JP2001201207A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an indoor environment which is felt comfortable, regardless of the indoor temperature by varying a target humidity depending on the indoor temperature, when dry operation is selected. SOLUTION: The air conditioner comprises an outdoor unit 10 comprising an outdoor heat exchanger 11 and a compressor 12, and an indoor unit 20 comprising an indoor heat exchanger 21, a reheating/drying indoor heat exchanger 22 and a drying solenoid valve 23 provided between the indoor heat exchanger 21, 22 where the indoor heat exchanger 21 dehumidifies indoor air by throttling the drying solenoid valve 23 to discharge heat to refrigerant and the reheating/ drying indoor heat exchanger 22 can perform reheating/drying operation for heating the dehumidified air with waste heat of refrigerant before supplying it into a room. In such an air conditioner, operating state of the compressor 12 is varied, such that the indoor humidity approaches a target level at reheating/drying operation, by determining the target humidity previously and individually for each value in a set temperature region.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reheat dry type air conditioner capable of controlling the temperature of conditioned air supplied from an indoor unit even when a dry operation is selected.

[0002]

2. Description of the Related Art In a conventional air conditioner, when a dry operation is selected, a refrigeration cycle is performed so that the indoor humidity approaches a preset target humidity based on a detection result of a humidity sensor. Control.

[0003] In the above-mentioned dry operation, since the cooling operation is actually performed, it is undeniable that the temperature in the room is lower than when the dry operation is started. In order to solve this problem, it is necessary to adjust the temperature of the conditioned air supplied from the indoor unit during the refrigeration cycle in the upward direction, but this is not possible with a conventional air conditioner due to its structure.

[0004] In recent years, reheat dry type air conditioners have been developed which enable temperature control of conditioned air even when dry operation is selected. This is for the indoor unit,
A heat exchanger for reheating and drying is provided separately from the conventional indoor heat exchanger.When normal cooling or heating operation is selected, the same operation as the indoor heat exchanger is performed for the heat exchanger for reheating and drying. When the dry operation is selected, the heat exchanger for reheating and drying is operated in the same manner as the outdoor heat exchanger (that is, exhaust heat).
And heats the conditioned air dehumidified (cooled) by the indoor heat exchanger, and finally controls the temperature of the conditioned air supplied from the indoor unit to approach the original indoor temperature. I have.

[0005] According to the reheat dry type air conditioner, the above-mentioned problems are solved, and even when the dry operation is selected, the temperature and humidity in the room can be appropriately maintained.

[0006]

SUMMARY OF THE INVENTION A reheat dry type air conditioner having excellent functions as described above,
Regarding this, the following problems have been pointed out. In the current reheat dry type air conditioner, the target humidity during the dry operation is constant irrespective of the indoor temperature, but the humidity that a person feels comfortable differs depending on the indoor temperature. The psychrometric chart of FIG. 8 shows an example of a relative humidity area (comfort area) where a person feels comfortable with respect to dry bulb humidity. According to this chart, the humidity at which a person feels comfortable is
For example, if the indoor temperature is 18 ° C., 80% to 100%, and if the indoor temperature is 30 ° C., 40% to 55%, the lower the indoor temperature, the higher the humidity, the more comfortable it is.
If the room temperature is high, the lower the humidity, the more comfortable it feels.

However, in the current reheat dry type air conditioner, the target humidity during the dry operation is constant irrespective of the indoor temperature, so that it may be physically unpleasant due to the current indoor temperature. There are many.

The present invention has been made in view of the above circumstances, and when dry operation is selected, the target humidity is changed in accordance with the indoor temperature to make the room feel comfortable regardless of the indoor temperature. It aims to provide an environment.

[0009]

As means for solving the above-mentioned problems, an air conditioner having the following configuration is employed. That is, the air conditioner according to claim 1 performs an heat exchange between the outdoor heat exchanger that performs heat exchange between the outdoor air and the refrigerant, and heat exchange between the outdoor heat exchanger or the indoor air and the refrigerant. An outdoor unit including a compressor that sends a refrigerant to a first indoor heat exchanger, and an outdoor fan that allows outdoor air to flow through the outdoor heat exchanger; and the first indoor heat exchanger;
A second indoor heat exchanger that performs heat exchange between indoor air and a refrigerant similarly to the first indoor heat exchanger, and the first and second indoor heat exchangers;
A solenoid valve provided between the indoor heat exchangers of the first, the first,
An indoor unit having an indoor fan that allows indoor air to flow through the second indoor heat exchanger. The indoor unit is squeezed to function as an expansion valve. The second indoor heat exchanger absorbs heat to dehumidify the indoor air, and in the second indoor heat exchanger, heats the air after the dehumidification by heating the air after the dehumidification and supplies the air indoors. In advance, target humidity is individually determined in advance for each value in the set temperature area,
In the reheat dry operation, the operation state of the compressor is changed so that the indoor humidity approaches the target humidity.

The air conditioner according to a second aspect of the present invention is the air conditioner according to the first aspect, wherein the operating state of the outdoor fan and the indoor fan is also changed with a change in the operating state of the compressor. And

According to a third aspect of the present invention, in the air conditioner according to the first or second aspect, when the reheat dry operation is instructed, the room temperature is lower than a set temperature and the set temperature and the current temperature. If the difference from the indoor temperature is larger than a predetermined value, the heating operation is temporarily performed before the reheat dry operation is started.

According to a fourth aspect of the present invention, in the air conditioner of the first, second or third aspect, when the reheat dry operation is instructed, the room temperature is higher than a set temperature and the current temperature is higher than a set temperature. If the difference between the room temperature and the set temperature is larger than a predetermined value, the cooling operation is temporarily performed before the reheating dry operation is started.

According to a fifth aspect of the present invention, in the air conditioner according to the first, second, third or fourth aspect, the indoor unit is provided with a plurality of flickering display units, and the air conditioner is used during the reheating dry operation. Is characterized in that the degree of comfort in the room is determined according to the current values of the temperature and humidity in the room, and the result of the determination is represented by the explicit number of the display unit.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an air conditioner according to the present invention will be described with reference to FIGS. FIG. 1 shows a system configuration of the air-conditioning apparatus according to the present embodiment. This air conditioner includes an outdoor unit 10 and an indoor unit 20. The outdoor unit 10 and the indoor unit 20 are connected by a refrigerant pipe 30 through which the refrigerant flows, an electric wiring (not shown), and the like.

The outdoor unit 10 includes an outdoor heat exchanger 11 for exchanging heat between outdoor air and a refrigerant, and a compressor 12 for sending the refrigerant to the outdoor heat exchanger 11 or an indoor heat exchanger 21 described later. A four-way valve 13 that regulates the flow direction of the refrigerant flowing through the refrigerant pipe 30, an electromagnetic expansion valve 14 that expands a high-temperature and high-pressure liquid refrigerant during cooling operation to produce a low-temperature and low-pressure liquid refrigerant, and an outdoor heat exchanger. 11 is provided with a propeller fan (indoor fan) 15 for circulating outdoor air.

The indoor unit 20 includes an indoor heat exchanger (first indoor heat exchanger) 21 for exchanging heat between indoor air and a refrigerant, and an indoor heat exchanger 21 between the indoor air and the refrigerant. A reheat drying indoor heat exchanger (second indoor heat exchanger) 22 for performing heat exchange and a refrigerant pipe 30 between the indoor heat exchanger 21 and the reheat drying indoor heat exchanger 22 are provided. A dry solenoid valve 23 that functions as an expansion valve during dry operation;
Indoor heat exchanger 21 and indoor heat exchanger 22 for reheat drying
And a tangential fan (indoor fan) 24 for circulating indoor air.

Further, the indoor unit 20 is provided with a room temperature sensor 25 for detecting indoor temperature (air temperature) and a humidity sensor 26 for detecting indoor humidity. These sensors are connected to a control unit (not shown). In the control unit, the operating state of the compressor, the switching of the four-way valve 13, the switching of the four-way valve 13, the electromagnetic expansion valve Controls such as intermittent or step-by-step changes in the opening degree of the 14 and the dry solenoid valve 23 and the operating state of the propeller fan 15 and the tangential fan 24 are performed.

Next, a description will be given of how the air conditioner constructed as described above operates during the heating operation and the cooling operation. During the heating operation, the refrigerant flowing through the refrigerant pipe system is compressed by the compressor 12 to become a high-temperature and high-pressure gas refrigerant, sent to the indoor unit 20 through the refrigerant pipe 30, and
It flows in the order of the indoor heat exchanger 21 and the indoor heat exchanger 22 for reheat drying. In the indoor unit 20, heat is given to the indoor air taken in by the tangential fan 24 from the high-temperature and high-pressure gas refrigerant passing through the indoor heat exchanger 21 and the indoor heat exchanger 22 for reheating and drying. Hot air will be supplied.

The high-temperature and high-pressure gas refrigerant exhausted to the indoor air is condensed and liquefied in the indoor heat exchanger 21 and the reheat-drying indoor heat exchanger 22 to become a high-temperature and high-pressure liquid refrigerant.
The high-temperature and high-pressure liquid refrigerant is sent to the outdoor heat exchanger 11 in the outdoor unit 10 through the refrigerant pipe 30. In the outdoor unit 10, the high-temperature and high-pressure liquid refrigerant passing through the outdoor heat exchanger 11 takes heat from the outdoor air taken in by the propeller fan 15. As a result, the high-temperature and high-pressure liquid refrigerant evaporates and becomes a low-temperature and low-pressure gas refrigerant.
This is sent again to the compressor 12, and the above process is repeated.

Next, during the cooling operation, the refrigerant flows through the refrigerant piping system in a direction opposite to the above. First, the high-temperature and high-pressure gas refrigerant compressed by the compressor 12 passes through the refrigerant pipe 30 and is sent to the outdoor heat exchanger 11, and gives heat to outdoor air to be condensed and liquefied to become a high-temperature and high-pressure liquid refrigerant. . The high-temperature and high-pressure liquid refrigerant becomes a low-temperature and low-pressure liquid refrigerant in the process of passing through the electromagnetic expansion valve 14 whose opening is narrowed, and is sent to the indoor unit 20 through the refrigerant pipe 30 to be used for indoor heat exchange for reheating and drying. Vessel 22,
It circulates in the order of the indoor heat exchanger 21. In the indoor unit 20, the low-temperature and low-pressure liquid refrigerant takes heat from the indoor air to cool, and the refrigerant itself evaporates and becomes a low-temperature and low-pressure gas refrigerant. This is sent to the compressor 24 again, and the above process is repeated.

Next, the manner of operation of the air conditioner configured as described above during the reheating dry operation will be described. The flow of the refrigerant during the reheating dry operation is the same as that during the cooling operation, but the electromagnetic expansion valve 14 remains open, the opening of the dry electromagnetic valve 23 is reduced, and a function as an expansion valve is provided. Thereby, in the indoor unit 20, after the indoor air is dehumidified (cooled) by the indoor heat exchanger 21, the dehumidified air is heated by the reheat drying indoor heat exchanger 22 and then supplied to the room. .

During the reheating dry operation, the following control is performed. The control flow will be described with reference to the flowchart shown in FIG. In FIG. 2, the set temperature is denoted by SP, the current indoor temperature is denoted by TIon, and the indoor humidity is denoted by HS.

First, in step S1, the set temperature (S
P; the settable area is 18 ° C. or more and 30 ° C. or less), and the set temperature and the current room temperature are determined in step S2.
(TIon), and if the current room temperature is lower than the set temperature minus 3 ° C., the start of the reheat dry operation is postponed, and the heating operation is started in step S3. Further, even if the current room temperature is equal to or higher than the set temperature plus 3 ° C., the start of the reheat dry operation is postponed, and in this case, the cooling operation is started in step S4. If the current room temperature is equal to or higher than the set temperature minus 3 ° C. and lower than the set temperature plus 3 ° C., the area is determined in step S5 for the current room temperature and the room humidity (HS).

After starting the heating operation in step S3,
In step S6, the set temperature is compared with the current room temperature. If the current room temperature becomes higher than the set temperature minus 1 ° C., the heating operation is stopped, and the process proceeds to step S5 to determine the current room temperature and room humidity. An area determination is performed. If the current room temperature is equal to or lower than the set temperature minus 1 ° C., the heating operation is continued.

After starting the cooling operation in step S4,
In step S7, the set temperature is compared with the current room temperature. If the current room temperature becomes lower than the set temperature plus 1 ° C., the cooling operation is stopped, and the process proceeds to step S5 to determine the current room temperature and the room humidity. An area determination is performed. If the current room temperature is equal to or higher than the set temperature plus 1 ° C., the cooling operation is continued.

In step S5, first, as for the current room temperature, as shown in FIG.
° C (region (I)) or higher than the set temperature minus 2 ° C and lower than the set temperature plus 2 ° C (region (I)
I)) or whether the temperature is equal to or higher than the set temperature plus 2 ° C. (region (III)).

FIG. 4 shows the current indoor humidity.
Threshold value (a, b, c) depending on the set temperature value
Then, as shown in FIG. 3 (b), the current room humidity is smaller than the middle threshold value b (region (a)) or is equal to or more than the lower limit threshold value a and the upper limit threshold value. c (area (b)) or more than the intermediate threshold b (area
(C)) is determined.

The operation state of the air conditioner is switched between three patterns based on the determination results of FIGS. 3 (a) and 3 (b). How to switch the operation state is determined according to the chart of FIG. When the current indoor temperature is in the area (I) and the indoor humidity is in the area (A), when the indoor temperature is in the area (I) and the indoor humidity is in the area (B), the indoor temperature is in the area (II). )
And the room humidity is in the region (A), in these cases, it is assumed that the room is in a low humidity state, and in order to increase both the room temperature and the room humidity, the reheat dry (thermo) operation (FIG. 6) Is started. In this reheat dry (thermo) operation, the compressor 1
2 is stopped, the propeller fan 15 is stopped, and the tangential fan 24 is rotated at a low speed.

After the start of the reheat dry (thermo) operation, it is determined in step S9 whether three minutes have elapsed since the start of the operation. If three minutes have elapsed, the process proceeds to step S10, where three minutes have elapsed. If not, reheating dry (thermo) operation is continued.

In step S10, it is determined whether or not one hour has elapsed since the start of this control (at the time of start). If one hour has elapsed, the flow returns to step S2 to return to the set temperature and the current room temperature ( TIon) is compared again. If one hour has not elapsed since the start of this control, step S5
And the area determination for the current room temperature and room humidity is performed again.

When the current room temperature is in the region (I) and the room humidity is in the region (C), when the room temperature is in the region (II) and the room humidity is in the region (B), the room temperature is Area (I
When the room temperature is in the region (III) and the room humidity is in the region (A) when the room humidity is in the region (C) and the room humidity is in the region (C),
When the room temperature is in the region (III) and the room humidity is in the region (b), in these cases, the room is assumed to be in a comfortable humidity state, and in order to maintain the room temperature and the room humidity at the current state, reheating is performed in step S11. The dry (standard) operation (pattern B shown in FIG. 6) is started. In the reheat dry (standard) operation, the compressor 12 is operated to exhibit a medium capacity, the propeller fan 15 is rotated at a low speed, and the tangential fan 24 is rotated at a medium speed.

After starting the reheat dry (standard) operation, it is determined in step S12 whether three minutes have elapsed since the start of the operation, and if three minutes have elapsed, the reheat dry (thermo) is performed.
As in the case of the operation, the process proceeds to step S10 to determine the elapsed time from the start of this control, and if three minutes have not elapsed, the reheat dry (standard) operation is continued.

When the current room temperature is in the region (III) and the room humidity is in the region (C), in this case, it is determined that the room is in a high humidity state, and a step is taken to reduce both the room temperature and the room humidity. In S13, the reheating dry (high capacity) operation (pattern C shown in FIG. 6) is started. In the reheat dry (high capacity) operation, the compressor 12 is operated to exhibit a large capacity, the propeller fan 15 is rotated at a medium speed, and the tangential fan 24 is rotated at a high speed.

After starting the reheat dry (high capacity) operation, it is determined in step S14 whether or not three minutes have elapsed since the start of the operation, and if three minutes have elapsed, the reheat dry (thermo) operation or reheat is performed. As in the case of the dry (standard) operation, the process proceeds to step S10 to determine the elapsed time from the start of this control, and if three minutes have not elapsed, the reheat dry (high capacity) operation is continued.

In the above air conditioner, when the reheat dry operation is started, the degree of comfort in the room is determined based on the region determination in step S5. The result of the determination is transmitted to the indoor user on the indoor unit 20 side. It has become known. The housing of the indoor unit 20 is provided with a display panel 27 for displaying the indoor temperature during normal heating operation and cooling operation. The display panel 27 has a plurality of LED lamps (display units) 28 arranged in a row.
The indoor temperature is represented by the number of lighting of the LED lamp 28.

In the reheat dry operation, the degree of comfort in the room is divided into three of "low humidity", "comfortable humidity", and "high humidity" according to the above-described case of selecting the three operation patterns. This determination result is represented by the number of lighting of the LED lamp 28. For example, as shown in FIGS. 7A to 7C, only one LED lamp 28 is turned on when the room is in a low humidity state, and two LED lamps 28 are turned on when the room is in a comfortable humidity state. Then, three LED lamps 28 are turned on.

According to the air conditioner of the present invention configured as described above, even when indoor drying is desired, a desired temperature is set, and moderate drying that always feels comfortable while maintaining this temperature is performed. Get the status. In addition, if the set temperature is low, the target humidity is set to be high, and the operation of unnecessarily lowering the indoor humidity is refrained, so that the operation time can be reduced, the power consumption can be reduced, and energy can be saved.

By the way, in the present embodiment, the propeller fan 1
5. Although the tangential fan 24 is also controlled to change the operation state, the compressor 12 alone may be controlled, and the propeller fan 15 and the tangential fan 24 may be operated in a steady state.

[0039]

As described above, according to the air conditioner of the first aspect of the present invention, the target humidity is individually determined in advance for each value within the set temperature range, and the target humidity is determined again. During the thermal dry operation, by changing the operation state of the compressor so that the indoor humidity approaches the target humidity, it is possible to obtain appropriate drying while maintaining the set temperature and always keep the indoor environment in a comfortable state. Can be. In addition, if the set temperature is low, the target humidity is set to be high, and the operation of lowering the indoor humidity needlessly is refrained, so that it is possible to shorten the operation time, reduce the power consumption, and save energy. .

According to the air conditioner of the second aspect of the present invention, the operating state of the outdoor fan and the indoor fan is also changed with the change of the operating state of the compressor.
A dry operation pattern can be selected according to the set temperature and the current indoor temperature and humidity, and the indoor temperature and humidity can be shifted to a desired state more quickly, thereby obtaining a comfortable indoor environment and operating time. Energy can be saved by shortening the time.

According to the air conditioner of the third aspect of the present invention, when the reheating dry operation is instructed, the room temperature is lower than the set temperature and the difference between the set temperature and the current room temperature. Is larger than a predetermined value, by temporarily performing a heating operation before the start of the reheat dry operation, the temperature and humidity in the room can be shifted to a desired state more quickly, thereby providing a comfortable indoor environment. And energy saving by shortening the operation time can be achieved.

According to the air conditioner of the fourth aspect of the present invention, when the reheat dry operation is instructed, the room temperature is higher than the set temperature and the difference between the current room temperature and the set temperature. Is larger than a predetermined value, by temporarily performing the cooling operation before the start of the reheating dry operation, the temperature and humidity in the room can be shifted to a desired state more quickly, thereby providing a comfortable indoor environment. And energy saving by shortening the operation time can be achieved.

According to the air conditioner of the fifth aspect of the present invention, during the reheating dry operation, the degree of the indoor comfort is determined according to the current values of the indoor temperature and humidity.
By expressing the determination result by the explicit number on the display unit, the user can visually recognize the state of the room. A user who knows that the room is in a desired state can use the power wisely and wisely, for example, by stopping the air conditioner itself, thereby helping to save energy.

[Brief description of the drawings]

FIG. 1 is a plan view showing a system configuration of an air conditioner according to the present invention.

FIG. 2 is a flowchart showing a control flow during a reheating dry operation of the air-conditioning apparatus according to the present invention.

FIG. 3 is a chart showing criteria for comparing a set temperature with a current room temperature.

FIG. 4 is a table showing threshold values (a, b, c) of room humidity determined by values of a set temperature.

FIG. 5 is an object table for determining an operation pattern of the air conditioner.

FIG. 6 is a table showing the contents of three operation patterns.

FIG. 7 is a state explanatory view showing a display example of an operation pattern by an LED lamp.

FIG. 8 is a psychrometric chart showing an area of relative humidity where a person feels comfortable with respect to dry bulb humidity.

[Explanation of symbols]

Reference Signs List 10 outdoor unit 11 outdoor heat exchanger 12 compressor 14 electromagnetic expansion valve 15 propeller fan (outdoor fan) 20 indoor unit 21 indoor heat exchanger (first indoor heat exchanger) 22 indoor heat exchanger for reheat drying (first 2 indoor heat exchanger) 23 dry solenoid valve 24 tangential fan (indoor fan) 25 room temperature sensor 26 humidity sensor 27 display panel 28 LED lamp (display unit) 30 refrigerant pipe

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kei Matsuda 3-1-1 Asahicho, Nishibiwajima-cho, Nishi-Kasugai-gun, Aichi Prefecture Inside Air Conditioning Works of Mitsubishi Heavy Industries, Ltd. 3-chome, Mitsubishi Heavy Industries, Ltd. Air Conditioning Works F-term (reference) 3L060 AA05 CC02 CC07 DD07 EE02 EE05 EE06 EE10 3L061 BC07 BD02

Claims (5)

[Claims] An outdoor heat exchanger for exchanging heat between outdoor air and a refrigerant, and a first indoor heat exchanger for exchanging heat between the outdoor heat exchanger or indoor air and a refrigerant. An outdoor unit including a compressor that sends a refrigerant to the outdoor heat exchanger and an outdoor fan that allows outdoor air to flow through the outdoor heat exchanger; the first indoor heat exchanger; and the same as the first indoor heat exchanger. A second indoor heat exchanger that performs heat exchange between indoor air and a refrigerant, an electromagnetic valve provided between the first and second indoor heat exchangers, and the first and second indoor heat exchangers. And an indoor unit having an indoor fan that allows indoor air to flow through the indoor heat exchanger. The throttle unit squeezes the solenoid valve to function as an expansion valve, and the first indoor heat exchanger absorbs heat in the refrigerant. Dehumidifies indoor air and exhausts heat from the refrigerant in the second indoor heat exchanger. This is an air conditioner that can perform reheat dry operation that heats the air in the room and supplies it indoors. The target humidity is individually determined in advance for each value within the set temperature range, and the reheat dry operation is performed. An air conditioner wherein the operating state of the compressor is changed so that the indoor humidity approaches the target humidity during operation. 2. With the change in the operating state of the compressor,
The air conditioner according to claim 1, wherein the operation states of the outdoor fan and the indoor fan are also changed. 3. When the reheat dry operation is instructed, if the room temperature is lower than a set temperature and a difference between the set temperature and the current room temperature is larger than a predetermined value, the reheat dry operation is performed. The air conditioner according to claim 1 or 2, wherein a heating operation is temporarily performed before the start of the operation. 4. When the reheat dry operation is instructed, if the room temperature is higher than a set temperature and a difference between the current room temperature and the set temperature is larger than a predetermined value, the reheat dry operation is performed. 4. The air conditioner according to claim 1, wherein a cooling operation is temporarily performed before the start of the operation. 5. A plurality of blinking display units are provided in the indoor unit, and during the reheating dry operation, the degree of indoor comfort is determined according to the current indoor temperature and humidity values. The air conditioner according to claim 1, 2, 3, or 4, wherein a determination result is represented by an explicit number of the display unit.