling and dehumidification and approaches a prescribed temperature to the optimum room temperature, the capacity of the compressor 3 is maintained to be a prescribed one. When the room temperature still lowers and drops below the optimum room temperature, the capacity of the compressor 3 is reduced with time to decrease the amount of circulation of the refrigerant, while the degree of opening of a restrictor 5 is maintained to be a prescribed one. When the room temperature lowers to a prescribed temperature or below from the optimum room temperature, the degree of opening of the restrictor 5 is lessened directly to restrict the amount of inflow of the refrigerant into an indoor heat exchanger 7, and the temperature of vaporization of the refrigerant is lowered.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention relates to an air conditioner using a refrigeration cycle, and in particular to an air conditioner that reliably does not lower the room temperature even when the cooling load is small. The present invention relates to an air conditioner that can perform dehumidification operation.

(Prior Art) Generally, an air conditioner using a refrigeration cycle as shown in FIG. 10 is known.

As shown in the figure, this refrigeration cycle mainly consists of a compressor a, an outdoor heat exchanger b, a constrictor C, and an indoor heat exchanger d, which are sequentially connected by refrigerant piping. The air conditioner is configured such that the diaphragm and diaphragm C are housed in an outdoor unit g, and the indoor heat exchanger d is housed in an indoor unit h. Also, inside the indoor unit h, there is an indoor blower C for exchanging indoor air with the indoor heat exchanger d and then blowing it out, and inside the outdoor unit g, there is an outdoor blower C for exchanging heat of the outside air with the outdoor heat exchanger d. f is provided respectively.

Therefore, the refrigerant flowing through this refrigeration cycle is compressed into high-temperature, high-pressure gas by compression Ra, becomes a high-pressure condensate in the outdoor heat exchanger, is depressurized through the constrictor C, enters the indoor heat exchanger d, and enters the indoor heat exchanger d. It is evaporated in heat exchanger d and returned to compressor a, and when the air conditioner is in cooling operation, indoor air passes through indoor heat exchanger d, where it is heat exchanged and cooled and dehumidified. become.

By the way, when performing dehumidification operation using this air conditioner, the following three types of methods are mainly adopted.

First, the first method is to operate the air conditioner equipped with the refrigeration cycle shown in Fig. 10 with a reduced cooling capacity. When the indoor unit h is operated, the amount of heat exchanged between the indoor heat exchanger d provided in the indoor unit h and the indoor air is reduced to dehumidify the indoor air.

In addition, the second method, as shown in FIG.
An electric heater i is provided for heating and dehumidifying indoor air that has been cooled and dehumidified by an indoor heat exchanger d.

After fi, the third method is to add a dehumidifying circuit as shown in Fig. 12, and the cold tank from the outdoor heat exchanger is placed in the indoor unit h with the wringer C and the indoor heat exchanger d. In addition to the cooling circuit that constitutes a normal refrigeration cycle that flows sequentially, the refrigerant from the outdoor heat exchanger is passed through an air warming condenser j installed in the indoor unit h, and then the refrigerant is A dehumidification circuit is provided in which the depressurized indoor air is passed through an indoor heat exchanger d, and the indoor air that has been heat exchanged and dehumidified by the indoor heat exchanger d is heated.

When using this air conditioner for dehumidifying operation,
The cold tofu switching valve k is opened and the cold tofu switching valve j is closed to form a dehumidifying circuit, and the indoor air is transferred to the indoor heat exchanger d and the air heating condenser j by the indoor blower e in the indoor unit h. The indoor air passes through the indoor heat exchanger d and becomes low temperature and low humidity, and then passes through the air warming condenser j where it is heated and blown into the room as low humidity air. In addition, when performing cooling operation, the refrigerant switching valve k is closed and the refrigerant switching valve J is opened to form a cooling circuit, and the indoor air is passed only to the indoor heat exchanger d by the indoor blower e in the indoor unit h. Indoor air will be cooled.

(Problems to be Solved by the Invention) However, conventional air conditioners have had the following problems during dehumidification operation.

First, when the first conventional dehumidification method is adopted, the entire refrigeration cycle including compression 1ia is designed assuming cooling operation, so compression 111a is used intermittently or at low capacity during dehumidification operation with a small cooling load. Even when the system is in operation, the capacity of the refrigeration cycle is too large, and there is a problem that the room temperature becomes too cold when attempting to achieve sufficient dehumidification.

In addition, when the second dehumidification method is adopted, a large-capacity electric heater l is required to exhibit a heating capacity commensurate with the cooling capacity of the air conditioner, resulting in poor efficiency and a large indoor unit h. There was a problem of becoming

Furthermore, when the third dehumidification method is adopted, full-fledged dehumidification ability is demonstrated, but J is installed in the air warming condenser j, the diaphragm C, and the refrigerant switching valve in the indoor unit h. Therefore, there was a problem that the indoor unit h became larger. In addition, J! There was a problem in that the valve actuation stand was likely to occur indoors.

Thus, the present invention was devised to effectively solve the above problems, and its purpose is to reliably lower the room temperature even when the cooling load is small during dehumidification operation of an air conditioner using a refrigeration cycle. To provide an air conditioner that can dehumidify without causing heat.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides a method for transferring refrigerant that has passed through a compressor, an outdoor heat exchanger, and a diaphragm provided in an outdoor unit to an indoor unit. In an air conditioner having a refrigeration cycle that causes the air to pass through an indoor heat exchanger installed in the room to exchange heat with indoor air, the air conditioner includes a room temperature sensor for detecting the temperature of the indoor air and a setting means for presetting the i&suitable room temperature. In addition, when the actual room temperature obtained from the room temperature sensor becomes equal to the optimum room temperature preset by the setting means during dehumidification operation, the compressor is operated at a low capacity, and the compressor is operated at a low capacity. The indoor heat exchanger is equipped with a controller for restricting the flow of refrigerant to the indoor heat exchanger.

(Function) During dehumidification operation of an air conditioner, the compressor is operated at a low capacity as the actual room temperature becomes equal to the optimum room temperature, so the amount of refrigerant circulating in the refrigeration cycle is reduced. Cooling capacity decreases. On the other hand, since the refrigerant flowing into the indoor heat exchanger through the restrictor is also restricted, the refrigerant evaporation temperature within the indoor heat exchanger decreases and the sensible heat ratio decreases. Therefore, the dehumidification function can be fully demonstrated without lowering the room temperature.

<Example) Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a first embodiment of an air conditioner according to the present invention.

As shown in the figure, the air conditioner 1 transfers the refrigerant that has passed through a pressure filter 3, an outdoor heat exchanger 4, and a diaphragm 5 provided in an outdoor unit 2 to an indoor heat exchanger provided in an indoor unit 6. 7 and has a refrigeration cycle that exchanges heat with indoor air.

The indoor unit 6 includes a setting means (not shown) for setting the optimum room temperature and the operation mode of the air conditioner 1 (cooling, heating, dehumidification, ventilation, etc.), and indoor air flowing into the indoor heat exchanger 7. A room temperature sensor 9 is provided in the outdoor unit 2 to detect the temperature of the refrigerant, that is, the actual room temperature. A controller 11 is connected to the heating degree sensor 10 and performs system control of the air conditioner 1 based on the setting information of a setting means (not shown) and the detection output of the room temperature sensor 9.

The controller II includes a determining means for determining the difference between the optimum room temperature set in advance in a setting means (not shown) and the detection output of the room temperature sensor 9, and controls the capacity of the compressor 3 based on the determining means. The program includes a compressor control means for controlling the compressor and a restrictor control means for directly controlling the throttle opening of the restrictor 5 based on the above-mentioned determination means.

Here, as shown in FIG. 8, the compressor control means makes sure that the room temperature T is higher than a predetermined temperature ( When the room temperature T is within a predetermined range (B zone) with respect to the optimum room temperature T3, the capacity of the compression a13 is kept constant. In order to maintain the temperature, when the room mT falls beyond the optimum room temperature Ts (zone C), the capacity of the compressor 813 is controlled to be reduced to the minimum capacity at predetermined time intervals. In addition, as shown in FIG. 9, the diaphragm control means controls a diaphragm 5 that keeps the degree of heating of the refrigerant constant when the room temperature T is equal to or higher than the optimum room temperature Ts (zone D) in the process of decreasing the room temperature T. so that the aperture opening is
When the room temperature T exceeds the optimum room temperature Ts and falls (E zone), the opening degree of the wringer 5 is maintained constant.
When the room temperature T is below a predetermined temperature (1'' zone) with respect to the optimum room temperature Ts, the opening degree of the diaphragm 5 is controlled to decrease at predetermined time intervals.

In addition, 12 is a four-way switching valve for switching between air conditioning and heating of the indoor unit 6, 13 is an outdoor blower for exchanging outside air with the outdoor heat exchanger 4, and 14 is for exchanging indoor air with the indoor heat exchanger 7. The indoor blower 15 is a compressor motor rotation speed control device for controlling the capacity of the compressor 13 based on commands from the controller 11.

Next, the operation of this first embodiment will be explained.

First, when the optimum room temperature Ts is set by the setting means (not shown) and then the operation mode is set to dehumidification, the controller 11
The difference between the in room temperature Ts and the actual room temperature T, which is the detection output of the room temperature sensor 9, is determined, and if the difference is at least a predetermined temperature, the capacity of the compressor 3 is increased and the refrigerant heating degree is kept constant. indoor air is cooled and dehumidified.

Accordingly, when the room temperature T decreases and approaches the optimum room temperature T's to a predetermined temperature, the capacity of the pressurizer 3 is maintained constant, but if the room temperature T still decreases and exceeds the optimum room temperature Ts, The capacity of the compressor 1113 is reduced over time to reduce the amount of cold coke circulation in the refrigeration cycle, and the opening degree of the restrictor 5 is maintained constant.

And room temperature 1゛ is l1ft, li! When the temperature drops from the room temperature Ts to a predetermined temperature or less, the opening degree of the restrictor 5 is directly reduced, the amount of refrigerant flowing into the indoor heat exchanger 7 is restricted, and the refrigerant evaporation temperature is lowered.

Therefore, in this first embodiment, the air conditioner 1
During the dehumidification operation, the cooling capacity is reduced by controlling the capacity of the compressor 3 so that the room temperature T matches the optimum room temperature Ts, and then the refrigerant evaporation temperature in the heat exchanger 7 is reduced by controlling the throttle opening of the diaphragm 5. Therefore, even when the cooling load is small, indoor air can be dehumidified without lowering the room temperature.
Indoor comfort improves.

Furthermore, since no heating structure, refrigerant valve mechanism, or diaphragm is required inside the indoor unit 6, there is no refrigerant noise or valve actuator in the room, and the size of the indoor unit 6 can be maintained. .

FIG. 2 shows a modification of the air conditioner 1 explained in FIG. 1.

In this second embodiment, an electric heater 16 is added at a position downstream of the air flow path from the indoor heat exchanger 7 of the first embodiment, and this is controlled on and off during low capacity operation of the compressor 3 to heat the indoor air. It is something to do. That is, when the room temperature T decreases and becomes lower than the optimum room temperature Ts during the dehumidifying operation of the air conditioner AL, as in the first embodiment, the electric heater 16 is activated by the controller 11 in order to bring the room temperature from 1 to Ts. It is turned on and off more,
Nevertheless, when the room temperature T decreases, the opening degree of the wringer 5 is reduced.

Therefore, according to the second embodiment, it is possible to reliably dehumidify even when the cooling load is extremely small or zero.

FIG. 3 shows a modification of the air conditioner Ill explained in FIG.

In this third embodiment, a blowout temperature sensor 17 for detecting the temperature of the air blown out from the indoor unit 6 is added at a position further downstream of the electric heater 16 in the second embodiment in the air flow path. The electric heater 16 and the wringer 5 are connected so that the output is higher than the detection output of the room temperature sensor 9.
It controls the

That is, when the room temperature T decreases and becomes lower than the appropriate temperature TS during the dehumidifying operation of the air conditioner 1, the indoor unit 6 detected by the air outlet temperature sensor 17
The controller 11 performs on/off control of the electric heater 16 so that the temperature of the air blown from the room becomes higher than the actual room temperature T, and then controls the throttle opening of the diaphragm 5.

Therefore, according to the third embodiment, the slow response in the room temperature control of the second example can be eliminated, and a quick response can be achieved.

FIG. 4 shows another embodiment of the air conditioner according to the present invention.

That is, in this fourth embodiment, as shown in the figure,
The air conditioner 21 transfers refrigerant that has passed through a pressure machine 23, an outdoor heat exchanger 24, and a diaphragm 25 provided in an outdoor unit 22 to a variable volume Ik type indoor heat exchange unit provided in an indoor unit 26. 27 to exchange heat with indoor air.

And, the indoor unit 26 has an optimal room temperature and air conditioning at 8m.
A setting means (not shown) for setting 21 operation modes (cooling, heating, dehumidification, ventilation, etc.) and a room temperature sensor for detecting the temperature of indoor air flowing into the indoor heat exchange unit 27, that is, the actual room temperature. 29 is provided in the outdoor unit 22, and the degree of heating of the refrigerant after heat exchange in the indoor heat exchange unit 27 is detected, and the degree of opening of the diaphragm 25 is adjusted to keep the degree of heating constant. Heating degree sensor 3 to control
0, the setting information of the setting means (not shown), and the detection output of the room temperature sensor 29, the air conditioning ll! A controller 31 for system control of 121 is provided.

As shown in FIG. 5, the indoor heat exchange unit 27 includes an indoor heat exchanger 32 having three refrigerant paths of equal capacity and formed in parallel, and an inlet of the two refrigerant paths of the indoor heat exchanger 32. It is comprised of valves 33 and 34 provided on each side to open and close the refrigerant path.

Further, the controller 31 includes a determining means for determining the difference between the optimum room temperature set in advance in the setting means (not shown) and the detection output of the room temperature sensor 29, and a determining means for determining the difference between the optimum room temperature set in advance in the setting means (not shown) and the detection output of the room temperature sensor 29, and this "1!" j A compressor control means for controlling the capacity of the compression a23 based on another means, and a valve 33 for varying the capacity of the indoor heat exchange unit 27, that is, the refrigerant path of the indoor heat exchanger 32, based on the above-mentioned discrimination means. .34 and indoor heat exchange unit control means for controlling opening and closing are included on the 10 grams.

Here, as shown in FIG.
In the process of decreasing, when the room temperature T is a predetermined temperature or higher (A zone) with respect to the optimum room temperature Ts, the capacity of the compressor 23 is increased to the maximum capacity at predetermined intervals, so that the room temperature T is set to the optimum room temperature Ts. When the room temperature T is within a predetermined range (B zone), the capacity of the compressor 1fi23 is maintained constant, and when the room temperature T drops beyond the optimum room temperature 'rS (zone C), the capacity of the compressor 23 is kept constant. The drum wheel capacity is controlled to be decreased at predetermined time intervals. Further, as shown in FIG. 9, the indoor heat exchange unit control means increases the capacity of the indoor heat exchanger 32 at predetermined time intervals when the room temperature T is equal to or higher than the optimum room temperature 'rS (zone D). ,
When the room temperature T falls below the optimum room temperature Ts (Zone E), the capacity of the indoor heat exchanger 32 is maintained constant, and when the room temperature T is below a predetermined temperature (Zone F) with respect to the optimum room temperature Ts, The valves 33 and 34 are controlled to open and close so as to reduce the capacity of the indoor heat exchanger 32 at predetermined intervals.

In addition, 35 is a four-way switching valve for switching between air conditioning and heating of the indoor unit 26, 36 is an outdoor blower for exchanging heat with the outdoor heat exchanger 24, and 37 is a four-way switching valve for switching indoor air to the indoor heat exchanger 3.
2 and an indoor blower for heat exchange; 38 is a controller 31;
This is a compressor motor rotation speed control device for controlling the capacity of the compressor 23 based on commands from the compressor.

Next, the operation of this fourth embodiment will be explained.

First, when the optimum room temperature Ts is set by the setting means (not shown) and then the operation mode is set to dehumidification, the controller 3
1, the difference between the optimum room temperature Ts and the actual room temperature T, which is the detection output of the room temperature sensor 29, is determined, and if this difference is equal to or higher than a predetermined temperature, the capacity of the compressor 23 is increased, and the valves 33, 34 are increased. 11#1 is made in order, the capacity of the indoor heat exchanger 32 is increased, and the indoor air is cooled and dehumidified. Then, when the room temperature T decreases and approaches the predetermined temperature I & optimal room temperature Ts, the capacity of compression 1!23 is maintained constant, and even then, when the room temperature 'r decreases and exceeds the optimal room temperature Ts,
The capacity of the compression @23 is reduced over time to reduce the amount of refrigerant circulating in the refrigeration cycle, and the valves 33 and 34 are kept open and closed to maintain the capacity of the indoor heat exchanger 32.

Here, pressure all! Due to the lower capacity of 23, the wringer 25
works to keep the degree of heating of the refrigerant constant, which increases the evaporation temperature of the refrigerant and reduces the dehumidification function.
When the room temperature T is not lowered to below a predetermined temperature with respect to the optimum room temperature Ts, the valves 33 and 34 are sequentially closed and the indoor heat exchanger 3
By reducing the capacity of 2, the opening degree of the diaphragm 25 is reduced, the heat exchange area of the indoor heat exchanger 32 is reduced, and the cold cob evaporation temperature is lowered, so that the dehumidification function is maintained. .

Therefore, in this fourth embodiment, air conditioner R2
During the dehumidification operation in step 1, after reducing the cooling capacity by controlling the capacity of the compression unit 123 so that the room temperature 'r matches the optimum room temperature TS, the amount of heat exchanged with the indoor air and the refrigerant evaporation temperature are controlled by the capacity control of the indoor heat exchanger 32. Therefore, even when the cooling load is small, indoor air can be dehumidified without lowering the room temperature, improving indoor comfort. In particular, in this embodiment, the capacity of the indoor heat exchanger 32 is made variable by selecting its refrigerant path, so full-scale dehumidification can be performed without causing troublesome problems such as superheating. I can do it.

FIG. 6 shows a modification of the air conditioner 21 explained in FIG. 4.

In this fifth embodiment, an electric heater 39 is added to the air flow path downstream of the indoor heat exchanger 32 of the fourth embodiment, and this is controlled on and off during low capacity operation at a pressure [123] to heat indoor air. It is something to do.

FIG. 7 shows a modification of the air conditioner 21 explained in FIG. 6.

This sixth embodiment adds a blowout temperature sensor 40 for detecting the temperature of the blowout air from the indoor unit 26 at a position further downstream of the electric heater 39 in the fifth embodiment in the air flow path.
The electric heater 39 and the outdoor heat exchanger unit 27 are controlled so that the detection output of the blowout temperature sensor 40 is higher than the detection output of the room temperature sensor 29.

[Effects of the Invention] As explained above, according to the present invention, the following excellent effects are exhibited.

(1) Even when the cooling load is small, dehumidifying operation can be performed continuously without making the room temperature too cold.
Indoor comfort improves.

(2) Even if a heating device such as an electric heater is added to the indoor unit, it only requires a small capacity and small device.

[Brief explanation of the drawing]

FIG. 1 is a schematic circuit diagram showing a first embodiment of the invention, FIG. 2 is a schematic circuit diagram showing a second embodiment of the invention, and FIG. 3 is a schematic circuit diagram showing a third embodiment of the invention. , FIG. 4 is a schematic circuit diagram showing a fourth embodiment of the present invention, FIG. 5 is an enlarged view of main parts of the fourth embodiment, and FIG. 6 is a schematic circuit diagram showing a fifth embodiment of the present invention. FIG. 7 is a schematic circuit diagram showing a sixth practical example of the present invention;
Fig. 8 is an explanatory diagram showing a method for controlling the capacity of the compressor, Fig. 9 is an explanatory diagram showing a method for controlling the opening of the constrictor and a method for controlling the capacity of the indoor heat exchanger, Figs. 10, 11, and 12. The figure is a schematic circuit diagram showing a conventional example. In the figure, 1 is an air conditioner, 2 is an outdoor unit, 3 is a compressor, 4 is an outdoor heat exchanger, 5 is a diaphragm, 6 is an indoor unit,
7 is an indoor heat exchanger, 9 is a room temperature sensor, and 11 is a controller.

Claims (1)

[Claims] 1. Air that has a refrigeration cycle that allows the refrigerant that has passed through the compressor, outdoor heat exchanger, and diaphragm installed in the outdoor unit to pass through the indoor heat exchanger installed in the indoor unit to exchange heat with indoor air. The conditioner is equipped with a room temperature sensor that detects the temperature of indoor air and a setting means for presetting the optimal room temperature, and the actual room temperature obtained from the room temperature sensor and the setting means preset by the setting means during dehumidification operation. It is characterized by comprising a controller for operating the compressor at a low capacity in accordance with the optimum room temperature and for restricting the flow rate of refrigerant to the indoor heat exchanger using the diaphragm. Air conditioner.