1. What is natural gas? Natural gas is a combustible gas directly mined from underground natural gas deposits or oil-natural gas deposits, and it is a gas mixture with hydrocarbons as the main component.

Natural gas is generally divided into four types: gas field gas (or pure natural gas) mined from gas fields; Petroleum gas (also known as petroleum associated gas) produced by petroleum; Condensed gas field gas containing petroleum light fraction; Mine gas extracted from coal seam in coal mine. 2. What is the composition of natural gas? What are the main ingredients? Natural gas is composed of methane, ethane, propane, isobutane and n-butane. , and contains a small amount of hydrocarbons, nitrogen, helium, sulfur dioxide, etc.

The main component of natural gas is methane, and the methane content of pure natural gas generally accounts for more than 90% (the methane content of natural gas supplied by our company reaches 96%). 3. What are the main characteristics of natural gas? Although there are many components in natural gas, there is no chemical interaction between them, and the nature and content of each component in natural gas determine the nature of natural gas.

Because the content of methane in natural gas is above 90%, natural gas is also called methane gas, and we often regard the characteristics of methane gas as the characteristics of natural gas. The characteristics of methane are as follows: methane is a colorless and odorless gas, which has a slightly glowing light blue flame when burning, is lighter than air, and can become a liquid at low temperature and high pressure. The critical temperature is -82. 1℃ and the critical pressure is 4.64Mpa, and the volume will be reduced by 600 times after liquefaction. Burning 1 m3 of methane requires 9.52 m3 of air, and the explosion limit of methane in air is 5%. The upper limit is 15%.

4. What are the explosion limit, upper explosion limit and lower explosion limit of combustible gas? The concentration range of combustible gas that can explode when it meets an open flame after being mixed with air is called the explosion limit of this combustible gas. In this mixed gas, when the content of combustible gas is reduced to the extent that it cannot explode, it is called the lower explosion limit of combustible gas; When the content of combustible gas increases to the point where explosion cannot occur, it is called the upper explosion limit.

The mixture of gas and air must be within the explosion limit to catch fire, burn and explode. The lower explosion limit is 5% by volume of natural gas in natural gas-air mixture, and the upper explosion limit is 15%.

5. What is the calorific value of natural gas? What's the difference between high and low calorific value? 1 standard cubic meter of natural gas is called natural gas calorific value. High calorific value refers to the heat released when 1 standard cubic meter of gas is completely burned and the waste gas is cooled to the original temperature, and the water vapor in it is discharged in the state of condensed water.

Low calorific value refers to the heat released when 1 standard cubic meter of gas is completely burned and the waste gas is cooled to the original temperature, and the water vapor in it is still in vapor state. Generally speaking, we say that the calorific value of natural gas is low, about 37.62 MJ (9000 kcal)/standard cubic meter.

6. What is the bromine smell in the natural gas used by residents? Natural gas is flammable and explosive, colorless, odorless and nontoxic. The bromine smell in the used natural gas is an added bromine agent, which is convenient for detecting natural gas leakage; Gas bromination is to add odorous liquid medicine to colorless and odorless gas. With the gasification of the liquid medicine, the gas has the special taste of the medicine, thus ensuring that when the gas leaks, it can be immediately detected by people or instruments. At present, the brominating agent used by our company is tetrahydrothiophenol, the dosage of which meets the relevant regulations and will not cause any harm to human body.

7. What is the comparison between the prices and calorific values of various energy sources on the market at present? The price of energy type generates heat. Every dollar of calories needs 1000 calories. 8. What is the density (ρ) and relative density (s) of natural gas? At 0℃, the density of natural gas (methane) is 0.7 174kg/nm3,1kloc-0/.325kpa; The relative density of natural gas (let the density of air s = 1) be 0.5548. It can be seen that natural gas is about half as light as air. If there is leaking natural gas in the room, it will inevitably condense in the upper part of the room. To eliminate it, a hole leading to the outside should be opened in the upper part of the room to increase the natural convection of air.

9. Will the use of natural gas lead to poisoning? The main component of natural gas is methane, which itself is a non-toxic combustible gas. Like all other fuels, the combustion of natural gas needs a lot of oxygen.

If residential users do not pay attention to ventilation when using stoves or water heaters, indoor oxygen will be greatly reduced, resulting in incomplete combustion of natural gas. The consequence of incomplete combustion is the production of toxic carbon monoxide, which may eventually lead to user poisoning or suffocation due to oxygen-deficient gas.

10. Why are there more moist and greasy substances in the kitchen using natural gas? When natural gas is used for cooking, people will think that the kitchen is very humid and there is a lot of oil on the walls. Some users installed a large-flow (8~ 10l/min) gas water heater in the kitchen. When using it, water droplets appeared on the kitchen ceiling, which were all formed by natural gas combustion products.

After 1Nm3 natural gas is completely burned, 1m3 carbon dioxide and 2m3 water vapor will be produced. The rated flow of natural gas double-eye boiler is 0.6m3/h, and the rated flow of natural gas large-flow water heater is about 2m3/h. ..

It can be seen that using binocular focusing, about 1.2m3 of water vapor is generated per hour. Use a large-flow water heater to generate about 4m3 of water vapor per hour. When water vapor meets cold walls and ceilings, it condenses into water droplets.

Cooking fumes can also adhere to the surface of cold objects. So there are more damp and greasy substances in the kitchen.

In addition, the carbon dioxide produced by combustion is slightly soluble in water and acidic, so the iron in the kitchen is easy to rust. To solve the problem of damp and greasy kitchen, the key is to strengthen ventilation, open the window when cooking, and preferably add an exhaust fan.

For large-flow water heaters, a flue must be installed to discharge the exhaust gas to the outside. 1 1 What are the uses of natural gas? Natural gas can be mainly used for power generation. The waste emission level of gas turbine power plant burning natural gas is much lower than that of coal-fired and oil-fired power plants, and it has high power generation efficiency, low construction cost and fast construction speed. In addition, the gas turbine has fast start-stop speed, strong peak-shaving ability, less water consumption and less land occupation.

Natural gas can also be used as a chemical raw material. The primary processing products of natural gas mainly include nearly 20 varieties such as synthetic ammonia, methanol and carbon black, and the important chemical products after secondary or tertiary processing include more than 50 varieties such as formaldehyde, acetic acid and dimethyl carbonate.

The chemical production plant with natural gas as raw material has the advantages of less investment, low energy consumption, less land occupation, less personnel, good environmental protection and successful operation.

2. Gas safety knowledge

Matters needing attention in gas use

1. After using gas, be sure to turn off the stove switch and gas pipeline valve at the same time;

2. Always check whether the hose joint is fixed with clips and whether the hose is aging and cracked;

3. When the smell is found, open the doors and windows immediately and call the gas company to report the leakage in time;

4. Long-term use of gas must be ventilated;

5. Please read the gas safety propaganda content on the back of the gas purchase invoice carefully;

6. gas appliance meeting national standards must be used, and infrared cookers are strictly prohibited.

Extended data:

In addition to the kitchen gas leakage, the bathroom is also a frequent area of gas poisoning, especially in winter. Most of these gas poisoning incidents occurred in rental houses. Because the gas water heater is installed in the home and there is no ventilation device, when the weather is cold, the doors and windows are closed, which makes the gas burn insufficiently, resulting in a large amount of carbon monoxide and poisoning.

Experts advise not to close the doors and windows when taking a bath with a gas water heater. Hypoxia is very harmful to people. Brain hypoxia will lead to irreversible necrosis of brain cells, dementia, slow response and other sequelae, and even serious poisoning death.

References:

People's Network —— Six principles that must be familiar with when using gas carefully

3. Know some common sense about gas.

The gas is flammable and explosive, and the carbon monoxide contained in it is harmful to human body. Excessive inhalation can lead to death. When cooking boiled soup on the stove, pay attention to prevent hot water from overflowing and pouring out the fire; Or blow out the flame in case of wind, so that the gas leaks, and it will deflagrate in case of open fire.

In life, if you smell an odor, it may be gas or liquefied petroleum gas leakage. At this time, you should open the windows and doors quickly to make the air circulate, then close the air source valve and carefully check the leaking part. The correct inspection method is: dip a soft brush, brush, toothbrush, etc. in soapy water. Gas or liquefied petroleum gas valve, pipe joint, both ends of rubber pipe, cooker switch valve, voltage regulator, etc. If you find soapy water bubbling, it means there is air leakage here. At this time, it is absolutely forbidden to use open flame to test leakage! Don't switch on or off household appliances (electrical switches will cause sparks) or make indoor calls. You should call the relevant departments outside for repair in time. When using gas water heater, please pay special attention to the following points:

Pay attention to ventilation: If the ventilation is not smooth, a large amount of waste gas generated during the combustion of the water heater cannot be discharged in time, and the content of indoor harmful gas (mainly carbon monoxide) increases sharply, which may cause suffocation and even endanger life.

Check the working condition: when the water heater is working, first pay attention to the combustion condition, especially to prevent backfire, which is characterized by increased combustion noise and insufficient combustion, resulting in an increase in carbon monoxide content in the exhaust gas. Tempering is not only easy to burn out the machine, but also easy to poison people. Therefore, when flashback is found, it should be closed and reopened in time until normal combustion.

Frequent maintenance: always check whether the gas supply pipeline is in good condition and whether the water supply pipeline leaks; Clean the filter regularly; Regularly clean up the ignition carbon deposit to ensure the ignition quality; Always observe the flames. If the flame turns from blue to yellow or there are other abnormal conditions, the maintenance department should be informed in time for handling. You should always wipe it and keep the cover clean.

4. Knowledge about gas

Because of the different fuels used, gas water heaters are subdivided into artificial gas, natural gas and liquefied petroleum gas.

1, artificial gas: artificial gas is a mixture of various gases, including water, tar dust, aminonaphthalene and hydrogen sulfide, and the conveying pressure is 1000Pa. Artificial gas is characterized by convenient use and low calorific value, which will directly lead to life injury accidents. In addition, artificial gas contains more impurities, which will easily lead to electromagnetic valve pollution of ordinary showers and directly lead to electric valve damage and combustion. Regular safety maintenance is needed, otherwise there will be red fire and other phenomena, which will seriously lead to incomplete combustion, red flame and long flame, and the corresponding objects in the shower will be burned. 2. Natural gas: Natural gas is a combustible gas buried underground, including gas well natural gas, petroleum associated gas, condensate gas field gas and mine gas. The main component of natural gas is methane, and the transportation pressure is 2000Pa. Natural gas is characterized by high calorific value, cleanliness, basically no sulfur, colorless, tasteless, non-toxic and non-corrosive. The density of natural gas is lighter than that of air, so it will not volatilize quickly, and it is not easy to gather in the air, so the probability of gas accidents is relatively small. 3. Liquefied petroleum gas: Liquefied petroleum gas is a by-product in the process of oil exploitation and refining, and its main components are carbon 3 and carbon 4. The conveying pressure is 2800 Pa. Liquefied petroleum gas is characterized by the highest calorific value and cleanliness. At normal temperature and pressure, liquefied petroleum gas is gaseous, but it is easy to change from gaseous to liquid when it is boosted at normal temperature or cooled at normal pressure, which brings convenience to transportation. Knowing the characteristics of the three most commonly used gases is very useful for us to maintain the shower, because the structure of the shower used will change accordingly because of the different gas characteristics. It is necessary to judge the fault according to the type of gas used.

5. Some practical common sense of safe gas use?

Seven preventive measures for gas safety:

First, pay attention to indoor ventilation when using gas.

Entering winter is also the season with frequent gas accidents. Residents should use gas while closing doors and windows for heating, but they must pay attention to ventilation to avoid accidents. If the indoor ventilation is poor, the oxygen content in the air will gradually decrease when the gas is burned, and insufficient oxygen supply will lead to incomplete combustion, which will easily produce a large amount of toxic carbon monoxide gas and cause personnel poisoning.

Second, remember to close the "double valve" after using gas.

When using gas, someone must take care of it, and the gas stove and the valve in front of the stove must be turned off every time the gas is used up. It is found in the household security inspection that some residents often only turn off the switch of the gas stove after using up the gas, but not the valve in front of the stove (the riser valve of the gas meter). Once the hose is loose and falls off, it will easily lead to gas leakage, and the consequences will be unimaginable.

Third, the hose needs to be replaced every two years.

Users should change the gas hose regularly when using gas, and the longest time should not exceed two years. If the hose is found to be aging, cracked, hard and yellow, it should be replaced in time. The length of gas transmission hose shall not exceed 2m, and there shall be no interface (no tee). Hoses must not be wound or penetrated through walls. Especially in the damp and dark kitchen.

Always check whether the rubber hose is aging and cracked, and especially remind users to buy gas-specific rubber hoses from regular manufacturers.

Four, the pipe clamps at both ends of the hose must be tightened.

One end of the gas hose is connected to the cooker, and the other end is connected to the gas pipeline. The joints at these two ends should be tightened with pipe clamps. Residents must always check whether the pipe clamp is firm, and tighten it in time if it is loose or falls off, so as to avoid accidents.

6. Question: Some knowledge about gas.

The gas used in the early days was methane, the main component of which was CH4. In fact, the main component of natural gas currently used by people is CH4 (methane). Other gases that can be used as gas are CO (a poisonous gas), which is the chief culprit of gas poisoning.

H2S, as well as other gases, can also be burned-

-I don't know if this is what you want to know.

7. Gas safety knowledge

Instructions for users of natural gas In order to ensure the smooth installation of natural gas and the safe use of natural gas by users, our company puts forward the following requirements for users in view of the common mistakes made by some users in using natural gas: 1. Users must widely publicize the "User Instructions" to users in their own units or areas, so that all users can understand this "User Instructions" and follow it.

2. Without the permission of the supplier, the gas pipeline shall not be added, dismantled or modified, and the gas supply facilities shall not be changed or damaged. If the gas supply facilities are damaged, or the pressure test must be re-tested because of the removal of the gas pipeline, the relevant construction costs must be borne by the user.

3. The gas metering device shall not be replaced or changed without authorization, and the gas pipeline and gas meter shall not be wrapped during decoration. Otherwise, normal gas supply can only be carried out after removing all obstacles that hinder safe gas supply. Four, according to state regulations, users who use natural gas are not allowed to use the second fire source in the same space.

The user's gas place must be spacious and well ventilated. If the conditions are not up to standard, the conditions for safe gas use shall be created according to the requirements of suppliers. Otherwise, the supplier will stop gas supply until the safety conditions are met. 5. Users who stop using gas or change the use of gas or expand the scope of gas use shall apply to the supplier for relevant procedures, and the supplier will be held accountable according to relevant laws and regulations.

Publicity Sheet for Safe Use of Natural Gas Natural gas has been accepted by the general public because of its advantages of convenience, cleanliness, economy, energy saving and environmental protection, and the number of users is increasing day by day. However, many users lack the knowledge of safe use of natural gas and the experience of emergency treatment in case of accidents. In order to reduce and avoid the occurrence of user safety accidents, we now publicize the nature and safe use of natural gas in the form of questions and answers. Please follow this operation strictly.

1. What are the components and properties of natural gas? A: Composition: The main component is methane (more than 95%), and a small amount of hydrogen sulfide and water vapor. Properties: colorless and transparent, lighter than air, flammable and explosive, etc.

It is particularly important to note that natural gas belongs to Class A flammable and explosive gas, with an explosion limit of 5.3%- 1.5% and a minimum ignition energy of 0.28 mJ. 2. Does natural gas smell? What is that smell? Why? Answer: Natural gas itself is colorless and odorless, but in order to prevent leakage and facilitate users to smell it, odorizing agent is specially added in the process of natural gas transmission and distribution.

3. What gas will be produced by natural gas combustion? Under what conditions? How to use it safely? A: Under the condition of air circulation, methane burns to produce carbon dioxide and water. Although a small amount of sulfur dioxide is produced, the combustion of hydrogen sulfide produces sulfur dioxide and water, which will not cause any harm to human body. In a closed space without air circulation, methane combustion will produce carbon monoxide due to lack of oxygen, which will cause death.

Proper use, when using gas appliance, the place where it is located must keep air circulation. (1 m3 natural gas (purity calculated by 100%) needs about 2.0 m3 oxygen and about 10 m3 air to burn completely. 4. What about natural gas leakage? Answer: In case of natural gas leakage, all indoor valves should be closed, doors and windows should be opened, indoor air circulation should be maintained, and the gas company should be reported immediately (Tel:).

Don't use any gas appliance at this time, don't switch the power supply, and don't bring any Mars to prevent objects from colliding and sparking. 5. What if there is natural gas poisoning? Answer: For mild patients (runny nose, tears, dizziness, brain swelling, etc.). ), just move the patient outdoors to breathe fresh air and recover in a short time.

Severe cases (numbness of limbs, vomiting, coma, unconsciousness, foaming at the mouth, etc.). ) should be sent to the hospital for emergency treatment, be sure to explain to the doctor that it is natural gas poisoning. 6. What if the natural gas catches fire? Answer: If possible, close all valves and report to the gas company and "1 19" as soon as possible.

Don't panic, explain that the fire was caused by natural gas, and explain the detailed location and contact number of the fire. 7. What are the requirements for using gas? Answer: No one is required to stay when using. If the gas stops during use (mostly due to facility failure), you should close the valve of gas appliance and call the gas company. Never make a phone call without closing the valve.

8. What should the natural gas company pay attention to when notifying to stop gas? Answer: The valve should be closed when the gas is stopped. Do not open the valve until ventilation is restored. If there is no gas when the gas supply is resumed, you should contact the natural gas company by telephone.

9. What should the market pay attention to when purchasing gas stoves, wall-hung boilers, water heaters and other products? Answer: The purchase of gas stoves, wall-hung boilers, water heaters and other commodities must be produced by manufacturers with production licenses, product certificates, safety instructions and obvious warning signs. The gas appliances used must be tested by the testing center designated by the local gas administrative department; After being registered by the safety supervision department designated by the local administrative department, it can be sold and used.

Prevent fake and shoddy products from endangering the safety of citizens' lives and property. 1 1. After installation, how do users manage indoor and outdoor gas supply facilities? How to apply for ventilation? Answer: After installation, all valves are closed and must not be opened! If you need gas, please ask the natural gas company to ventilate and debug you, and explain how to use natural gas facilities, gas appliance and related matters needing attention correctly. Please sign the safety disclosure form when you are familiar with the explanation.

12. Can a second fire source be used near gas appliance? No second fire source is allowed near gas appliance. Such as electric furnace, liquefied petroleum gas furnace, coal furnace, etc. , so as not to cause a fire accident.

13. Why can't people live in places with natural gas facilities? What should I pay attention to? In kitchens and places equipped with natural gas pipelines, gas meters, stoves and other equipment, sundries, inflammable and explosive articles and open flames are not allowed to be piled up. It is forbidden to live as a bedroom.

Because, once natural gas pipelines, gas meters, stoves and other equipment are damaged and leaked, it is easy to cause fire or poisoning and other dangers. 14. How to check air leakage? Users should always pay attention to check whether natural gas pipelines and equipment are leaking. When checking, soapy water can be applied to places where air leakage may occur, such as the joints of pipes, instruments, stove switches, etc. If there is air leakage, bubbles will be blown up there.

It is forbidden to check the leakage with open flame. Natural gas companies regularly strengthen public inspections, and full-time inspectors equipped by the company enter users' homes.