JPS6223236B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to exhaust gas recirculation in motor vehicle internal combustion engines, and more particularly to a device for cooling exhaust gas returned to the combustion cycle.

Since approximately 1971, the automobile industry has been adding an ever-increasing number of elements to automobiles or to automobile internal combustion engines in order to increase automobile safety or reduce the emissions inherent in exhaust gases from internal combustion engines. In other words, it has been requested that additional equipment be added. Such elements include positive crankcase ventilation, exhaust gas recirculation, evaporative control devices, and catalytic converters in the exhaust system.

Of primary interest are the emissions from the exhaust gases of internal combustion engines, which have been blamed for the smog-like conditions that occur in large cities with large numbers of automobiles traveling every day. Nitrogen oxides are one such exhaust gas, and exhaust gas recirculation cycles are used to reduce these oxides in engine exhaust gases. The formation of nitrogen oxides takes place at very high temperatures and therefore occurs at the peak temperatures of the combustion process. A slight reduction in peak temperature is required to reduce and control nitrogen oxide formation.

This reduction in temperature is achieved by introducing a small amount of inert gas into the combustion process so that the end products of combustion are continuously supplied with relatively inert gases; will be used in the correct proportions. The recirculation passageway is thus connected to the exhaust manifold and to a vacuum modulated shutoff and control valve mounted on the intake manifold for controlling the flow of exhaust gases. Recirculation or additional exhaust gas passages may be located close to the engine or integrally formed within the composite runner arrangement of the intake manifold.

However, the exhaust gas from the internal combustion engine cycle is still very hot, and it is desirable to reduce its temperature considerably before the gas is reintroduced into the combustion cycle.

Conventional devices for purifying exhaust gas from internal combustion engines include those shown in, for example, Japanese Utility Model Publication No. 37-17408 or Japanese Patent Application Laid-Open No. 48-59214. However, the device shown in the former type is designed to form an envelope of coolant around a chamber that purifies exhaust gas, but purification is performed by putting purification liquid into the chamber, so exhaust gas from automobiles, etc. It is difficult to apply it as a purification device in terms of weight reduction and miniaturization.

Furthermore, the latter type of device has problems in that it is large in size and has poor thermal efficiency, and the heat of the exhaust gas is dissipated to the outside of the heat exchanger.

The problem to be solved by the present invention is to enable an exhaust gas heat exchanger to be easily and inexpensively assembled to a desired size, and to improve thermal efficiency by reducing the flow resistance or pressure drop of the exhaust gas. It is.

The present invention comprises a series of flanged plates, each plate having a peripheral flange, each plate having a first fluid inlet opening defined by the flange, a first fluid outlet opening and one or more a pair of plates having an elongated second fluid passage opening, with all flanges of each plate extending from one side of the plate and adapted to engage the unflangeed side of an adjacent plate; an end plate, one end plate being adapted to communicate with the first inlet aperture of the plate; a first inlet aperture adapted to communicate with the first outlet aperture of the plate; one or more second fluid passage openings adapted to communicate with the first outlet opening of the plate and the second fluid passage opening of the plate; a pair of end plates having one or more second fluid passage openings adapted to communicate with said second fluid passage openings of said plates, each of said plates having one or more second fluid passage openings adapted to communicate with said second fluid passage openings of one or more apertures formed in the flange defining an aperture and a fluid outlet aperture and communicating the first fluid inlet aperture and the second fluid outlet aperture with the gap between the plates; In a two-fluid heat exchanger in which a series of plates are stacked and suitably joined together to form a heat exchanger, said end plates being disposed at opposite ends of said stack of plates, each of said plates a plurality of slits are formed to increase heat transfer between the first fluid and the second fluid, the first inlet and outlet openings being disposed on opposite sides of the plate and the second fluid A passage opening is disposed adjacent the outer edge of the plate between the inlet and outlet openings, a pair of end covers are disposed at opposite ends of the stack next to the end plate, one of the end covers being disposed adjacent the outer edge of the plate; a first fluid inlet and a fluid outlet, and a second fluid inlet, the other end lid having a second fluid inlet;
It is configured with a fluid outlet.

Embodiments of the present invention will be described below with reference to the drawings.

1 to 4, a two-fluid heat exchanger 111 according to this embodiment is shown. This heat exchanger consists of a plurality of integrated approximately oblong perforated plates 1
It has 12. Each plate 112 has a first
a fluid or gas inlet opening 114, a gas outlet opening 116 defined by a flange 117;
and are punched out to form several long narrow openings 118 defined by flanges 119. All flanges 113, 115, 117
and 119 project from one side 121 of plate 112, and all plates are oriented such that the flange of one plate abuts the unflangeed side 122 of the next adjacent plate. The flanges and apertures of each set are axially aligned to form a continuous passage through the plate.

Each plate 112 may be perforated, but preferably has a series of slits 123 formed between openings 114 and 116 to enhance heat transfer from the hot exhaust gases to the excitation water. . Front end plate 11
2a is the gas inlet opening 1 except that there is no slit.
14, gas outlet opening 116 and narrow opening 118
and the rear end plate 112b is the same as the front end plate 112a except that it lacks flanges or gas inlet and outlet openings. Also, each flange 11
5, 117 each have one or more openings 124, 125 for passage of exhaust gases across and between the plates. A domed end cap 126 is secured to the front end plate 112a and an inlet conduit 127 is defined by a flange 128.
and an outlet conduit 129 defined by flanges 131, flanges 128, 131
are aligned with openings 114 and 116, respectively, and secured to front end plate 112a. A second fluid or cooling fluid inlet conduit 132 is connected to the end cap 12.
6 and communicates with chamber 133 to distribute fluid to opening 118 . A second domed end cap 134 is secured to end plate 112b and forms a chamber 135 that collects fluid from opening 118 for exit through fluid outlet conduit 136.

For assembly, plates 112, 112a, 11
2b and end caps 126 and 134 are assembled in a suitable jig with the flange of one plate abutting the surface 122 of the next adjacent plate and the end caps are suitably joined, such as by brazing or welding. . A peripheral flange 113 of the plate provides an outer shell for the heat exchanger. In use, cooling water enters through conduit 132 and passes through flanges 113 and 113 at the end of the heat exchanger.
chamber 13 to passage 118 formed by 119
3 (arrow L) and exits from the opposite end of passage 118 through chamber 135 and through conduit 136. However, the hot exhaust gas enters the inlet conduit and into the passage formed by the flange 15 (arrow M). Gas flows between plates 112 through openings 124 in flange 115 and exits the heat exchanger through openings 125 in flange 117 and out of the passageway formed by flange 117 and through conduit 129 (arrow N). The gas flows through the plate 11 with slits or shutter-like openings 123 to enhance heat transfer.
2, and the heat is transferred to the cooling water in the passage formed by the flange 119.

According to the present invention, a heat exchanger can be made by laminating a large number of flanged plates of the same shape, so by appropriately adjusting the number of plates, a heat exchanger of a desired size can be easily manufactured. It can be made cheaply. Furthermore, since flow resistance can be reduced, thermal efficiency can also be improved.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an embodiment of the heat exchanger according to the present invention with the end portion omitted, and FIG. 2 is a top plan view of the heat exchanger of FIG. 1 including the end portion, showing the front and rear portions. Figure 3 is a diagram with the lines removed, Figure 3 is the line in Figure 2.
Figure 4 is a cross-sectional view taken along the line of Figure 3.
FIG. 3 is a cross-sectional view of the heat exchanger plate taken along. 111: Heat exchanger, 112: Plate, 113, 11
5,117,119: flange, 122: surface, 1
14: inlet opening, 116: outlet opening, 127: inlet conduit, 129: outlet conduit.

Claims (1)

[Claims] 1 a series of flanged plates, each plate having a peripheral flange, each having a first fluid inlet opening defined by the flange, a first fluid outlet opening and one or more elongated first 2 fluid passage openings, with all flanges of each plate extending from one side of the plate and adapted to engage the unflangeed side of an adjacent plate; and a pair of end plates; one end plate is adapted to communicate with the first inlet aperture of the plate; a first inlet aperture adapted to communicate with the first outlet aperture of the plate; a first outlet opening and said second outlet opening in said plate;
one or more second fluid passage openings adapted to communicate with the fluid passage openings of the plate, the other end plate being in communication with the second fluid passage opening of the plate; a pair of end plates having one or more second fluid passage openings that are connected to each other;
each of said plates is formed in said flange defining said first fluid inlet opening and fluid outlet opening and communicating said first fluid inlet opening and second fluid outlet opening with a gap between said plates; two or more apertures, said series of plates being stacked and suitably joined together to form a heat exchanger, said end plates being located at opposite ends of said stack of plates; In the heat exchanger, each of the plates is formed with a plurality of slits to increase heat transfer between the first fluid and the second fluid, and the first inlet and outlet openings are formed in the plate. and the second fluid passage opening is disposed adjacent an outer edge of the plate between the inlet and outlet openings, and a pair of end covers are located at opposite ends of the stack and the second fluid passage opening is disposed adjacent the outer edge of the plate. a two-fluid thermal system, wherein one of the end caps has a first fluid inlet and a fluid outlet and a second fluid inlet, and the other end cap has a second fluid outlet. exchanger.