JPS5934413A - Catalytic recombustion apparatus for engine exhaust - Google Patents

Abstract

PURPOSE:To obtain high combustion efficiency for a various kinds of exhaust gas by passing the exhaust which is discharged from an exhaust inlet pipe, through the catalyst for preheating, and blasting said exhaust onto the catalyst for finishing combustion through the exhaust inlet pipe and heating the exhaust gas which is supplies after preheating the exhaust inlet pipe, by the crossing exhaust described in the above. CONSTITUTION:An exit 2 for reombustion-processed exhaust, catalyst 3 for finishing combustion, inlet pipe 4 for engine exhaust, and the catalyst for preheating combustion are installed in an inner cylinder 8. A circulation passage 7 for exhaust is formed on the right and left and front and back sides with reseect to the direction of the pipe diameter of the exhaust inlet port 4, and the exhaust is fed into the catalyst 3 for finishing combustion from the catalyst 5 for preheating combustion. The combustion heat under the catalyst is transmitted to an intermediate cylinder 9 through an intermediate heat conductor 15, and said heat is absorbed by the cooling water which passes through a hot-water passage 16. Said cooling water is introduced to an effluence port 26 from the inflow port 25 of a heat exchanger R for heat exchange, running across a thin pipe 23 group. Thus, even when the gas which contains a large amount of uncombusted components such as methane, ethane, etc. and requires high reaction temperature is treated, said operation can be executed efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a catalytic reburning device for engine exhaust gas, and an object thereof is to preliminarily combust the exhaust gas and then pass it through a catalyst to improve combustion performance.

Conventionally, when engine exhaust gas is guided into a combustion case filled with a catalyst to reprocess unburned components in the exhaust gas, the combustion catalyst and exhaust outlet are placed deep from the exhaust inlet pipe. In some reburning cases, the exhaust gas from the engine is sent to the catalyst through the artificial pipe to reburn unburned components more effectively.

However, the combustion efficiency of the exhaust gas often decreases because the temperature of the exhaust gas passing through the catalyst is not sufficient. In particular, in engines that use LNG as fuel, the exhaust gas contains low alkanes, mainly unburned methane. Since it contains a large amount of system gases and the reaction temperature of these gases is high, it has not been possible to increase the combustion efficiency.

The present invention is intended to solve the above-mentioned problem, and includes a catalyst for finishing combustion,
An engine exhaust inlet pipe and a pre-combustion catalyst are arranged in this order, and an exhaust outlet is provided in the part of the peripheral wall of the exhaust inlet pipe that faces the pre-combustion catalyst, and the pre-combustion is provided on both sides of the exhaust inlet pipe in the radial direction. To provide a device that forms a circulation space for exhaust gas from a combustion catalyst to a final combustion catalyst. As a result, the exhaust gas sent from the exhaust inlet 171 is passed through the pre-combustion catalyst located on one side of the inlet pipe, and then crosses the exhaust manifold pipe again to be guided to the final combustion catalyst. can preheat the exhaust manifold to raise the reaction temperature of the exhaust gases before passing them through the combustion catalyst.

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

Fig. 1 is a schematic system diagram of a heat pump system using Ennon as a power source and heat source, and Fig. 2 is a longitudinal cross-sectional view of a reburning case, in which a cooling system 1 is operated by a flood cycle engine I.
While driving the refrigerant compressor 15 of No. 2, engine cooling water is guided by a circulation pump P to a hot water storage tank 14 for heating and hot water supply for heat exchange.

Then, the unburned components in the exhaust from the Ennon are re-burned in the combustion case 1, and at the same time, the engine cooling water is guided to the heat exchanger rt installed on the right side of the combustion case 1 to recover exhaust heat. The exhaust gas cooled by the heat exchanger is muffled by the muffler M and then discharged to the outside air.

The reburning case 1 includes an inner cylinder 8 containing a combustion catalyst.
It consists of a middle cylinder 9 which is fitted into this via a plurality of heat conductors 15, and an outer cylinder 10 which is fitted externally with a hot water passage 16 in the gap between these three cylinders. 8, 9, and 10 are formed into a cylindrical shape with a bottom, the rear portions of which are bent into a flange shape, and secured together with bolts and nuts.

An outlet 2 for the reburned exhaust gas is arranged on the right side of the inner cylinder 8, and a finishing combustion catalyst 6, an artificial pipe 4 for the ennon exhaust gas, and a pre-combustion catalyst 5 are provided in this order toward the left.

That is, an elongated cylindrical exhaust manifold 4 is inserted into the middle part of the inner cylinder 8 through the outer cylinder 10 and the middle cylinder 9, and an exhaust air outlet is inserted toward the pre-combustion catalyst 5 located on the left side. 6 is cut out, and auxiliary outlets 17 are also opened at the front and rear of the artificial tube 4.

The left side of this pre-combustion catalyst 5 is connected to the bottom plate 18 of the inner cylinder 8.
A foul space 19 for the exhaust gas is left a little apart from the exhaust gas.

In addition, an exhaust circulation space 7 is provided across both left and right front bodies 1 in the pipe radial direction in front of the exhaust inlet 4, and a pre-combustion space 7 is provided on the left side of the artificial pipe 4.
1', the exhaust gas is set to be sent from the Q catalyst 5 to the final combustion catalyst 6 located on the right.

On the other hand, a water inlet 20 is attached to the lower part of the outer cylinder 10 to receive the cooling water coming from the hot water storage tank 14 for hot water supply, and a water outlet 21 is attached to the lower side of the outer cylinder 10 to transfer the combustion heat under the catalyst to intermediate heat. conductor 1
5 to the inner cylinder 9, and this heat is absorbed by the cooling water passing through the hot water channel 16 between the inner cylinder 9 and the outer cylinder 10.

On the other hand, a heat exchanger F can be arranged near the outlet 2 of the reburning case 1, and the exhaust gas entering from the exhaust intake port 22 can be connected to a plurality of thin tubes 2.
6 and is sent from the exhaust outlet 24 to the muffler 2, and at the same time, it is routed from the lower inlet 25 of the heat exchanger R to the upper outlet 26 of the hot water storage tank 14 so as to cross the group of thin tubes 26. Cooling water is circulated to perform heat exchange.

Therefore, in the integrated reburning case 1 and heat exchanger 1, the exhaust gas G enters from the exhaust inlet pipe 4 protruding from the outer cylinder 10 and is discharged from the exhaust outlet 24 of the heat exchanger R.

-5- Also, the cooling water W from the hot water storage tank is divided into two parts, one of which crosses the heat exchanger R, and the other of which crosses the outer cylinder 10 and the inner cylinder 8.
The hot water crosses the hot water passage 16 between them, joins each other in the middle of the water passage, and circulates to the hot water storage 4￥J14.

Since the exhaust inlet pipe 4 is located near the lower center of the reburning case 1, if the case 1 is oriented horizontally, it is possible to add more copies to the engine IC in a well-balanced manner. However, the mounting direction of the case is not particularly limited, and when the case is mounted vertically, the exhaust inlet pipe 4 does not need to be located in the middle of the case in the longitudinal direction.

The effects of the present invention will be described below. By arranging a pre-combustion catalyst and a finishing combustion catalyst on both sides of an exhaust inlet pipe, the exhaust gas exiting the inlet pipe is routed to the pre-combustion catalyst and then returned to the exhaust inlet. By blowing across the pipe toward the final combustion catalyst, the traversing exhaust air can preheat the exhaust inlet pipe and preheat the exhaust gas entering the afterburn case.

Therefore, the exhaust gas can be introduced at a high temperature in advance without passing through the pre-combustion and final combustion catalysts, so it contains a large amount of unburned components such as methane and ethane, like the exhaust gas of Ennon, which uses LNG as fuel. Even gases that require high reaction temperatures can be efficiently processed, and high combustion efficiency can be obtained for various exhaust gases.

[Brief explanation of the drawing]

Drawings (d) Show an embodiment of the present invention; Fig. 1 is a schematic system diagram of a heat pump system using Ennon as a power source and heat source, and Fig. 2 is a longitudinal cross-sectional view of a reburning case. 1. Reburning case, 2. Exhaust outlet, 6. Final combustion catalyst, 4. Exhaust inlet pipe, 5. Pre-combustion catalyst, 6.
・Exhaust outlet, 7...Exhaust circulation space. -7-

Claims (1)

[Claims] ]-1 An outlet 2 for the reburned exhaust gas at one end of the reburned case 1
A finishing combustion catalyst 6, an engine exhaust inlet pipe 4, and a pre-combustion catalyst 5 are arranged in order from the outlet 2 toward the back inside the reburning case 1. An exhaust outlet 6 is provided in a portion facing the combustion catalyst 5, and a circulation space 7 for exhaust gas from the pre-combustion catalyst 5 to the final combustion catalyst 6 is provided on both sides of the exhaust inlet pipe 4 in the radial direction within the re-combustion case 1. A catalytic re-combustion device for engine exhaust, characterized by the formation of