JPH1089803A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the drop of outlet temperature at dehumidification while improving the air-conditioning capacity by equipping an air conditioner with an indoor auxiliary heat exchanger upstream of the indoor heat exchanger of a refrigerant passage at operation of dehumidification. SOLUTION: An indoor heat exchanger 1 is constituted sot that the heat transfer tube may be two systems of refrigerant passages 54 and 55 by connecting a front upper stage part 3 and a rear part 4 integrally Then, the heat exchanger part 2 on the lower stage separated thermally by a cutting line 24 is constituted of two refrigerant passages 56 and 57. These heat transfer refrigerant passages 54 and 55, and 56 and 57 are connected with each other through a throttle device 5 for dehumidification by connection tubes 6 and 7. Furthermore, an indoor auxiliary heat exchanger 26 constituted of an indoor heat exchanger 59 is connected by a connection pipe. Hereby, the drop of the outlet temperature at dehumidification can be prevented while improving the air conditioning capacity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner capable of cooling operation or cooling operation and heating operation,
The present invention relates to an air conditioner that enables a dehumidifying operation in which room air is heated by condensation heat of a refrigeration cycle.

[0002]

2. Description of the Related Art In a conventional air conditioner, as a dehumidifying operation for lowering humidity, a system in which a cooled and dehumidified air flow is reheated by the heat of condensation of a refrigeration cycle is known. And JP-A-2-183776 (Document 1).

[0003] To this end, a compressor, a four-way valve, an outdoor heat exchanger, a throttle device, an indoor heat exchanger, and the like are sequentially connected by a refrigerant pipe, and the indoor heat exchanger is divided into upper and lower parts to be divided therebetween. A cycle configuration having a two-way valve with a small hole for a dehumidifying operation is disclosed. During the dehumidifying operation, the two-way valve with a small hole is closed, and the refrigerant is caused to flow through the small hole to perform a throttling action. The upper indoor heat exchanger is a condenser and the lower indoor heat exchanger is an evaporator. Furthermore, the indoor air flow is passed in parallel to these indoor heat exchangers, cooled and dehumidified by an evaporator, and heated by a condenser, thereby enabling a dehumidifying operation for reducing humidity while preventing overcooling.

On the other hand, Japanese Patent Application Laid-Open No. Hei 7-139848 (Document 2) also discloses that the upper side is operated as a reheater and the lower side is operated as a cooler, and air is taken in from a suction port provided in the entire panel to dehumidify. A room air conditioner with a dehumidifying function that has adjustable temperature and blows air that has been dehumidified and adjusted to the desired temperature from the outlet at the bottom of the main body by blending cold and warm air inside, is described. .

[0005] In the air conditioner, a cooling operation and a heating operation are performed in addition to the dehumidifying operation. Recently, there is a great need for energy saving. One way to satisfy this is to make the heat transfer area of the indoor heat exchanger sufficiently large. However, in a small air conditioner such as a room air conditioner, the size of the indoor unit is limited. Therefore, in order to increase the heat transfer area under these restrictions, the literature: "GD series energy-saving air conditioners employing a new dehumidification method: Toshiba Review, Vol. 51,
No.2, 1996, pp. 67 to 70 ”(Reference 3), recently, the indoor heat exchanger is provided from the front to the back of the indoor unit, or the heating unit is used for heating operation. An air conditioner provided with an indoor auxiliary heat exchanger used as a subcooler downstream of the indoor heat exchanger in the above has been developed.

[0006]

As described above, in the case of an air conditioner having an indoor heat exchanger which is sufficiently large in an indoor unit, or an air conditioner provided with an indoor auxiliary heat exchanger, cooling / cooling is not possible.
The dehumidification operation can be performed simultaneously with the heating operation, and the piping configuration of the indoor heat exchanger and the relationship between this and the air flow are devised to perform heat transfer in the indoor heat exchanger in each of the cooling, heating, and dehumidifying operations. It is necessary to improve the performance as much as possible and keep the performance of the refrigeration cycle high enough.

On the other hand, in the above-mentioned Documents 1 and 2, the air conditioner performs dehumidification while preventing a decrease in room temperature by simply dividing the indoor heat exchanger into two and passing an expansion valve therebetween. However, there is no description that considers the above-mentioned performance aspects. Further, during the dehumidifying operation, unpleasant refrigerant flow noise is generated at the dehumidifying expansion device, but no consideration is given to the refrigerant flow noise.

Now, in order to improve the heat exchange rate during cooling and heating, a heat exchanger as described in Reference 3 is used instead of a flat heat exchanger as described in References 1 and 2. The heat transfer area is increased by forming the vessel in a multi-stage bending or arc shape,
Intake air from the inlet provided on the front and top,
The air after heat exchange is blown out from the lower outlet.

However, the air conditioner described in Document 3 has a reheater on the indoor unit side described in Documents 1 and 2, and does not dehumidify while controlling the temperature. That is, the thing described in the above-mentioned document 3 is that an indoor heat exchanger is divided into two parts, and a throttle device for a dehumidifying operation is provided between the two. During the dehumidifying operation, the upstream side of the throttle device is a heater (condenser) and the downstream side The cooler
(Evaporator)
The dehumidification operation is not performed while simultaneously performing the dehumidification and the heating, and the room temperature must be reduced because there is no heat exchanger that generates heat in the indoor unit during the dehumidification.

Meanwhile, the indoor heat exchanger of the air conditioner having the dehumidifying function having the reheater described in Documents 1 and 2 is described in Document 3 in order to improve the heat exchange capacity during cooling and heating. When using a multi-stage or arc heat exchanger, the humidity is high such as during the rainy season, but during the dehumidifying operation on chilly days or winter, despite being heated by the reheater,
There was a problem that the temperature was lowered.

A first object of the present invention is to improve the cooling / heating capacity and prevent a decrease in the blow-out temperature during dehumidification.

[0012]

SUMMARY OF THE INVENTION The object of the present invention is to provide a compressor for compressing a refrigerant, and a thermally split indoor heat exchanger in which the refrigerant from the compressor flows through an outdoor heat exchanger. ,
An air conditioner provided between the thermally split indoor heat exchanger and a dehumidifying throttle unit used as a throttle during a dehumidifying operation, wherein the indoor heat exchange of the refrigerant flow path during the dehumidifying operation is performed. This is achieved by providing an indoor auxiliary heat exchanger upstream of the vessel.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention is shown in FIGS. FIG. 1 is a diagram showing a side cross section of the indoor unit according to the present embodiment. In FIG. 1, reference numeral 1 denotes an indoor heat exchanger having a multi-stage (three-stage) bending structure incorporated in an indoor unit, which is cut from a lower front part 2 and a front upper part 3 in the indoor unit by a thermal cutting line 24. It is configured so as to be thermally separated from a portion extending to the portion 4. An indoor auxiliary heat exchanger 26 is provided in the refrigerant flow path at a position upstream of the indoor heat exchanger 1 during a dehumidifying operation or a cooling operation, and downstream of the indoor heat exchanger 1 during a heating operation. It is. In these heat exchangers, 20 indicated by a circle denotes a heat transfer tube provided so as to penetrate a plurality of radiating fins 23, and a broken line 22 denotes a heat transfer tube 20.
It is a connecting pipe between each other. Reference numeral 5 denotes a dehumidifying throttle device that performs a throttling action during the dehumidifying operation. The upper front portion 3 and the rear portion 4 of the indoor heat exchanger 1 are thermally integrally connected, and the dehumidifying throttle device 5 is connected by a connection pipe 6. Connected to one connection port, the other connection port of the dehumidifying throttle device 5 is connected to a connection pipe 7.
Is connected to the lower part 2 of the front surface of the indoor heat exchanger 1 which is thermally separated through the heat exchanger.

Reference numeral 9 denotes a once-through fan type indoor fan, 10 denotes a front suction grill, 11 denotes a front upper suction grill, 12 denotes a rear upper suction grill, 13 denotes a filter,
Reference numeral 4 denotes a rear casing, 15 denotes an air outlet, 16 denotes an air outlet wind direction plate.
1, 92, 93, respectively, front suction grill 1
0, the air is sucked through the filter 13 from the front-side upper suction grill 11 and the rear-side upper suction grill 12 and exchanges heat with the refrigerant in the multi-stage bending indoor heat exchanger 1.
, And is blown into the room from the outlet 15.

Reference numeral 17 denotes a dew tray for the front side portions 2 and 3 of the multi-stage bending indoor heat exchanger 1, and 18 denotes a dew tray for the rear portion 4 of the multi-stage bending indoor heat exchanger 1, which is generated during a cooling operation or a dehumidifying operation. Works to receive dehumidified water.

FIG. 2 is a view showing one embodiment of the dehumidifying throttle device 5 in FIG. 1. FIG. 2 (a) is a diagram showing an operation state of the dehumidifying throttle device 5 during a dehumidifying operation. FIG.
(B) is a figure which shows the operation state of the throttle device 5 for dehumidification at the time of cooling and heating operation.

In these figures, reference numeral 30 denotes a valve body, 31
Is a valve seat, 32 is a valve body, 33 is a valve portion of the valve body 32, 34, 3
5 is a connecting pipe, 36 is an electromagnetic motor for moving the valve element 32, larger arrows 38 and 39 indicate the refrigerant flow direction (pipe direction), and arrow 40 indicates the refrigerant flow direction during the dehumidifying operation.

During the dehumidifying operation, the valve body 32 is closed by the electromagnetic motor 36 as shown in FIG. At this time, the indoor auxiliary heat exchanger 2 serving as a condenser
6 and the high-pressure condensed liquid refrigerant that has passed through the portions 3 and 4 from the upper front to the back of the indoor heat exchanger 1
And flows through a narrow passage 37 formed by a gap between the valve portion 33 and the valve seat 31 as shown by an arrow 40. Then, it flows into the lower part 2 on the front surface of the indoor heat exchanger 1 serving as an evaporator.

As a result, the portions 3 and 4 of the indoor auxiliary heat exchanger 26 and the indoor heat exchanger 1 from the upper front stage to the rear surface
Is a heater (reheater), and the lower part 2 on the front side is a cooler, which enables the dehumidification operation of heating and cooling and dehumidifying indoor air at the same time.

In the cooling and heating operations, FIG.
As described above, the valve element 32 of the dehumidifying throttle device 5 is pulled up by the electromagnetic motor 36 and is fully opened. As a result,
The connecting pipes 34 and 35 communicate with almost no flow resistance, and the refrigerant flows with almost no resistance.

FIG. 3 is a diagram showing the entire cycle configuration of the present embodiment, wherein 50 is a compressor for compressing a refrigerant having a variable capacity by controlling the number of revolutions, 51 is a four-way valve for switching the operation state, and 52 is The outdoor heat exchanger 53 is a motor-operated expansion valve that can be fully opened without a throttling effect, and further includes the indoor auxiliary heat exchanger 26, the multistage bending indoor heat exchanger 1, and the dehumidifying throttle device 5, Are connected in a ring by a connection pipe to form a refrigeration cycle. In FIG. 3, the indoor auxiliary heat exchanger 26 and the multi-stage bending indoor heat exchanger 1 are shown.
1 schematically shows an embodiment of the flow path state of the heat transfer tube. In the indoor auxiliary heat exchanger 26, a heat transfer tube is configured by a refrigerant passage 59 of one system, and is connected to the indoor heat exchanger 1 by a connection pipe 29.

The indoor heat exchanger 1 has an upper front portion 3 and a rear portion 4 which are integrally connected to each other and have two heat transfer tubes.
4 and 55, and the lower heat exchanger portion 2 thermally separated by the cutting line 24 is constituted by two refrigerant passages 56 and 57. Further, these heat transfer tube refrigerant passages 54, 55, 56, and 57 are connected by connection tubes 6 and 7 via a dehumidifying expansion device 5. Further, 58 is an outdoor fan.

In the above indoor unit structure and refrigeration cycle configuration, during the dehumidifying operation, the four-way valve 2 is switched in the same manner as during the cooling operation, the dehumidifying expansion device 5 is appropriately throttled, and the electric expansion valve 53 is fully opened. As shown by a dashed line, the refrigerant is the compressor 50, the four-way valve 51, the outdoor heat exchanger 52, the electric expansion valve 53, the indoor auxiliary heat exchanger 26, the front upper part 3 and the rear part 4 of the indoor heat exchanger 1, dehumidification. Throttle device 5, lower part 2 on the front of indoor heat exchanger 1, four-way valve 51, compressor 5
0, the outdoor heat exchanger 52 is the upstream condenser, the indoor auxiliary heat exchanger 26 and the upper front part 3 and the rear part 4 of the indoor heat exchanger 1 are the downstream condenser and the indoor heat exchanger. 1 is operated so that the lower part 2 on the front side becomes an evaporator.

When the indoor air is flown by the indoor fan 9 as shown by arrows 91, 92, and 93, the indoor air is cooled and dehumidified by the front lower heat exchanger portion 2 acting as an evaporator, and at the same time, downstream. Is heated by the indoor auxiliary heat exchanger 26 as a condenser or a heater and the upper front part 3 and the rear part 4 of the indoor heat exchanger, and these airs are mixed and blown out into the room.

In this case, by controlling the number of revolutions to control the capacity of the compressor 50 and the blowing capacity of the indoor fan 9 and the outdoor fan 58, the capacity of the cooler 2 and the heaters 26, 3, and 4 is adjusted. Therefore, the amount of dehumidification and the temperature of the blown air can be changed in a wide range.

As described above, when the indoor auxiliary heat exchanger 26 is not provided during the dehumidifying operation, the front upper part 3 and the rear part 4 of the indoor heat exchanger 1 acting as a reheater are present. First, the reason why the room temperature decreases will be described.
Referring to FIG. 1, in such a fan structure, arrows 9
70% of the suction air of 1, 92 and 93 is air from arrow 91 from the front of the panel, and the remaining 30% is arrow 9
When the heat exchanger acting as a cooler is arranged in the upper stage and the reheater is arranged in the lower stage, the dehumidified water is evaporated again by the reheater and does not dehumidify. The heat exchanger must be arranged in the lower part of the front, and as shown in FIG. 1, it is necessary to arrange a reheater and a cooler. The amount of air flowing through the lower part 4 acting as a cooler is smaller than the amount of air flowing through the lower front part 2, and there is a problem that the room temperature decreases when the outside air temperature is correspondingly low.

In the present embodiment, since the indoor auxiliary heat exchanger 26 acting as a reheater is provided in the ventilation path during the dehumidifying operation, a decrease in temperature during the dehumidifying operation can be suppressed. In addition, since this indoor auxiliary heat exchanger is provided on the reheating side, the amount of heat exchange of the reheater increases, the amount of refrigerant condensed increases, the capacity of the entire cycle improves, and the dehumidifying throttle device 5 is provided.
In addition, the gas phase of the gas-liquid two-phase flow that causes the refrigerant flow noise is reduced, and the refrigerant flow noise during the operation of the dehumidifying expansion device 5 (during the dehumidification operation) can be reduced.

As described above, according to the present embodiment, during the dehumidifying operation, the upstream side of the dehumidifying throttle device in the indoor auxiliary heat exchanger and the thermally split indoor heat exchanger are each provided with the heater 1. The downstream side of the heater 2 and the dehumidifying expansion device becomes a cooler, and the air sucked into the indoor unit is heated by the heater 1 and the heater 2 and simultaneously cooled by the cooler to remove moisture and then mixed. The air is blown out, and a comfortable dehumidifying operation without excessive cooling can be performed. In particular, the number of heaters is two, and the heat transfer area of the heater is sufficiently larger than the heat transfer area of the cooler to increase the heating capacity, so that a comfortable dehumidifying operation without excessive cooling can be performed.

As described above, in the dehumidifying operation,
Unpleasant refrigerant flow noise is generated by the throttle (decompression) action at the dehumidifying throttle device. This refrigerant flow noise is greatly influenced by the flow pattern of the high-pressure refrigerant flow on the inlet side in the dehumidifying expansion device. When the inlet refrigerant flow is in a liquid state, the noise level of the refrigerant flow noise is the lowest and the sound quality is good, but the inlet refrigerant flow is good. However, when the state becomes a gas-liquid two-phase state, the noise level increases and the sound quality deteriorates.

However, in the present invention, the indoor auxiliary heat exchanger 26 also functions as a condenser during the dehumidifying operation, and the condensing capacity increases. As a result, the refrigerant flow on the inlet side of the dehumidifying throttle device becomes a liquid state from a place where the degree of dryness is smaller, the noise level of the refrigerant flow noise is reduced, and the sound quality is also improved.

Further, by making the indoor heat exchanger 1 a multi-stage bending heat exchanger to increase the heat transfer area, the size of the cooler portion becomes relatively large and the dehumidifying ability can be improved. Further, in order to increase the amount of heating in the heater in the dehumidifying operation, it is necessary to increase the ratio of the heater portion of the indoor heat exchanger as compared with the cooler portion. The heater part is formed by making the portions 3 and 4 from the front upper stage to the rear surface of the indoor heat exchanger 1 formed as a multistage bend into a heater and the front lower portion 2 of the indoor heat exchanger 1 into a cooler. Can have a sufficiently large heat transfer area than the cooler portion.

Further, the heaters (the indoor auxiliary heat exchanger 26 and the portions 3, 4 from the front upper stage to the rear surface of the indoor heat exchanger) are not arranged below the cooler (the lower front portion 2 of the indoor heat exchanger). Therefore, the dehumidified water generated in the cooler does not reach the heater and re-evaporate.

Next, during the cooling operation, the dehumidifying throttle device 5 is opened, the electric expansion valve 53 is appropriately throttled, and the refrigerant is circulated as shown by the solid line arrow, so that the outdoor heat exchanger 52 is connected to the condenser and the auxiliary room. Indoor cooling is performed using the heat exchanger 26 and the multi-stage bending indoor heat exchanger 1 as evaporators.

In the heating operation, the four-way valve 51 is switched, the dehumidifying expansion device 5 is opened, the electric expansion valve 53 is appropriately throttled, and the refrigerant is circulated as indicated by the dashed arrow, so that the multistage bending indoor heat exchanger 1 is operated. Condenser, indoor auxiliary heat exchanger 26
Is used as a supercooler and the outdoor heat exchanger 52 is used as an evaporator to heat the room.

It is necessary to ensure efficient cycle operation and heat exchange performance in the multistage bending indoor heat exchanger 1 and the indoor auxiliary heat exchanger 26 for each of the cooling and heating operations. Hereinafter, this method will be described.

First, in FIG. 3, in the cooling operation, the refrigerant flows from the indoor auxiliary heat exchanger 26 to the multi-stage bending indoor heat exchanger 1, and both of these heat exchangers have a low pressure, a large specific volume of the gas refrigerant, and a large volume flow rate. Since the number of evaporators increases, if the flow path area is small, the pressure loss here becomes large and the performance of the cycle decreases. Therefore, in FIG. 3, the refrigerant flow paths of the portions 3 and 4 from the front upper stage to the rear surface and the front lower portion 2 of the multistage bending indoor heat exchanger 1 as the main heat exchanger are respectively denoted by 54, 55 and 56 and 57. There are two systems. As a result, the pressure loss in the refrigerant flow path is sufficiently reduced, and the performance degradation due to this is sufficiently reduced. Furthermore, since the indoor auxiliary heat exchanger 26 is provided or the indoor heat exchanger 1 is provided from the front to the back, the heat transfer area as the evaporator can be sufficiently increased, so that the performance can be improved, and the performance can be improved as a whole. It is possible.

Further, in order to improve the performance in the heating operation, it is necessary to take sufficient supercooling at the outlet of the indoor heat exchanger serving as a condenser. In this supercooling region, the refrigerant temperature is gradually lowered from the condensing temperature at the same time as the refrigerant is in a liquid state, so that the speed of the liquid refrigerant flow is increased to increase the heat transfer coefficient in the heat transfer tube, Is required to be on the windward side to exchange heat with a relatively low-temperature air flow before heat exchange. Furthermore, the temperature of the high-temperature gas refrigerant is reduced to the condensing temperature at the inlet portion of the lower front portion 2 of the indoor heat exchanger 1 at the time of the heating operation. I need to do it.

In FIG. 3, the outlet side of the condenser is an indoor auxiliary heat exchanger 26, which has a single refrigerant flow path and a sufficiently small flow path area. Can be made sufficiently high, and it is arranged on the windward side of the indoor heat exchanger 1. Therefore, the indoor auxiliary heat exchanger 1 can exhibit sufficient performance as a subcooler. Further, in the lower part 2 on the front surface of the indoor heat exchanger in which the refrigerant flow paths are divided into two systems of 56 and 57, a piping configuration is provided in which the inlet side of the high-temperature gas refrigerant flow during the heating operation is provided on the leeward side of the air flow. In the vessel part 2, the refrigerant flow and the air flow are made to be countercurrent,
Heat exchange performance can be improved.

Here, when the size of the indoor unit cannot be sufficiently increased, the indoor auxiliary heat exchanger 26 may not be sufficiently large as a subcooler in the heating operation. FIG. 4 shows an embodiment capable of solving this problem.

In FIG. 4, a multi-stage bending indoor heat exchanger 1 is shown.
The portions 3 and 4 from the upper front side to the rear side of the above are composed of a single-system refrigerant flow path portion 60 and two-system refrigerant flow path portions 61 and 62 provided on the windward side. Further, the refrigerant flow path of the front lower part 2 of the indoor heat exchanger 1 is made into two systems of 56 and 57, and at the same time, the refrigerant inlet part at the time of heating operation in the front lower part 2 is provided on the leeward side of the air flow. It is. Those denoted by the same reference numerals as those in FIG. 3 indicate the same parts.

With this cycle configuration, in the heating operation, the high-temperature and high-pressure gas refrigerant that has exited the compressor 50 and passed through the four-way valve 51 enters the indoor heat exchanger 1 and passes through the refrigerant flow path in the front lower part 2. Diverges through the two heat transfer tubes 56 and 57 and then passes through the fully open dehumidifying throttle device 5 to the portions 3 and 4 from the upper front to the back of the indoor heat exchanger 1.
And the refrigerant flow path branches and flows through the two heat transfer tubes 61 and 62, and then merges to form a single heat transfer tube 60.
, And the refrigerant passage is a single-system indoor auxiliary heat exchanger 2
Flow through 6.

In this case, in the lower front part 2 of the indoor heat exchanger 1, the inlet side where the high-temperature gas refrigerant flows is on the leeward side of the air flow, and the outlet side where the two-phase refrigerant flows is on the leeward side of the low-temperature air flow. In the lower front part 2, the refrigerant flow and the air flow are in a counterflow state with excellent heat exchange performance. Also, a part 3 from the upper front to the back of the multi-stage bending indoor heat exchanger 1,
Heat transfer tube 60 on the refrigerant outlet side and the indoor auxiliary heat exchanger 2
The sixth heat transfer tube 59 is a single-system refrigerant flow path, and further, these heat transfer tubes 60 and 59, which form a subcool region where the temperature gradually decreases from the saturation temperature, exchange heat with the low-temperature upstream airflow. As a result, a sufficient subcool is obtained, and the temperature of the refrigerant flowing from the indoor unit to the outdoor unit becomes almost room temperature, so that the heating performance can be improved.

Further, in the cooling operation, the electric expansion valve 5
The two-phase refrigerant which has been squeezed into a low pressure and low temperature in step 3 first enters the indoor auxiliary heat exchanger 26 and has a refrigerant flow path of one system of the heat transfer tube 59.
, And then enters the indoor heat exchanger 1, passes through one system of heat transfer tubes 60 in the heat exchanger portions 3 and 4 from the front upper stage to the rear surface, and branches into two systems of heat transfer tubes 61 and 62. , And further through the dehumidifying squeezing device 5 to lower the front lower part 2
Into the heat transfer tubes 56 and 57 of two systems. In this case, since the dryness of the refrigerant in the heat transfer tubes 59 and 60 is relatively small, the pressure loss is relatively small even in a single-system refrigerant flow path. The heat transfer tubes 61, 62 and 5 having relatively large dryness
At portions 6 and 57, the pressure loss is sufficiently reduced because the refrigerant flow paths are divided into two systems. As a result, a decrease in cooling performance due to pressure loss can be prevented. Further, by providing the indoor auxiliary heat exchanger 26, the heat transfer area as the evaporator increases, and the cooling performance improves.

Here, in the embodiment shown in FIGS. 3 and 4, the case where the heat transfer tubes of the indoor heat exchanger 1 are divided into two systems and the case where one system and two systems are combined are shown, but the present invention is not limited to these. Instead, it is possible to divide the refrigerant flow path into more systems, and in this case as well, the pressure loss of the refrigerant flow in the indoor heat exchanger 1 can be reduced, and particularly, the cooling performance can be prevented from lowering. However, if the number of refrigerant channels is too large, the pressure loss of the refrigerant flow is reduced, but the heat transfer coefficient is significantly reduced, and the performance of the air conditioner as a whole in the cooling operation and the heating operation is reduced. Therefore, it is necessary to set an optimal number of refrigerant channels in the system, and the number of systems is determined mainly according to the inner diameter of the refrigerant pipe. Indoor heat exchanger 1
Thus, the same effect can be obtained by using a heat transfer tube having a large pipe diameter at the place where the refrigerant flow path of the multi-system is formed and a single refrigerant flow path (not shown). That is, by increasing the diameter of the pipe, the flow velocity of the refrigerant flow is reduced, and it is possible to prevent performance degradation particularly during cooling operation.

Further, since the indoor auxiliary heat exchanger 26 in FIGS. 1, 3 and 4 is provided on the windward side of the indoor heat exchanger 1 with respect to the airflow, the indoor auxiliary heat exchanger 26 and the indoor heat exchanger 1 In the overlapped portion, the airflow decreases due to the increase in ventilation resistance, and the heat transfer performance decreases. Therefore, it is necessary that the indoor auxiliary heat exchanger 26 has a small ventilation resistance with respect to the indoor heat exchanger 1. For this purpose, the indoor auxiliary heat exchanger 2
Numeral 6 indicates that the fin pitch is increased or the depth dimension (dimension in the direction in which the wind flows) as compared with the indoor heat exchanger 1.
Or the indoor heat exchanger 1 has a structure in which no slit is provided while a slit is provided in the fin in order to improve the heat transfer performance (not shown).

Next, in the indoor unit structure shown in FIG. 1, the wind speed distribution of the intake air indicated by arrows 91, 92 and 93 in the multi-stage bending indoor heat exchanger 1 is relatively fast at 91 corresponding to the lower part 2 on the front side. Further, from the design point of view, as shown in FIG. 5, there is a case where the upper part 80 is not covered with the air suction port at the front surface of the indoor unit, and only the lower part is a suction grille 81. , Arrows 91, 9
As for the wind speed distribution of the suction airflow indicated by 2, 93, the wind speed distribution indicated by an arrow 91 corresponding to the front lower suction grille 81 is the fastest. In FIG. 5, the same reference numerals as in FIG. 1 denote the same parts.

In such a case, as shown in FIG. 5 as a representative example, by providing the auxiliary heat exchanger 26 on the windward side of the lower front part 2 of the multistage bending indoor heat exchanger 1, the cooling and heating performance is further improved. can do. That is, in the cooling and heating operations, since the air volume corresponding to the arrow 91 is relatively large, the indoor auxiliary heat exchanger 2 corresponding to this air volume is used.
Even if the heat exchanger portion composed of 6 and the lower front portion 2 of the indoor heat exchanger becomes thicker in the depth direction in which the wind flows, the temperature efficiency of this heat exchanger portion is kept relatively high. Further, since the auxiliary heat exchanger 26 having a (slightly) ventilation resistance is provided at a place where the wind speed distribution in the indoor heat exchanger 1 is fast, the suction wind speed distribution on the front surface of the entire indoor heat exchanger 1 becomes more uniform. As a result, the indoor unit structure of FIG. 5 can improve the cooling and heating performance as compared with the indoor unit structure of FIG.

The performance of the dehumidifying operation in the structure of FIG. 5 is not greatly different from the indoor unit structure of FIG. 1 according to actual measurement (the amount of dehumidification tends to decrease slightly, while the temperature of the blown air tends to increase). ), It is possible to perform comfortable dehumidifying operation without excessive cooling.

Furthermore, if the indoor auxiliary heat exchanger 26 cannot be located on the windward side of the rear part 4 or the windward side of the front lower part 2 of the indoor heat exchanger due to structural restrictions of the indoor unit, The performance of the auxiliary heat exchanger in the dehumidification, cooling and heating operations described above can be obtained, although the performance may slightly decrease on the windward side of the upper front section 3 of the indoor heat exchanger.

3 and 4, the indoor unit structure of FIG. 5 or the indoor unit structure in which the indoor auxiliary heat exchanger 26 is provided on the windward side of the upper front part 3 of the indoor heat exchanger can be applied. The same effect can be obtained (not shown).

In the embodiments shown in FIGS. 1, 3, 4, and 5, the indoor heat exchanger 1 is bent into three steps of a lower front part 2, a front upper part 3, and a rear part 4. However, the present invention is not limited to this, and each part may be configured in multiple stages as needed. FIG. 6 shows the lower part 2 ′ of the front of the indoor heat exchanger 1, which is the lower part of the thermal cutting line 63.
The case where there are three stages of 4, 65 and 66 is shown. Thereby, the heat transfer area can be made larger than that of FIG. Furthermore, as shown in FIG. 7, the lower part of the front surface, the upper part of the front part, and the back part have an integrated structure that is not a broken line but a continuous curve. The lower part of the front surface is connected to 68 and 69 by a cutting line 67.
The structure may be thermally separated into two, and the heat transfer area can be similarly increased. In particular, room air conditioners, which are small air conditioners, often do not have enough room to accommodate the indoor heat exchanger. In this case, the number of bending times of the indoor heat exchanger is increased or the indoor heat exchanger is curved. Thus, the indoor heat exchanger having a sufficient heat transfer area can be stored in a small space. Also in the case of these indoor heat exchangers, a similar effect can be obtained by providing an indoor auxiliary heat exchanger on the windward side of the indoor heat exchanger as shown in FIG. 1 or FIG.

The dehumidifying throttle device 5 and the electric expansion valve 53 shown in FIGS. 1, 3, 4 and 5 may have a configuration in which a capillary tube or a normal expansion valve and a two-way valve are provided in parallel. Often (not shown), by opening and closing the two-way valve, the same operation as in the previous embodiments can be realized.

Here, in the dehumidifying operation, if the blowing capacity of the outdoor fan 58 in FIG. 3 is reduced, the ability of the outdoor heat exchanger 52 to radiate heat to the outside air decreases, and the indoor auxiliary heat exchanger 26 and the indoor heat exchange, which serve as heaters, The heat dissipating ability in the portions 3 and 4 from the upper front stage to the rear surface of the container 1 is increased. Further, by increasing the capacity of the compressor 50, the heating capacity of these heaters can be increased, and the dehumidifying capacity of the lower front part 2 of the indoor heat exchanger 1 serving as a cooler can be increased. Further, by changing the air blowing capacity of the indoor fan 9, a dehumidifying operation suitable for various use conditions can be performed. For example, in a normal dehumidifying operation, the indoor air volume is changed according to the preference of a person, and the laundry is operated by increasing the indoor air volume when drying the laundry, and by decreasing the indoor air volume when sleeping. In this case, recently, a DC motor fan or an inverter compressor has been adopted, and since the number of rotations is easily controlled, the capacity of the fan or the compressor is easily changed so that the heating capacity in the dehumidifying operation can be widened. The various dehumidifying operations described above can be performed by changing the outlet temperature from cooling to isothermal and heating, changing the dehumidifying capacity, and changing the amount of indoor air in accordance with the use condition.

Heretofore, the structure in which the indoor heat exchanger is provided from the front to the back of the indoor unit has been considered. However, the present invention is not limited to this. In the case of an indoor unit structure in which an auxiliary heat exchanger is provided on the windward side (not shown; for example, when the rear portion 4 of the indoor heat exchanger 1 is not provided in FIG. 1 or FIG. 5) ), The same effect of the indoor auxiliary heat exchanger as described above can be obtained.

Further, with respect to the indoor heat exchanger structure provided from the front to the back of the indoor unit, in the embodiments of FIGS. 1, 3, 4 and 5 described above, from the upper front to the back. And the lower front part are thermally divided into two parts, and a dehumidifying throttle device is provided between them. However, the present invention is not limited to this, and the entire front part (upper and lower parts) and the rear part are separated. It is thermally divided into two by a cutting line or the like, and a dehumidifying throttle device is provided between the two. A portion 3 from the upper front stage to the rear surface of the indoor heat exchanger 1 in FIGS. The portion corresponding to No. 4 is formed as portions 2 and 3 from the lower front stage to the upper front portion of the indoor heat exchanger 1, and the portion corresponding to the lower front portion 2 is formed as a rear portion 4 (not shown). The exchanges are shown in FIGS. 1, 3, 4,
Similarly to FIG. 5 and the like, the same operation and effect can be obtained by providing the air conditioner upstream of the indoor heat exchanger in the refrigerant flow path during the dehumidifying operation and on the windward side of the indoor heat exchanger in the indoor unit air passage. That is, in the dehumidifying operation, the entire front part of the indoor auxiliary heat exchanger and the indoor heat exchanger becomes a heater, the rear part of the indoor heat exchanger becomes a cooler, and the heater part is larger than the cooler part. Since the heater is not disposed below the cooler, the dehumidified water generated in the cooler does not reach the heater and re-evaporate. In addition, by making the refrigerant flow path of the front part and the rear part of the indoor heat exchanger two or more each, or by making the refrigerant flow path of the indoor auxiliary heat exchanger one system and arranging it on the windward side of the indoor heat exchanger In addition, the pressure loss can be reduced in the cooling operation or the heating operation, and the refrigerant flow and the air flow can be made to flow in opposite directions. Further, during the heating operation, the indoor auxiliary heat exchanger acts as a subcooler to efficiently perform sufficient subcooling. Can be taken. Therefore, in the cooling operation and the heating operation, a sufficiently efficient operation can be performed as in the embodiment described with reference to FIGS.

In the embodiment described above, the case where a single refrigerant such as HCFC22 (abbreviation of hydrochlorofluorocarbon 22) often used in an air conditioner is used has been described. However, in recent years, research on alternative refrigerants replacing HCFC22 has been actively conducted from the viewpoint of depletion of the ozone layer and global warming, and the use of mixed refrigerants as well as single refrigerants as alternative refrigerants is being studied.
On the other hand, it is clear that the control method of the structure, cycle configuration, and operation of the indoor unit described in the embodiment shown in FIGS. 1 to 5 can be applied, and the same effect can be obtained.

[0057]

As described above, according to the air conditioner of the present invention, the indoor heat exchanger is thermally divided into two parts, and the dehumidifying throttle device for performing the throttling action during the dehumidifying operation is provided therebetween. During operation, the heater is located upstream of the dehumidifying expansion device.
(Condenser), a cycle configuration in which the downstream side is a cooler (evaporator), and a cycle configuration in which an indoor auxiliary heat exchanger is provided upstream of the heater during the dehumidification operation.
In addition, the indoor heat exchanger is provided from the front to the back of the indoor unit, and has a structure in which a sufficiently large heat transfer area can be ensured even in a compact indoor unit.

As a result, in the dehumidifying operation, since the dehumidifying efficiency (dehumidifying amount / power consumption) can be improved and the amount of heating in the heater can be increased, the temperature of the blown air can be sufficiently increased. Since the condensation capacity for the flow can be increased and the refrigerant flow at the inlet of the dehumidifying expansion device can be brought into a liquid state (from a place where the dryness is sufficiently low),
Refrigerant noise caused by the dehumidifying throttle device can be reduced. Even in a compact indoor unit, the heat transfer area can be made sufficiently large in the cooling and heating operations, and in particular in the heating operation, the indoor auxiliary heat exchanger can be effectively used as a subcooler, so that the performance is improved. Power saving can be achieved.

Further, the flow resistance of the refrigerant flow in the indoor heat exchanger provided from the front to the rear in the indoor unit is increased by making each of the refrigerant flow paths of the thermally split indoor heat exchanger into two or more systems. Or to prevent a sufficient refrigerant subcooling during the heating operation by making the outlet part during the heating operation in the refrigerant flow path of the indoor heat exchanger a single system,
Furthermore, by making the piping configuration such that the refrigerant flow and the air flow in the indoor heat exchanger are as opposed to each other as possible,
It is possible to prevent the size of the heat exchanger from being increased to make the refrigerant flow path longer, and to prevent performance degradation due to the provision of the dehumidification control valve.

The capacity of the outdoor fan and the compressor can be controlled, and by appropriately controlling the performance of these devices, the amount of heating by the heater can be controlled in a wide range so that a sufficient amount of dehumidified water can be obtained. Thus, the dehumidifying operation of the heating, isothermal, and cooling feelings can be performed, and at the same time, the dehumidification operation of various usages can be performed by controlling the capacity of the indoor fan.

Further, the above-described dehumidifying operation method and the piping configuration of the indoor heat exchanger can be applied to a single refrigerant or a mixed refrigerant, and the same effects can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing an indoor unit structure of an air conditioner according to an embodiment of the present invention.

FIG. 2 is a diagram showing a structure and an operation state of an example of a dehumidifying throttle device in FIG. 1;

FIG. 3 is a diagram showing a cycle configuration of an air conditioner according to an embodiment of the present invention.

FIG. 4 is a diagram showing a piping configuration of an indoor heat exchanger according to another embodiment of the present invention.

FIG. 5 is a diagram showing an indoor unit structure of an air conditioner according to another embodiment of the present invention.

FIG. 6 is a diagram showing a shape of an indoor heat exchanger according to another embodiment of the present invention.

FIG. 7 is a view showing a shape of an indoor heat exchanger according to still another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Indoor heat exchanger, 2 and 2 '... Lower front part of indoor heat exchanger, 3 ... Upper front part of indoor heat exchanger, 4 ... Rear part of indoor heat exchanger, 5 ... Dehumidifying throttle device, 6 , 7, 27,
28, 29: Connection piping, 9: Indoor fan, 10: Front suction grill, 11: Top suction grill, 12: Rear suction grill, 13: Filter, 14: Rear casing, 15: Air outlet, 16: Air outlet wind direction plate , 17 ... front dew tray, 18 ...
Back dew receiving tray, 20: heat transfer tube, 21, 22: connection pipe of heat transfer tube, 23: radiating fin, 24, 63, 67: thermal cutting line, 26: indoor auxiliary heat exchanger, 30: valve body, 31 ... Valve seat, 32 ... valve element, 33 ... valve part, 34, 35 ... connection pipe, 3
6 ... Electromagnetic motor, 37 ... Refrigerant flow path during dehumidification operation, 50 ...
Compressor, 51: Four-way valve, 52: Outdoor heat exchanger, 53: Electric expansion valve, 54, 55, 56, 57, 59, 60, 6
1, 62 ... refrigerant flow path, 58 ... outdoor fan, 64, 65,
66, 68, 69: heat exchanger part, 80: front upper panel, 81: front lower suction grille, 91, 92, 93: indoor unit suction air flow.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Mitsuo Kudo 502 Kandate-cho, Tsuchiura-shi, Ibaraki Pref. Machinery Research Laboratories, Hitachi, Ltd. Within Hitachi Machinery Research Laboratories (72) Inventor Motoo Morimoto 800, Tomita, Ohira-cho, Shimotsuga-gun, Tochigi Prefecture Inside the Cooling and Cooling Division, Hitachi, Ltd. Hitachi, Ltd.Cooling Division (72) Inventor Hiroshi Kogure 800, Tomita, Ohira, Ohira-cho, Shimotsuga-gun, Tochigi Prefecture

Claims (3)

[Claims] 1. A compressor for compressing a refrigerant, a thermally split indoor heat exchanger into which the refrigerant from the compressor flows through an outdoor heat exchanger, and a thermally split indoor heat exchanger. Air conditioner provided with a dehumidifying throttle means used as a throttle during a dehumidifying operation provided between indoor heat exchangers, wherein an indoor auxiliary is provided upstream of the indoor heat exchanger in the refrigerant flow path during the dehumidifying operation. An air conditioner equipped with a heat exchanger. 2. The indoor unit in which the indoor heat exchanger is housed,
An air inlet is provided on the front surface and the upper surface, and the indoor heat exchanger is provided from the front surface to the rear surface of the indoor unit, and the indoor auxiliary heat exchanger includes a wind at a rear portion of the indoor heat exchanger. The air conditioner according to claim 1, wherein the air conditioner is provided on an upper side. 3. The indoor unit in which the indoor heat exchanger is stored,
An air inlet is provided on a front surface and an upper surface, and the indoor heat exchanger is provided from a front surface to a rear surface of the indoor unit. The indoor auxiliary heat exchanger is provided between the front air inlet and the indoor heat exchanger. The air conditioner according to claim 1, which is provided between the air conditioners.