Both water-tube boilers and fire-tube boilers are relatively common boiler models. The difference between the two makes their target user groups different. So how do you choose to use water-tube boilers or fire-tube boilers? What is the difference between these two types of boilers? Let Zhengzhou Fangkuai Boiler Factory tell you.

The difference between water tube boiler and fire tube boiler lies in the difference of the medium in the tube. The water inside the tube of the water tube boiler heats the water through the external flue gas convection/radiation heat exchange; the inside of the fire tube boiler tube is flue gas, which allows the flue gas to heat the medium outside the tube to achieve heat exchange.

Fire tube boilers have simple structure, large water and steam volumes, good adaptability to load changes, and lower water quality requirements than water tube boilers. They are mostly used in small-scale enterprise production processes and domestic heating. The heating surface of the water tube boiler is convenient to arrange and has good heat transfer performance. It is structurally used for large-capacity and high-parameter working conditions, and has high requirements for water quality and operating level.

The main difference between the two types of boilers is:
       (1) Water tube boiler has a wider range of pressure adaptation, breaking through the pressure limit and meeting the 2.5MPa upper steam supply requirements. The fire tube boiler is used under the pressure of 2.5 MPa by the material wall thickness and pressure limitation;
       (2) Fire tube boiler shell boilers are too large due to the current equipment and tooling restrictions of various boiler manufacturers. Fire tube boilers are difficult to manufacture, usually 35t/h down-pipe structure boilers to achieve large-scale boilers. 35t/h upper boilers usually adopt water-pipe structure;
       (3) Fire tube boilers have the characteristics of compact structure. At the same output, the appearance and equipment weight are lower than fire tube boilers. Water tube boilers have more space for superheaters because of their larger size. Therefore, water tube boilers occupies a relatively large boiler room.

Gas-fired hot water boilers often use natural gas as a fuel, and natural gas as one of the clean fuels is not only very environmentally friendly, but also greatly improves the operating efficiency of the boiler. But one drawback of natural gas is that it is more expensive. If the boiler can be operated more energy-efficiently, it will inevitably save natural gas, thereby reducing input costs. Zhengzhou Fangkuai Boiler Factory has summarized some tips and tricks for making gas-fired hot water boilers more energy-efficient for your reference and understanding.

1. Strengthen the insulation performance of the house
       Use gas hot water boilers for heating. Indoors usually use floor heating or radiators to dissipate heat. If the house is not well insulated, a large amount of indoor heat is lost to the outside through thermal convection, while a large amount of outdoor cold air flows into the room, and the gas boiler continues to heat it. , The gas consumption is naturally large. Installing double glazing on the windows can save 20% of energy. If thick curtains are added to the doors and windows, it can save 5% to 10% of energy; close all doors and windows before leaving the house, and draw all the curtains , Insulate the house.

2. Control the indoor temperature scientifically and reasonably
       To make the gas hot water boiler more energy-saving, the room temperature must be controlled scientifically. The ideal indoor temperature is 20°C during the day and 15°C to 17°C at night. Since the wall gas boiler is normally open in winter, the temperature does not have to be set high, it is comfortable. In principle, the outlet water temperature (or return water temperature) should be lower when it is warmer, and the outlet water temperature (return water temperature) when the weather is cold. Temperature) should be higher; when the weather is warm, the starting temperature difference should be larger, and when the weather is cold, the starting temperature difference should be smaller.

In the process of using a gas hot water boiler, the heating valve of an uninhabited room can be closed or lowered, which can save gas to a certain extent. If you are on a long-term business trip or have not lived in, the water in the gas boiler, floor heating or radiator should be drained cleanly. This will not only eliminate the use of gas, but also don't worry about the gas boiler or the end of the radiator being frozen.

Compared with fuels such as coal and biomass, the calorific value of natural gas is 8500 kcal/m3, which is still relatively high. Therefore, the use of natural gas boilers is also more energy-efficient than other types of boilers. However, the price of natural gas is still a bit expensive at present. How can we use natural gas boilers correctly to help save energy? Zhengzhou Fangkuai Boiler Factory is here to answer you.

During the operation of a general natural gas boiler, the extra part becomes superheated steam during the burning process and is discharged with the flue gas, so the exhaust flue gas temperature can reach about 220 degrees, which is not conducive to energy saving, but also Not friendly to the environment. We can install a tubular waste heat recovery device at the flue gas outlet, and use the flue gas heat to heat and prepare to be pumped into the boiler, which can save more than 5% of natural gas. In this way, the boiler thermal efficiency can be increased from 88% to 92% to 98% to 102% based on the low calorific value.

1. Improve the conditions for airflow encounters
       The purpose of improving the communication conditions of the two air streams of gas and air in a gas boiler is to increase their contact area. The larger the contact area, the larger the reaction area, which intensifies the combustion. Specifically, the gas and air can be divided into multiple streams, so that the two air streams have a certain speed and meet each other; one air stream (usually gas) passes through and is submerged in the other air stream, and so on.

2. Strengthen mixing and disturbance
       The combustion of gaseous fuels in gas-fired boilers is a single-phase reaction. It is easier to ignite and burn than solid fuels, but its combustion speed and combustion perfection are closely related to the mixing of gas and air. The better the mixing, the more rapid and complete the combustion, and the shorter the flame. Therefore, as long as the stability of the flame is not destroyed, the airflow velocity in the airflow outlet or combustion chamber should be increased as much as possible, and even barriers with high resistance such as baffles should be installed at the entrance to allow it to hit and blast the flame to increase the disturbance of the airflow. , To strengthen the mixing.

3. Preheat gas and air
       Increasing the temperature of gas and air can strengthen the combustion reaction. Therefore, the waste heat of the exhaust smoke should be used to preheat the gas and air temperature, so as to increase the combustion temperature and flame propagation speed, so that the combustion process can be strengthened.

4. Rotating and circulating air flow
       Promoting the rotation of the airflow can enhance turbulence and mixing. At the same time, a recirculation zone will be formed in the center of the rotating airflow to guide a large amount of flue gas to recirculate and circulate, which not only strengthens the mixing, but also prolongs the flow route and residence time of the flue gas in the gas boiler and reduces the loss of incomplete combustion.

5. Recirculation of flue gas
       In order to increase the temperature of the combustion reaction zone of the gas boiler, a part of the high-temperature flue gas can be led to the combustion chamber to mix it with the unburned or burning combustible mixture to increase the combustion intensity. However, it should be noted that the amount of recirculated flue gas should not be too large, otherwise it will dilute the combustible mixing hook due to too much inert material, which will slow the combustion speed, even lack of oxygen and pyrolysis, resulting in incomplete combustion loss of the gas boiler.

There are many types of boilers on the market, such as oil-fired boilers, coal-fired boilers, biomass boilers, and gas-fired boilers. The advantages of gas-fired boilers in these types of boilers are extremely high, and sales are gradually increasing. So, compared with other boilers, what are the advantages of gas boilers? Zhengzhou Fangkuai Boiler Factory will answer for you.

First, gas-fired boilers do not require coal ash stacking land, saving land.

Second, save water for auxiliary production of boilers. Coal-fired boilers and gas-fired boilers use the same normal production water, but gas-fired boilers save auxiliary water used for dust removal and slag removal in coal-fired boilers.

Third, reduce staff. Gas-fired boilers have fewer auxiliary equipment than coal-fired boilers, require fewer staff, and bear much less wages and welfare costs.

Fourth, save electricity costs for boiler production. The gas boiler has less fuel delivery and other auxiliary equipment, low power, and short continuous operation time, so it consumes low power and saves costs.

Fifth, reduce labor intensity. Coal-fired boilers require high-intensity physical labor in the process of coal transportation and slag removal, while the labor intensity of gas-fired boiler workers is relatively small.

Sixth, the layout of the gas boiler room is flexible, the floor space is small, and the noise generated is low.

Seventh, improve the environment. Coal-fired boilers produce a large amount of smoke and dust during operation, which causes great pollution to the environment, while natural gas is a clean energy source, which greatly improves the environment.

Therefore, gas-fired boilers have more advantages than traditional coal-fired boilers. The use of gas-fired boilers is safe and convenient. It can also improve air quality and give you a fresh living space.

For oil-fired and gas-fired boilers, emergency shutdown refers to immediately stopping the supply of fuel and air to the boiler and quickly stopping its operation. And when the oil and gas boiler is in operation, what situations need to start the emergency shutdown when it encounters it? Zhengzhou Fangkuai Boiler Factory will answer for you.

When the water level is lower than the visible water level of the water level gauge or higher than the maximum allowable water level, that is, when the boiler is seriously short of water or is seriously full of water.

When the main water supply pipe, main steam pipe, and reheat steam pipe burst.

When the superheater tube bursts, or the water wall tube bursts, the water level of the steam drum cannot be maintained. When deflagration occurs in the furnace or flue, causing serious damage to the equipment, and when the furnace is extinguished.

When secondary combustion occurs in the flue at the tail of the boiler, the exhaust gas temperature suddenly rises abnormally.

When all suction, blower or rotary air preheater stops running. When the safety valve does not return to its seat after the action, the steam pressure drops, and the steam temperature changes to a degree not allowed by the steam turbine.

When the steam pressure exceeds the operating pressure of the safety valve and the safety valve does not operate, at the same time, the exhaust steam valve to the empty and the primary and secondary bypass cannot be opened.

When all water level gauges are damaged and all water level gauges lose their indication.

When other irresistible accidents that endanger the safety of people and equipment occur.

Condensing technology is a new energy-saving and environmentally friendly technology, and it is the key to improving the efficiency of condensing oil and gas boilers. The principle of condensing technology is not complicated. A simple summary is to recover the heat energy in the flue gas by condensing the flue gas. Zhengzhou Fangkuai Boiler Factory will explain in detail the application of condensing technology to effectively improve the operating efficiency of oil-fired and gas-fired boilers.

The exhaust gas temperature of traditional boilers is generally around 160~250℃ or even higher, so that the water produced during fuel combustion (such as natural gas: CH4+2O2→CO2+2H2O) is in the superheated state of water vapor in the flue gas, and the smoke Gas is lost from the chimney. The thermal efficiency of traditional boilers can only reach 85%~91%. The condensing gas boiler reduces the exhaust gas temperature to 50~70℃, fully recovers the sensible heat in the flue gas and the condensation latent heat of water vapor, and the thermal efficiency can reach up to 109%.

The core of the condensation technology is to reduce the heat loss of fuel combustion and efficiently absorb the heat generated by the fuel. At the same time, due to the condensation of the flue gas, the harmful substances in the flue gas are collected into the condensed water, reducing acidic substances and other pollutants into the air. emission. More advanced condensing gas boilers use smokeless combustion technology, which reduces the emission of nitrogen oxides (NOx can cause acid rain and greenhouse effect) to beyond 35mg/kwh.

Oil and gas boilers are highly intelligent. They don’t need a large number of firemen like traditional coal-fired boilers, but only need 1-2 firemen for regular inspections. But this does not mean that we can ignore the operation of the boiler. If there is a problem during the operation of the boiler, we must also know how to deal with it correctly.

1. Severe water shortage in the boiler will cause deformation and damage of the pressure components, and even explosion of the furnace tube. If the boiler is not handled properly, a boiler explosion may occur. The causes of boiler water shortage accidents are mostly related to the lax paralysis and misoperation of the operators, or to the blockage of the water level meter due to no flushing measures. When we find that the boiler is in a state of water shortage, water should be strictly prohibited, and emergency shutdown measures should be taken.

2. The characteristic of co-boosting of soda and water is that the water level of the water level gauge fluctuates violently, the boiler water bubbles, a large amount of water is contained in the steam, the temperature of the steam drops, and water shock occurs in the pipeline when it is severe. The main reasons for this situation are poor water quality, high salt content, or excessive increase in boiler load. When we discover that the oil and gas boilers have steam and water co-emission, we must strengthen water quality treatment and increase continuous sewage discharge.

3. If the boiler is operated with overpressure, it may cause deformation of the components and damage to the edges; in severe cases, it may cause an explosion accident. The main reason for the occurrence of boiler overpressure is that the furnace staff blindly increase the working pressure or leave the job without authorization. Sometimes the boiler overpressure can also be caused by the failure of the pressure gauge and the safety valve at the same time. Therefore, it is necessary to strengthen the responsibility system of the stover's position and the inspection of safety accessories.

4. When the furnace tube is blasted, there will be noticeable blasting sound and steam injection sound, and the water level and steam pressure will decrease obviously. When this situation is discovered, emergency shutdown measures must be taken. The general reason for this situation is that poor water quality causes the furnace tube to scale or corrode; water shortage and tube bursting may also cause each other; in addition, due to design defects, insufficient material strength and poor welding quality, they may all cause tube burst accidents.

Now there are a large number of steam boiler manufacturers in our market, and the overall strength of the major manufacturers and the quality of their products are also uneven. So, as consumers who need to purchase boilers, how should we identify and choose to cooperate with boiler manufacturers with excellent quality? Zhengzhou Fangkuai Boiler Factory will answer for you.

Generally speaking, if you want to accurately select the steam boiler suitable for your business, you can refer to these standards. 1. Energy consumption index of steam boiler; 2. Heat output time of steam boiler; 3. Rated output of steam boiler; 4. Types of steam boiler

The above-mentioned content is that the purchase of steam boilers should be generally inappropriate, and it is also the most improper that must be considered. From a batch of standards here, it should be seen whether the steam boiler is stable or not. Obviously, choose a steam boiler The most important thing is to choose a steam boiler that is the best and cost-effective for your business.

In recent years, clean, environmentally friendly, and highly efficient fuel and gas boilers have been favored and recognized by more and more users, and their market share in various cities has gradually increased. So, have we performed the correct operation of the purchased fuel and gas boiler? Zhengzhou Fangkuai Boiler Factory will answer for you.

First of all, the firemen responsible for daily operations must learn the relevant knowledge about the use of burners. Furnace keepers who meet the standards of "three understandings and four meetings" understand operating principles, operating procedures, and safety standards; they can operate boilers, check faults, perform simple repairs, and perform routine maintenance. When the burner is found to be abnormal during its work, it should be shut down in time and the maintenance personnel should be notified. If the burner needs to be disassembled for inspection or maintenance, the power supply and fuel must be cut off.

1. When the boiler door is locked, ensure that the furnace door does not move and is safe and reliable.

2. It is forbidden to burn paper and garbage in a boiler.

3. The protection system of boiler and burner includes: explosion-proof door (boiler body), heating system pressure protection, water level protection, wind pressure protection, high pressure protection, low pressure protection, flame monitoring protection, etc. When the burner is actually working, various protection signals are sent to the program controller. Among the protection signals that the program controller has received, the burner can only be started when all the protection signals are normal.

4. The tightness of the gas pipeline has been checked during the installation process. Under normal circumstances, it should not be disassembled. When it needs to be disassembled, after reconnecting the pipeline, check its air tightness.

5. The gas supply pressure cannot exceed the maximum allowable pressure of the valve group indicated on the burner nameplate. When the gas supply pressure is found to be abnormal, the burner should be turned off in time.

6. When the filter on the gas pipeline is dirty, close the valve on the pipeline and clean (or replace) the filter on the gas pipeline.

7. The photosensitive part in front of the photosensitive sensor should be kept clean, please take it out and wipe it regularly. But please note that when the photosensitive sensor is put back into the socket of the sensor, the photosensitive part of the sensor should be facing forward.

8. The temperature near the burner should not be too high, otherwise it will damage some components of the burner, especially the control box.

9. The vicinity of the burner should be kept clean, and no debris should be piled up to avoid being inhaled by the burner and causing losses.

10. Excessively high, low or unstable voltage will damage some components of the burner, and may also affect the normal operation of the burner.

11. Avoid the burner from being splashed with water; keep the room dry and ventilated.

12. The burner needs a certain volume of flame-retardant air during combustion. Please pay attention to keep the air circulating in the boiler room.

13. If the burner fails to ignite and needs to be restarted, you must wait for about 10 minutes, and the burner can be restarted after the combustible gas in the furnace has dissipated. After 3 consecutive failures, the burner should not be started, and professionals should be notified to repair it in time.

Judging from the current relevant policies in my country, the requirements for pollutant emissions in various provinces and cities in the future will become more and more stringent, and the emissions of nitrogen oxides in natural gas boilers will also be reduced through technical means to meet environmental protection requirements. So how do boiler manufacturers reduce the combustion temperature of natural gas boilers through technical means, so as to achieve environmental protection standards? Let Zhengzhou Fangkuai Boiler Factory come to elaborate for you.

(1) The mixing method of natural gas and air (pre-mixing or diffusion combustion, air segmentation method, primary and secondary air ratio and total excess air coefficient).

(2) Whether the air is preheated and the preheating temperature.

(3) The layout of the heating surface in the furnace.

Modern large boilers are designed with low nitrogen emissions to avoid the simultaneous occurrence of high oxygen concentration and high temperature in the same area. Therefore, it can be assumed that the boiler adopts air segmented combustion, and the primary air and fuel are premixed. But CFD simulation shows that in the center of the flame, the maximum temperature is still between 1600-1900 degrees Celsius. Outside the flame center, the temperature should be quickly reduced to below 1500 degrees Celsius, and the walls and corners should be lower.

After a 6-ton natural gas boiler is stable, it can produce 6 tons or more of hot water or steam per hour for use. To say how much natural gas a 6-ton natural gas boiler consumes per hour, this should be one of the issues that users are most concerned about. Zhengzhou Fangkuai Boiler Factory will do the calculations for everyone.

The gas consumption of a natural gas boiler is mainly related to the tonnage of the boiler and the thermal efficiency during operation. The specific calculation formula is as follows:

(Steam enthalpy value—feed water enthalpy value) X evaporation capacity / thermal efficiency / calorific value of natural gas = gas consumption

According to different factors such as furnace type and thermal efficiency, the approximate air consumption for producing 1 ton of steam is 70 to 90 square meters per hour, and the air consumption for producing 6 tons of steam or hot water is multiplied by 6 on the basis of 1 ton. At 420-540 bid square per hour.

If you want the natural gas boiler you use to be more energy-efficient, you can think of ways to improve the operating thermal efficiency of the boiler.

The thermal efficiency of the natural gas boilers launched by Zhengzhou Fangkuai Boiler Factory is generally above 98%, which is much higher than that of other natural gas boilers on the market. After one year of operation, it can save at least tens of thousands to hundreds of thousands of yuan in fuel. Cost, very energy-saving and money-saving.

In theory, when two 3-ton natural gas boilers and a 6-ton natural gas boiler are operating at full capacity, the output of steam or hot water is the same, but if two 3-ton natural gas boilers are purchased, the user can Choose to start one of them, or start both, so that not only can meet the actual production needs of users, but also can effectively save energy, and achieve double benefits. So when two 3-ton natural gas boilers are started at the same time, how much natural gas will be used per hour? Zhengzhou Fangkuai Boiler Factory will answer for you.

Generally speaking, to measure the gas consumption of natural gas boilers, it is necessary to combine different furnace types, thermal efficiency and other factors. The approximate gas consumption of producing 1 ton of steam is 70 to 90 square meters per hour, and the gas consumption of producing 3 tons of steam or hot water. It is multiplied by 3 on the basis of 1 ton, which is about 210-270 square meters per hour. If two 3-ton natural gas boilers are started at the same time, it will need to use 420-540 standard square meters of natural gas per hour.

Many users don't know much about the "rated power" of the boiler. The rated power of the boiler is the heat generated by the boiler per hour.

The power of the hot water boiler is expressed in MW (1MW=1000kW) or ten thousand kcal/h (ten thousand kcal/h).

The power of the steam boiler is also known as the evaporation capacity, which is the amount of water turned into steam per hour: ton/hour (T/h) or kilogram/hour (kg/h). Of course, it can also be expressed in MW or kW.

In my country, the corresponding relationship between evaporation and power is: 1T/h=1000kg/h=0.7MW=720kW=600,000 kcal/h=600Mcal/h.