ES2257360T3 - CONDENSER. - Google Patents

Abstract

A condenser includes a pair of headers (11) and a plurality of heat exchanging tubes (12) disposed between the headers (11) with their opposite ends connected to the headers (11). The plurality of heat exchanging tubes (12) are grouped into three paths P1-P3 by partitions (16). A refrigerant introduced from a refrigerant inlet 11a provided at the lower portion of one of headers passes upwardly through the paths P1-P3 in sequence, and flows out of a refrigerant outlet 11b provided at an upper portion of one of headers. The cross-sectional area of each path decreases stepwise towards a downstream side path, and the reduction rate of the cross-sectional are of the downstream side path of the adjacent two paths to the cross-sectional area of the upstream side path thereof is set to 20%. Thereby, the cooling performance can be achieved. <IMAGE>

Description

Condenser.

1. Sector of the invention

The present invention refers to the use of a condenser and a cooling system, for example for air conditions for cars.

2. Description of the related technique

As can be seen in Figure 8, a conventional multiflow type condenser, to be used in car air conditioners, includes a couple of vertical heads 1 and 1 arranged apart from each other and a series of horizontal flat tubes 2 as exchange tubes heat, arranged between the heads at certain intervals in upward and downward direction with their opposite ends connected to the heads. One of the heads 1 has a refrigerant inlet 1a in the upper end portion of the same, while the other head 1 has an output of refrigerant 1b in the lower portion thereof. In addition, the heads 1 are provided with partitions 5 each of which is placed at a predetermined portion to divide the interior of the head so as to group together the aforementioned series of tubes 2 planes in a series of routes P1 to P3.

So, in this condenser, the refrigerant introduced by the refrigerant inlet 1a passes sequentially down through each path P1 to P3 as a coil, and then exits through the refrigerant outlet 1b. During its passage to through these paths, the refrigerant exchanges heat with ambient air to condense in a liquid refrigerant.

The inventors of the present application analyzed the stagnation of the liquid refrigerant in the before mentioned capacitor using a thermography. According to results of the analysis, as can be seen in figures 9 and 10, RL liquefied refrigerant tends to stagnate in the portion lower downstream of each route P1-P3. In detail, in the conventional condenser, coolant liquefaction has already begun in the portion end of the first route P1. Therefore, the refrigerant RL smoothie starts at the bottom of the head portion that connect the first and second paths P1 and P2, which can produce the so-called liquid stagnation. Since this liquid refrigerant stagnating RL blocks the tube inlets in the lowest portion of the second path P2, just the RL liquid refrigerant passes into the lower tubes 2 of the second tour P2. Similarly, only the refrigerant RL smoothie flows into the lower tubes 2 of the third P3 tour. Since those portions for which only RL liquid refrigerant passes can not perform an effective thermal exchange, an effective transfer area is reduced thermal, which causes performance deterioration refrigerant.

In addition, the liquid refrigerant RL prevents refrigerant circulation, resulting in an increase in resistance to coolant flow.

US 6,021,846 describes a duplex heat exchanger comprising: a series of unit heat exchangers; having each unit heat exchanger a circuit formed in it for a heat exchanger medium; and connection means to connect with each other the circuits in fluid communication, comprising Each heat exchanger unit: a series of pipes arranged in parallel with respect to each other; and a pair of hollow heads to which are connected both ends of each tube in communication of fluid, so that the unit heat exchangers are placed forward and backward in the direction of air flow, of so that one of said unit heat exchangers is face the wind, while the other heat exchangers units are on the side opposite to the wind, being connected in parallel with each other, for the heat exchanger medium, the circuits formed by unit heat exchangers.

US Patent 5,730,212 describes a refrigerant condenser to be used in a system of car air conditioning, comprising in pair of heads forming an inlet and outlet for refrigerant, and which are connected by a series of tubes, so that you can set the number of turns in two by means of dividers, where the tubes can be fixed for a combination of 11, 11, and 10 or 16, 12, and 4.

US Patent 6,062,303 describes a multiflow type condenser comprising a pair of tubes heads arranged in parallel to each other and placed to have an entrance and an exit; a series of tubes, each of the which is connected to said head tubes at the ends opposite of it, with at least one pair of baffles arranged in said head tubes; and an area of passage in the input side defined by the camera on the input side of the chambers divided by the baffles, in which introduce the refrigerant through said inlet and that is formed in one of the head tubes while the camera opposite is formed in the other of the head tubes, and being a series of tubes that extend between the chambers approximately from 30 to 65% of the global area of all steps.

US Patent 5,482,112 describes a capacitor comprising a series of tubular elements that define flow steps, and a pair of heads arranged in the opposite ends of the tubular elements, defining one and the other heads a coolant inlet and a coolant outlet, so that both heads are divided into two sections through a partition that divides the entire refrigerant passage inside an entry side group, an intermediate group and a group lateral exit, and in which the intermediate group has an area of cross section smaller than that of the input side group and greater than that of the output side group.

Summary of the invention

It is an object of the present invention to provide a capacitor that has a reduced resistance to the passage of refrigerant and better cooling performance.

This is achieved through the subjects that they have the characteristics set forth in claim 1 and in claim 3, respectively.

With this condenser, the gaseous refrigerant that comes out of the heat exchanger tubes that make up the upward side travel (lower side travel) passes vigorously in the refrigerant spin portion of the head that connects the adjacent paths, and the refrigerant ascending passes inside the heat exchanger tubes that they constitute the path of the descending side (route of the upper side). Therefore, the liquid refrigerant is pushed by the blowing effect of this ascending refrigerant, and passes gently inside the heat exchanger tubes that they constitute the descending lateral path (lateral path higher). This prevents stagnation of the liquid refrigerant, the which maintains a large area of effective thermal transfer of the heat exchanger portion and allows a smooth flow of refrigerant distributed equally on each tour.

According to the invention, the series of steps includes three or more routes that comprise a first tour, a second tour and a third tour through which sequentially passes the refrigerant introduced by the inlet of refrigerant, being the reduction rate of a section area transverse of the second path with respect to an area of the cross section of the first run of 50% or more, and the rate of reduction of a cross-sectional area of the third path with with respect to an area of cross section of the second path of the 40% or more. This has the effect that it can be achieved completely The aforementioned coolant blowing effect caused by the refrigerant spin portion that connects the paths adjacent, which can prevent refrigerant stagnation smoothie in the refrigerant spin portion.

In the complementary claims 2 and 4, describe other embodiments of the invention.

Other objects and particularities of the invention will be apparent from the following detailed description of the present invention, made with reference to the drawings attached.

Brief description of the drawings

It will be described more fully and you will better understand the present invention from the following description, made with reference to the attached drawings, in the which:

Figure 1 is a front view showing a condenser to be used in air conditioning systems for automobiles according to an embodiment of the present invention;

Figure 2 is a schematic front view showing an arrangement of the condenser refrigerant circuit according to the embodiment;

Figure 3 is a cross-sectional view. enlarged, showing a first portion of the refrigerant spin and the condenser environment according to the form of realization;

Figure 4 is a schematic sectional view. transverse, showing a refrigerant circuit arrangement of a condenser to be used in air conditioners for cars, according to a second embodiment of the present invention;

Figure 5 is a schematic sectional view. cross section showing a refrigerant circuit arrangement of a condenser to be used in air conditioners for cars, according to a third embodiment of the present invention;

Figure 6 is a schematic sectional view. cross section showing a refrigerant circuit arrangement of a condenser to be used in air conditioners for cars, according to a comparative example;

Figure 7 is a graph showing a relationship between the resistance to the flow of refrigerant and the refrigerant circulation above the condensers according to the invention and comparative;

Figure 8 is a front view, partially suppressed, showing a conventional capacitor for use in air conditions for automobiles;

Figure 9 is a schematic front view showing a refrigerant circuit arrangement of the condenser conventional; Y

Figure 10 is a schematic, sectional view. transverse, showing a first portion of the refrigerant spin and the conventional condenser environment.

Detailed description of the embodiments preferred

Figures 1 and 2 show a condenser type multiflow to be used in air conditions for automobiles, according to an embodiment of the present invention.

As these figures show, this capacitor It has a pair of heads, right and left 11 and 11, arranged At a certain distance. Between said heads 11 and 11, it is placed horizontally a series of flat tubes 12, such as tubes heat exchangers, at certain intervals in the direction vertical with its opposite ends connected to heads 11 and 11. In addition, there are corrugated fins 13 arranged between the tubes adjacent planes 12 and placed in the outermost flat tubes 12. Also, on the outer side of each wavy fin more external 13, a cinch-shaped side plate 14 is placed to protect the outermost wavy fin 13.

On the lower side of one of the heads 11 (the right head), is a refrigerant inlet 11a. On the other hand, on the upper side of the other head 11 (head left), there is a refrigerant outlet 11b.

Also, in a predetermined portion of each head 11, there is a partition 16 that divides the inside of the head 11, longitudinally thereof, thus grouping the before mentioned series of flat tubes 12 in three paths, the first route P1 (lower route), the second route P2 (central route) and the third route P3 (route higher).

The head portion of the unwanted head 11 which connect the first path P1 with the second path P1 and P2 constitutes a first rotating portion of refrigerant T1, and the head portion of the right head 11 connecting the second route P2 with the third route P3 constitutes a second T2 refrigerant spin portion.

In the aforementioned embodiment, even when the head portion constituting the turning portion T1 or T2 is formed by the division of a simple cylindrical head 11 with partition 16, the present invention is not limited thereto. For example, each head portion that constitutes the portion of turn T1 and T2 can be formed by a single head tube separated.

In this embodiment, each path P1-P3 has the cross-sectional area staggered downward to the descending lateral side (upper lateral path) for each path. In the present invention, the reduction rate of the cross-sectional area of the descending lateral path (upper lateral path) of the two adjacent paths to the ascending lateral path (lower lateral travel) must be set at 20% or more, and preferably said reduction rate is set to 30% or more. The aforementioned reduction rate (%) can be obtained through following formula: (1-PL / PU) x100 (%), where "PU" is an area of the cross section of the lateral path ascending, and "PL" is the area of the lateral path falling. If the aforementioned reduction rate is less than 20%, a sufficient flow rate (vigor) cannot be guaranteed of the refrigerant in the rotating portion of the refrigerant T1 and T2 in head 11 between adjacent paths, resulting in an inefficient refrigerant blowing effect, which in turn can cause a stagnation of the liquid refrigerant.

In the present invention, it is preferable that the The aforementioned reduction rate is set to 25% or more in either of the two adjacent paths. It is more preferable than the reduction rate of the cross-sectional area of the second travel with respect to the cross-sectional area of the first travel is 50% or more and that the reduction rate of the area of the cross section of the third path with respect to the area of the cross section of the second path is 40% or more.

In the condenser of this embodiment, all flat tubes 12 have the same structure, and therefore the cross section area of each path P1-P3 is proportional to the number of tubes in each P1-P3 route. Therefore, the rate of reduction of the cross-sectional area between the paths adjacent corresponds to the rate of reduction of the number of tubes between adjacent paths. In the condenser in this way embodiment, as can be seen in figure 2, the first path P1 includes 22 flat tubes, the second route P2 includes 9 tubes flat and the third path P3 includes 5 flat tubes. By consequently, the reduction rate of section areas transversal between the first and second paths P1 and P2 is of the 59.1%, and the one between the second and third routes P2 and P3 It is 44.4%.

However, in the present invention, the rate of reduction of cross-sectional areas between paths adjacent can be established so that each route is constituted by the same number of tubes that have different area of cross section.

In the present invention, even if the total number of routes is not particularly limited, it is preferable that the total number be 2 to 5, more preferably 3 or 4. The most appropriate total number is 3. If the total number of paths is excessive, the reduction rate of cross-sectional areas between adjacent paths, that is, the rate of reduction of the number of pipes between adjacent paths in the aforementioned embodiment, is too low, which results in a disturbance. in the security of the aforementioned rate of
reduction.

Furthermore, in the present invention, it is preferable that the cross-sectional area of each path is reduced staggered for each path to the flow side descending (upper side). However, the core heat exchanger can include adjacent paths each of which has the same cross-sectional area. By consequently, it should be understood that the present invention covers such condenser including adjacent paths each of which It has the same cross-sectional area, unless indicated clearly otherwise.

Returning to the condenser of the form of embodiment mentioned above, the refrigerant introduced by the coolant inlet 11a passes sequentially upwards to through the first to the third route P1-P3 by way of coil, and comes out of the refrigerant outlet 11b. While passes through these paths, the refrigerant exchanges heat with ambient air to be gradually condensed and smoothie.

At this time, coolant liquefaction gas introduced by the refrigerant inlet 11a starts at the extreme portion of the first path P1, for example, and the RL liquid refrigerant flows through the tube outlets of the first path P1 and tends to descend in the rotating portion of refrigerant T1, as can be seen in figure 3. On the other On the other hand, the RG gas refrigerant exits through the tube outlets of the first route P1 and rises vigorously in the first portion of turn T1. This rising GG refrigerant pushes towards above the aforementioned liquid refrigerant RL. So the RL liquefied refrigerant ascends through the first turning portion of T1 refrigerant together with the RG gaseous refrigerant, and this Ascending coolant mixture will be regular and smoothly distributed within each flat tube 12 which constitutes the second P2 tour.

In this embodiment, since the cross-sectional area of the second path P2 is established according to the aforementioned specific reduction area so that in the first path P1, the flow rate of the liquid refrigerant that ascends through the first portion of T1 refrigerant rotation between the first and second paths P1 and P2 can be sufficiently secured. Accordingly, a sufficient blowing effect can be obtained in the refrigerant rotating portion T1 by the rise of the refrigerant, which in turn can safely prevent the stagnation of the liquefied refrigerant RL in the lower portion of the refrigerant rotating portion -
rant T1.

With respect to the refrigerant that will pass through the third path P3 through the second turning portion of refrigerant T2 from the second path P2, a similar phenomenon. RG gas refrigerant that rises vigorously in the second refrigerant turn portion T2 will push towards above the RL liquefied refrigerant that tends to go down, and therefore this ascending refrigerant can flow smoothly into each flat tube 12 constituting the third path P3.

As a result stagnation can be prevented of liquid using the liquid refrigerant.

Therefore, according to the capacitor of this embodiment, since it is possible to avoid stagnation of the liquid refrigerant, the entire core surface can be used effectively as a heat exchange portion, giving As a result, better cooling performance.

Also, since the refrigerant is not will stagnate and pass through the entire region of each route in a regularly distributed way, resistance can be reduced of refrigerant passage, resulting in another improvement in the heat exchange performance.

Examples of agreement will be explained below. with the present invention, as well as a comparative example.

First example

A capacitor was manufactured according to the before mentioned embodiment represented in figures 1 and 2. Said capacitor has three paths, namely the first lowest travel P1, the second central travel P2 and the third highest travel P3. The first, second and third routes P1, P2 and P3 includes twenty two (22) tubes, nine (9) tubes and five (5) tubes, respectively. In this capacitor, the reduction rate of the cross-sectional area of the second path P2 with with respect to the first route P1 is 59.1%, and the rate of reduction of the cross-sectional area of the third path P3 with respect to the second route P2 is 44.4%.

Second example

As can be seen in Figure 4, it was manufactured a capacitor with three paths, that is, the first path bottom P1, the second central path P2 and the third path top P3. The first, second and third routes P1, P2 and P3 include eighteen (18) tubes, nine (9) tubes and five (5) tubes, respectively. The other structure is the same as the condenser from the first example. In this capacitor, the reduction rate of cross-sectional area of the second path P2 with respect to the First tour P1 is 50%, and the reduction rate of the area of cross section of the third path P3 with respect to the second P2 travel is 44.4%.

In the second embodiment represented in figure 4, the same reference numbers have been used or equivalents of the first example to the same portion or portion equivalent (similarly, it will be indicated with the same number of Eference or equivalent in the following third example represented in figure 5 and in the following comparative example shown in the figure 6).

Third example

As it appears in figure 5, a capacitor that has four paths, that is, the first lower travel P1, the second lower central travel P2, the third upper central path P3 and the fourth upper path P4 The first, second, third and fourth routes P1, P2, P3 and P4 include thirteen (13) tubes, nine (9) tubes, six (6) tubes and four (4) tubes, respectively. Otherwise, the structure is the same as the condenser of the first example. In this capacitor, the rate of reduction of the cross-sectional area of the second path P2 with respect to the first route P1 is 30.8%, the rate of reduction of the cross-sectional area of the third path P3 with respect to the second route P2 is 33.3% and the rate of reduction of the cross-sectional area of the fourth path P4 with respect to the third route P3 is 33.3%. In figure 5, reference number T4 indicates a fourth turn portion of refrigerant (the same number will be used in figure 6).

Example comparative

As can be seen in figure 6, it was manufactured a capacitor that has four paths, that is, the first upper travel P1, the second upper central travel P2, the third lower center path P3 and the fourth lower path P4 The first, second, third and fourth routes P1, P2, P3 and P4 include thirteen (13) tubes, nine (9) tubes, six (6) tubes and four (4) tubes, respectively. Otherwise, the structure is the same as the condenser of the first example. In this capacitor according to the comparative example has a symmetrical configuration rotated 180 degrees compared to the aforementioned capacitor according to the third example. Therefore, in this capacitor, the rate of reduction of the cross-sectional area of the second path P2 with respect to the first route P1 is 30.8%, the rate of reduction of the cross-sectional area of the third path P3 with respect to the second route P2 is 33.3% and the rate of reduction of the cross-sectional area of the fourth path P4 with respect to the third route P3 is 33.3%.

Assessment of a stagnant liquid refrigerant (at rest)

In the aforementioned examples, and in the comparative example, it was observed that a liquefied refrigerant (low temperature refrigerant) is stagnant or not depending on the Temperature distribution of a thermographic image. According to observation, in the condensers from the first to the third examples, the coolant temperature gradually decreased towards the descending portion of each route, there is no variation in temperature distribution, and no observed stagnation of a liquid refrigerant. In addition, in the condenser according to the comparative example, there was a region of low temperature in the lower portion of each route, observing a stagnation of the liquid refrigerant in the portion lower.

Coolant flow resistance rating

The relationship between the coolant flow resistance (kPa) and the amount of refrigerant circulation (kg / h) in each condenser of the Examples cited above and the comparative example. The results measured appear in the graph of figure 7. In said graph "A1", "A2" and "A3" indicate the first, second and third examples, respectively, while "B" indicates the comparative example.

As will be evident in this graph, in the capacitor according to the first to the third examples A1-A3, the coolant flow resistance for a predetermined circulation of refrigerant was reduced by comparison with the capacitor according to the example comparative.

Among these three examples, especially the first and second examples A1 and A2 were able to reduce notably the resistance to flow. The reason is considered as continue: since the reduction rate of the section area transverse of the second path P2 with respect to the area of the cross section of the first path P1 is set at 50% or more, and the reduction rate of the cross-sectional area of the third path P3 with respect to the cross-sectional area of the second path P2 is set to 40% or more, the effect of coolant blowing between adjacent paths can be achieved completely, and therefore the circulation of Refrigerant can be performed in a much milder way.

Therefore, between adjacent paths, with the refrigerant leaving the path of the upper side (lower lateral path) ascends and leaves the lateral path lower (upper side travel), the liquid refrigerant is pushed up by the coolant blowing effect ascending and enters the lower lateral path (upper lateral travel). As a result, you can avoid stagnation of the liquid refrigerant, guaranteeing a sufficient effective area of the heat exchanger portion, what which allows better cooling performance. Also given that the liquefied refrigerant passes through the entire region of each travel without stagnation in it, the coolant flow resistance, which results in a better performance. In cases where the reduction rate of the area of specified cross section between adjacent paths By default, the aforementioned effects can be obtained with all security

This request claims priority to the Japanese patent application no. 2000-183966 filed June 20, 2000.

The terms and descriptions of this specification are used for explanatory purposes only, by what the present invention is not limited to said terms and descriptions It should be noted that there are many modifications and Possible substitutions without departing from the scope of the present invention which is defined in the appended claims. The present invention allows any design change if it is within the limits which is set forth in the claim.

Claims (4)

1. Use of a capacitor, comprising: a pair of right and left heads (11, eleven); a series of heat exchanger tubes (12) arranged at predetermined intervals between said heads with the opposite ends thereof connected to said heads at least one partition (16) arranged in one corresponding of said heads (11) to group said series of heat exchanger tubes (12) in a series of paths (P1, P2, P3); Y a coolant inlet (11a) arranged in an extreme portion of one of said heads (11), and a coolant outlet (11b) arranged in an extreme portion opposite of the other of said heads (11); in which said series of routes includes three or more steps that include a first tour (P1), a second route (P2) and a third route (P3) through which sequentially passes said refrigerant introduced by said coolant inlet (11a), so that a section area Transversal of each of said paths (P1, P2, P3) is reduced staggered downward side of said paths (P1, P2, P3) for each step, in which a reduction rate of said cross-sectional area of said second path (P2) with with respect to the cross-sectional area of said first path (P1) is 50% or more, and in that the reduction rate of an area of cross section of said third path (P3) with respect to the cross-sectional area of the mentioned second path (P2) is 40% or more; so that the condenser is provided with its heads (11, 11) extended vertically and with exchanger tubes of heat (12) extended horizontally, so that said inlet of refrigerant (11a) is in a lower position, and the said refrigerant outlet (11b) is in a position upper so that a refrigerant introduced by the inlet of refrigerant (11a) pass sequentially upwards through said series of paths (P1, P2, P3) as a coil, and exit by said refrigerant outlet (11b). 2. Use of the condenser as indicated in claim 1, wherein each of said reduction rates is it reaches by decreasing the number of said exchanger tubes of heat (12) that constitute each of the aforementioned path (P1, P2, P3). 3. A cooling system that has a condenser which in turn comprises a pair of right heads and left (11, 11); a series of heat exchanger tubes (12) arranged at predetermined intervals between said heads with the opposite ends thereof connected to said heads, with at least one partition (16) arranged in one corresponding of said heads (11) to group said series of heat exchanger tubes (12) in a series of paths (P1, P2, P3); a coolant inlet (11a) arranged in an extreme portion of one of said heads (11); and one coolant outlet (11b) arranged in an extreme portion opposite of the other of said heads (11); in which said series of tours includes three or more steps that include a first route (P1), a second route (P2) and a third route (P3) through which said refrigerant passes sequentially introduced by said refrigerant inlet (11a), so that a cross-sectional area of each of said paths (P1, P2, P3) is reduced stepwise to a falling side of said routes (P1, P2, P3) for each step, in which a rate of reduction of said cross-sectional area of said second path (P2) with respect to the cross-sectional area of said first run (P1) is 50% or more, in which the reduction rate of a cross-sectional area of said third path (P3) with respect to the cross-sectional area of said second travel (P2) is 40% or more; Y in which the capacitor is arranged in such a way that their heads (11, 11) extend vertically with the tubes heat exchangers (12) extended horizontally, so that the coolant inlet (11a) is in a position bottom, and said coolant outlet (11b) is in an upper position, so that a refrigerant introduced through the refrigerant inlet (11a) pass sequentially to above through said series of routes (P1, P2, P3) by way of coil, and exits through said refrigerant outlet (11b). 4. The cooling system as it has been indicated in claim 3, wherein each of said rates of reduction is achieved by decreasing the number of said tubes heat exchangers (12) that constitute each of the cited route (P1, P2, P3).