JPS6119940A - Method of introducing intake-air and discharging exhaust gas - Google Patents

Abstract

PURPOSE:To purifying exhaust gas, by supplying ammonium into intake-air and exhaust pipes in a Diesel-engine in synchronism with the timing of intake and discharge of the engine so that neutralization of acid components in the cylinder and denitration of exhaust gas are carried out. CONSTITUTION:An ammonium diluted gas C is introduced through a neutralizing ammonium injection nozzle 6 and a denitrating ammonium injection nozzle 7 provided respectively in intake and exhaust pipes 2, 3 in a Diesel-engine, to be mixed with combustion air A and exhaust gas B. Ammonium gas injected from the nozzle 6 netralizes acid components in SOX gas adhered to the cylinder wall surface, and ammonium gas injected from the nozzle 7 denitrates NOX in exhaust gas so that NOX is changed into N2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for intake and exhaust of a diesel engine.

Currently, with regard to fuel for diesel engines, the use of high sulfur-containing fuel is increasing due to the trend toward energy saving and resource saving, and at the same time, there is a demand for engines with improved efficiency. For this reason, in the 8-engine body,
Abnormal cylinder liner wear and piston ring breakage accidents are more likely to occur due to sulfur oxides SOx generated during combustion, and the concentration of nitrogen oxides in the combustion exhaust gas increases to increase combustion efficiency. , which causes air pollution.

SUMMARY OF THE INVENTION The present invention provides an intake and exhaust method that can reduce or suppress the above-mentioned problems by creating usage conditions that are better than conventional ones even when inferior fuel is used.

The feature of this system is that in diesel engines that use fuel containing sulfur, a fixed amount of NH, gas, or a mixed gas of NH3 is supplied to the intake and exhaust pipes at the timing of intake and exhaust. The process involves neutralizing acidic components within the cylinder and denitrifying the exhaust gas.

In this case, the same gaseous substance (ammonia gas) is used to achieve the purpose through the following actions.

(1) Since So in the combustion exhaust gas diffuses in a gaseous state, an alkaline reactant (ammonia gas) is introduced into the entire intake side and similarly reacted in a gaseous state. Until now, an alkaline agent (solid substance) was added to cylinder oil to cause a reaction.

(2) By alternately supplying to the intake side and exhaust side, the intake side is used for neutralization and the exhaust side is used for denitrification.

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

FIG. 1 is an explanatory diagram showing a diesel ennon combustion section according to one embodiment of the present invention, and FIG. 2 is an explanatory diagram showing seven NH3 supply stems.

The content of the present invention is to attach a simple injection nozzle to an intake pipe and an exhaust pipe and operate it in the following manner.

In Fig. 1, 51 is a heat injection nozzle, 2 is an intake pipe,
3 is an exhaust pipe, 4 is a cylinder, 5 is a piston, 6 is an ammonia injection nozzle for neutralization, 7 is an ammonia injection nozzle for denitrification, A is combustion air, B is combustion exhaust gas, C is ammonia (
dilution) gas.

In the case of a 4-stroke engine, there is intake, compression, and combustion.

Each exhaust is performed as one stroke, but at the time of intake, an appropriate amount (determined by the amount of fuel used) of ammonia gas (NH3) C is injected into the combustion air A that passes through the intake pipe 2 and goes to the combustion chamber. The stone is mixed through the nozzle 6 to neutralize acidic components caused by SOx gas adhering to the cylinder wall surface, etc.

The remaining ammonia is oxidized during combustion, and most of it changes into nitrogen, and some of it changes into nitrogen oxides, NOx.

However, during combustion, No is also generated from nitrogen in the air and is discharged outside as exhaust gas B through the exhaust pipe 3.
At that time, at the same time as the exhaust operation is activated, an appropriate amount (NOx in the exhaust gas) is removed.
Ammonia gas C (determined by the concentration) is injected into the exhaust gas from the denitrification ammonia injection nozzle 7 to cause a selective denitrification reaction and convert NOx in the exhaust gas to N2. By alternately supplying the same ammonia gas from the intake side and exhaust side nozzles in accordance with the timing of the intake stroke and exhaust stroke, sulfuric acid corrosion in the cylinder internal pressure is reduced and the amount of NOx generated in the exhaust gas is suppressed.

Describe the action and effect.

(1) Regarding the neutralization reaction, the currently implemented method is to contain alkaline earth metals (mainly Ca) in cylinder oil.
The compound is stably maintained in a dissolved or suspended state, and is supplied at the timing of lubrication, and is scraped up by piston rings etc. and reacts with sulfur oxides attached to the cylinder surface from the exhaust gas side. However, one reaction is a gas-liquid reaction, which has a lower reaction efficiency than that occurring in oil where SO is difficult to dissolve, and the range in which the oil can circulate is limited. It does not match the distribution of SOx concentration and the reaction probability is also poor. Furthermore, what is produced is calcium sulfate (CaSO4), which is a solid substance and is not corrosive, but it is likely to cause problems due to scale adhesion.

An example of the reaction is shown below.

Ca-R or CaCO3+SO2+02+H20→C
aSO4+ HR or CO2+H20 where -R is an organic substance.

However, since the present invention is a gas reaction, the SOx distribution and N
When the distribution of H matches, ammonium sulfate (NH6)2S04 etc. generated decomposes in a high temperature area,
5 because Ca SO4 does not adhere strongly in the low region.
Reactivity and scale troubles are improved. The main reactions are shown below.

2NH6+SO2+11202+H20→CNH,)2
Assuming that the NH3 gas concentration supplied to the So4 intake side contains 8% of the current 2% as fuel, the SO concentration in the exhaust gas will be about 450 ppm at CO75%, and the required NH3 amount will be about 800p. If you want to supply about 1000 ppm of gas with a gas concentration of about 10% (the remaining 90% is nitrogen or air) on the intake side so that it is almost excessive, then about 1.0% of the intake gas amount is supplied. /100 will be supplied during inspiration.

(2) Regarding the denitrification reaction, let us assume that 11,000p
If there is an engine that generates NOx of 2,000 p, and if all the NH added to it during intake changes to NOx (this is impossible), then the NO in the exhaust gas is 2,000 p.
pp K becomes. However, if enough NH, about 20,009p, is added at the time of exhaust to compensate for the amount of NOx, the efficiency is 8.
Even if it is 0%, NOx in exhaust gas can be suppressed to about 400 ppm.

6 No +4 NH5→5N2+6H20, 6NO□
+8NH, →7N+12H20 (3) This system investigates the amount of NOx generated due to the characteristic combustion of the engine, determines the supply NH and gas concentration, and easily performs neutralization and denitration by controlling the amount. If set automatically, it can become a very effective 7 stem.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a diesel eno-combustion section according to one embodiment of the present invention, and FIG. 2 is an explanatory diagram showing an NH and supply system. 2... Intake pipe, 3... Exhaust pipe, 6... Ammonia injection nozzle for neutralization, 7... Ammonia injection nozzle for denitrification. ↓ Fang 4

Claims (1)

[Claims] 1. In a diesel engine that uses fuel containing sulfur, a certain amount of NH_3 gas or a mixed gas containing NH_3 is supplied to the intake pipe and exhaust pipe at the timing of intake and exhaust to eliminate acidic components in the cylinder. An intake and exhaust method characterized by neutralizing and denitrifying exhaust gas.