Gas-fired boilers use gaseous flammable gases (including liquefied combustible gases) as fuel. These gaseous fuels have relatively higher calorific value and less pollutant emissions, and are gradually becoming popular among corporate users.

Some common gas-fired boilers and gas fuels are mainly these types. The small-scale boilers are simple to introduce to you, and compare the cost-effectiveness of each fuel.
       1. LPG (Liquefied Petroleum Gas): LPG
       Main ingredients: propane, other ingredients: butane, ethane, etc.
       The calorific value is approximately 46,000 KJ/kg.
       2. LNG (Liquefied natural Gas): natural gas
       Main components: methane, a small amount of ethane and other gases
       The calorific value is approximately 8600 Kcal/Nm3.
       3. Gas
       Gas hungry components are more complex, with a calorific value of about 3000-4000 Kcal/Nm3.
       4. Air mixing (LPG-AIR)
       A mixture of liquefied gas and air with a calorific value of approximately 9000-10000 Kcal/Nm3.

Comparison of calorific value: liquefied petroleum gas>air-mixed gas>natural gas>gas
       Economic level: gas > natural gas > air admixture > liquefied petroleum gas.

According to the structural design, the use of atmospheric hot water boilers should be of no risk. This is mainly due to the fact that the top of the atmospheric hot water boiler is open to the atmosphere, and the internal pressure is always the same as the outside. Many residential and breeding centers choose to use this type of boiler.

Although the safety of atmospheric pressure hot water boilers is very high, this does not mean that the furnace personnel can be negligent. A relatively old steam boiler located in a fish farm in Wangtan Village, Rudong Town, Rudong County, exploded due to improper operation of the boiler operator.

When using a normal pressure hot water boiler, pay attention to the regular observation of the water level to avoid low water level and dry burning. Otherwise, there will be certain dangers, and the service life of the boiler will be seriously reduced. Boiler operators should pay attention to the following matters:
       1. Strictly implement various rules and regulations, earnestly study the professional knowledge of boilers, continuously improve the level, and ensure the safe and economic operation of boilers.
       2. After the normal pressure hot water boiler is put into use, the unit and individual may not change the boiler structure, valve and pipeline system without authorization.
       3. Inspect and inspect various equipments according to regulations before taking over, including: water level of water tank (hot water tank, expansion water tank), energy consumption (boiler gas meter), thermometer (hot water tank temperature, boiler heat medium water temperature), etc. Check the operation records, check the equipment, and learn more about the boiler operation when you transfer the shift.
       4. The succession personnel will go to the boiler room in advance to prepare for the work according to the regulations, shifts and prescribed time, and understand the boiler operation.
       5. The shifter should prepare in advance, carry out serious and comprehensive inspections and investigations, and keep the boiler running normally.
       6. The shifting staff should introduce the relevant problems of equipment operation, water quality and boiler discharge to the successor. If the handover procedure is not completed, the handover personnel must not leave the job. 7. Keep the boiler body clean when the boiler is running, no dirt, no leakage, no rust and corrosion, and fill in the equipment maintenance record carefully and in detail.
       8. The boiler room is one of the key departments of the boiler unit. Except for the boiler room staff, relevant leaders, and safety, security, and department management personnel, other personnel are not allowed to enter without permission.
       9. It is forbidden to store inflammable, explosive and other miscellaneous items in the boiler room. It is necessary to install oil drums and oil pots with a small amount of lubricating oil and cleaning oil. Store them at the designated place and pay attention to check whether there is explosives in the burning.
       10. The boiler room should be equipped with fire-fighting equipment, carefully managed, do not move or use it for other purposes.
       11. The floor, walls, doors and windows of the boiler room are always kept clean and hygienic.
       12. The supervisors should check the operation records and environmental sanitation regularly and irregularly, find problems and solve them in time.
       13. Go to work on time according to the prescribed time, do a good job of shifting records, and do not leave the job casually.
       14. It is strictly forbidden to drink alcohol, sleep, gamble, and fight in the boiler room.
       15. After equipment failures and accidents are reported in time (timely reported to the person in charge at night), the written accident report is written in a realistic manner. After the investigation is clear, after the responsibility is clarified, the accidental loss is caused to the dereliction of duty, and the responsibility is handled.

There are three reasons for the explosion of a gas boiler: gas (fuel), air and heat. Once the three reach a certain level, it is not far from the explosion of the boiler.

The key to preventing the explosion of gas boilers is to prevent the three from reaching certain limits at the same time. Among them, air is ubiquitous, it is very difficult to remove this condition, so the focus of explosion-proof is concentrated on gas and heat sources. Therefore, almost all gas explosion-proof technologies at this stage focus on how to treat gas and heat sources.

A large number of accidents indicate that the explosion of the gas boiler boiler or flue site is caused by the accumulation of gas and air in the furnace or flue, and the fire or high-temperature heat source. The combustible mixture is obviously mixed with air from the air. Forming. Therefore, the core of preventing gas boiler explosion is to prevent the boiler from entering the furnace when it is not running (no flame in the furnace); and it should be noted that the boiler must be "fire and other gas" when it starts, that is, the gas is first supplied and then ignited to form a heat source.

To this end, "Steam Boiler Safety Technical Supervision Regulations" and "Hot Water Boiler Safety Technical Supervision Regulations" clearly stipulate that: gas (including fuel, pulverized coal) boilers must be equipped with reliable ignition program control and flameout protection devices; Explosion-proof doors should also be installed in inflammable and explosive parts such as furnaces and flue ducts. The first half of the regulation is actually based on the mechanism of the explosion to prevent the formation of a mixture of gas and air, and to ensure the realization of "fire and other gas"; the latter part is used as a remedy, once the furnace or flue explosion, through the explosion-proof door Reduce the damage caused by the explosion.

Pickling is the main method for removing a large amount of oxidizing substances and corrosion products inside a gas boiler, and also has the effect of eliminating scale. The pickling process is usually carried out after 1-3 weeks of boiler operation. FANGKUAI Boiler summarizes the steps of boiler pickling for your reference and understanding.

First, cleaning tools
       Boiler energy saver, steam drum, water wall, hydrochloric acid, ammonium bifluoride.

Second, the cleaning method
       1. First, at the beginning of the pickling work, the boiler's economizer, steam drum and water wall are filled with demineralized water.
       2. The boiler is ignited. When the temperature of the boiler rises to 70-80 ° C, the boiler is turned off, and then the pickling operation can be performed. Before the pickling operation, the superheater should also be recharged with demineralized water until the water overflows into the steam drum to prevent acid or acid vapor from being introduced into the superheater.
       3. When the acid is charged into the boiler, the boiler should not be ignited under any circumstances. The steam drum and other venting holes should be opened to remove the hydrogen generated by the reaction of acid and iron. Before making sure that the hydrogen has dissipated, avoid open flames or use electrical equipment that generates sparks to avoid the risk of hydrogen explosion.
       4. Finally, after the acid filling is completed, let the boiler and economizer soak for about 6 hours in the solution, then drain the acid and rinse the superheater with demineralized water. The acid is discharged. After the acid is drained, the boiler feed water pump is operated, and the water of one economizer is filled into the boiler to prevent the water supply shutoff valve from leaking.

Third, matters needing attention
       The gas boiler can be pickled with 5% hydrochloric acid with 0.25% ammonium difluoride inhibitor added. The acid solution is injected into the boiler through the pickling joint on the steam drum down pipe, and the acid filling of the economizer is carried out through the recirculation pipe. The filling of the acid solution should be carried out until the liquid level in the steam drum temporary water level gauge rises significantly until the liquid level rises above the cyclone separator, but it should be noted that the acid liquid cannot enter the superheater, otherwise it will cause serious damage.