JP2003343996A - Heat exchanger and method for controlling flow rate of refrigerant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanger and a method for controlling flow rate of refrigerant enabling the reduction of temperature unevenness of heat- exchanged external fluid. <P>SOLUTION: This heat exchanger 10 is provided with a plurality of tubes provided with a refrigerant passage in which refrigerant flows, an inlet header part 11 for distributing the refrigerant flowing in from the upstream side into a plurality of tubes, and an outlet header part 12 for collecting the refrigerant passing through a plurality of tubes. A temperature change means 14 having a cooling function and/or a heating function is provided on a side of the inlet header part 11 of the tube. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger and a refrigerant flow rate control method, and more particularly to an evaporator as a heat exchanger.

[0002]

2. Description of the Related Art FIG. 6 shows an example of a conventional one-turn, all-pass type (lower tank type) heat exchanger (e.g., evaporator) used in an air conditioner, particularly an air conditioner for a vehicle. It is a schematic whole perspective view shown. Such a heat exchanger 10
At 0, the inlet side of the inlet header portion 101 (refrigerant inlet) 10
The tube on the side close to 1a has a low refrigerant flow rate and a high dryness. On the contrary, the inlet side 1 of the inlet header section 101
The tube far from 01a has a large refrigerant flow rate and a low dryness. Note that reference numerals 102 and 103 in FIG.
Indicate the exit header portion and the corrugated fin, respectively. The arrow F indicates the flow direction of the external fluid (for example, air).

FIG. 7 schematically shows this state. In FIG. 7, the white arrow indicates the flow direction of the refrigerant, the solid arrow indicates the liquid flow rate, the broken arrow indicates the vapor flow rate, and the shaded area indicates the superheated vapor region. The lengths of the solid line arrow and the broken line arrow are proportional to each flow rate. That is, when the refrigerant flows as shown in FIG. 7, the side farther from the inlet side 101a (the inner side) becomes a dead end in the inlet header portion 101, so that the internal pressure becomes high and the tube t1 on the side closer to the inlet side 101a becomes dead. A small amount of highly dry refrigerant is supplied,
On the contrary, a large amount of low-dryness refrigerant is supplied to the tube t5 on the side far from the inlet side 101a.

[0004]

As described above, the difference in the flow rate and dryness of the refrigerant distributed to each tube causes a difference in the superheated steam region in each tube.

In the distribution of the superheated steam region as shown in FIG. 7, the heat exchange efficiency is very poor, the heat exchange efficiency is lowered, and the external fluid (for example, air) passing through this heat exchanger is
Unevenness occurs in the temperature of (1), where high temperature and low temperature are generated, resulting in non-uniformity. That is, there is a problem that the temperature of the blown air is not uniform.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a heat exchanger and a refrigerant flow rate control method capable of reducing the temperature unevenness of a heat-exchanged external fluid.

[0007]

In order to solve the above-mentioned problems, the heat exchanger and the refrigerant flow rate control method of the present invention employ the following means. That is, according to the heat exchanger of claim 1, a plurality of tubes each having a refrigerant flow path through which a refrigerant flows, and an inlet header for distributing the refrigerant flowing from the upstream side to the plurality of tubes, respectively. Department,
In a heat exchanger comprising an outlet header section for collecting the refrigerant passing through the plurality of tubes, a temperature changing means having a cooling function and / or a heating function is provided on the side of the inlet header section of the tube. It is characterized by being provided.

In this heat exchanger, the temperature changing means provided on the inlet side of the tube cools or heats the refrigerant passing through the tube.

According to another aspect of the heat exchanger of the present invention, a pair of flat plates that have been subjected to drawing processing are superposed on each other, and an inlet that is substantially parallel to the longitudinal axis of the flat plates is provided between the adjacent flat plates. A plurality of heat exchanger segments forming a side refrigerant flow path and an outlet side refrigerant flow path are connected, and the flat plate has a first refrigerant inlet and a first refrigerant inlet respectively communicating with one end and the other end of the inlet side refrigerant flow path. Two refrigerant inlets are formed, and a first refrigerant outlet and a second refrigerant outlet that communicate with one end and the other end of the outlet-side refrigerant passage are formed, and the heat exchanger segments are stacked on each other. , The first refrigerant inlets, the second refrigerant inlets, the first refrigerant outlets, and the second refrigerant outlets are communicated with each other, respectively, to the first inlet header portion and the second inlet, respectively. Forming a dur portion, a first outlet header portion, and a second outlet header portion, and forming an inlet system path of the refrigerant by the inlet-side refrigerant flow path, the first inlet header portion, and the second inlet header portion. At the same time, the outlet side refrigerant flow path, the first outlet header section, and the second outlet header section constitute an outlet system path of the refrigerant, and the first inlet header section, the second inlet header section, the first Heat exchange for dividing the inlet system path and / or the outlet system path into a plurality of blocks by providing at least one partition plate in at least one of the outlet header section and the second outlet header section In the heat exchanger segment, a temperature change having a cooling function and / or a heating function on the side of the inlet side refrigerant passage and / or the outlet side refrigerant passage into which the refrigerant flows. Wherein the stage is provided.

In this heat exchanger, the refrigerant passing through the refrigerant passage is cooled by the temperature changing means provided on the inlet side of the inlet refrigerant passage and / or the outlet side refrigerant passage of the heat exchanger segment. Alternatively, it will be heated.

According to a third aspect of the heat exchanger of the present invention, in the heat exchanger of the first or second aspect, the side of the outlet header portion of the tube provided with the temperature changing means,
Alternatively, temperature detecting means is provided on a side of the heat exchanger segment provided with the temperature changing means, on the side of the inlet side refrigerant passage and / or the outlet side refrigerant passage where the refrigerant flows out. And

In this heat exchanger, the temperature of the refrigerant is measured by the temperature detecting means, and the cooling amount or the heating amount by the temperature changing means is determined based on the measured temperature.

According to the heat exchanger of claim 4, in the heat exchanger of claim 3, the temperature changing means and the temperature detecting means are provided for all tubes or all heat exchanger segments. It is characterized by being provided.

In this heat exchanger, the temperature changing means and the temperature detecting means are provided for all the refrigerant passages, so that the refrigerant passing therethrough is cooled or heated for each refrigerant passage. At the same time, the temperature detection means measures the temperature of the refrigerant.

According to the heat exchanger of the fifth aspect, in the heat exchanger of the third aspect, the temperature changing means and the temperature detecting means have a refrigerant flowing into the inlet header of the tube. It is provided for the tube located closest to the inlet and / or the tube located farthest from the refrigerant inlet through which the refrigerant flows into the inlet header.

In this heat exchanger, the temperature changing means and the temperature detecting means have a refrigerant inlet through which the refrigerant flows into the tube and / or the inlet header which is closest to the refrigerant inlet through which the refrigerant flows into the inlet header. Will be provided for the tube located furthest away from. That is, the temperature changing means and the temperature detecting means are respectively provided in the tube having the smallest flow rate of the refrigerant flowing in and / or the tube having the highest flow rate of the refrigerant flowing therein. This reduces the difference between the maximum flow rate and the minimum flow rate of the refrigerant flowing into the tube.

According to the heat exchanger of claim 6, in the heat exchanger of claim 3, the temperature changing means and the temperature detecting means are located on the most upstream side of the plurality of blocks. And / or all heat exchanger segments of the most downstream block.

In this heat exchanger, the temperature changing means and the temperature detecting means include all the inlet side refrigerant flows of the block located at the most upstream side and / or the block located at the most downstream side among the plurality of blocks. It is provided for the passage and / or the outlet side refrigerant passage.
That is, the temperature changing means and the temperature detecting means are respectively provided for all the inlet side refrigerant flow paths and / or the outlet side refrigerant flow paths of the block having the smallest amount of superheated steam and / or the block having the largest amount of superheated steam. Will be done. As a result, the difference between the superheated steam amount in the block located on the most upstream side and the superheated steam amount in the block located on the most downstream side is reduced.

According to a seventh aspect of the heat exchanger, in the heat exchanger according to any of the third to sixth aspects, the temperature changing means is a Peltier element.

In this heat exchanger, the temperature changing means is a Peltier element which has cooling and heating functions, is easily available, and is small and lightweight.

According to an eighth aspect of the present invention, there is provided an air conditioner comprising the heat exchanger according to any one of the first to seventh aspects and a compressor for compressing a refrigerant. And

This air conditioner is suitable when the refrigerant compressed by the compressor is distributed to each tube.

According to the refrigerant flow rate control method of the ninth aspect, a plurality of tubes each having a refrigerant flow path through which the refrigerant flows, and a refrigerant flowing from the upstream side are respectively distributed to the plurality of tubes. A refrigerant flow rate control method for controlling a refrigerant flow rate into a plurality of tubes of a heat exchanger comprising an inlet header section and an outlet header section that collects the refrigerant that has passed through the plurality of tubes. ,
The flow rate of the refrigerant flowing into the plurality of tubes may be controlled by cooling or heating the side of the inlet header portion of the tubes.

In this refrigerant flow rate control method, the dryness of the refrigerant is reduced by cooling the inlet side of the tube, or the dryness of the refrigerant is increased by heating the inlet side of the tube. By changing the ratio of the liquid phase inside, the flow rate of the refrigerant flowing into each tube is adjusted.

According to the refrigerant flow rate control method of the tenth aspect, in the refrigerant flow rate control method of the eighth aspect, the cooling amount or the heating amount on the inlet header section side of the tube is the outlet of the tube. It is characterized in that it is determined based on the temperature on the side of the header portion.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIGS. Figure 1
1 is a schematic overall perspective view showing an embodiment of a one-turn, all-pass type (lower tank type) evaporator (heat exchanger) used in an air conditioner, particularly an air conditioner for a vehicle. FIG. 2 is a diagram schematically showing FIG. In addition,
In FIG. 2, only representative five tubes t1, t2, t3, t4, t5 out of the plurality of tubes t are drawn.

As shown in FIGS. 1 and 2, the evaporator 10
Is composed of an inlet header section 11, an outlet header section 12, and a plurality of (for example, 20) tubes t as main elements. Each of the plurality of tubes t has a refrigerant flow path in which a refrigerant flows and makes a U-turn. The inlet header section 11 distributes the refrigerant flowing from the upstream side of the evaporator 10 to the plurality of tubes t described above. The outlet header section 12 is for collecting the refrigerant that has passed through the plurality of tubes t. In FIG. 1, reference numeral 13 is a corrugated fin.

Further, in this embodiment, the Peltier element (temperature changing means) 14 is provided at each of the end portions of all the tubes t on the inlet header 11 side, that is, at the portions where the inlet header 11 and each tube are connected. Is provided. The Peltier element 14 is a thermoelectric element capable of cooling and heating by changing the direction of current. On the other hand, a temperature sensor (temperature detecting means) 15 is provided at each end of the all tubes t on the outlet header 12 side, that is, at a portion where the outlet header 12 and each tube are connected. The Peltier element 14 and the temperature sensor 15 are respectively provided in the controller 1
Connected to 6.

The data obtained by the temperature sensor 15 is input to the controller 16 via, for example, a wiring, processed by the controller 16, and then transmitted to each Peltier element 14 via an electrical signal, for example. Is output. That is, each Peltier element 14 is controlled to be cooled or heated based on the temperature near the outlet of each tube t.

As described above, the temperature near the outlet of each tube t is detected by the temperature sensor 15, and the Peltier element 14 provided near the inlet of each tube t is controlled for cooling or heating based on the detected temperature. By doing so, for example, the state as shown in FIG. 2 can be obtained. In FIG. 2, the white arrow indicates the flow direction of the refrigerant, the solid arrow indicates the liquid flow rate, the broken arrow indicates the vapor flow rate, and the shaded area indicates the superheated vapor region. The lengths of the solid line arrow and the broken line arrow are proportional to each flow rate.

That is, in the case where the refrigerant distribution is uneven as shown in FIG. 7, for example, in the tube t1 near the inlet side (refrigerant inlet) 11a of the inlet header portion 11 where the refrigerant flow rate is small and the dryness is large, The Peltier element 14 cools the refrigerant to reduce the dryness of the refrigerant at the inlet of the tube t1 (that is, increase the liquid ratio). This reduces the refrigerant pressure loss in the tube t1 and narrows the superheated steam region near the outlet of the tube t1 to increase heat exchange efficiency, so that the refrigerant circulation amount flowing in the tube t1 increases.

On the other hand, in the tube t5 that is farthest from the inlet side 11a of the inlet header portion 11 and has a large refrigerant flow rate and a small dryness, the refrigerant is heated by the Peltier element 14 so that the superheated steam region near the outlet of the tube t5 is generated. By increasing the refrigerant pressure loss, the refrigerant circulation amount decreases.

By carrying out such adjustment for each tube t, the flow rate of the refrigerant flowing through each tube t can be made uniform as shown in FIG. 2, and thus the optimum two-phase flow distribution can be realized. As a result, the heat exchange performance of the evaporator can be improved. Also, the temperature distribution of the external fluid passing through this evaporator can be made uniform. Further, since the refrigerant temperature near the outlet of each tube t is constantly monitored to control the cooling amount or the heating amount, for example, even if the refrigerant flow rate and dryness flowing into the evaporator are changed depending on the operating conditions, Appropriate distribution adjustments can be made accordingly.

Next, another embodiment according to the present invention will be described with reference to FIG. In the embodiment shown in FIG. 3, the tube t1 located closest to the inlet side 11a of the inlet header portion 11 and the inlet side 11 of the inlet header portion 11 are provided.
Only the two tubes t5 located farthest from a are connected to the Peltier element 14 and the temperature sensor 15 described above.
2 is different from that of the embodiment shown in FIG.

That is, as shown in FIG. 7, the Peltier element 14 and the temperature sensor 15 are provided only in the tubes t1 and t5, which have a particularly bad distribution, and the refrigerant flow rate in these tubes t1 and t5 is adjusted as described above. 7 can be improved over that of FIG. As a result, the performance of the entire evaporator can be improved, and the number of Peltier elements 14 and temperature sensors 15 can be reduced, so that the cost can be significantly reduced.

The Peltier element 14 described above is attached to the outer surface of the tube t or the inner surface of the tube t as shown in FIG. 4, for example. FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 1, in which (a) is an arrangement example of a Peltier element and (b) is another arrangement example.
Similarly to the Peltier element 14, the temperature sensor 15 is also attached to the outer surface of the tube t or the inner surface of the tube t.

The present invention is not limited to the one-turn, all-pass type evaporator described above. For example, a conventionally known 4-block type evaporator shown in FIG.
It can also be applied to an upper and lower tank type evaporator (not shown).

A four-block type evaporator 50 shown in FIG.
Is a first inlet header portion 51 and a second inlet header portion 52.
And a first outlet header portion 53 and a second outlet header portion 54 as main elements. Further, reference numeral 55 is a partition plate provided in the first inlet header portion 51, and reference numeral 56 is a partition plate provided in the first outlet header portion 53. With this configuration, the refrigerant is in the first block B1 → second
Heat is exchanged with the external fluid while flowing through the block B2 → the third block B3 → the fourth block B4. In such a four-block type evaporator 50, the refrigerant is superheated vapor at the tube outlet and is located at the most downstream side (for example, has ten tubes).
The Peltier element 14 described above is attached to each tube of the block B4.
Also, the temperature sensor 15 may be attached.

Besides the one-turn / all-pass type, four-block type, upper and lower tank type so-called laminated type evaporators, the present invention can also be applied to multi-flow type evaporators having flat tubes and corrugated fins. it can.

Further, it can be applied not only to the heat exchanger having the function as an evaporator as described above, but also to the heat exchanger having the function as a condenser. Also in this case, the heat exchange capacity of the heat exchanger can be improved by appropriately distributing the refrigerant in each tube and making the degree of supercooling at the outlet of each tube uniform.

[0041]

According to the heat exchanger and the refrigerant flow rate control method of the present invention, the following effects can be obtained. According to the heat exchanger of claim 1, since the refrigerant passing through the tube is cooled or heated by the temperature changing means provided on the inlet side of the tube, the refrigerant passing through the tube is cooled. The dryness can be changed.

According to the second aspect of the heat exchanger, the inside of the refrigerant passage is provided by the temperature changing means provided at the inlet side of the inlet side refrigerant passage and / or the outlet side refrigerant passage of the heat exchanger segment. Since the refrigerant passing through is cooled or heated, the dryness of the refrigerant passing through the refrigerant passage can be changed.

According to the heat exchanger of the third aspect, the temperature of the refrigerant is measured by the temperature detecting means, and the cooling amount or the heating amount by the temperature changing means is determined based on the measured temperature. Therefore, the dryness of the refrigerant passing through the refrigerant channel can be changed more appropriately.

According to the heat exchanger of the fourth aspect, the temperature changing means and the temperature detecting means are respectively provided for all the refrigerant flow paths, and the refrigerant passing therethrough is provided for each refrigerant flow path. Since the temperature of the refrigerant is measured by the temperature detecting means while being cooled or heated, the flow rate of the refrigerant passing through each refrigerant flow path can be made uniform and the heat exchange performance can be improved. The temperature distribution of the external fluid passing through this heat exchanger can also be made uniform.

According to the heat exchanger of the fifth aspect, since the difference between the maximum flow rate and the minimum flow rate of the refrigerant flowing into the tube is reduced, the difference between the refrigerant flow rates passing through the respective refrigerant flow paths is reduced. Can be reduced, the heat exchange performance can be improved, and the temperature unevenness of the external fluid passing through this heat exchanger can be reduced.

According to the heat exchanger of the sixth aspect, the difference between the amount of superheated steam in the block located on the most upstream side and the amount of superheated steam in the block located on the most downstream side is reduced. Therefore, the difference in heat exchange performance between the blocks can be reduced, the heat exchange performance can be improved, and the temperature unevenness of the external fluid passing through the heat exchanger can be reduced.

According to the heat exchanger of the seventh aspect, since the temperature changing means is a Peltier element which has cooling and heating functions and is easily available, and is small and lightweight, fine control is possible. In addition, it is possible to reduce the cost because it is not necessary to newly design and develop such temperature changing means, and it is possible to suppress an increase in the weight of the heat exchanger itself.

According to the air conditioner of the eighth aspect, the refrigerant compressed by the compressor is substantially evenly distributed to the tubes, so that the heat exchange performance of the heat exchanger can be improved. As a result, the performance of the entire air conditioner can be improved, and the temperature unevenness of the external fluid passing through the heat exchanger can be reduced.

According to the refrigerant flow rate control method of the ninth aspect, the dryness of the refrigerant is reduced by cooling the inlet side of the tube, or the dryness of the refrigerant is controlled by heating the inlet side of the tube. The rate of the liquid phase in the refrigerant is changed by increasing it, and the flow rate of the refrigerant flowing into each tube is adjusted accordingly. Therefore, the dryness of the refrigerant passing through the tubes can be changed.

According to the refrigerant flow rate control method of the tenth aspect, the cooling amount or the heating amount at the tube inlet side is determined based on the temperature of the refrigerant at the tube outlet side. The dryness of the passing refrigerant can be changed more appropriately.

[Brief description of drawings]

FIG. 1 is a schematic overall perspective view showing an embodiment of a heat exchanger according to the present invention.

FIG. 2 is a diagram schematically showing FIG.

FIG. 3 is a view showing another embodiment of the heat exchanger according to the present invention and is a view similar to FIG. 2.

4 is a sectional view taken along the line IV-IV of FIG.
(A) is a figure which shows one arrangement example of a Peltier element, (b) is a figure which shows another arrangement example.

FIG. 5 is a schematic overall perspective view showing another embodiment of the heat exchanger according to the present invention.

FIG. 6 is a schematic overall perspective view showing a specific example of a conventional heat exchanger.

FIG. 7 is a diagram schematically showing FIG.

[Explanation of symbols]

10 heat exchanger 11 Entrance header section 11a entrance side 12 Exit header section 14 Peltier element (temperature changing means) 15 Temperature sensor (temperature detection means) 20 heat exchanger 50 heat exchanger 51 First entrance header section 52 Second entrance header section 53 First exit header section 54 Second exit header section 55 Partition Plate 56 partition boards 100 heat exchanger 101 Entrance header section 101a entrance side 102 exit header B1 First block B2 Second block B3 Third block B4 4th block t tube t1 tube t2 tube t3 tube t4 tube t5 tube

Continued front page    (72) Inventor Hiroshi Mizutani             60, Kyutansho, Iwatsuka-cho, Nakamura-ku, Nagoya-shi, Aichi             Ground No. 1 Churyo Engineering Co., Ltd.

Claims (10)

[Claims] 1. A plurality of tubes each having a refrigerant flow path through which a refrigerant flows, an inlet header section for distributing the refrigerant flowing from an upstream side to each of the plurality of tubes, and the plurality of tubes. An outlet header section for collecting the passed refrigerant, wherein a temperature changing unit having a cooling function and / or a heating function is provided on the side of the inlet header section of the tube. Characteristic heat exchanger. 2. An inlet-side refrigerant flow channel and an outlet-side refrigerant flow channel in which a pair of drawn flat plates are overlapped with each other and between the flat plates adjacent to each other and substantially parallel to the longitudinal axis of the flat plates. A plurality of heat exchanger segments that form a first refrigerant inlet and a second refrigerant inlet that communicate with one end and the other end of the inlet-side refrigerant passage, respectively, and the outlet. A first refrigerant outlet and a second refrigerant outlet, which communicate with one end and the other end of the side refrigerant passage, respectively, are formed, and by stacking the heat exchanger segments, the first refrigerant inlet and the second refrigerant inlet are connected to each other. The two refrigerant inlets, the first refrigerant outlets, and the second refrigerant outlets are communicated with each other to form a first inlet header section, a second inlet header section, a first outlet header section, and The second
An outlet header section is formed, and an inlet system path of the refrigerant is constituted by the inlet side refrigerant flow path, the first inlet header section, and the second inlet header section, and the outlet side refrigerant flow path, the first side The outlet header part and the second outlet header part constitute an outlet system path of the refrigerant, and the first inlet header part, the second inlet header part, the first outlet header part, and the second outlet header part A heat exchanger that divides the inlet system path and / or the outlet system path into a plurality of blocks by providing at least one partition plate in at least one header part of the heat exchanger segment. A temperature changing means having a cooling function and / or a heating function is provided on the side of the side refrigerant passage and / or the outlet side refrigerant passage where the refrigerant flows. Heat exchanger. 3. The heat exchanger according to claim 1, wherein the outlet header section of the tube provided with the temperature changing means is provided, or the heat exchanger segment provided with the temperature changing means. Of the inlet side refrigerant flow path and / or
Alternatively, the heat exchanger is characterized in that temperature detecting means is provided on a side of the outlet side refrigerant flow path on which the refrigerant flows. 4. The heat exchanger according to claim 3, wherein the temperature changing means and the temperature detecting means are provided for all tubes or all heat exchanger segments. Exchanger. 5. The heat exchanger according to claim 3, wherein the temperature changing unit and the temperature detecting unit are located at a position closest to a refrigerant inlet of the tubes where the refrigerant flows into the inlet header. And / or a heat exchanger provided for a tube located farthest from a refrigerant inlet through which refrigerant flows into the inlet header. 6. The heat exchanger according to claim 3, wherein the temperature changing unit and the temperature detecting unit are located on the most upstream side and / or the most downstream side of the plurality of blocks. A heat exchanger provided for all heat exchanger segments of the block. 7. The heat exchanger according to claim 3, wherein the temperature changing unit is a Peltier element. 8. An air conditioner comprising the heat exchanger according to claim 1 and a compressor for compressing a refrigerant. 9. A plurality of tubes each having a refrigerant flow path through which a refrigerant flows, an inlet header section for distributing the refrigerant flowing from an upstream side to each of the plurality of tubes, and the plurality of tubes. A refrigerant flow rate control method for controlling a flow rate of a refrigerant flowing into the plurality of tubes in a heat exchanger comprising an outlet header section that collects the passed refrigerant, wherein a refrigerant flow rate flowing into the plurality of tubes. Is controlled by cooling or heating the side of the inlet header portion of the tube. 10. The refrigerant flow rate control method according to claim 9, wherein the cooling amount or the heating amount of the tube on the side of the inlet header portion is determined based on the temperature of the tube on the side of the outlet header portion. A method for controlling a refrigerant flow rate, comprising: