CN106838951B - Shock wave soot blowing air distribution device - Google Patents

Abstract

The shock wave soot blowing and air distributing device comprises two constant volume tanks, an ignition tank and a pulse tank, and is characterized in that the volume of the two constant volume tanks is adjustable, pressure transmitters are respectively arranged on the two constant volume tanks, an air inlet electromagnetic valve and an air outlet electromagnetic valve are respectively arranged on the front side and the rear side of the two constant volume tanks, an output pipe of the two air outlet electromagnetic valves is connected with the fire tank, the ignition tank is provided with an igniter, an output pipe of the ignition tank is connected with the pulse tank, and the end of the output pipe of the pulse tank is a nozzle. The invention has the advantages of convenient operation and maintenance, less investment and maintenance cost, and adopts a relatively low method to improve the scavenging efficiency of the soot blowing system, so that the number of shock wave soot blowing is reduced on the basis of the original method, the fuel gas is saved, and the cost is reduced. The invention is suitable for the technical field of cleaning the accumulated ash and the cokes in heat exchange pipelines of boilers and heating furnaces.

Description

Shock wave soot blowing air distribution device

Technical Field

The invention relates to the technical field of boilers, in particular to a shock wave soot blowing air distribution device.

Background

The long-standing problem of ash deposition and coking in heat exchange tubes of boilers and heating furnaces is that the heat resistance of heating surfaces is increased, and the heat resistance is one of the main reasons for reducing the heat efficiency. In severe cases, corrosion and unexpected shutdown of the furnace tube may be caused, resulting in significant economic losses. For this reason, the means of steam soot blowing, high-pressure hydraulic soot blowing, steel ball soot blowing and the like are adopted, which are conventionally called traditional soot cleaning technology; although the traditional ash removal technology has certain effects in certain occasions, in general, the traditional ash removal technology has various problems such as limited ash removal range, dead angle dead zone, high energy consumption, poor equipment reliability, high maintenance cost, side effect on a furnace, huge auxiliary equipment, complex operation and the like. Especially steam soot blowing often leads to flue gas humidity increase, and the cold junction of furnace body is more easy to cause deposition and jam, can even make the corruption aggravate. Therefore, although most domestic and foreign boilers and heating furnaces are equipped with such ash removal equipment, the use efficiency is very low due to the above reasons, and most of the boilers and heating furnaces are in an idle state, so that the problem of accumulated ash coking cannot be really and fundamentally solved.

Shock wave soot blowing is to generate gas pulse by combustion and to remove ash on the heating surface of boiler, and is a new generation of ash removing technology in recent years. The principle is that combustible gases such as: the gas, natural gas, liquefied petroleum gas, acetylene and the like are uniformly mixed with air after being regulated and controlled by respective measurement and control pipelines, deflagration and detonation are generated in a combustion chamber with special design, and pulse shock waves are emitted through a nozzle on an output pipe. The energy is guided to the vicinity of the tube bundle to be acted, and the high-temperature and high-speed air flow is acted on the surface of the heat exchange tube bundle with huge sound intensity, so that the aim of removing ash on the surface area of the tube bundle is fulfilled by the comprehensive actions of various modes such as waveform disturbance, air flow scouring, high-temperature expansion, sound pressure vibration, impact vibration and the like. At present, the shock wave soot blowing system is popularized and used on power plant boilers in various places, the proportion control of fuel gas and compressed air of most of the shock wave soot blowing systems is realized by adopting electromagnetic valves, the proportion of air inflow is controlled by controlling the opening time length of the electromagnetic valves, because the amount of the fuel gas entering an ignition unit at the same time is also changed due to the change of the pressure of a gas source, the effective gas proportion is difficult to control, the air inflow time is required to be continuously tried to be adjusted according to the pressure change of the gas, and the effect of shock wave soot blowing is difficult to ensure.

The shock wave soot blowing air distribution device in the prior art has defects in practical use and needs to be improved. The inventor has the defect of the prior art to be improved, and is particularly and intensively studied and matched with trial and error, and finally provides the invention which has reasonable design and effectively improves the defect of the prior art.

Disclosure of Invention

The invention aims at solving the problem that the shock wave soot blowing system is difficult to effectively control the proportion of fuel gas and compressed air, achieves stable and high-level purging efficiency, and ensures normal and stable production.

The technical scheme of the invention is as follows:

the shock wave soot blowing and air distributing device comprises two constant volume tanks, an ignition tank and a pulse tank, and is characterized in that the volume of the two constant volume tanks is adjustable, pressure transmitters are respectively arranged on the two constant volume tanks, an air inlet electromagnetic valve and an air outlet electromagnetic valve are respectively arranged on the front side and the rear side of the two constant volume tanks, an output pipe of the two air outlet electromagnetic valves is connected with the fire tank, the ignition tank is provided with an igniter, an output pipe of the ignition tank is connected with the pulse tank, and the end of the output pipe of the pulse tank is a nozzle.

The invention aims to solve the problem that the effective proportion of fuel gas and compressed air of a shock wave soot blowing system is difficult to control due to the change of the pressure of a gas source. According to the same temperature and pressure, when two different gases are filled in two different tanks, the optimal reaction proportion of the fuel gas and the compressed air is controlled. Therefore, the shock wave soot blowing system can adjust the volume of the constant volume tank according to the optimal mixing reaction proportion of the fuel gas and the compressed air which are required to be used, and when the pressure of the container gas is also equal, the proportion of the two gases is the ratio of the quantity of the optimally reacted substances. By the method, stable optimal proportion precision can be realized, and the effect of shock wave soot blowing is stable and efficient. The electromagnetic valves are respectively arranged at the front and the rear of the two constant volume tanks, the air inlet electromagnetic valve has the function of enabling air to be filled into the constant volume tanks, and the air inlet electromagnetic valve is closed immediately when the air pressure is equal and meets the combustion requirement, and the air inlet electromagnetic valve has the function of ensuring the amount of the fuel gas and the compressed air entering the constant volume tanks. After the gas in the constant volume tank is filled up as required, the exhaust electromagnetic valve is opened to enable the gas and the compressed air to be quickly mixed and enter the ignition tank. The pressure transmitter is arranged on the constant volume tank, the pressure transmitter sends the pressure signal of the detected constant volume tank to the PLC control system, and the pressure transmitter mainly ensures the disconnected air inlet electromagnetic valve and simultaneously opens the air outlet electromagnetic valve when the pressures of the gases in the two constant volume tanks are consistent. Thereby realizing that the fuel gas and the compressed air can meet the control requirement of higher proportion precision. After ignition by the igniter 5, the mixed gas enters a pulse tank to generate detonation output. Based on the chemical nature of the shock wave soot-blowing gas, the ratio of the amount of the optimal substance to be reacted with the compressed air can be calculated, because the ratio of the amount of the substance can be filled with the gas by using the container with the corresponding ratio, when the pressure of the container gas is also equal, the container volume ratio is equal to the ratio of the amount of the gas substance, namely the optimal reaction ratio. Therefore, in practical application, after determining which fuel gas is used, the optimal reaction proportion is calculated, then the constant volume device with the proportional volume is adjusted, and the optimal proportion effect of shock wave soot blowing can be realized when the pressure is equal. The problem that the optimal deflagration effect is affected due to the fact that the ratio of fuel gas to air is difficult to control because of fluctuation and change of air source pressure in the actual use process is avoided.

The invention has the advantages of convenient operation and maintenance, less investment and maintenance cost, and adopts a relatively low method to improve the scavenging efficiency of the soot blowing system, so that the number of shock wave soot blowing is reduced on the basis of the original method, the fuel gas is saved, and the cost is reduced.

The invention is suitable for the technical field of cleaning the accumulated ash and the cokes in heat exchange pipelines of boilers and heating furnaces.

Drawings

FIG. 1 is a schematic diagram of the structure of the present invention;

in the figure: 1.1, an air inlet electromagnetic valve; 1.2, an exhaust electromagnetic valve; 1.3, an air inlet electromagnetic valve; 1.4, an exhaust electromagnetic valve; 2.1, a constant volume tank; 2.2, a constant volume tank; 3.1, a pressure transmitter; 3.2, a pressure transmitter; 4. igniting the tank; 5. an igniter; 6. a pulse tank.

Detailed Description

Example 1:

the invention relates to a technology for removing deposited dust and coking at the tail part of a boiler of a chemical company, wherein the gas of a shock wave soot blowing system adopts acetylene gas, pipelines of the gas and compressed air adopt DN15 galvanized pipes, the output from a igniting tank 4 to a pulse tank 6 adopts DN50 steel pipes, the output from the pulse tank 6 to the boiler adopts DN100 steel pipes, and a constant volume tank 2.1, a constant volume tank 2.2, an igniting tank 4 and a pulse tank 6 are sealed containers made of common steel materials. The pressure transmitter 3.1 is arranged above the constant volume tank 2.1, the pressure transmitter 3.2 is arranged above the constant volume tank 2.2, the pressure transmitter sends a pressure signal for detecting the constant volume tank to the PLC control system, and the igniter 5 is arranged on the ignition tank 4.

The optimal detonation ratio of acetylene to compressed air is known by chemical characteristics to be acetylene: compressed air=1:10, so the volumes of the constant volume tanks 2.1 and 2.2 are adjusted to 1:10. When shock wave soot blowing is started, the air inlet electromagnetic valve 1.1 and the air inlet electromagnetic valve 1.3 are firstly opened, when the pressure detected by the pressure transmitter 3.1 and the pressure detected by the pressure transmitter 3.2 reach 0.15MPa respectively, the air inlet electromagnetic valve 1.1 and the air inlet electromagnetic valve 1.3 are closed, then the air outlet electromagnetic valve 1.2 and the air outlet electromagnetic valve 1.4 are opened, and two paths of gases are rapidly mixed and enter the ignition tank 4. Under the ignition action of the igniter 5, the mixed gas can explode instantaneously, detonation is generated by output from the pulse tank 6, and pulse shock waves are emitted through a nozzle on the end of the output pipe. The energy generated by detonation sweeps the accumulated ash of the boiler to achieve higher soot blowing efficiency. The invention realizes high precision of gas configuration. The fuel gas can be acetylene or other types of fuel gas, and according to the nature of the fuel gas, the actual optimal proportion control can be realized by adjusting the volume of the container. The data in the description are for illustrative purposes only and do not represent that the invention must use this value.

The invention achieves the expected effect and better solves the problem of dust accumulation and coking of the heat exchange pipeline.

Claims (1)

1. The shock wave soot blowing and air distributing device comprises a constant volume tank, an ignition tank and a pulse tank, and is characterized in that the constant volume tank is a first constant volume tank (2.1) and a second constant volume tank (2.2), the volumes of the first constant volume tank (2.1) and the second constant volume tank (2.2) are adjustable, the first constant volume tank (2.1) is provided with a first pressure transmitter (3.1), the second constant volume tank (2.2) is provided with a second pressure transmitter (3.2), a first air inlet electromagnetic valve (1.1) is arranged in front of the first constant volume tank (2.1), a first air inlet electromagnetic valve (1.2) is arranged behind the first constant volume tank (2.1), a second air inlet electromagnetic valve (1.3) is arranged in front of the second constant volume tank (2.2), a second air outlet electromagnetic valve (1.4) is arranged behind the second constant volume tank (2.2), the first air outlet electromagnetic valve (1.2) and the second air outlet electromagnetic valve (1.4) are connected with an output pipe, the ignition tank (4) is connected with a pulse tank (6), and the ignition tank (4) is connected with a pulse tank (6) through an output pipe (6);

when the shock wave soot blowing is started, the first air inlet electromagnetic valve (1.1) and the second air inlet electromagnetic valve (1.3) are firstly opened, when the detection pressures of the first pressure transmitter (3.1) and the second pressure transmitter (3.2) reach 0.15MPa respectively, the first air inlet electromagnetic valve (1.1) and the second air inlet electromagnetic valve (1.3) are closed, then the first air outlet electromagnetic valve (1.2) and the second air outlet electromagnetic valve (1.4) are opened, two paths of gases are rapidly mixed and enter the ignition tank (4), under the ignition action of the igniter (5), the mixed gases can explode instantly, detonation is generated by outputting from the pulse tank (6), and pulse shock waves are emitted through a nozzle on the output pipe end.