KR20000077283A - Heat exchanger having fins formed thereon - Google Patents

Abstract

The present invention suppresses an increase in the area of the gas inlet-side heat transfer pipe and an increase in the pressure drop in the tube, and realizes a finned heat exchanger that can exhibit high performance even when used in both the condenser and the evaporator of the refrigeration cycle. To this end, the present invention comprises a secondary heat exchanger (11a) and the main heat exchanger (11b) installed in parallel from the gas inlet side (X) to the gas outlet side (Y), the heat and gas of the gas inlet side heat exchanger group (13a) A plurality of rows of the outflow side heat transfer pipe group 13b are separated, and the short pitch P1 of the gas inflow side heat transfer pipe group is smaller than the short pitch P2 of the gas outflow side heat transfer pipe group, and the number of heat transfer tubes in the first gas inlet side heat transfer pipe group. Is less than or equal to the number of rows 1 on the gas outlet side. This constitution suppresses increase in heat transfer area and increase in pressure loss in the gas inlet-side heat exchanger tube, thereby improving the performance of the auxiliary heat exchanger.

Description

Heat Exchanger with Fins {HEAT EXCHANGER HAVING FINS FORMED THEREON}

The present invention relates to a finned heat exchanger mainly used in air conditioners and the like.

The first conventional example as a fin heat exchanger in recent years will be described with reference to Figs. 8 and 9. 8 is a perspective view showing the basic configuration of the finned heat exchanger, Figure 9 is a side view thereof. As shown in Fig. 8 and Fig. 9, the finned heat exchanger is composed of an auxiliary heat exchanger 101a and a main heat exchanger 101b. The auxiliary heat exchanger (101a) consists of a fin group (102a) arranged side by side at predetermined intervals, and a heat transfer tube group (103a) which passes through the fin group at approximately right angles to form a row, and is arranged on the gas outlet side (X). . The main heat exchanger (101b) is composed of a fin group (102b) arranged side by side at predetermined intervals, and a heat transfer tube group (103b) which passes through the fin group at approximately right angles to form a row, and is disposed on the gas outlet side (Y). Reference numeral 104 denotes an airflow that causes the fin group 102a and the fin group 102b to flow in the direction of the arrow, and exchanges heat with the gas flowing through the tubes of the heat transfer tube group 103a and the heat transfer tube group 103b. Moreover, when loading this fin heat exchanger into the indoor unit of a separate type air conditioner, it is common to provide a cut part in several parts of fin group 102b, and to bend and load a plurality of parts.

In the above configuration, when used as a condenser of the refrigeration cycle of the air conditioner, the fluid flowing in the heat transfer tube flows in from the arrow A side in a gaseous state and is divided into the top and bottom of the heat transfer tube group 103b by the branch portion 105 ( It flows, becomes a liquid state through a gas-liquid two-phase state by heat exchange with the airflow 104, it joins again in the branch part 106, and flows out to the arrow B side via the heat exchanger tube group 103a. In this way, the finned heat exchanger includes the auxiliary heat exchanger 101a in which the fluid flowing in the heat transfer tube group 103a becomes almost liquid and the main heat exchanger 101b in which the fluid flowing in the heat transfer tube group 103b is in a gaseous state or a gas-liquid two-phase state. It consists of

Therefore, as the number of flow paths of the heat transfer pipe group 103a serving as the refrigerant pipe becomes closer to the refrigerant outlet, the flow rate is reduced to the gas inflow side X, which is a wind up side of the air flow 104 in the main flow direction. At the same time, the secondary heat exchanger 101a, which is a low temperature portion at the outlet side of the condenser, is separated from the main heat exchanger 101b, whereby heat conduction to the gas outflow side on the downwind side can be interrupted and supercooling becomes easy, thereby improving condensation performance. It is to plan.

Moreover, the typical figure of the JPA57-127732 publication which is a 2nd conventional example is shown in FIG. 10 is a perspective view of a heat exchanger. The heat exchanger 101c with fins consists of 103c and 103d which are groups of heat exchanger tubes, and the fin 102c attached in multiple numbers orthogonal to this.

When used as a condenser of a refrigeration cycle of an air conditioner, the finned heat exchanger 101c flows into the heat transfer tube group 103d side through the inside of the heat transfer tube group 103c inside the heat transfer tube group 103c. During this time, the refrigerant flowing inside the heat transfer pipe groups 103c and 103d condenses by exchanging heat with the air flow of the arrow 104. In this case, by arranging 103d of heat transfer tube groups of the microtubes on the gas inlet side X of the finned heat exchanger 101c, the flow velocity of the refrigerant flowing in the tube in the liquid state can be improved, thereby improving performance. It is called.

Moreover, the typical figure of the JPA6-174389 publication which is a 3rd conventional example is shown in FIG. Fig. 11 is a side view of the heat exchanger with fins, wherein the short pitch P3 of the heat transfer pipe group 103f on the gas outlet side Y of the heat exchanger 101e is short of the heat transfer pipe group 103e on the gas inlet side X; It is made longer than the pitch P4.

With such a configuration, the ratio of the exponential region 108 of the heat transfer tube group 103f to the opening area of the finned heat exchanger 101e through which the airflow 104 flows can be reduced, so that the blower ( 107), it is possible to reduce the noise generated when inhaled.

12 and 13 show representative drawings of JPA10-213386, which is a fourth conventional example. 12 is a perspective view of an independent fin tube heat exchanger showing a part of the finned heat exchanger in detail, and FIG. 13 is a view showing the outdoor unit of the package air conditioner to which the fourth conventional example is applied. Independent fin tube heat exchanger (101g) is formed by passing heat pipe (103g) through a plurality of independent fins (102g). Each independent pin 102g is configured to be in contact with the lower end portion 101i and the upper end portion 101h, and each end of the lower end portion 101i and the upper end portion 101h is configured to intersect at at least one point when contacted. . As a result, the drainage performance can be improved.

However, in the configuration of the first conventional example, the temperature difference between adjacent heat exchanger tubes 103b in the two-phase zone in the main heat exchanger 101b is less than 0.5 °, whereas the heat exchanger tubes 103a adjacent to each other in the auxiliary heat exchanger 101a which are liquid phases. The difference in temperature in a) is 0.5 ° or more, and the heat loss due to heat conduction in adjacent heat transfer tubes in the auxiliary heat exchanger has a problem that cannot be ignored.

Moreover, in the structure of the 2nd conventional example, if it is made into a microtube simply without changing the short pitch of the heat exchanger tube group 103d, there existed a subject that the factor of the pin efficiency fall rather than the improvement of the heat transfer rate in a tube, and high performance was not aimed at.

Moreover, in the structure of the 3rd conventional example, gas outflow is made by making the short pitch P3 of the heat exchanger tube group 103f row of the gas outflow side Y longer than the short pitch P4 of the heat exchanger tube group 103e row of the gas inflow side X. The capacity of the heat exchanger on the side is greatly reduced, and this decrease in capacity must be compensated for by the increase in the air volume, and consequently, it does not contribute to the reduction of the noise. When the short pitch P4 of the gas inlet side X is shortened while the short pitch P3 of the gas outlet side Y is kept, the effect of noise reduction described in the third example is not obtained. In the case of acting as a condenser, the capability of the air inlet side can be improved. However, when acting as an evaporator, the number of heat transfer tubes increases, and the capacity falls by an increase in pressure loss. This problem had the third conventional example.

In the configuration of the fourth conventional example, as shown in Fig. 13, by using independent fins at all stages, a large amount of cutouts exist between the lower end portion 101i and the upper end portion 101h, whereby the airflow passing through the heat exchanger is generated. The resistance of the airflow to be scattered and passing through the heat exchanger is significantly increased than that of a heat exchanger having no cut. Although the airflow resistance ratio is good, when the fin surface acts as a dry condenser, the resistance passing through the integrally formed fin without the lower end portion 101i or the upper end portion 101h increases and when loaded into the blower circuit, There was a problem that caused an increase in the noise value and a decrease in the air volume.

The present invention solves such a conventional problem, and provides a finned heat exchanger capable of suppressing an increase in the area of the gas inlet-side heat pipe and an increase in the pressure loss in the gas inlet, and exhibiting high performance even when used in both the condenser and the evaporator of the refrigeration cycle. For the purpose of

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, the invention of Claim 1 of this invention fin heat exchanger is provided in parallel and parallel in a predetermined space | interval, the fin group which gas flows through, and this fin group penetrates at substantially right angles, And a heat transfer tube group through which gas flows, and the short pitch between the heat transfer tubes of the gas inlet side heat transfer tube group is smaller than the short pitch between the heat transfer tubes of the gas outlet side heat transfer tube group, The number of heat transfer tubes in a column is less than the number in one column of the gas-flow side heat transfer tube group.

According to the above structure, the heat transfer area on the inner side of the gas inlet side heat transfer tube group is widened, and when used as a condenser, it can occupy a large amount of supercooled zone in a very low liquid state as the heat transfer performance in the tube, The increase is also suppressed. For this reason, the heat transfer area in the heat transfer pipe can be improved, and the number of heat transfer tubes can be limited, so that both the condensation capacity and the evaporation capacity can be improved.

Moreover, the invention of Claim 2 is comprised so that the pipe diameter of a gas inflow side heat exchanger tube group may be made smaller than the pipe diameter of a gas outflow side heat exchanger tube group.

According to the said structure, the ventilation resistance at the time of gas passing through the gas inflow side heat exchanger becomes small, the flow velocity of the gas which flows in a pipe increases, and the heat transfer rate can be improved.

Moreover, the invention of Claim 3 comprised the heat exchanger tube of the gas inflow side heat exchanger tube group in elliptical or flat shape.

According to the said structure, the distance between the fluid which flows near the center in a heat exchanger tube, and a pipe wall can be made small. For this reason, high performance can be attained by the improvement of the heat transfer rate of a heat exchanger.

In addition, the invention described in claim 4 makes the length of the fin between the heat transfer tube and the heat transfer tube of the gas inlet side heat transfer tube group longer than the short pitch between the heat transfer tube and the heat transfer tube, and in the gas discharge side heat transfer tube group between the heat transfer tube and the heat transfer tube. The short pitch between the length of the fin and the heat pipe is of approximately the same length.

According to this configuration, the length of the fin portion can be lengthened while the short pitch is maintained, the heat conduction between the ends of the heat transfer tube can be suppressed, and the heat conduction loss between the ends of the heat transfer tube is reduced, thereby achieving high performance. have.

The invention described in claim 5 is provided with a cutout or punching portion provided between the heat transfer pipe and the heat transfer pipe over the entire end of the fin of the gas inlet-side heat transfer pipe row, and the cutout or punching section is inclined with respect to the main flow direction of the air flow. It is. According to this structure, the loss by the heat conduction between a heat exchanger tube and the stage of a heat exchanger tube can be reduced, and high performance can be aimed at.

The invention described in claim 6 is a structure in which a plurality of lances or irregularities are provided on the fin between the heat transfer tube and the heat transfer tube at approximately right angles to the main air flow direction.

According to this configuration, it is possible to achieve high performance by enhancing the high performance by the boundary layer front edge effect at the front edge of the lance or by expanding the heat transfer area by the uneven shape and promoting the turbulence.

In the invention according to claim 7, the heat transfer area of the inner surface per unit length in the heat transfer tube of the gas fluid side heat is made larger than the heat transfer area of the inner surface of the gas discharge side heat transfer tube.

According to this configuration, the heat transfer area can be increased at the condenser outlet and the evaporator inlet portions as the gas inlet side, and the performance of the heat exchanger can be improved. In addition, it is easy to increase the heat loss area in the pipe, but it can be used at the condenser outlet and the evaporator inlet to increase the heat transfer area in the pipe while suppressing the decrease of the condensation temperature and the increase of the evaporation temperature. Therefore, the heat exchanger can be improved in performance.

1 is a side view of a finned heat exchanger showing a first embodiment of the present invention.

Figure 2 is a side view of a finned heat exchanger showing a second embodiment of the present invention.

3 is a cross-sectional view of an auxiliary heat exchanger in a finned heat exchanger according to a third embodiment of the present invention.

4 (a) is a perspective view of a main part of a finned heat exchanger showing a fourth embodiment of the present invention.

4 (b) is a front view of the main part of the auxiliary heat exchanger showing the fourth embodiment of the present invention.

5 is a cross-sectional view of an auxiliary heat exchanger in the heat exchanger showing the fifth embodiment of the present invention.

6 is a cross-sectional view of an auxiliary heat exchanger in a finned heat exchanger according to a sixth embodiment of the present invention.

Fig. 7A is a sectional view of a heat transfer tube of an auxiliary heat exchanger in the finned heat exchanger according to the seventh embodiment of the present invention.

Fig. 7B is a sectional view of the heat transfer tube of the main heat exchanger in the finned heat exchanger according to the seventh embodiment of the present invention.

8 is a perspective view of a finned heat exchanger showing a first conventional example.

9 is a side view of a finned heat exchanger showing a first conventional example.

10 is a perspective view of a finned heat exchanger showing a second conventional example.

11 is a side view of a finned heat exchanger showing a third conventional example.

It is a perspective view of the independent finned heat exchanger which showed the 4th conventional example.

It is a top view of the outdoor unit of the air conditioner equipped with the independent finned heat exchanger which showed the 4th conventional example.

(Explanation of the sign)

11a... Auxiliary heat exchanger 11b... Main heat exchanger

12a, 12b... Fin group 13a, 13b... Heat pipe

X… Gas inlet side Y.. Outflow side

P1... Short pitch

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described, referring drawings.

(First embodiment)

1 is a side view showing a finned heat exchanger of the invention of the first embodiment. This finned heat exchanger consists of the subsidiary heat exchanger 11a located in the airflow inlet side X of the airflow shown by the arrow 4, and the main heat exchanger 11b located in the gas outlet side Y. As shown in FIG. The auxiliary heat exchanger 11a comprises a plurality of fin groups 12a arranged side by side at predetermined intervals, and a heat transfer tube group 13a arranged through the fin groups at approximately right angles and twisted. The main heat exchanger 11b is composed of a plurality of fin groups 12b arranged side by side at predetermined intervals, and a heat transfer tube group 13b arranged through the fin groups at approximately right angles. The subsidiary heat exchanger 11a has six stages of heat transfer tubes of the heat transfer tube group 13a arranged in a row, and the heat transfer tube group 13a of the heat transfer tube group 13b having one column of the main heat exchanger 11b as 12 stages. It is less than the number of heat exchanger tubes in one column. That is, the auxiliary heat exchanger 11a makes the number of stages of the tubes of the heat exchanger tube group 13a in one row smaller than the number of stages of the tubes of the heat exchanger tube group 13b in the one row of the main heat exchanger 11b, and the heat transfer tube group 13a. ) And the plurality of heat transfer pipe groups 13b are separated. Further, the auxiliary heat exchanger 11a has a short pitch P1 which is the length between the heat transfer tube center of the heat transfer tube group 13a and the next heat transfer tube center, and the short pitch P2 between the heat transfer tubes of the heat transfer tube group 13b of the main heat exchanger 11b. Shorter) 15 is the inlet side branch part of the heat exchanger tube group 13b of the main heat exchanger 11b, and 16 is the same outlet side branch part.

Moreover, the airflow 4 flows the fin group 12a and the fin group 12b in the direction of an arrow, and heat-exchanges with the fluid which flows in the tubes of the heat exchanger tube group 13a and the heat exchanger tube group 13b. When loading in the indoor unit of a separate type air conditioner, it is common to provide a plurality of cut-out parts or cut-out parts in an auxiliary or main heat exchanger, and to bend them and load them.

In the above configuration, when used as a condenser of the refrigeration cycle of the air conditioner, the fluid flowing in the heat transfer tube flows from the heat transfer tube of the main heat exchanger 11b in the gaseous state as shown by arrow A, and is transferred to the heat transfer tube group by the branch portion 15 ( 13b), the heat exchanger tube group 13a formed into a liquid state through a gas-liquid two-phase state by heat exchange with the airflow 4, and joined again at the branch 16 to form a column of the auxiliary heat exchanger 11a. It flows in from heat transfer pipe of) and flows out like arrow B.

In addition, when used as an evaporator of the refrigeration cycle of the air conditioner, the fluid flowing in the heat transfer tube flows into the heat transfer tube of the heat transfer tube group 13a formed in the column of the auxiliary heat exchanger 11a as shown by arrow B in the gas-liquid two-phase state, and then flows again. The heat exchanger 4 is divided into upper and lower portions of the heat transfer tube group 13b at the branch 16 of the main heat exchanger 11b, and heat exchanged with the airflow 4, and then joined at the branch 15 again, and flows out as shown by arrow A from the heat transfer tube.

According to this structure, since the short pitch P1 of the heat exchanger tube group 13a of the auxiliary heat exchanger 11a is shorter than the short pitch P2 of the heat exchanger tube group 13b of the main heat exchanger 11b, the heat transfer area in a heat exchanger tube is expanded. This makes it possible to improve the performance of the auxiliary heat exchanger. Therefore, if it acts as a condenser, it is possible to occupy a large amount of supercooled zone of very low liquid state in the subsidiary heat exchanger 11a as the heat transfer performance in the heat transfer tube, whereby a two-phase state that is good as the heat transfer performance in the tube is obtained. It occupies much in the inside, can increase the heat exchange capacity, and can improve the performance of a finned heat exchanger. In addition, when acting as an evaporator, the number of stages of the heat transfer tubes in one column of the auxiliary heat exchanger 11a is less than the number of stages in one column of the heat transfer tube group 13b of the main heat exchanger, thereby suppressing an increase in the pressure loss in the tube and evaporating. We can improve ability.

Second Embodiment

Fig. 2 is a side view showing a finned heat exchanger of the second embodiment. This finned heat exchanger has a configuration in which the tube diameter of the heat transfer tube in the heat transfer tube group of the subsidiary heat exchanger is smaller than the pipe diameter in the heat transfer tube group of the main heat exchanger only in the first embodiment. The parts showing the effect are denoted by the reference numerals, and the detailed description is omitted, and the description will be mainly focused on other parts.

21a is a secondary heat exchanger and 21b is a primary heat exchanger. The auxiliary heat exchanger 21a is configured such that the outer diameter d of the heat transfer tube in the heat transfer tube group 23a is smaller than the outer diameter D of the heat transfer tube in the heat transfer tube group 23b of the main heat exchanger 21b. It is. In addition, P1 is the short pitch which is the length between the heat transfer tube center of the heat exchanger tube group 23a of the subsidiary heat exchanger 21a, and the next heat transfer tube center, and is shorter than the short pitch P2 of the heat transfer tube group 23b of the main heat exchanger 21b. Consists of. The auxiliary heat exchanger 21a sets the number of heat transfer tubes of the heat transfer tube group 23a to be equal to or less than the number of heat transfer tubes in one row of the heat transfer tube group 23b of the main heat exchanger 21b. 22a and 22b are fin groups of the subsidiary heat exchanger 21a and the main heat exchanger 21b, and 25 and 26 are branch parts of the heat exchanger tube group 23b. 4 is an arrow which shows the main flow direction of airflow.

In the above configuration, when used as a condenser of the refrigeration cycle of the air conditioner, as in the first embodiment, the fluid flowing in the heat transfer tube flows into the heat transfer tube of the main heat exchanger 21b in a gaseous state as shown by arrow A, and branches ( 25 into upper and lower portions of the heat exchanger tube group 23b, become a liquid state through a gas-liquid two-phase state by heat exchange with the airflow 4, and join again in the branch portion 26 to vertically arrange the auxiliary heat exchanger 21a. Inflow to the heat transfer pipe of the heat transfer pipe group 23a which is formed and flows out as arrow B.

In addition, when acting as an evaporator of the refrigeration cycle of the air conditioner, the fluid flowing in the heat transfer tube flows into the heat transfer tube of the heat transfer tube group 23a formed in the columnar state of the auxiliary heat exchanger 21a as shown by arrow B in a gas-liquid two-phase state, and again. The heat exchanger is divided into upper and lower portions of the heat exchanger tube group 23b at the branch portion 26 of the heat exchanger tube 21b of the main heat exchanger 21b, and exchanges heat with the airflow 4, then joins the branch portion 25 again and flows out as shown by arrow A from the heat exchanger tube. do.

According to this structure, the short pitch P1 of the heat exchanger tube group 23a of the subsidiary heat exchanger 21a is shorter than the short pitch P2 of the heat exchanger tube group 23b of the main heat exchanger 21b, and also the auxiliary heat exchanger ( Since the heat transfer tube outer diameter (d) in the heat transfer tube group (23a) of 21a) is a microtube smaller than the heat transfer tube outer diameter (D) in the heat transfer tube group (23b) of the main heat exchanger (21b), the fin efficiency by micromandarinization Can be reduced, the heat transfer area in the heat transfer tube can be increased, and the heat transfer performance can be improved by increasing the flow velocity of the fluid flowing in the heat transfer tube, thereby improving the performance of the auxiliary heat exchanger 21a. Therefore, if it acts as a condenser, it can occupy much of the supercooling zone of the liquid state which is very low as the tube heat transfer performance in the subsidiary heat exchanger 21a, and thereby the two-phase state which is favorable as the tube heat transfer performance in the main heat exchanger 21b can be occupied. It can occupy a lot, can increase heat exchange ability, and can improve the performance of a finned heat exchanger. In addition, when acting as an evaporator, the number of stages of the heat transfer tubes in one column of the auxiliary heat exchanger 21a is less than the number of stages of the heat transfer tubes in the one row of the main heat exchanger 21b, thereby suppressing an increase in the pressure loss in the tube and the evaporation capacity. Can be improved.

(Third Embodiment)

Fig. 3 is a sectional view showing a part of an auxiliary heat exchanger in the finned heat exchanger of the third embodiment. The finned heat exchanger has only a configuration in which the heat exchanger tube in the heat transfer tube group of the subsidiary heat exchanger is flat is different from the first embodiment. It abbreviate | omits and demonstrates centering on another part.

31a is an auxiliary heat exchanger. The auxiliary heat exchanger 31a constitutes a heat transfer tube in the heat transfer tube group 33a in a flat shape, and a partition wall is provided at the center of the heat transfer tube in the vertical direction to withstand the pressure against the internal pressure. In FIG. 3, there is only one partition wall, but usually, such a porous pipe is provided with about 4-20 partition walls. 32a is a fin of the auxiliary heat exchanger 31a, and 4 is the main flow direction of the airflow.

According to the above configuration, when used as a condenser or evaporator of a refrigerating cycle of an air conditioner, the fluid flows in the heat transfer tube similarly to the first embodiment, and heat exchanges with the airflow 4. The fluid near the central portion flowing in the heat transfer tube exchanges heat with the heat transfer tube inner wall by heat conduction and convection in the fluid region of the condenser, and heat exchanges with the airflow passing through the heat exchanger through the fin outside the heat transfer tube. The heat transfer tube of the heat transfer tube group 33a of the subsidiary heat exchanger 31a has a flat shape, that is, a semicircular shape and a straight line with upper and lower sides parallel to each other, so that the fluid at the central muscle flowing inside the tube can shorten the distance from the inner wall of the tube. It is possible to increase the heat exchange amount due to heat conduction. Moreover, by making it flat, it becomes small as a hydroulic diameter, the Reynolds number becomes large, and turbulence promotion makes it possible to further improve the performance of the auxiliary heat exchanger.

In addition, when acting as an evaporator, the number of stages of the heat transfer tubes in one column of the auxiliary heat exchanger 31a is less than the number of stages in one column in the main heat exchanger, thereby suppressing an increase in the pressure loss in the tube and improving the evaporation capacity. can do.

The same effect can also be obtained by using an elliptical shape instead of the flat shape of the heat transfer tubes of the heat transfer tube group 33a of the third embodiment.

(Example 4)

Fig. 4 (a) is a perspective view showing a finned heat exchanger of the fourth embodiment, and Fig. 4 (b) is a front view. This finned heat exchanger has a fin length between the heat pipes and the heat pipes of the gas inlet-side heat pipe group longer than the short pitch between the heat pipes. Since the points having shorter pitches having substantially the same length are different from those in the first embodiment, other parts having the same configuration and effect are denoted by the reference numerals, and detailed descriptions are omitted, and other parts will be mainly described.

41a is the auxiliary heat exchanger, and 41b is the main heat exchanger. 42a and 42b are fin groups of the auxiliary heat exchanger 41a and the main heat exchanger 41b, respectively. The fin group 42a of the auxiliary heat exchanger 41a is formed in a wave shape. However, the fin group 42a is not limited to the waveform, and may be any shape as long as the adjacent heat transfer tubes are not connected at the shortest distance. 43a and 43b are the heat exchanger tube groups of the subsidiary heat exchanger 41a and the main heat exchanger 41b, respectively. P1 and P2 are short pitches of the length between the heat transfer tube group 43a of the auxiliary heat exchanger 41a and the heat transfer tube center 43b of the main heat exchanger 41b and the next heat transfer tube center, respectively. d is the heat exchanger tube outer diameter of the heat exchanger tube group 42a of the subsidiary heat exchanger 41a, and D is the heat transfer tube outer diameter of the heat exchanger tube group 42b of the main heat exchanger 41b. The auxiliary heat exchanger 41a, which is the gas inlet side X, measures the length (L1 + L2 + L3 + L4) of the fins between the heat transfer tubes and the heat transfer tubes of the heat transfer tube group 42a between the heat transfer tubes. The main heat exchanger 41b which is longer than (P1) and which is the gas outlet side Y has a length equal to the length of the fin between the heat transfer tube and the heat transfer tube of the heat transfer tube group 43b and the short pitch P2 between the heat transfer tube. It is composed of.

According to the above constitution, when used as a condenser of the refrigeration cycle of the air conditioner, the fluid flowing in the heat transfer tube flows in from the main heat exchanger 41b side and flows out to the subsidiary heat exchanger 41a side as in the first embodiment. Moreover, when using as an evaporator, it flows in from the auxiliary heat exchanger 41a side like the 1st Example, and flows out to the main heat exchanger 41b side. In the case of acting as a condenser, the fluid in the heat transfer tube group 43b of the main heat exchanger 41b is in a two-phase state in the saturation region, and the temperature difference between the stages of the heat transfer tube group 43b is about 0.2 to 0.3 ° and there is almost no temperature difference. On the other hand, the fluid in the heat exchanger tube group 43a of the subsidiary heat exchanger 41a is in a liquid state, and the temperature difference between heat transfer tubes between each end of the heat exchanger tube group 43a is large.

However, in the invention of the fourth embodiment, the heat conduction loss due to the temperature difference between the heat transfer tube of the heat transfer tube group 43a of the auxiliary heat exchanger 41a and the end of the heat transfer tube is converted to the fin length (L1 + L2 + L3 + L4) between the heat transfer tubes. Since it is longer than the short pitch P1 of the liver, the heat conduction loss in the subsidiary heat exchanger 41a is reduced, and in the main heat exchanger 41b where the heat conduction loss due to the temperature difference between the ends is small, the heat transfer pipe of the heat exchanger group 43b By the structure in which the fin length and the short pitch P2 of a heat exchanger tube maintain substantially the same length, and maintain fin efficiency, the fin heat exchanger can be improved in performance.

In addition, in the case of acting as an evaporator, the number of pipe stages of the heat transfer tube group in one column of the auxiliary heat exchanger 41a is less than the number of pipe stages of the heat transfer tube group in the first column of the main heat exchanger 41b, thereby suppressing an increase in the internal pressure loss. And the evaporation capacity can be improved.

In addition, the effects such as microtubules and flat shapes of the heat transfer tubes in the heat transfer tube group of the auxiliary heat exchanger 41a also have the same effects as those in the first to third embodiments.

(Example 5)

Fig. 5 is a sectional view of an auxiliary heat exchanger in the finned heat exchanger of the fifth embodiment. This finned heat exchanger is different from the above-described first embodiment in that the fin between the heat-transfer tube and the heat-transfer tube of the gas inlet-side heat-transfer tube group is inclined with respect to the direction of air flow, and is different from that in the first embodiment. The part which showed the effect is attached | subjected with a code | symbol, detailed description is abbreviate | omitted and it demonstrates centering on another part.

51a is an auxiliary heat exchanger which consists of a fin group 52a provided in parallel at intervals, and the heat-transfer tube group 53a which penetrates through this fin group 52a at right angles, and is twisted and arranged. 57 is a straight cut-out part (also called a cutting part) provided in the inclination with the downward gradient with respect to the airflow direction shown by the arrow 4 in the fin between the heat exchanger tube group 53a and the heat exchanger tube. θ is an inclination angle between the cut portion 57 and the main flow direction of the airflow 4.

According to the above configuration, when used as a condenser of the refrigeration cycle of the air conditioner, as in the first embodiment, the fluid flowing in the heat transfer tube flows in from the main heat exchanger side and flows out to the subsidiary heat exchanger 51a side. Moreover, when using as an evaporator, it flows in from the auxiliary heat exchanger 51a side like the 1st Example, and flows out to the main heat exchanger side. In the case of acting as a condenser, the fluid in the heat transfer tube of the main heat exchanger is in a two-phase state in the saturation region, and the temperature difference between the heat transfer tube and the tube end of the heat transfer tube is about 0.2 to 0.3 ° and there is almost no temperature difference. On the other hand, in the fluid in the heat exchanger tube group 53a of the auxiliary heat exchanger 51a, it is a liquid state, and the temperature difference between the tube end of a heat exchanger tube and a heat exchanger tube is large.

However, in the invention of the fifth embodiment, the heat conduction loss due to the temperature difference between the heat transfer tube and the tube end of the heat exchanger tube in the auxiliary heat exchanger 51a is inclined to the air flow direction indicated by the arrow 4 provided on the fin between the heat transfer tube and the heat transfer tube. Since the cut-out part 57 saves, high performance of a finned heat exchanger can be achieved.

In addition, when acting as an evaporator, the number of stages of the heat transfer tubes in one column of the auxiliary heat exchanger 51a is less than the number of stages in one column of the main heat exchanger, thereby suppressing an increase in the pressure loss in the tube and improving the evaporation capacity. At the same time, the cut portion 57 forms an inclination angle θ with respect to the main flow direction of the airflow, so that the condensed water adhered to the pin surface can be discharged without being retained at the lance sections 58a and 58b. Increase of ventilation resistance when there is

In addition, in the fifth embodiment, the cut-out portion 57 is a straight line, but the same effect can be obtained even if it is a curve or a sawtooth shape. Moreover, the same effect is acquired even if it is a fine gap part (also called a punching part) instead of the cut-out part. In addition, although the cut-out part 57 of 5th Example extends the end surface 58a, 58b to the side of the heat exchanger tube of the heat exchanger tube group 53a, you may end in front of the heat exchanger tube of the heat exchanger tube group 53a.

(Example 6)

Fig. 6 is a sectional view of an auxiliary heat exchanger in the finned heat exchanger of the sixth embodiment. This finned heat exchanger differs from the first embodiment only in that a plurality of cutouts or irregularities are provided on the fins between the heat transfer tubes and the heat transfer tubes of the heat transfer tube group of the auxiliary heat exchanger at approximately right angles to the main flow direction of the airflow. Therefore, other parts having the same constitution and working effect are denoted by the reference numerals, and detailed description thereof is omitted, and the description will be mainly focused on other parts.

61a is an auxiliary heat exchanger which consists of fin group 62a provided in parallel at intervals, and the heat-transfer tube group 63a which penetrated and penetrated at right angles. 69 is a plurality of cut-out parts provided in the fin between the heat exchanger tube group 63a of the heat exchanger group 61a of the subsidiary heat exchanger 61a at substantially right angle with respect to the main flow direction of the airflow shown by the arrow 4. As shown in FIG.

According to the above configuration, when used as a condenser of the refrigeration cycle of the air conditioner, as in the first embodiment, the fluid flowing inside the heat transfer tube flows in from the main heat exchanger side and flows out to the subsidiary heat exchanger 61a side. Moreover, when used as an evaporator, it flows in from the auxiliary heat exchanger 61a side like the 1st Example, and flows out to the main heat exchanger side. Then, the heat transfer rate on the air side is promoted by the edge layer front edge effect by the cut-out portion 69 of the fin between the heat transfer tube of the heat transfer tube group 63a of the auxiliary heat exchanger 61a and the heat transfer tube. By using together with the structure of the invention of Example-Example 5, each effect is further promoted.

In the sixth embodiment, the cut 69 is straight, but the same effect can be obtained even if it is curved or saw-shaped. Moreover, if it is not a notch and it is an uneven | corrugated shape, although it is less effective than a lance shape, heat transfer promotion can be aimed at.

(Example 7)

Fig. 7 (a) is an enlarged cross-sectional view of the heat transfer tube of the auxiliary heat exchanger in the finned heat exchanger of the seventh embodiment, and Fig. 7 (b) is an enlarged cross-sectional view of the heat transfer tube of the main heat exchanger. This heat exchanger with fins differs from the first embodiment in that the heat transfer area of the inner surface per unit length of the heat transfer tube group of the heat exchanger group of the subsidiary heat exchanger is larger than the heat transfer area of the inner surface of the heat transfer tube group of the primary heat exchanger. The parts showing the same configuration and working effect of the reference numerals are omitted, and the other parts will be described mainly.

70a is a plurality of groove inner circumferential surfaces formed on the inner surface of the heat exchanger tube forming the heat transfer tube group 73a of the auxiliary heat exchanger, and has a height of h1. The groove inner circumferential surface 70a has a heat transfer area of the inner tube surface per unit length of the heat exchanger tube formed by the groove, which is lower than the mountain height h1 on the inner surface of the heat exchanger tube forming the heat transfer tube group 73b of the main heat exchanger. It is set larger than the heat transfer area of the inner surface of the heat exchanger tube in which the groove | channel inner peripheral surface 70b which has many is formed.

According to the above configuration, when used as a condenser of the refrigeration cycle of the air conditioner, as in the first embodiment, the fluid flowing in the heat transfer tube is introduced from the main heat exchanger side using the heat transfer tube group 73b, and the auxiliary heat exchange using the heat transfer tube group 73a. Outflow to the side. In addition, when used as an evaporator, it flows in from the subsidiary heat exchanger side using the heat exchanger tube 73a similarly to 1st Example, and flows out to the main heat exchanger side using the heat exchanger tube 73b. The heat transfer tube group 73a has a height h1 of the groove inner circumferential surface 70a higher than the mountain height h2 of the groove inner circumferential surface 70b of the heat transfer tube group 73b. By making it longer than the inner peripheral surface 70b, the heat transfer area in a heat exchanger tube can be enlarged and high performance of an auxiliary heat exchanger can be aimed at. On the other hand, by increasing the acid height of the inner circumferential surface 70a of the heat transfer pipe group 73a, an increase in pressure loss in the pipe is concerned, but the auxiliary heat exchanger is in a liquid phase, has a high density, and a flow velocity is low, so the influence of pressure loss is almost It can be said that there is no.

In addition, when used as an evaporator, by using the heat transfer tube group 73a of the subsidiary heat exchanger on the evaporator inlet side, the increase in the internal pressure loss is only a part of the inlet side, and the rise of the evaporation temperature can be suppressed, and the acid height (h1) is increased. Increase of heat transfer performance by the increase of) can be utilized, and the evaporation capacity can be improved.

Further, by combining the invention of the seventh embodiment with the inventions of the first to second embodiments and the fourth to sixth embodiments, it is possible to further improve the performance of the finned heat exchanger.

According to the present invention, the heat transfer area in the heat transfer tube can be improved, and the condensation capacity and the evaporation capacity can be improved by limiting the number of heat transfer tubes.

Claims (7)

A group of fins arranged parallel to each other at predetermined intervals, the gas flows therebetween, and a group of heat transfer tubes passing through the fin groups at approximately right angles, forming a row, and having a fluid flowing therein; The short pitch between the heat pipes of the gas inlet-side heat pipe group is smaller than the short pitch between the heat pipes of the gas-outlet heat pipe group, And a heat exchanger having a fin in which the number of heat transfer tubes in one column of the gas inlet side heat transfer tube group is less than or equal to the number in one column of the gas outlet side heat transfer tube group. 2. The finned heat exchanger according to claim 1, wherein the tube diameter of the gas inlet side heat exchanger tube group is smaller than the tube diameter of the gas outlet side heat exchanger tube group. 2. The finned heat exchanger according to claim 1, wherein the heat transfer tubes of the gas inlet side heat transfer tube group have an elliptical or flat shape. The length of the fin between the heat exchanger tube and the heat exchanger tube of a gas inflow side heat exchanger tube group is made longer than the short pitch between heat exchanger tube, and between the heat exchanger tube and a heat exchanger tube of a gas discharge side heat exchanger tube group. Heat exchanger with fins consisting of approximately the same length of the fin length and the short pitch between the heat transfer tubes. The fin or the cutting part of a predetermined length is provided in the fin between the heat exchanger tube and the heat exchanger tube of a gas inflow side heat exchanger tube group, The said cutting part or the punching part with respect to the main flow direction of an airflow of any one of Claims 1-4. Finned heat exchanger. The finned heat exchanger according to any one of claims 1 to 5, wherein a plurality of cutouts or irregularities are provided on the fin between the heat transfer tube and the heat transfer tube at approximately right angles to the main flow direction of the airflow. The heat transfer area according to any one of claims 1, 2, 5, and 6, wherein the heat transfer area is provided on the inner surface per unit length of the heat transfer pipe group of the heat transfer pipe group on the gas inlet side. Finned heat exchanger with larger heat transfer area.