FR2591728A1 - Heat exchanger, particularly for internal combustion engine - Google Patents

Abstract

Heat exchanger, especially for internal combustion engine, of the type comprising a tubular bundle 3 housed inside an external casing 1 and inlet 2, 6 and outlet 5,10 orifices for the cooling fluids and for the fluids to be cooled. According to the invention, the orifices 2, 5, 6, 10 are grouped together at one end of the exchanger so as to enable the tubular bundle to move without affecting their positions or layouts; a central partition 7 separates this exchanger into two half-exchangers coupled in series in order to organise the flow of the fluids; and this partition is heat-insulated to prevent a thermal transfer from the fluid to be cooled. Application : particularly to the cooling of an internal combustion engine.

Description

HEAT EXCHANGER, ESPECIALLY FOR A MOTOR
INTERNAL COMBUSTION.

The present invention relates to the design of a heat exchanger which can be used in particular for internal combustion engines.

In exchangers of known type, the coolant circulates inside tubes, these forming a bundle characterizing the type or model of one exchanger. The fluid to be cooled is channeled into the external part of these tubes and generally, the direction of flow of the fluids is crossed to increase thermal efficiency.

The thermal efficiency of an exchanger essentially depends on - the nature, geometry and arrangement of the tubes forming the bundle; - the shape and size of the volume delimited by the external part
tubes - and the organization of the direction of flow of the coolant and
fluid to cool.

one of the aims of the present invention is precisely to organize methodically the direction of flow of the fluids in order to obtain an optimal speed of the fluids, a factor characterizing the value of the
fluid-wall heat exchange coefficient - and a maximum temperature difference between fluid at
cool and coolant.

Generally, these two conditions impose - a large flow rate of the coolant - and a direction of flow called "cross-current", which brings
generally on the exchanger assembly
fluid inlet and outlet ports disposed at the ends of the
exchanger bundle explaining a modification of their locations
as soon as there is a change in the heat exchanger harness imposed in particular
by a different requirement of cooling power.

To overcome these requirements, the present invention presents a solution according to which, according to an essential characteristic, - the assembly of the outlet and inlet ports for the fluids is located on a
same face or end of the exchanger; - it is possible to modify the size of the beam without consequences
level of the locations of these orifices; - a central partition separates this exchanger into two half-exchangers
coupled in series to organize the circulation of fluids; - and this partition is insulated to avoid thermal transfer of the
fluid to cool.

According to another feature of the invention, this heat exchanger includes a valve mounted on this central partition to prevent this fluid to cool, any significant pressure drop.

Other objects, features and advantages of the invention will appear more clearly on reading the following description of two preferred embodiments, given by way of nonlimiting examples with reference to the appended drawings in which - Figure 1 shows an axial sectional view of an exchanger
thermal according to a first embodiment; - Figures 2, 3 and 4 show three respective cross sections of
this heat exchanger according to the plans AA, BB and CC of the
figure 1 ; - And Figures 5, 6 and 7 show three respective cross sections
of a second embodiment of this exchanger, according to the same
plans 4-A, 9-B and CC.

The exchanger assembly of FIG. 1 has an external casing l and an inlet orifice 2 which allows the cooling fluid to reach a tube bundle 3. The number of tubes of this bundle which is defined for each type of exchanger, is divided into two equal parts, a first half ensuring the passage of the fluid from the inlet 2 to an end portion 4 of the tube bundle. The cooling fluid ernprunts the other half of the tubes to be directed to an outlet orifice 5 r, e fluid to cool enters the exchanger through an orifice 6 and is directed towards the part of the exchanger (Figures 3 and 6, section B-9), delimited by a central partition 7 of the bundle 3 and the external casing 1. This fluid circulates between the tubes forming half of the bundle bringing the coolant from part 4 to the outlet orifice 5.

To accelerate and organize the flow of the fluid to be cooled according to the invention, partitions 8 are arranged on either side of the central partition 7. The number of these partitions is defined for each type of exchanger. The passage of the fluid to be cooled from the first half to the second half of the tube bundle takes place at the level of an orifice 9 (FIGS. 4 and 7, section CC). Then, the fluid to be cooled circulates between the tubes forming the half-beam channeling the coolant from the inlet orifice 2 to the part 4. As before, partitions
S ensure a methodical circulation of the fluid from the orifice 9 to an outlet 10.

Another particular feature of the invention is obtained by the embodiment of the central partition 7. The latter is produced using a material capable of providing thermal insulation so that the liquid to be cooled cannot heat transfer by conduction through the middle partition 7.

According to another particular feature of the invention, a valve It can be mounted on the central partition 7. The role of this valve is to allow the by-pass of the fluid to be cooled in the case where the latter being at low temperature has a viscosity high and thereby causes a significant pressure loss by the forced passage through the tube bundle.

Claims (2)

1. Heat exchanger in particular for an internal combustion engine, of the type comprising a tube bundle (3) housed inside an external casing (1) and inlet (2, 6) and outlet openings (5, 10) coolant and coolant fluids, characterized in that these orifices (2, 5, 6, 10) are grouped at one end of the exchanger to allow an evolution of the tube bundle without affecting their positions or locations , that a middle partition (7) separates this exchanger into two half-couplers coupled in series to organize the circulation of fluids, and that this partition is insulated to avoid thermal transfer of the fluid to be cooled. 2. Heat exchanger according to claim l, characterized in that it comprises a valve (lI) mounted on the central partition (7) to prevent the fluid from cooling any significant drop in pressure.