CN109439342B - A liquefied natural gas oven system and process method - Google Patents

Abstract

The invention provides a liquefied natural gas oven system and a process method, wherein the system comprises a coal pyrolysis gas heating furnace (1), an electronic igniter (2), an auxiliary fire source (3), an oven device (4), a combustion support Fan (5), combustion-supporting fan variable frequency regulator (6), hydraulic natural gas tanker (21), finned tube steam atomizer (23), natural gas pressure stabilizer (27), exhaust fan (37), exhaust fan Frequency conversion regulator (38), and temperature, pressure, flow detection system. The purpose is to 1) solve the problem of full atomization of low-temperature LNG in the forced smoke exhaust system, stable gas supply, balance between gas supply and forced smoke exhaust, and stable combustion. 2) Solve the technical problems of the existing oven device such as too long flame, too high combustion temperature, and difficulty in controlling the oven process.

Description

A liquefied natural gas oven system and process method

technical field

The invention relates to the technical field of liquefied natural gas ovens, in particular to a liquefied natural gas oven system and a process method.

Background technique

In the low-cost coal pyrolysis comprehensive utilization project, the coal pyrolysis gas (high calorific value gas produced by the coal pyrolysis furnace) heating furnace and the coal pyrolysis furnace are the key facilities of the whole process. Before the furnace is put into production, it is necessary to dry the furnace body refractory lining and the pipeline refractory lining to remove moisture, and make the lining body reach the working temperature (about 1000 ℃) and then put into normal production. Before the coal pyrolysis gas heating furnace and coal pyrolysis furnace are put into operation, there is no gas available for the furnace in the factory, and only tanker liquefied natural gas can be used as the furnace fuel. LNG is low temperature and high calorific value gas. How to ensure the forced exhaust gas It is critical to complete the oven in the system. This oven technology is invented for this specific situation.

SUMMARY OF THE INVENTION

In order to solve the problems described in the background art, the present invention provides a liquefied natural gas oven system and a process method, the purpose of which is to 1) solve the problem of full atomization, stable gas supply, gas supply and forced exhaust of low-temperature liquefied natural gas in the forced smoke exhaust system Smoke balance and stable combustion. 2) Solve the technical problems of the existing oven device such as too long flame, too high combustion temperature, and difficulty in controlling the oven process.

In order to achieve the above object, the present invention adopts the following technical solutions to realize:

A liquefied natural gas oven system, comprising a coal pyrolysis gas heating furnace (1), an electronic igniter (2), an auxiliary fire source (3), an oven device (4), a combustion-supporting fan (5), and the combustion-supporting fan is adjusted by frequency conversion (6), hydraulic natural gas tanker (21), finned tube steam atomizer (23), natural gas surge tank (27), exhaust fan (37), exhaust fan variable frequency regulator (38), and temperature , pressure, flow detection system.

The oven device (4) is a horizontally installed three-layer casing structure, which sequentially includes an air center pipe (46), a liquefied natural gas pipe (44) and an air main pipe (54) from the inside to the outside; One end is a flange (57), the other end is a flame nozzle, the nozzle end face (48) of the air central pipe (46) and the nozzle end face (50) of the LNG pipe (44) are located inside the end face of the air main pipe (54), and , the distance between the end face of the spout (50) of the LNG pipe 4 and the end face of the air main pipe (54) is greater than the distance between the end face of the spout (48) of the central air pipe (46) and the end face of the air main pipe (54).

The air main pipe (54) and the LNG pipe (44) are also provided with spoilers (45) and (52), and the spoilers (45) and (52) are connected to the air main pipe (54) or the LNG pipe. (44) At an angle of 30-60 degrees, the outside of the nozzle end face (50) of the LNG pipe 4 forms a closed surface with the spoiler at the end of the air main pipe (54), and the spoiler on the closed surface has a plurality of through holes , which is the nozzle (47) of the air main.

A process method for a liquefied natural gas oven system, comprising:

1) The LNG is supplied by the LNG tanker (21). The LNG is first sent to the finned tube steam atomizer (23) through the metal hose (22) for heating and gasification. The heating medium is high-temperature steam, which passes through the finned tube. , the liquefied natural gas passes outside the finned tube, and the liquefied natural gas becomes gaseous natural gas after being heated by the finned tube steam atomizer;

2) The natural gas is sent to the natural gas surge tank (27) through the pipeline, and the surge tank and its outlet pipeline are provided with an electric heating device (28), where the residual liquefied natural gas is heated and further heated, so as to ensure the complete gasification of the output natural gas, And has stable pressure and flow;

3) The combustion air is provided by the combustion-supporting fan (5). The pressure and flow of the combustion-supporting fan are adjusted by the fan frequency conversion regulator (6). The outlet pipe of the combustion-supporting fan is divided into two parts, and the combustion-supporting air is sent to the heating furnace (1) oven device respectively. (4) the main air duct and auxiliary air duct;

4) The heating furnace itself does not have a chimney, and the flue gas generated by the oven is sent to the purification device by the exhaust fan (37) and then discharged centrally from the chimney. The flow and pressure of the exhaust fan (37) are regulated by the frequency converter (38), and are controlled according to the flow and pressure of the combustion-supporting fan and the flow and pressure signals of the liquefied natural gas, so as to ensure the smooth progress of the oven process.

As an aid, the combustion-supporting fan (5) and the flue gas fan (37) are realized by controlling the outlet pipe regulating valves (11), (17), the bleed valve (10), and the flue gas pipe regulating valve (35) of the combustion-supporting fan (5). ) to match the flow and pressure.

Compared with the prior art, the beneficial effects of the present invention are:

1. The surge tank and its outlet pipeline are equipped with electric heating device, and the residual liquefied natural gas is heated here for further heating to ensure that the output natural gas is completely gasified, and has stable pressure and flow; the pressure and flow of the combustion fan are passed through the fan frequency conversion regulator Adjustment, the heating furnace itself does not have a chimney, and the flue gas generated by the oven is sent to the purification device by the exhaust fan and then discharged from the chimney. The flow and pressure of the exhaust fan are adjusted by the frequency converter, and controlled according to the flow and pressure of the combustion fan and the flow and pressure signals of the liquefied natural gas to ensure the smooth progress of the oven process;

2. In the oven device, the outer ring horizontal channel is the main air channel, the central horizontal channel is the air auxiliary channel, and the middle horizontal channel is the LNG channel. Easy to install and remove horizontally;

3. The front end of the oven device is an air and LNG nozzle, and the nozzle is at a certain angle to the horizontal line, so that the air and LNG can be fully mixed and completely burned near the front end of the nozzle, which can achieve horizontal flame and short combustion, and prevent the flame from being too long and the temperature is too high. Brick lining of high-burning furnace and kiln;

4. There is an air spoiler in the air outer ring, and an LNG spoiler in the LNG ring. The LNG and air are in a swirling state at the nozzle, which is convenient for the air LNG to be mixed in a short distance at the outlet. combustion;

5. Liquefied natural gas is a gas with high calorific value. During the oven, the method of excess air in the outer ring is used to control the oven temperature. At the same time, when the excess air passes through the oven, it also acts as a cooling protection for the outer casing of the oven. The process does not need to replace the oven device;

Description of drawings

Fig. 1 is the process structure schematic diagram of the present invention;

FIG. 2 is a structural diagram of the oven device of the present invention.

Among them: 1- Heating furnace 2- Electronic igniter 3- Auxiliary fire source 4- Oven device 5- Air supply system including combustion-supporting fan 6- Combustion-supporting fan frequency conversion regulator 7- Combustion-supporting air outlet pipe 8- Outlet pipe cut-off valve 9- Combustion-supporting air release pipeline 10-combustion-supporting air release valve 11-combustion-supporting air main control valve 12-main-pipe flowmeter 13-main-pipe thermometer 14-combustion-supporting air main-pipe 15-main-pipe pressure gauge 16-combustion-supporting air branch pipe 17-combustion-supporting air branch pipe regulating valve 18- Combustion air branch pipe flowmeter 19-combustion air branch pipe thermometer 20-branch pipe pressure gauge 21-liquefied natural gas system including LNG tanker 22-tank truck outlet metal hose 23-liquefied natural gas atomizer 24- atomizer outlet pipe 25- outlet pipe Regulating valve 26-outlet pipeline shut-off valve 27-natural gas surge tank 28- surge tank heating device 29- surge tank outlet pipeline 30- surge tank outlet pipeline flowmeter 31-thermometer 32-pressure gauge 33-heating furnace flue gas Outlet pipe 34- Flue gas outlet pipe cut-off valve 35- Flue gas regulating valve 36- Flow meter 37- Exhaust fan 38- Exhaust fan variable frequency regulator 39- Exhaust fan outlet pipe 40- Thermometer 41- Pressure gauge 42- Air Main pipe 43 - Oven device connecting flange 44 - LNG annular channel 45 - Air annular main channel spoiler 46 - Air central channel 47 - Air annular main channel nozzle 48 - Air central channel nozzle 49 - Electronic ignition device 50 - Liquefaction Natural gas spout 51-air main pipe anchoring nail 52-liquefied natural gas annular channel spoiler 53-air main pipe refractory insulation material 54-air main ring channel 55-air central pipeline 56-liquefied natural gas pipeline 57-air pipeline connecting flange.

Detailed ways

The specific embodiments provided by the present invention will be described in detail below with reference to the accompanying drawings.

As shown in Figure 1, the present invention consists of a heating furnace system, an air supply system, a liquefied natural gas system and a smoke exhaust system.

The heating furnace system comprises a coal pyrolysis gas heating furnace (1), an electronic igniter (2), an auxiliary fire source (3), and an oven device (4).

The air supply system includes a combustion-supporting fan (5), a combustion-supporting fan frequency conversion regulator (6), a combustion-supporting air outlet pipe (7), a shut-off valve for the outlet pipe (8), a combustion-supporting air release pipe (9), and a combustion-supporting air release valve (10) , combustion air main control valve (11), main flow meter (12), main thermometer (13), main combustion air (14), main pressure gauge (15), combustion air branch pipe (16), combustion air branch control valve ( 17), the combustion air branch pipe flowmeter (18), the combustion air branch pipe thermometer (19), and the branch pipe pressure gauge (20).

The LNG system includes an LNG tanker (21), a metal hose (22) for the tanker outlet, an LNG atomizer (23), an outlet pipe of the atomizer (24), a regulating valve for the outlet pipe (25), and a shut-off valve for the outlet pipe (26), natural gas surge tank (27), surge tank heating device (28), surge tank outlet pipeline (29), surge tank outlet pipeline flowmeter (30), thermometer (31) and pressure gauge (32) ).

The flue gas system includes a heating furnace flue gas outlet pipe (33), a flue gas outlet pipe cut-off valve (34), a flue gas regulating valve (35), a flow meter (36), a flue gas exhaust fan (37), and the flue gas exhaust fan is adjusted by frequency conversion device (38), exhaust fan outlet pipe (39), thermometer (40), pressure gauge (41).

As shown in FIG. 2 , the oven device (4) is a three-layer casing structure installed horizontally, and includes an air center pipe (46), a liquefied natural gas pipe (44) and an air main pipe (54) in sequence from the inside to the outside; One end of the three-layer casing structure is the flange (57), and the other end is the flame nozzle. 54) inside the end face, and the distance between the end face of the spout (50) of the LNG pipe 4 and the end face of the air main pipe (54) is greater than the distance between the end face of the spout (48) of the air central pipe (46) and the end face of the air main pipe (54).

The air main pipe (54) and the LNG pipe (44) are also provided with spoilers (45) and (52), and the spoilers (45) and (52) are connected to the air main pipe (54) or the LNG pipe. (44) At an angle of 30-60 degrees, the outside of the nozzle end face (50) of the LNG pipe 4 forms a closed surface with the spoiler at the end of the air main pipe (54), and the spoiler on the closed surface has a plurality of through holes , which is the nozzle (47) of the air main.

A process method for a liquefied natural gas oven system, comprising:

1) The LNG is supplied by the LNG tanker (21). The LNG is first sent to the finned tube steam atomizer (23) through the metal hose (22) for heating and gasification. The heating medium is high-temperature steam, which passes through the finned tube. , the liquefied natural gas passes outside the finned tube, and the liquefied natural gas becomes gaseous natural gas after being heated by the finned tube steam atomizer;

2) The natural gas is sent to the natural gas surge tank (27) through the pipeline, and the surge tank and its outlet pipeline are provided with an electric heating device (28), where the residual liquefied natural gas is heated and further heated, so as to ensure the complete gasification of the output natural gas, And has stable pressure and flow;

3) The combustion air is provided by the combustion-supporting fan (5). The pressure and flow of the combustion-supporting fan are adjusted by the fan frequency conversion regulator (6). The outlet pipe of the combustion-supporting fan is divided into two parts, and the combustion-supporting air is sent to the heating furnace (1) oven device respectively. (4) the main air duct and auxiliary air duct;

4) The heating furnace itself does not have a chimney, and the flue gas generated by the oven is sent to the purification device by the exhaust fan (37) and then discharged centrally from the chimney. The flow and pressure of the exhaust fan (37) are regulated by the frequency converter (38), and are controlled according to the flow and pressure of the combustion-supporting fan and the flow and pressure signals of the liquefied natural gas, so as to ensure the smooth progress of the oven process.

As an aid, the combustion-supporting fan (5) and the flue gas fan (37) are realized by controlling the outlet pipe regulating valves (11), (17), the bleed valve (10), and the flue gas pipe regulating valve (35) of the combustion-supporting fan (5). ) to match the flow and pressure.

In the oven device of the present invention, the outer ring horizontal channel is the main air channel (54), the central horizontal channel is the air auxiliary channel (46), the middle horizontal channel is the liquefied natural gas channel (44), and both air and liquefied natural gas flow horizontally. After passing through the spoiler, the flow direction changes and becomes a swirling state, which is beneficial to the full mixing of the air LNG at the outlet and the realization of short combustion.

The LNG nozzle (50) and the air nozzles (48) and (47) are located at the front end of the oven device, the central area and the outer ring area are air nozzles, the middle ring area is the LNG nozzle (50), and the nozzles are of the contraction and expansion type, and Make an angle with the horizontal line so that the air and LNG can be quickly and fully mixed after flowing out of the nozzle to form a short combustion and prevent the flame from burning and damaging the kiln lining.

Liquefied natural gas is a gas with high calorific value. During the oven, the method of excess air in the outer ring is used to control the oven temperature. At the same time, when the excess air passes through the oven device, it also plays a role in cooling and protecting the outer shell of the oven device, prolonging the use of the oven device. life.

After the oven is finished, dismantle the oven device as a whole, and close the installation holes with blind plates.

The above embodiments are implemented on the premise of the technical solutions of the present invention, and provide detailed embodiments and specific operation processes, but the protection scope of the present invention is not limited to the above-mentioned embodiments. The methods used in the above embodiments are conventional methods unless otherwise specified.

Claims (3)

1. The liquefied natural gas drying system is characterized by comprising a pyrolysis coal gas heating furnace (1), an electronic igniter (2), an auxiliary fire source (3), a drying device (4), a combustion fan (5), a combustion fan frequency conversion regulator (6), a hydraulic natural gas tank truck (21), a finned tube steam atomizer (23), a natural gas pressure stabilizing tank (27), a smoke exhaust fan (37), a smoke exhaust fan frequency conversion regulator (38) and a temperature, pressure and flow detection system;

the drying furnace device (4) is of a horizontally-mounted three-layer sleeve structure and sequentially comprises an air central pipe (46), a liquefied natural gas pipe (44) and an air main pipe (54) from inside to outside; one end of the three-layer sleeve structure is a flange (57), the other end of the three-layer sleeve structure is a flame nozzle, the nozzle end surface (48) of the air central pipe (46) and the nozzle end surface (50) of the liquefied natural gas pipe (44) are both positioned inside the end surface of the air main pipe (54), and the distance between the nozzle end surface (50) of the liquefied natural gas pipe 4 and the end surface of the air main pipe (54) is greater than the distance between the nozzle end surface (48) of the air central pipe (46) and the end surface of the air main pipe (54);

spoilers (45) and (52) are further arranged in the air main pipe (54) and the liquefied natural gas pipe (44), the spoilers (45) and (52) form an angle of 30-60 degrees with the air main pipe (54) or the liquefied natural gas pipe (44), the outer side of the nozzle end face (50) of the liquefied natural gas pipe 4 and the spoilers at the tail end of the air main pipe (54) form a closed surface, and a plurality of through holes are formed in the spoilers on the closed surface and are nozzles (47) of the air main pipe.

2. The process of a lng furnace system according to claim 1, comprising:

1) liquefied natural gas is provided by a liquefied natural gas tank truck (21), the liquefied natural gas is firstly sent to a finned tube steam atomizer (23) through a metal hose (22) to be heated and gasified, a heating medium is high-temperature steam and passes through the finned tube, the liquefied natural gas passes through the outside of the finned tube, and the liquefied natural gas is heated by the finned tube steam atomizer to become gas natural gas;

2) the natural gas is sent to a natural gas pressure stabilizing tank (27) through a pipeline, the pressure stabilizing tank and an outlet pipeline thereof are provided with an electric heating device (28), the residual liquefied natural gas is heated to be further heated, the output natural gas is ensured to be completely gasified, and the pressure and the flow rate are stable;

3) combustion air is provided by a combustion-supporting fan (5), the pressure flow of the combustion-supporting fan is regulated by a fan frequency conversion regulator (6), an outlet pipeline of the combustion-supporting fan is divided into two parts, and the combustion-supporting air is respectively sent to a main air pipeline and an auxiliary air pipeline of a furnace drying device (4) of the heating furnace (1);

4) the heating furnace is not provided with a chimney, smoke generated by the furnace baking is sent to the purifying device by the smoke exhaust fan (37) and then is intensively discharged by the chimney, the flow and the pressure of the smoke exhaust fan (37) are adjusted by the frequency converter (38), and the control is carried out according to the flow and the pressure of the combustion-supporting fan, the flow and the pressure of liquefied natural gas and pressure signals, so as to ensure the stable operation of the furnace baking process.

3. A process of an lng baking system according to claim 2, characterized in that the flow and pressure matching of the combustion fan (5) and the flue gas fan (37) is achieved as an aid by controlling the combustion fan (5) outlet duct regulating valves (11), (17), the blow-off valve (10), and the flue gas duct regulating valve (35).

Images