Prevention and treatment of gas leakage in the hot

Prevention and treatment of gas leakage in natural gas-fired boiler rooms

overview

in recent years, with the increasingly tight supply of coal in China and 3. The models of this equipment can be divided into digital display and microcomputer control. With the rising price of coal, more and more heating enterprises are turning their attention from traditional coal-fired heating to gas-fired heating. Gas-fired heating has been more and more widely used throughout the country for its environmental protection and energy conservation, In particular, gas-fired boiler rooms for central heating are the most popular. Therefore, the safety management of gas-fired boiler room has also become an important topic of concern in the heating industry. Over the past few years, Nanquan boiler house has taken the ems/osh/hse management system of the heating company as the carrier, continuously analyzed the hazards and risks of natural gas leakage in the boiler house, formulated effective preventive measures, and adopted many advanced new technologies, processes and equipment at home and abroad to ensure the safe and stable operation of the boiler house

1 natural gas leakage in gas-fired boiler room is seriously harmful

the main components of natural gas we use are: methane content of 98%, propane content of 0.3%, butane content of 0.3%, nitrogen content of 1% and other substances, high calorific value of 9650 kcal/standard cubic meter, low calorific value of 8740 kcal/standard cubic meter, explosion limit: 5%-15%. The area where natural gas may leak refers to the natural gas pipeline, valve meter, accessories, etc. from the pressure regulating station to the boiler (including the boiler). Among them, the underground pipeline is from the pressure regulating station to the fan room, and the overhead open pipeline is from the fan room to the boiler

natural gas explosion is a combustion process that produces high temperature (up to 3000 ℃) and high pressure in an instant (one thousandth of a second). The explosion wave speed can reach 300m/s, causing great destructive power

if natural gas leakage encounters open fire, static electricity, lightning or improper operation, explosion and fire will occur, which will make people lack oxygen, suffocate or even die in the confined space, and bring immeasurable losses to the safety production of the unit and the life and property of the country and people

2 possible natural gas leakage in gas-fired boiler room and its cause analysis

2.1 classification of natural gas leakage in gas-fired boiler room

according to the leakage position, it is divided into: outdoor buried pipeline leakage, indoor gas pipeline leakage, boiler body leakage, burner leakage, control, regulation, measurement and other parts and their connecting parts leakage

2.1 analysis of possible causes of leakage

natural gas leakage in gas boiler room is mainly caused by the following reasons, in addition to the illegal operation of employees and natural and external forces

2.1.1 the leakage efficiency of outdoor buried gas pipeline is low: the construction quality is not qualified, and the pipeline is corroded and perforated

2.1.2 indoor gas pipeline leakage: poor construction quality during construction, or long-term operation pipeline corrosion

2.1.3 boiler body leakage: because the gas-fired boiler was not constructed according to the relevant technical requirements at the initial stage of design or installation. For example, the welding of boiler mode wall is not strict; Due to the failure to dry the furnace according to the relevant technical requirements after the construction, or the boiler temperature rises and falls too fast, the brick joint of the furnace wall is cracked and the seal is not tight; When the gas-fired boiler is running, the vibration is large, the welding seam is desoldered or the insulation layer of the furnace wall is cracked; The fire observation hole, explosion-proof door, manhole door, etc. are not closed tightly; The boiler shuts down automatically during operation

2.1.4 burner leakage: design reasons or inadequate installation and commissioning; After long-term operation of the burner, the air-fuel ratio is misadjusted, which changes the combustion condition

2.1.5 leakage of control, adjustment, measurement and other parts and their connecting parts: gbt17600.2 ⑴ elongation conversion of 998 steel part 2 austenitic steel due to the frequent action of these parts may cause inflexible switching and lax closing, or loose natural gas leakage at the connecting parts due to large vibration during boiler operation, or lax closing and gas leakage due to poor quality of control, adjustment, measurement and other parts; Or leakage due to aging of flange, sealing gasket, sealant, etc