ES2325193A1 - Flap for the conduction of a fluid to refrigerate, and heat exchanger of stacked plates given of such fins (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Flap for the conduction of a fluid to be cooled, and heat exchanger of stacked plates equipped with such fins. The flap comprises a plurality of ducts (4), through which the fluid to be cooled circulates from an entrance zone (3a) to an exit zone (3c) disposed respectively on opposite ends of the flap (3). It is characterized by the fact that the passage surface of the ducts (4) decreases according to the direction of advance of the flow of fluid to be cooled, keeping the total surface of passage along the fin (3) substantially constant, so that that the thermal transfer of said fin is optimized. Preferably, the fin comprises at least two zones (3a to 3c) of ducts (4) arranged adjacently according to the direction of advance of the flow of fluid to be cooled, so that the width of the ducts (4) of the respective zones (3a) a 3c) decreases gradually, while the number of ducts (4) increases. (Machine-translation by Google Translate, not legally binding)

Description

Flap for the conduction of a fluid to refrigerate, and stacked plate heat exchanger equipped with such fins

The present invention relates to a fin for the conduction of a fluid to be cooled. The invention also refers to a stacked plate heat exchanger endowed of such fins.

The invention especially applies to Exhaust gas recirculation exchangers of an engine (Exhaust Gas Recirculation Coolers or EGRC), and refrigerators of the supercharger air or intercoolers (Charge Air Coolers or CAC).

Background of the invention

A heat exchanger may have different  configurations: for example, it can consist of a housing tubular inside which are arranged a series of parallel tubes for the passage of gases, circulating the refrigerant through the housing, externally to the tubes; in another embodiment, the exchanger consists of a series of parallel plates that they constitute the heat exchange surfaces, so that Exhaust gases and refrigerant circulate between two plates, in alternating layers. It may also include disturbing means of gas, such as fins, arranged between the plates that lead the gas to be cooled Said fins comprise a plurality of ducts

Gas temperatures in EGR and CAC type heat exchangers experience high variations, which means that gas densities They will also vary considerably. Occasionally, the densities of the gases reach twice their value inside the exchanger, so the gas velocities are reduced to 50%.

In conventional designs, the surface of heat exchange is not optimized to suit the density changes The heat exchange surfaces and the fins are equal in the gas inlet zone (where the gas is hotter, less dense and has higher speeds), such as in the gas outlet zone (where the gas is colder). The designs Conventionals are not as compact as they should be, which means that heat exchangers are large and considerably expensive.

They are known exchangers in the form of "U", that is to say, that present the entrance and exit of gases at the same end of the exchanger housing, which apply this concept, where the path of the return gas flow has been reduced in relation to the flow path of the gas inlet

Spanish patent application 200301093 of same holder of the present application, refers to a U-shaped heat exchanger, whose section of passage of the tubes of the section corresponding to the inlet of the gas flow is greater than the pipe passage section of the section corresponding to the gas flow outlet.

Patent application WO03102483 refers to a stacked plate exchanger with the gas circuit to cool U-shaped, in which the surface of the plates corresponding to the entrance of the gas flow is greater than the surface of the plates corresponding to the flow outlet of gases

However, in heat exchangers of stacked plates whose trajectory of the gases to be cooled is linear, that is, where the inlet and outlet of gases are arranged at each end of the exchanger, it is currently not solved the aforementioned problem of the variation of densities of gases inside the exchanger.

Description of the invention

The purpose of the fin for driving a  Cooling fluid of the present invention is to solve the drawbacks of the fins known in the art, providing a fin that optimizes the transfer thermal throughout it.

The fin for the conduction of a fluid to refrigerate, object of the present invention, especially for Stacked plate heat exchangers, is the type that it comprises a plurality of ducts, through which the fluid to be cooled circulates from an inlet zone to a exit zone arranged respectively at both ends opposite of the fin, and is characterized by the fact that the passage surface of the ducts decreases according to the direction of advance of the flow of fluid to be cooled, keeping noticeably constant the total surface area along the fin, so that the thermal transfer of said fin.

In this way, you get a fin with greater exchange area in areas where the fluid to be cooled is colder, that is, in the area near the exit, which prevents thermal transfer from decreasing, being achieved by both a correct thermal performance throughout the entire fin.

According to an embodiment of the invention, the fin comprises at least two areas of contiguously arranged ducts according to the direction of advance of the flow of fluid to be cooled, of so that the width of the ducts of the respective zones goes decreasing stepwise, while the number is increasing of ducts

This staggered configuration of the sections of ducts is structurally simple, which does not imply a increased manufacturing cost of the fin.

Preferably, the fin comprises three zones of ducts, a first entrance area, a second zone intermediate, and a third exit zone, arranged contiguously according to the direction of advance of the flow of fluid to be cooled, of mode the exit zone has a greater number of ducts smaller width than in the intermediate zone and, in turn, the zone intermediate has a larger number of smaller ducts than in the entrance area.

According to another aspect, the invention also refers to a stacked plate heat exchanger, of the type comprising a plurality of plates stacked between the which circulate the fluid to be cooled and the cooling fluid in two independent circuits defined by said plates, and that includes a set of fins, as defined above, each fin being arranged between each pair of plates that lead the fluid to cool.

Brief description of the drawings

In order to facilitate the description of how much  It has been exposed above are attached some drawings in which, schematically and only by way of non-limiting example, represents a practical case of realization of the fin for the conduction of a fluid to be cooled of the invention, in the which:

Figure 1 is a partial perspective view of a conventional stacked plate heat exchanger;

Figure 2 is a cross section of the exchanger of figure 1; Y

Figure 3 is a perspective view of a fin applicable to a linear configuration exchanger, according to An embodiment of the invention.

Description of preferred embodiments

Figures 1 and 2 show an exchanger of heat 1 of conventional EGR type comprising a plurality of stacked plates 2 between which the gas to be cooled circulates and the coolant in two independent circuits 2a, 2b defined by said plates 2, and a plurality of fins 3 provided with conduits 4 for the conduction of the gas to be cooled, each fin 3 being arranged between each pair of plates 2 which They lead the gas to cool.

The passage surface of the ducts 4 decreases according to the direction of advance of the fluid flow to refrigerate, keeping the surface substantially constant total passage along fin 3, so that the thermal transfer of said fin.

According to the embodiment represented in the figure 3, fin 3 comprises three zones of ducts 4, a first zone input 3a, a second intermediate zone 3b, and a third zone output 3c, contiguously arranged according to the direction of travel of the fluid flow to be cooled, so the outlet zone 3c it has a greater number of ducts 4 of smaller width than in the intermediate zone 3b and, in turn, intermediate zone 3b has a greater number of ducts 4 of smaller width than in the area of 3rd entry.

By presenting said fin 3 a larger area of exchange in areas where the fluid to be cooled is more cold, that is, in zone 3c near the exit, you get prevent the thermal transfer from decreasing, obtained by both correct thermal performance throughout the entire fin 3.

The exchanger 1 also comprises wells of inlet 5 and outlet (not shown) of the coolant, a inlet 6 and an outlet (not shown) of the gas to be cooled arranged in the direction of the recirculation line of the exhaust gases, upper 7 and lower 8 support plates, and connection means (not shown) of the input and output of the gas with the recirculation line.

Claims (4)

1. Flap (3) for the conduction of a fluid to be cooled, especially for heat exchangers (1) of stacked plates (2), comprising a plurality of ducts (4), through which the fluid circulates to cooling from an inlet zone (3a) to an outlet zone (3c) arranged respectively at opposite ends of the fin (3), characterized by the fact that the passage surface of the ducts (4) decreases according to the direction of advancing the flow of fluid to be cooled, the total surface area along the fin (3) being kept substantially constant, so that the thermal transfer of said fin is optimized. 2. Flap (3) according to claim 1, characterized in that it comprises at least two zones (3a to 3c) of ducts (4) contiguously arranged according to the direction of advance of the flow of fluid to be cooled, so that the width of the ducts (4) of the respective zones (3a to 3c) is gradually decreasing, while the number of ducts (4) is increasing. 3. Flap (3) according to claim 2, characterized in that it comprises three zones of ducts (4), a first inlet zone (3a), a second intermediate zone (3b), and a third outlet zone (3c), arranged contiguously according to the direction of advance of the flow of fluid to be cooled, so that the outlet zone (3c) has a larger number of ducts (4) of smaller width than in the intermediate zone (3b) and, a in turn, the intermediate zone (3b) has a greater number of ducts (4) of smaller width than in the entrance zone (3a). 4. Plate heat exchanger (1) stacked, of the type comprising a plurality of plates (2) stacked between which circulate the fluid to be cooled and the coolant in two independent circuits (2a, 2b) defined by said plates (2), and that includes a set of fins (3), defined according to any of claims 1 to 3, each fin (3) being disposed between each pair of plates (2) that lead the fluid to cool.