JPH0426651Y2 - - Google Patents

Description

[Detailed Description of the Invention] <<Industrial Application Field>> The present invention relates to a device for recovering exhaust heat from an engine using a heat exchanger, and particularly relates to a structure for attaching the heat exchanger to an exhaust manifold.

<<Prior Art>> A device for recovering exhaust heat from an engine using a heat exchanger is often incorporated into an engine-driven heat pump device, and a conventional structure is shown in FIG. 4, for example.

This includes an exhaust flow path 53 that collects and flows exhaust gas from a group of exhaust ports 52 into an exhaust manifold 51 connected to the engine E, and a heat transfer fluid inlet 5.
A heat medium fluid flow path 55 is formed to flow the heat medium fluid supplied from 4 around the exhaust flow path 53, thereby configuring an auxiliary heat exchanger 56 that uses the engine exhaust as a heat source,
The heat medium fluid and exhaust gas led out from the exhaust manifold 51 having an auxiliary heat exchanger 56 therein are introduced into the heat medium fluid inlet 58 and the exhaust gas inlet 59 of a heat exchanger 57 arranged on the side of the exhaust manifold 51, respectively. The heat medium fluid is supplied through the connecting pipes 60 and 61 for further heat exchange, and the heated heat medium fluid is taken out from the outlet 62 formed at the upper part of the heat exchanger 57, and the exhaust gas after the heat exchange is heated. It is designed to lead to a muffler 63 connected to the lower part of the exchanger 57.

<<Problem to be solved>> In the conventional exhaust heat recovery device, the heat exchanger 5
Since the heat exchanger 7 is placed on the side of the exhaust manifold 51, the heat exchanger protrudes outward from the side of the exhaust manifold, increasing the external size of the engine. Since it is far away from the center, its amplitude increases and a large vibration force is generated. Therefore, there is a problem in that the connection pipes and connecting members between the exhaust manifold 51 and the heat exchanger 57 are likely to suffer fatigue damage due to the large vibration force acting on the heat exchanger 57. In order to sufficiently withstand the large vibration force of the heat exchanger 57, the supporting structure of the heat exchanger 57 becomes complicated and also increases in size.

<Means for Solving the Problems> The present invention provides an exhaust heat recovery device that allows a heat exchanger to be firmly fixed to the exhaust manifold with a simple structure and that allows the external shape of the engine to be made compact. To this end, the top surface of the exhaust manifold is used as the mounting surface for the heat exchanger, and multiple small heat exchangers are arranged in the upper space of the exhaust manifold along its length, facing each heat exchanger on the mounting surface. A merging chamber outlet and an exhaust hole are opened for each part, the exhaust inlet of each heat exchanger is connected and fixed to the merging chamber outlet, the exhaust outlet is connected to the exhaust port, and each exhaust hole is communicated with the muffler. It is characterized by this.

<Operation> In this invention, multiple small heat exchangers are arranged above the exhaust manifold.
The weight of each heat exchanger is reduced, and the distance from the center of vibration of the engine is also reduced, reducing the vibratory force of the heat exchanger.

In addition, since multiple small heat exchangers are installed in parallel on the exhaust manifold, the flow rate of exhaust gas per heat exchanger is reduced, so a constant back pressure is maintained in the exhaust gas pipes at the heat exchanger. In order to obtain this, the cross-sectional area of the exhaust gas pipe becomes smaller, making the heat exchanger smaller.

<<Example>> FIG. 1 is a sectional view of the main part, and FIG. 2 is a partially cutaway sectional view of the engine exhaust manifold.

In the figure, reference numeral 1 denotes an exhaust manifold of a six-cylinder engine 2, in which a merging chamber 4 communicating with each exhaust port 3 of the engine 2 is formed, and a heating medium fluid flow path 5 surrounding the outer periphery of the merging chamber 4. is formed to constitute the auxiliary heat exchanger 6.

A heating medium fluid inlet 7 is provided on the front surface of the exhaust manifold 1, and a heating medium fluid outlet 8 and a merging chamber outlet 9 are formed on the upper surface of both ends in the longitudinal direction. An exhaust gas intake port 11 of a substantially U-shaped exhaust gas discharge hole 10 is formed. Further, an exhaust outlet 12 of the exhaust outlet 10 is formed at the upper front surface of the central portion in the longitudinal direction of the exhaust manifold 1, and a muffler (not shown) is communicatively connected to the exhaust outlet 12.

The upper surface of the exhaust manifold 1 is formed as a mounting surface 14 for the heat exchanger 13, and the two heat exchangers 13 are arranged symmetrically on the heat exchanger mounting surface 14 in the longitudinal direction of the exhaust manifold 1. It is directly connected to the installation.

The heat exchanger 13 is composed of a casing 16 forming a heat medium fluid chamber 15, a heat dissipation core 18 having an exhaust gas pipe line 17 therein, and a bottom plate 19. And, this heat exchanger 13 includes the heat medium fluid chamber 1
The heat medium fluid inlet 20 provided at the bottom of one end of the heat transfer core 5 connects to the heat transfer fluid outlet 8 of the exhaust manifold 1, and the exhaust introduction port 21 provided at the bottom of one end of the heat dissipation core 18 connects to the confluence chamber outlet 9 of the exhaust manifold 1. The exhaust outlet 22 provided at the bottom of the other end of the heat dissipating core 18 is fixed in communication with the exhaust intake port 11 of the exhaust manifold 1 .

And the heat medium fluid chamber 15 in the heat exchanger 13
The outlet 23 is provided at the upper part of the other end of the casing 16.

The heat dissipation core 18 has a large number of flat oblong core units each having a hollow interior stacked one on top of the other at appropriate intervals, and each core unit is connected to each other at both ends thereof through circular communication portions 24a and 24b. The exhaust gas inlet 21 is located at the lower end of one of the communicating portions 24a, and the exhaust outlet 22 is located at the lower end of the other communicating portion 24b. are doing. The intermediate portion of each core unit is subdivided into a large number of parallel passages by inserted corrugated plates to increase the area of contact with the exhaust gas.

[Effects] As described above, in this invention, the upper surface of the exhaust manifold is used as the mounting surface for the heat exchanger, and a plurality of small heat exchangers are arranged along the length direction on this mounting surface. A merging chamber outlet and an exhaust exhaust hole are opened in each portion facing each heat exchanger, and the exhaust gas inlet of each heat exchanger is connected and fixed to the merging chamber outlet, and the exhaust outlet port is connected and fixed to the exhaust exhaust hole. Therefore, the exhaust manifold and the heat exchanger can be directly and firmly fixed, and the vibration force of the heat exchanger can be sufficiently suppressed to prevent fatigue damage.

Moreover, since multiple small heat exchangers are installed side by side on the exhaust manifold, the weight of each heat exchanger is reduced, and the distance from the center of engine vibration is also shortened, which reduces the vibration of the heat exchanger. force can be reduced.

Additionally, since multiple heat exchangers are installed in parallel on the exhaust manifold, the cross-sectional area of the exhaust gas pipe becomes smaller in order to provide a constant back pressure to the exhaust gas within the heat exchanger. , it can be formed into a compact heat exchanger.

Furthermore, since the muffler is communicated with the exhaust discharge hole formed in the exhaust manifold, the vibration force of the muffler is not applied to the heat exchanger.

Moreover, even if strongly acidic condensed water is generated in the exhaust gas pipe inside the heat exchanger, the condensed water will flow smoothly into the exhaust outlet from the exhaust outlet that opens downward at the bottom of the heat exchanger. This prevents the heat exchanger from being corroded by strongly acidic condensed water.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of the main parts, Figure 2 is a partially cutaway cross-sectional view of the engine exhaust manifold, and Figure 3 is a cross-sectional view of the engine exhaust manifold.
4 is a diagram corresponding to FIG. 2 of the conventional example. 1...exhaust manifold, 2...multi-cylinder engine, 3...exhaust port, 4...merging chamber of 1, 9...
...Outlet of 4, 10...Exhaust outlet, 13...Heat exchanger, 14...Mounting surface, 21...Exhaust inlet,
22...Exhaust outlet.

Claims (1)

[Scope of utility model registration request] A heat exchanger 13 is provided between the exhaust manifold 1 connected to the exhaust port 3 of the multi-cylinder engine 2 and the muffler.
In an exhaust heat recovery device for a multi-cylinder engine, in which the exhaust inlet 21 of a heat exchanger 13 is connected and fixed to the outlet 9 of the merging chamber 4 of the exhaust manifold 1 with the upper surface of the exhaust manifold 1 interposed A plurality of small heat exchangers 13 are arranged along the length direction in the upper space of the exhaust manifold 1, and each part of the mounting surface 14 facing each heat exchanger 13 has a confluence chamber outlet. 9 and exhaust outlet 1
0 and the exhaust gas inlet 21 of each heat exchanger 13.
This exhaust heat recovery device for a multi-cylinder engine is constructed by connecting and fixing an exhaust outlet to a merging chamber outlet 9, an exhaust outlet 22 to an exhaust exhaust hole 10, and communicating each exhaust exhaust hole 10 to a muffler.