JP3021226B2 - Air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner having a plate fin and tube type indoor heat exchanger.

[0002]

2. Description of the Related Art One of conventional refrigerant circuits of this type of air conditioner is disclosed.
Examples of which are illustrated in FIG. At the time of the dry operation of the air conditioner, the gas refrigerant compressed by the compressor 1 enters the outdoor heat exchanger 3 via the four-way switching valve 2 and partially radiates heat to the outside air sent by the outdoor fan 4. Condensed and liquefied.

The refrigerant enters a reheater 8 via a bypass pipe 5 and a solenoid valve 6 interposed therebetween, and radiates heat to the indoor air sent by the indoor fan 9 to condense and liquefy to form a liquid refrigerant. Becomes This liquid refrigerant is adiabatically expanded by being throttled by the capillary tube 10 and then enters the indoor heat exchanger 11, where it absorbs heat from the indoor air sent by the indoor fan 9 to evaporate and evaporate to a gas refrigerant. It is sucked into the compressor 1 via the switching valve 2.

[0004] The indoor air is cooled in the process of flowing through the indoor heat exchanger 11 so that the moisture in the air is condensed and dehumidified. Then, the dehumidified cold air is added in the process of flowing through the reheater 8. It is heated and blown out into the room.

During cooling operation, the solenoid valve 12 is opened and the solenoid valve 6
Is closed. Then, the refrigerant circulates in the order of the compressor 1, the four-way switching valve 2, the outdoor heat exchanger 3, the capillary tube 13, the reheater 8, the solenoid valve 12, the indoor heat exchanger 11, the four-way switching valve 2, and the compressor 1. The reheater 8 functions as an evaporator together with the indoor heat exchanger 11.

During the heating operation, the solenoid valve 12 is opened and the solenoid valve 6 is opened.
Is closed, and the four-way switching valve 2 is switched in the reverse manner. Then, the refrigerant flows into the compressor 1, the four-way switching valve 2, the indoor heat exchanger 11, the solenoid valve 12, the reheater 8, the capillary tube 13,
Circulating in the order of the outdoor heat exchanger 3, the four-way switching valve 2, and the compressor 1, the reheater 8 functions as a condenser together with the indoor heat exchanger 11.

The indoor heat exchanger 11 and the reheater 8 are plate fin and tube type heat exchangers each having a single circuit, and are manufactured individually and arranged so as to be in close contact with each other and polymerize. Have been.

[0008]

In the above-mentioned conventional air conditioner, the indoor heat exchanger 11 and the reheater 8 are each composed of a single circuit. After the refrigerant condensed and liquefied by the reheater 3 and the reheater 8 is throttled by the capillary tube 10 and adiabatically expanded, the volume thereof gradually increases in the process of flowing through the indoor heat exchanger 11. Therefore, the pressure loss of the refrigerant when flowing through the indoor heat exchanger 11 is large, and as a result, there is a problem that the performance of the air conditioner is reduced.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the gist of the first invention is to provide a plurality of rows along the air flow direction, and In an air conditioner provided with a plate fin and tube heat exchanger in which tubes are arranged in multiple stages for each row, an upstream tube row and a downstream tube row for the airflow of the heat exchanger By providing a fixed or variable throttle means between the upper and lower tubes in the dry operation of the air conditioner to function as a cooler, the tubes in the downstream as a reheater, and the upstream as a cooler The air conditioner is characterized in that the refrigerant flow path of the tube row is constituted by a plurality of circuits.

[0010] The refrigerant flow path of the downstream tube row functioning as the reheater can be constituted by a plurality of circuits.

The number of rows of the tubes is at least three, and two rows on the upstream side with respect to the air flow are provided with a cooler,
The rows can function as reheaters.

[0012]

The gist of the second invention is to provide a plate fin and tube type heat exchanger in which tubes are arranged in a plurality of rows along the air flow direction and in multiple stages for each row. in the air conditioner, the air by providing a fixed or variable throttle means between the tube rows and a downstream side of the tube row on the upstream side with respect to air flow of the heat exchanger
During the dry operation of the conditioner, the upstream tube row functions as a cooler and the downstream tube row functions as a reheater, and the fixed or variable throttle means is disposed on the downstream back side of the heat exchanger with respect to the air flow. An air conditioner characterized by the following.

[0014]

In the present invention, during the dry operation of the air conditioner, air flows from the upstream to the downstream in the tube row of the plate fin-and-tube heat exchanger, and the refrigerant flows into the downstream tube with respect to the air flow. The air is reheated by being condensed and liquefied in the course of flowing through the row, adiabatically expanded in the course of flowing through the fixed or variable throttle means, and is evaporated and vaporized in the course of flowing through the upstream tube row. Cooling.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention is shown in FIG. FIG. 1 (B) shows a wall-mounted indoor unit 30 of a separate type air conditioner, in which a casing 31 is provided with a suction grill 32 at an upper front portion thereof, and an outlet 33 at a lower front portion thereof. . A filter 34 is provided behind the suction grill 32, and a plate fin-and-tube heat exchanger 20 stands upright with a slight inclination behind the filter 34. Behind the lower part of the heat exchanger 20, an indoor fan 9 composed of a once-through blower is horizontally disposed. A drain pan 35 also serving as a stabilizer is provided below the heat exchanger 20.

When the indoor fan 9 is driven to rotate in the direction of the arrow, the indoor air is sucked into the casing 31 from the suction grill 32, flows through the filter 34 and the heat exchanger 20 in this order, and is urged by the indoor fan 9. Horizontal louver from outlet 33
It is guided by 36 and the vertical louver 37 and blown out into the room.

The plate fin and tube type heat exchanger 20, as shown in FIG. 1 (A), consists of a number of tubes 22 for fixed thereto therethrough and plate fins 21. The plate fins 21 are arranged parallel to each other with a minute gap in a direction perpendicular to the air flow A, and the tubes 22 are arranged in a plurality of rows (three rows in the figure) along the air flow A, and for each row. They are arranged in multiple stages.

An upstream tube row 22A for the air flow A
The refrigerant flow paths of the tube rows 22C and 22B are a plurality of circuits, and the refrigerant flow path of the tube row 22C on the downstream side is a single circuit. The capillary tube 10 is located between the upstream tube rows 22A and 22B and the downstream tube row 22C.
And a parallel circuit 23 comprising the solenoid valve 12. 24 is a distributor. The other configuration is the same as that of the conventional one, and the corresponding members are denoted by the same reference numerals.

During the dry operation of the air conditioner, the refrigerant partially condensed and liquefied in the outdoor heat exchanger (not shown) passes through the bypass pipe 5 and the solenoid valve 6 interposed therebetween to form a plate fin and tube heat exchanger. The refrigerant enters the downstream tube row 22C of the exchanger 20 and condenses and liquefies by exchanging heat with the air flow A in the process of flowing through the refrigerant flow path composed of a single circuit formed by this. This liquid refrigerant is supplied to the distributor 24
After being adiabatically expanded by being throttled in the process of flowing through the capillary tube 10 and flowing through the capillary tube 10, it enters the upstream tube rows 22A and 22B via the distributor 24, and is connected to the two circuits of the refrigerant flow path formed by these. And then 4
In the course of passing through the two circuits, the heat exchange with the air flow A evaporates. After the gas refrigerant is joined by the distributor 24, it is sucked into a compressor (not shown) through the four-way switching valve 2.

The indoor air is sucked by the indoor fan 9 so that a plate fin and tube heat exchanger is provided.
It flows between the 20 plate fins 21 and the tubes 22.
In this process, after being cooled and dehumidified when flowing between the tube rows 22A and 22B on the upstream side and the plate fins 21 in the vicinity thereof, it flows between the tube row 22C on the downstream side and the plate fins 21 in the vicinity thereof. Then, it is heated and then urged by the indoor fan 9 to be blown into the room.

During the cooling operation of the air conditioner, the solenoid valve 6 is closed and the solenoid valve 12 is opened, so that the tube rows 22A, 22B and 22B of the plate fin and tube heat exchanger 20 are provided.
Each of 22C functions as an evaporator. In addition, during the heating operation of the air conditioner, the four-way switching valve 2 is switched in the opposite direction, so that the plate fin and tube heat exchanger is used.
The twenty tube rows 22A, 22B and 22C all function as condensers.

During the dry operation of the air conditioner, the refrigerant which has been adiabatically expanded by being throttled by the capillary tube 10 is provided with the upstream tube row 22A which functions as a cooler.
In the process of flowing through the refrigerant flow path composed of 22B, the volume gradually increases due to evaporation and vaporization, but the number of circuits in the refrigerant flow path increases according to the increase in volume, so this upstream tube row
The pressure loss of the refrigerant when flowing through 22A and 22B is reduced, so that the performance of the air conditioner can be prevented from deteriorating.

FIG. 2 shows a second embodiment of the present invention. In the second embodiment, the inlet side of the refrigerant flow path of the downstream tube row 22C functioning as a reheater has one circuit, and the outlet side has two circuits. Other configurations are the same as those of the first embodiment shown in FIG. 1, and corresponding members are denoted by the same reference numerals.

Thus, in this second embodiment,
During the cooling operation of the air conditioner, the refrigerant adiabatically expanded by the capillary tube 13 enters the downstream tube row 22C of the plate fin-and-tube heat exchanger 20, and one circuit on the inlet side of the refrigerant flow path constituted by the refrigerant flows. After that, two circuits are passed. After a while, solenoid valve 12
After passing through the upstream tube rows 22A and 22B through the two circuits on the inlet side of the refrigerant flow path constituted by these, they flow through the four circuits.

As a result, during the cooling operation of the air conditioner, the refrigerant evaporates in the course of flowing through the tube rows 22C, 22A, 22B, and the number of circuits in the refrigerant flow path gradually increases as the volume increases. Therefore, the pressure loss of the refrigerant can be reduced. Also, during the heating operation of the air conditioner, the number of circuits in the refrigerant flow path gradually decreases as the refrigerant condenses in the process of flowing through the tube rows 22A, 22B, and 22C and decreases in volume, so that the refrigerant Pressure loss can be reduced.

[0026]

[0027]

[0028]

[0029]

[0030] FIG. 3 shows a third embodiment of the present invention. In the third embodiment, the capillary tube 10, the solenoid valve 12, and a complicated refrigerant pipe 26 for connecting these to the heat exchanger 20 are provided at the upper portion of the downstream back surface of the heat exchanger 20 with respect to the airflow, that is, It is arranged an air flow which flowed through the heat exchanger 20 to interfere up no site.

However, as in the prior art, the heat exchanger 20
One side of the capillary tube 10, solenoid valve 12, refrigerant pipe 26
Since there is no need to provide a space for installing the unit or the like, the width of the casing 31 of the indoor unit 30 can be reduced.

In each of the above embodiments, the parallel circuit 23 including the capillary tube 10 and the solenoid valve 12 is provided.
Instead, a variable throttle means such as an electronic expansion valve is provided, and the variable throttle means is fully opened during the cooling operation and the heating operation of the air conditioner, and the opening degree of the variable throttle means is reduced during the dry operation. Can be.

[0033]

According to the present invention, since the refrigerant flow paths of the tube rows on the upstream side with respect to the air flow of the plate fin-and-tube heat exchanger are constituted by a plurality of circuits, the air conditioner can be used as a cooler during the dry operation. The pressure loss when the refrigerant flows through the functioning upstream tube row can be reduced.

Further, if the refrigerant flow path of the downstream tube row functioning as a reheater in a dry operation is constituted by a plurality of circuits, a plate fin and tube type heat exchanger can be provided during a cooling operation and a heating operation of the air conditioner. The pressure loss of the refrigerant flowing through the plurality of tube rows of the exchanger can be reduced.

[0035]

Further, if the fixed or variable throttle means is disposed on the back surface downstream of the heat exchanger with respect to the airflow, the width of the casing of the indoor unit can be reduced.

[Brief description of the drawings]

1A and 1B show a first embodiment of the present invention, wherein FIG. 1A is an explanatory view showing a partial refrigerant system of an air conditioner, and FIG. 1B is a schematic longitudinal sectional view of an indoor unit.

FIG. 2 is an explanatory view of a partial refrigerant passage showing a second embodiment of the present invention.

FIG. 3 is a schematic vertical sectional view of an indoor unit showing a third embodiment of the present invention.

FIG. 4 is a refrigerant circuit diagram of a conventional air conditioner.

[Explanation of symbols]

 20 Heat exchanger 21 Plate fin 22 Tube 22A, 22B, 22C Tube row 10 Throttle means

────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Yoichi Mihara 3-1-1 Asahicho, Nishibiwajima-cho, Nishi-Kasugai-gun, Aichi Pref. Mitsubishi Heavy Industries, Ltd. Aircon Works (56) , U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F24F 1/00 451

Claims (4)

(57) [Claims] 1. A plurality of rows along the direction of air flow, and
In an air conditioner provided with a plate fin and tube heat exchanger in which tubes are arranged in multiple stages for each row, an upstream tube row and a downstream tube row for the airflow of the heat exchanger By providing a fixed or variable throttle means between the upper and lower tubes in the dry operation of the air conditioner to function as a cooler, the tubes in the downstream as a reheater, and the upstream as a cooler An air conditioner characterized by comprising a plurality of circuits in a refrigerant flow path of a tube row. 2. The air conditioner of claim 1 that constitute the refrigerant flow path on the downstream side of the tube column that serves as the reheater into a plurality circuits and JP <br/> symptoms. 3. The number of rows of the tubes is at least three, and two rows on the upstream side with respect to the air flow are provided with a cooler, and
2. The method according to claim 1, wherein the row functions as a reheater.
The air conditioner as described. 4. A plurality of rows along the direction of air flow, and
In an air conditioner provided with a plate fin and tube heat exchanger in which tubes are arranged in multiple stages for each row, an upstream tube row and a downstream tube row for the airflow of the heat exchanger By providing a fixed or variable restrictor between the above, the tube row on the upstream side functions as a cooler and the tube row on the downstream side functions as a re-heater during the dry operation of the air conditioner, and the fixed or variable restrictor means serves as the heat source. An air conditioner, wherein the air conditioner is disposed on the downstream side of the exchanger with respect to the air flow.