JP2001091099A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a parallel flow type heat exchanger capable of removing a condensate generated, when it is heat exchanged. SOLUTION: This heat exchanger 1 is provided in parallel in a substantially horizontal direction to heat exchange the air flowing outside of a flowing tube 11 by the tubs 11, having many channel holes for supplying a refrigerant at an inside comprises a plurality of heat exchange units 1A, 1B provided in the vertical direction and each having a flowing tube group 12 having a plurality of the tubes 11, corrugated fins 21 disposed in the lateral directions between the tubes 11, and header pipes 13, 14 provided at both ends of the group 12 to distribute and collect the refrigerant, and a channel-switching means 18 for selectively switching a first mode for supplying the refrigerant in parallel with the units 1A, 1B and a second mode for supplying the refrigerant only to any of the plurality of the units 1A, 1B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parallel flow type heat exchanger which is provided in parallel with each other in a horizontal direction and exchanges heat with air flowing outside by a plurality of flow tubes for flowing refrigerant inside. The present invention relates to a heat exchanger used for an air conditioner or the like as an evaporator or as a dual-purpose heat exchanger that is switched between an evaporator and a condenser.

[0002]

2. Description of the Related Art FIG. 4 is a front view showing an example of a conventional multi-flow heat exchanger. The heat exchanger 100 corresponds to, for example, a condenser or an evaporator arranged on the indoor unit side when heating or cooling the room in a heat pump for air conditioning the room. The refrigerant r flowing from the refrigerant inlet nozzle 101 flows through the flow pipe 111a from the header pipe 120a and reaches the header pipe 120b as shown by a broken line 110. Next, the gas flows from the header pipe 120b to the circulation pipe 111b to reach the header pipe 120c.
Hereinafter, similarly, the distribution pipe 111c and the header pipe 120
d, flows to the circulation pipe 111d, the header pipe 120e, and flows out from the refrigerant outlet nozzle 130.

[0003] In the heat exchanger 100 used as an indoor unit for cooling the room, there is a problem that dew water is generated when the cooling operation is continued, and the flow pipe is arranged in a horizontal state. In addition, since corrugated fins that are bent in a corrugated manner are provided between the circulation pipes, much of the condensed water generated during heat exchange stays without being discharged, increasing ventilation resistance and increasing heat transfer. There has been a problem that the performance is reduced.

[0004] In view of this, it is conceivable to arrange the header pipes vertically so that the flow pipes are directed vertically so that the dew water can easily flow down.

[0005]

However, in the case of such a configuration in which the flow pipes are arranged vertically, the direction of the refrigerant flowing through the flow pipes is limited to one direction from bottom to top,
There has been a problem that the flow rate of the refrigerant decreases and the heat transfer performance decreases. Since the refrigerant changes its phase from a liquid refrigerant to a gaseous refrigerant in the evaporator, it is necessary to flow the refrigerant upward from below in terms of heat exchange efficiency.

The present invention has been made in view of the above points, and is directed to a parallel flow in which heat is exchanged with air flowing outside by a plurality of flow pipes provided parallel to each other in a horizontal direction and flowing a refrigerant inside. It is an object of the present invention to provide a heat exchanger of the type that can remove dew water generated during heat exchange when functioning as an evaporator.

[0007]

SUMMARY OF THE INVENTION The present invention provides a flow pipe having a plurality of flow passage holes which are provided substantially parallel to each other in a horizontal direction and through which a refrigerant flows, and which exchanges heat with air flowing outside the flow pipe. In the heat exchanger, a flow pipe group having a plurality of the flow pipes, corrugated fins disposed between the flow pipes in a corrugated shape in the left-right direction, and the refrigerant provided on both sides of the flow pipe group. A plurality of heat exchange units having a header pipe to be distributed and assembled are provided in the vertical direction,
Flow path switching means for switching and selecting a first mode for supplying a refrigerant in parallel to each heat exchange unit and a second mode for supplying a refrigerant only to one of the plurality of heat exchange units. Features.

[0008] By using this configuration, it is possible to periodically discharge the dew water accumulated in the heat exchange unit,
A decrease in heat transfer performance can be prevented.

More specifically, a blower for blowing outside air to the plurality of heat exchange units, a temperature detecting means for detecting a temperature of a refrigerant supplied to the heat exchange units, and a control for controlling a rotation speed of the blower Means for increasing the number of revolutions of the blower by a predetermined amount by the control means, and detecting the rate of dew condensation of the heat exchange unit based on the amount of change in the detected temperature detected by the temperature detecting means at that time. Means, wherein the flow path switching means switches and selects the first mode or the second mode based on the detection result of the detecting means. By using this configuration, it is possible to detect the ratio of dew condensation that accumulates in the heat exchanger, and to perform dew-removal processing based on the detected amount, thereby performing unnecessary removal processing. Therefore, a decrease in the operation efficiency of the apparatus can be suppressed.

[0010] The flow path switching means may be configured to select the first mode at normal times and to select the second mode periodically for a predetermined time. By using this configuration,
The flow path switching can be realized with a simple configuration.

Further, the flow pipe is a flat pipe having a large number of flow holes inside.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the heat exchanger according to the present invention will be described below with reference to the drawings. FIG. 1 is a front view showing an embodiment of a parallel flow type heat exchanger according to the present invention.

In FIG. 1, a heat exchanger 1 of the present embodiment is provided with a number of flow pipes, for example, flat pipes 11 through which a refrigerant r flows inside, which are provided in parallel with each other in the horizontal direction.
1 to exchange heat with air flowing outside. Corrugated fins 21 formed by corrugating flat plates are provided between the flat tubes 11 to promote heat exchange between the refrigerant r and air. In FIG. 1, only a part of the corrugated fin 21 is shown.

Further, the heat exchanger 1 is provided on both sides of a flow tube group 12A, 12B comprising a plurality of the flat tubes 11A, 11B (18 in the present embodiment) arranged in parallel in the vertical direction. And header pipes 13A, 13B, 14A, and 14B, which are distribution collecting pipes for distributing and assembling. The refrigerant r is supplied to the refrigerant inlet nozzle 15A (15B).
From the header pipes 13A, 14A (13B,
14B) and flows out of the refrigerant outlet nozzle 16A (16B) through the flow passage hole in the flat tube 11A (11B).

The heat exchanger 1 includes a flow pipe group 12A, corrugated fins 21A, and header pipes 13A, 14A.
A heat exchange unit 1A having A and the like, and a flow pipe group 12B,
Corrugated fin 21B and header pipe 13B, 1
A heat exchange unit 1B having 4B and the like is vertically arranged, and the refrigerant exchanges heat with external air through the corrugated fins 21A and 21B when the refrigerant passes through the flat tubes 11A and 11B.

The refrigerant inlet nozzles 15A and 15B are provided with opening / closing valves 17A and 17B, respectively, and their opening and closing are controlled based on a command from the flow path switching means 18. The flow path switching means 18 includes a first mode in which the on-off valves 17A and 17B are fully opened to supply the refrigerant in parallel to the heat exchange units 1A and 1B, and a heat exchange unit in which the on-off valves 17A or 17B are fully closed. Switching between the second mode for supplying the refrigerant to one of 1A and 1B is selected. The details will be described later.

Further, as shown in FIG. 1, the header pipes 13A and 14A of the heat exchange unit 1A have partition plates 19a and 19b arranged in a horizontal direction, and the refrigerant inlet nozzle 15A of the heat exchange unit 1A. Is supplied from the lower flat tube 11A to the upper flat tube 11A and flows out from the refrigerant outlet nozzle 16A. Similarly, header pipes 13B and 14 of heat exchange unit 1B
B also has partition plates 20a and 20b arranged in the horizontal direction as shown in FIG.

Here, the header pipes 13A, 13B, 14A, 14B, the flat pipe 11
A, 11B, corrugated fins 21A, 21B, partition plates 19a, 19b, 20a, 20b, etc. are formed of aluminum or an aluminum alloy. In particular, header pipes 13A, 13B, 14A, 14B and flat pipes 11A,
11B is an extruded shape member, and corrugated fins 21A and 21B.
Is often formed from a plate material. In addition, it is usual that the components are assembled and then brazed. However, in this case, it is convenient to attach a brazing material to at least one of the joining members.

Next, the operation of the present invention will be described by taking as an example the case where the heat exchanger 1 having the above configuration is applied to a refrigerating device such as a heat pump. FIG. 2 is a schematic configuration diagram showing a refrigerant circuit of a refrigeration apparatus using the heat exchanger 1 as an evaporator.

As shown in the figure, the refrigerant circuit of the refrigeration system
The evaporator 1, the compressor 2, the condenser 3, and the decompressor 4 including the expansion valve are connected to each other by a pipe 5 to constitute a refrigeration cycle for circulating the refrigerant in the direction of the arrow in the figure.

In FIG. 1, reference numeral 6 denotes a blower which is arranged near the evaporator 1 and blows air to the evaporator 1, and performs heat exchange with air passing through the evaporator 1 by rotation of the blower 6. . Reference numeral 7 denotes a temperature sensor as temperature detecting means for detecting the refrigerant temperature near the refrigerant discharge side of the evaporator 1, and inputs the detected temperature of the temperature sensor 7 to the control device 8.

The control device 8 sends a control command for controlling the number of revolutions to the blower 6, estimates the amount of dew condensation on the evaporator 1 based on the temperature detected by the temperature sensor 7, and controls each heat exchange unit 1 A of the evaporator 1. , 1B of the switching valves 17A and 17B. The control device 8 performs processing of the flow path switching means 18 and a detecting means for detecting the dew condensation ratio of the evaporator 1.

Specifically, in order to detect the rate of dew condensation on the evaporator 1, the rotation speed of the blower 6 is periodically increased by a predetermined amount from a rated rotation speed (700 rpm), and the blower 6 is operated at a predetermined rotation speed for a predetermined time. ing. In this embodiment, the blower 6 is set to 8
It is operated at a rotation speed of 00 rpm for 30 seconds.

The control device 8 outputs a control command to the blower 6 to increase the rotation speed by a predetermined amount, and obtains a degree of superheat (= detection temperature−evaporation temperature) based on the temperature detected by the temperature sensor 7 during that period. The superheat degree is taken into an internal storage unit (not shown), and the rate of dew condensation of the evaporator 1 is detected based on the detected change in the superheat degree. Here, as the evaporation temperature, a set temperature preset according to the refrigerant to be used is used.

Next, the contents of the detecting means for detecting the rate of dew condensation on the evaporator 1 in the control device 8 will be described.

The storage unit of the control device 8 causes the evaporator 1 to have a predetermined amount of dew condensation in advance by an experiment, and operates the blower 6 at the above-mentioned predetermined number of rotations for a predetermined time for each amount of the dew condensation.
The degree of superheat during that period is stored. More specifically, an experiment result when the amount of adhesion is changed from 0% to 50% in increments of 10% is stored in the storage unit of the control device 9. As shown in FIG. 3, the smaller the dew condensation rate of the evaporator 1, the larger the temperature change amount of the temperature sensor 7, that is, the degree of superheat. Therefore, the superheat degree H1 obtained from the temperature detected by the temperature sensor 7 at the time of starting the operation of the blower 6 at the above-mentioned predetermined number of revolutions, and the superheat degree H2 obtained from the temperature detected by the temperature sensor 7 after a certain period of time have elapsed. Change rate (= H2-
By judging which amount of H1) corresponds, the rate of dew condensation of the evaporator 1 is detected. Here, the ratio of dew condensation on the evaporator 1 is expressed as a ratio of the cross-sectional area of the ventilation passage closed by dew condensation to the total cross-sectional area of the air passing through the evaporator 1 as 100%. I have.

As described above, when the rate of dew condensation of the evaporator 1 detected by the control device 8 (detection means) is equal to or more than a predetermined amount (in this embodiment, 30% or more), dew removal processing is performed. It is possible to suppress a decrease in the operating efficiency of the apparatus without performing unnecessary removal processing.

Next, the flow path switching means 1 in the control device 8
8 will be described.

In the control device 8, after the start of the operation of the device and when the rate of dew condensation on the evaporator 1 is less than a predetermined amount, the on-off valve 17
The refrigerant is supplied in parallel to each of the heat exchange units 1A and 1B by fully opening A and 17B (first mode selection).

When it is detected that the rate of dew condensation on the evaporator 1 is equal to or more than a predetermined amount, first, the on-off valve 17A is fully closed for a predetermined time (5 minutes in this embodiment) to open the heat exchange unit 1B. , And then fully open the on-off valve 17A and fully close the on-off valve 17B for a predetermined time (5 minutes in this embodiment) to supply the refrigerant only to the heat exchange unit 1A (second mode selection). . As a result, the refrigerant flow paths of the heat exchange units 1A and 1B are alternately closed for a predetermined period of time. In addition, the accumulated dew water can be discharged by accelerating the flow of the dew condensation water by the wind blown from the blower 6.

Thereafter, the on-off valves 17A and 17B are fully opened, and the refrigerant is supplied in parallel to the heat exchange units 1A and 1B (first mode selection).

The description of the above embodiment is for the purpose of describing the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope thereof. Also, the configuration of each part of the present invention is not limited to the above-described embodiment,
It goes without saying that various modifications are possible within the technical scope described in the claims.

In the above-described embodiment, the case has been described where the controller 8 detects the amount of dew condensation on the evaporator 1 and switches between the first mode and the second mode based on the detected amount. However, the present invention is not limited to this, and the first mode may be simply selected at normal times, and the second mode may be selected periodically (for example, after one hour has elapsed) for a predetermined time (about 5 to 10 minutes). With this configuration, the flow path switching can be realized with a simple configuration.

In the above embodiment, the case has been described where the refrigerant flow paths of the heat exchange units 1A and 1B are continuously and alternately closed when the second mode is selected. However, the present invention is not limited to this. When the two modes are selected, only the refrigerant flow path of one heat exchange unit may be closed, and when the next second mode is selected, only the refrigerant flow path of the other heat exchange unit may be closed.

Further, in the above embodiment, the case where the heat exchange unit 1B is arranged in the lower region and the heat exchange unit 1A is arranged in the upper region has been described. The pipes may be arranged alternately in the vertical direction. In this case, even when only the refrigerant flow path of one of the heat exchange units is closed, heat exchange can be performed by effectively using the outside air from the blower.

[0036]

According to the present invention described above, it is possible to periodically discharge the dew water accumulated in the heat exchange unit,
A decrease in heat transfer performance can be prevented.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of a parallel flow heat exchanger according to the present invention.

FIG. 2 is a schematic configuration diagram showing a refrigerant circuit of a refrigeration apparatus to which the heat exchanger 1 of FIG. 1 is applied.

FIG. 3 is an explanatory diagram for explaining the contents of a detecting means in a control device 8 of the apparatus in FIG. 2;

FIG. 4 is a front view showing a conventional parallel flow heat exchanger.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat exchanger (evaporator) 2 Compressor 3 Condenser 4 Expansion valve (decompression means) 5 Pipe 6 Blower 7 Temperature sensor (temperature detection means) 8 Control device (detection means, flow path switching means) 11 Flat pipe (distribution) Pipe) 12A, 12B Flow pipe group 21A, 21B Corrugated fin 13A, 13B Header pipe 14A, 14B Header pipe 15A, 15B Refrigerant inlet nozzle 16A, 16B Refrigerant outlet nozzle 18 Refrigerant flow switching means

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Toshiki Takeuchi 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Taiji Yamamoto 2-chome Keihanhondori, Moriguchi-shi, Osaka No. 5-5 Sanyo Electric Co., Ltd. (72) Inventor Kenji Nasako 2-5-5 Keihan Hondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd.

Claims (4)

[Claims] 1. A flow pipe provided in a substantially horizontal direction in parallel with each other and having a large number of flow passage holes for flowing a refrigerant therein.
In a heat exchanger that exchanges heat with air flowing outside the flow pipe, a flow pipe group having a plurality of the flow pipes, and between the flow pipes, corrugated fins arranged in a corrugated shape in a left-right direction; A first mode in which a plurality of heat exchange units having header pipes provided on both sides of a flow pipe group and distributing and gathering the refrigerant are provided in a vertical direction, and a first mode for supplying the refrigerant in parallel to each heat exchange unit; A heat exchanger, comprising: flow path switching means for switching and selecting a second mode for supplying a refrigerant to only one of the exchange units. 2. A blower for blowing outside air to the plurality of heat exchange units, a temperature detection unit for detecting a temperature of a refrigerant supplied to the heat exchange unit, a control unit for controlling a rotation speed of the blower, Detecting means for increasing the rotation speed of the blower by a predetermined amount by control means, and detecting a rate of dew condensation of the heat exchange unit based on a change amount of the detected temperature detected by the temperature detecting means at that time. The heat exchanger according to claim 1, wherein the flow path switching unit switches and selects the first mode or the second mode based on a detection result of the detection unit. 3. The heat exchanger according to claim 1, wherein the flow path switching unit selects the first mode at a normal time and periodically selects the second mode for a predetermined time. 4. The heat exchanger according to claim 1, wherein the flow pipe is a flat pipe having a number of flow holes inside.