There are many types of boilers on the market. The once-through boiler is one of the most frequently used boiler equipment, which means that the feed water is passed through the economizer, evaporating heating surface (water wall), superheater and all changes by the pressure of the feed water pump. It is a boiler for superheated steam. So, compared with other types of boilers, what are the advantages of once-through boilers? Let Zhengzhou Fangkuai Boiler Factory tell you the answer.

After the feed water enters the boiler, the heating, evaporation and superheating of water vapor are all carried out continuously in the heating surface, so there is no need to separate steam and water in the middle of heating. Therefore, it does not have a steam drum for a natural circulation boiler. There is no fixed dividing point between the heating surface of the economizer, the heating surface of the evaporator and the heating surface of the superheater, which changes with the boiler load. There is no steam drum (drum). The feed water is preheated and evaporated by the pressure of the feed water pump. When it comes to overheating, it is a power plant boiler that generates steam with rated parameters and capacity by passing through the heating surfaces at all levels at one time. The circulation rate of the evaporation zone is 1.

Since there is no obvious boundary between the evaporation and superheating heating surface of the once-through boiler, problems such as unstable flow and pulsation sometimes occur in the evaporation heating surface. It is necessary to install a throttle orifice at the inlet of the tube group, and between the inlet and outlet headers. Measures such as installing a breathing header to improve. In addition, film boiling (that is, the vapor bubbles generated on the heating surface are too late to separate and form a vapor film) phenomenon occurs on the evaporation heating surface, which is not conducive to heat conduction, resulting in overheating of the tube wall, which affects the safety of boiler operation. In this regard, spoilers or internally threaded pipes can be installed in the water wall in the high heat load area to delay the appearance of film boiling. Measures such as flue gas recirculation or adjustment of burner layout can also be used to reduce the maximum heat load in the furnace.

As the operating conditions demand higher and higher requirements for the peak regulation characteristics of the boiler, the adaptability of the once-through boiler to load changes has been paid more attention. The once-through boiler with spirally rising tube coil has the least sensitivity to the thermal deviation in the furnace, there is no two-phase fluid distribution problem between the tubes, and there is no need to install an orifice at the nozzle, so it has good low-load operation characteristics. However, the requirements for water quality and automatic adjustment are high, the resistance of the soda system is large, and the power consumption of the water pump is relatively large.

Electric boiler is a kind of boiler equipment that directly uses electric energy as fuel energy and realizes heating high-temperature hot water or outputting high-temperature steam through a series of chemical energy conversion. In recent years, as my country’s environmental protection policies have become more stringent, coal-fired and biomass-fired boilers have been gradually banned. Electric boilers have been favored by users due to their clean, environmentally friendly, and non-polluting characteristics. The frequency of use is also increasing year by year. . Many users are not very familiar with some problems when using electric boilers for the first time. Let Zhengzhou Fangkuai Boiler Factory tell you the answers.

If the electric boiler is under normal pressure, it does not belong to special equipment, while the large-scale electric boiler belongs to special equipment, which is based on the definition of "boiler". Boiler refers to equipment that uses various fuels, electricity or other energy sources to heat the contained liquid to certain parameters and outputs heat energy to the outside. It is specified as a pressurized steam boiler with a volume greater than or equal to 30L; the outlet water pressure is greater than Or equal to 0.1MPa (gauge pressure), and the rated power is greater than or equal to 0.1MW pressurized hot water boiler; organic heat carrier boiler.

For the electric boilers used in food factories, wood factories, paper mills and other industries, most of them are electric steam boilers. In other words, the function of these boilers is to use electric energy to generate high-temperature steam by converting energy, and then deliver the steam to various production workshops to achieve various technological purposes such as cooking and drying. For example, in a paper mill, steam enters the steaming ball to cook the paper-making raw materials, and steam enters the dryer to dry the wet paper passing through the dryer. And the food factory can use steam to steam the food, and can also use the steam to dry the food indirectly, or use the steam to sterilize some food indirectly or directly, etc. The wood mill uses steam to heat the wood, or indirectly heats the drying room for further training and drying.

Gas-fired steam boilers are special equipment. Regardless of whether they are manufactured, produced or used, they are subject to the control of relevant departments, and a series of certificates are required before the boiler is used. Zhengzhou Fangkuai Boiler Factory summarized some documents that need to be processed for 1 ton gas-fired steam boilers.

Before the installation of a one-ton gas-fired steam boiler, the installation unit shall inform the local special equipment safety supervision department, and the installation supervision and inspection shall be carried out by the local special equipment supervision and inspection agency, and an inspection report shall be issued.

And bring boiler-related technical documents and boiler installation quality certificate and boiler installation supervision and inspection report to the local special equipment safety supervision agency to apply for the special equipment use registration certificate.
       1. The furnace worker must hold a special equipment operator certificate and work item: boiler operation.
       2. The water treatment personnel must hold a special equipment operator certificate, and the work item: boiler water quality treatment.
       3. The management personnel must hold the special equipment management personnel certificate, and the work item: the safety management of the boiler, pressure vessel and pressure pipeline.

In addition, a 1-ton gas-fired steam boiler must undergo an external inspection every year, an internal inspection every 2 years, and a hydraulic test every 6 years.

Atmospheric boilers and pressure-bearing boilers, as the name implies, atmospheric boilers refer to boiler equipment with a normal pressure inside, while pressure-bearing boilers are boiler equipment with a certain pressure inside. According to different pressures, they are divided into overpressure. , High-pressure, medium-pressure, and low-pressure boilers, the applicable industry groups are also different.

For users who are new to boilers, how to quickly distinguish whether it is an atmospheric boiler or a pressure boiler through the boiler nameplate? Let Zhengzhou Fangkuai Boiler Factory tell you the answer.

First of all, we need to know all the parameters on the boiler nameplate. If the boiler nameplate has a rated steam pressure, even if it is 0.1MPA, it is a pressure-bearing boiler. Generally speaking, steam boilers are pressure boilers, and most of hot water boilers are atmospheric pressure boilers.

The steam boiler nameplate is generally marked with the model number. Take the WNS2-1.25-Q boiler as an example. WNS refers to the classification of the boiler, that is, the horizontal internal combustion chamber fired boiler. 2 refers to the rated steam volume of two tons, 1.25 It means that the rated steam pressure is 1.25Mpa, which is generally referred to as a pressure of 13 kg. The following Q refers to the type of boiler fuel, and Q refers to the gas furnace.

The 3-ton hot water boiler is commonly used in the heating and heating field. The boiler directly outputs high-temperature hot water and provides air-conditioning, radiator and other channels to send warmth to thousands of households. Combining with the current strict environmental protection policies in our country, coal-fired and biomass-burning boiler equipment that pollutes the environment have been gradually banned and replaced by more energy-efficient and environmentally-friendly boiler equipment such as gas, oil, and electricity. When purchasing hot water boilers, many users are very concerned about how much heating demand the boiler can meet. Zhengzhou Fangkuai Boiler Factory takes a 3-ton gas-fired hot water boiler as an example to briefly explain the heating area of ​​the boiler.

First, we analyze the parameters of the 3-ton gas-fired hot water boiler. A 3-ton gas-fired hot water boiler is equivalent to 2.1 megawatts, or 2,100 kilowatts, or 2,100,000 watts.

If a 3-ton gas-fired hot water boiler is used to heat the plant, it can provide an area of ​​more than 20,000 square meters. Of course, the specific heating area that can be met depends on the actual situation of the plant, such as how high the height is and whether it has heat preservation treatment. , Construction years, etc.

The operating efficiency of the 3-ton gas-fired hot water boiler launched by the Zhengzhou Fangkuai boiler manufacturer is above 98%, and the inside of the boiler has been fully insulated, which can fully meet the heating area of ​​30,000 square meters, which is comparable to ordinary gas-fired hot water on the market. Compared with the boiler, the cost performance is greatly improved, so it is also loved and used by more and more users.

Atmospheric hot water boiler is a type of hot water boiler, mainly used in winter heating, hot water supply and other fields. Due to the high safety performance of the boiler, it is trusted and used by the majority of users. Although the safety performance of atmospheric hot water boilers is very high, there are strict standard requirements in terms of design, manufacturing, inspection, acceptance and delivery technical documents, which should meet JB/T7985-2002 "Small Boilers and Atmospheric Heating Technical Conditions for Water Boilers", according to the requirements of JB/T7985-2002 "Technical Conditions for Small Boilers and Atmospheric Hot Water Boilers" [New Standard].

Recently, Zhengzhou Fangkuai Boiler Factory found that many users who use atmospheric hot water boilers do not care much about the installation and use of boiler air pipes. In fact, this is a very dangerous behavior, and improper operation can easily cause boiler damage.

According to the provisions of Article 6.2.9 in the “Conditions” mentioned above, the equivalent diameter Dd of the atmospheric pipe connecting pipe of the atmospheric hot water boiler should be calculated as follows: Dd=88×√(Q), where Dd——atmosphere The equivalent diameter of the connecting pipe, in millimeters (mm); Q——The rated thermal power of the atmospheric hot water boiler, in megawatts (MW). The calculated Dd value is rounded according to the diameter of the pipe specification and can only be increased, not reduced.

According to the provisions of Article 6.3.5 of JB/7985-95 [Old Standard], the pipe diameter should be calculated according to the following formula: Dd=20+88×√(Q), where Dd——the equivalent diameter of the atmospheric connecting pipe, unit It is millimeter (mm); Q——The rated thermal power of atmospheric hot water boiler, the unit is megawatt (MW). The calculated Dd value is rounded according to the diameter of the pipe specification and can only be increased, not reduced.

According to the difference in output medium, gas boilers are divided into gas steam boilers and gas hot water boilers. A 4-ton boiler refers to boiler equipment that outputs 4 tons of steam or 4 tons of high-temperature hot water per hour. This is a brief introduction for you. Explanation of boiler model parameters. For users who need to purchase boilers, what are the parameters and prices of 4-ton gas boilers are questions worthy of attention, let Zhengzhou Fangkuai Boiler Factory answer for you.

First of all, according to the difference of the output medium, Zhengzhou Fangkuai Boiler Factory will separately describe the parameters of the steam boiler and the hot water boiler.

Parameters of 4 ton gas boiler (steam):
       The total electric power of burning heavy oil is 26.2KW of three-phase electricity;
       The total electric power of burning light oil is 13.0KW of three-phase electricity;
       The total gas electric power of three-phase electricity is 13.0KW;

Parameters of 4 ton gas boiler (hot water):
       The total electric power of burning heavy oil is 22.2KW of three-phase electricity;
       The total electric power of burning light oil is 9KW of three-phase electricity;
       The total gas electric power of three-phase electricity is 6.5KW;

Recently, some users are consulting Zhengzhou Fangkuai Boiler Plant about the selling price of steam boilers. The user needs to purchase steam boilers for processing and production in food plants. For this reason, the technical engineer of Zhengzhou Fangkuai Boiler Factory recommended a 4-ton gas-fired steam boiler for the user after understanding the user’s needs in detail and visiting the user’s site for on-site inspection. The current price of the equipment is between RMB 250,000 and RMB 350,000. Wait.

For oil and gas boiler equipment, in order to improve operating efficiency, it is an indispensable way to achieve full combustion of fuel, which is also beneficial to the optimization of environmental protection performance of the boiler. So, how to ensure that the oil and gas boiler can fully burn? Let Zhengzhou Fangkuai boiler manufacturer tell you the answer.

1. Ensure the right amount of air is supplied
       The ratio of the volume of carbon dioxide in the flue gas to the total volume of the flue gas is called the carbon dioxide content of the flue gas. Under normal combustion conditions, the volume of carbon dioxide in the flue gas is unchanged, but the total volume of the flue gas is affected by the excess air volume. When the amount of excess air increases, the total volume of flue gas will increase, and the carbon dioxide will decrease accordingly. On the contrary, when the amount of excess air is small, the carbon dioxide content will increase accordingly. The carbon dioxide content in the flue gas of the oil burner is about 12%.

2. The furnace maintains a certain high temperature and burning time
       The furnace temperature is an important condition for the complete combustion of fuel, and the combustion method of each boiler is suspension combustion. When burning in suspension, the temperature of the combustion center should be between 1300 and 1600, and the flame should be bright white. The fuel must have enough residence time in the furnace to completely release the heat. At present, all boilers are three-pass combustion, so it is very important to adjust the air distribution reasonably. When the flame is burning normally, the flame in the furnace is stable, white-orange, and there is generally a rumbling sound. If the flame jumps or makes an abnormal sound, the oil volume and air volume should be adjusted in time. If there is no improvement after adjustment, the flame should be turned off to find out the cause, and the ignition should be restarted after measures are taken.

3. Adjustment of fuel volume and air volume
       The adjustment range of a simple mechanical atomization nozzle is usually only 10%-20%. When the boiler load changes little, the method of changing the oil pressure in front of the furnace can be used to adjust, and the oil pressure can be increased to achieve the goal of fuel injection. When the load of the boiler changes greatly, atomizers with different apertures can be replaced to increase or decrease the fuel injection volume. Within a certain range, with the increase of air supply, the mixture of oil mist and air is improved, which is beneficial to combustion, but too much air volume will reduce the furnace temperature, increase the heat loss of incomplete combustion, and increase the heat loss of exhaust smoke. , Causing black smoke from the chimney, causing carbon deposits at the tail, and prone to secondary combustion accidents. In actual operation, employees can adjust the air supply volume according to the ignition of the fuel nozzle and the carbon dioxide content in the flue gas. It can be adjusted to normal by adjusting the frequency conversion of the fan or adjusting the opening of the fan baffle (strengthen the maintenance of the air regulator when the furnace is shut down for maintenance and make it flexible).

Zhengzhou Fangkuai Boiler Factory is a boiler equipment manufacturer specializing in energy saving, environmental protection, intelligence, and cost-effectiveness, such as oil-fired gas boilers and electric boilers. It has a comprehensive pre-sale, in-sale and after-sales service system, whether you want to consult Boiler knowledge or planning to purchase boiler equipment, we will arrange one-to-one technical engineers to provide you with free help and guidance.

Many users and friends are more interested in the oil and gas boilers launched by the Zhengzhou Fangkuai boiler manufacturer, and are very concerned about the quality of the equipment. Today, I will give you a detailed answer.

First of all, the oil and gas boilers of the Zhengzhou Fangkuai Boiler Factory can ensure complete combustion of fuel, which not only improves operating efficiency, but is also good for saving fuel and improving environmental protection coefficients.

During normal combustion, the temperature of the furnace is high enough to meet the requirements of combustion chemical reaction. Therefore, the burning speed of fuel oil is determined by the evaporation speed of oil droplets and the mixing speed of air and oil vapor. The higher the temperature, the smaller the particles, and the faster the oil will evaporate. For this reason, it is necessary to improve the atomization fineness of the oil, and strengthen the heating of the atomized oil flow by the high-temperature flue gas. At the same time, the mixing speed of the air is required to be compatible with the evaporation speed of the oil droplets, but the mixing speed of the oil vapor and air is increased. The key is to improve the air supply conditions.

Superheaters and reheaters are very important to the normal use of industrial boilers. Companies that use industrial boiler equipment must not neglect the overhaul and maintenance of these two auxiliary machines. Zhengzhou Fangkuai Boiler Factory has many years of working experience in the field of industrial boilers, and has a lot of hard work in auxiliary equipment such as superheaters and reheaters. Today I will briefly tell you about the use of superheaters and reheaters in industrial boilers. Issues that need attention.

Superheater (Superheater) is a component in the boiler that further heats steam from saturation temperature to superheat temperature, also known as steam superheater. According to different heat transfer methods, it can be divided into convection, radiant and semi-radiative; according to structural characteristics, it can be divided into serpentine tube, screen, wall and wall-wrapped. All of them are combined with parallel pipes and inlet and outlet headers.

The main function of the superheater is to heat saturated steam into superheated steam. When the boiler load changes, ensure that the boiler's superheated steam temperature fluctuates within the allowable range. At present, the temperature of superheated steam in power plant boilers is maintained at 540-555℃.

The reheater is essentially a steam superheater that reheats the low-pressure steam that has done work to reach a certain temperature. The function of the reheater further improves the thermal efficiency of the power plant cycle and controls the steam temperature of the last stage of the steam turbine. Within the allowed range. The superheater is a heater in the boiler that heats the steam from the steam turbine into superheated steam.

There are two main functions of the reheater. One is to reduce the humidity of water vapor, which is beneficial to protect the blades of the steam turbine; the other is to improve the relative introversion rate and absolute internal efficiency of the steam turbine. The exhaust steam from the high-pressure cylinder of the steam turbine is returned to the boiler to be heated again, and then sent to the low-pressure cylinder for expansion to perform work. The purpose is to control the steam humidity of the final stage blades of the steam turbine within the allowable range. The reheated steam pressure is 20% of the superheated steam pressure. All units above 125MW in our country use an intermediate reheating system.

Periodic blowdown of industrial boilers is to make the boiler water quality meet the required standards, reduce the adverse effects of scale on the boiler, and keep the impurities in the water within a certain concentration. It is necessary to continuously remove the salt and alkali content from the boiler. Larger boiler water and deposited residues, sludge and various sediments allow the safe operation of industrial boilers and prolong the service life of industrial boilers.

For industrial boilers, the blowdown is divided into two types: continuous blowdown and regular blowdown. Zhengzhou Fangkuai Boiler Factory will give you a brief introduction to these two blowdown methods.

1. Continuous blowdown
       Continuous blowdown can remove part of the salt dissolved in the boiler water to maintain a controllable amount of salt and alkalinity in the boiler water, and prevent excessive concentration from affecting the quality of boiler steam. Generally, the continuous blowdown outlet is installed at 200-300mm below the normal water level of the steam drum. The boiler water is continuously heated and concentrated, so that the salt is collected on the surface of the boiler water. The continuous outlet is installed at the place with the highest salt content in the boiler water. In order to discharge high-concentration salt water, a new water supply treatment is carried out.

2. Regular sewage discharge
       Regular sewage discharge is mainly to remove rust slag, calcium, magnesium and other flocculent sediments that have not been desalinated. Reduce its adhesion on the boiler wall and improve the thermal efficiency of the boiler. It is generally intermittent, also known as intermittent blowdown or bottom blowdown. The nozzle for regular blowdown is generally set at the lowest point of the boiler water cycle. The fixed discharge time is intermittent. Generally, the discharge is carried out when the boiler load is low. The fixed discharge discharge is large. Generally, only a short period of time can be used to achieve the purpose of sewage discharge, usually 0.5-1 minutes, depending on the boiler water quality. , But it should be avoided for a long time to schedule so as not to affect the normal circulation of boiler water. The regular work of chemical operation is selected in each post-night shift. The correct and reasonable blowdown device can discharge impurities, sludge, scale, etc. in the boiler water, control the alkalinity and salt content of the boiler water, ensure the cleanliness of the boiler heating surface, ensure that the boiler produces high-quality steam, and extend the boiler In the service life, the waste heat of the boiler is fully utilized, which can achieve the effect of energy saving.

Industrial boilers are one of the necessary equipment in many industrial industries. The high-temperature steam output by the boiler and the heat it brings can provide a source of power for the industrialized process. Zhengzhou Fangkuai Boiler Factory, as a company with many years of cooperation experience in the field of industrial boilers, has a lot of knowledge about boiler operation, maintenance, and maintenance. Today, I will tell you how much damage is caused by scaling to industrial boilers.

First of all, after the formation of scale inside the industrial boiler, the heat transfer performance of the heating surface becomes poor, and the heat released when the fuel is burned cannot be quickly transferred to the boiler water; therefore, a large amount of heat is taken away by the flue gas, causing the exhaust gas temperature to rise and increase The heat loss of exhaust gas reduces the thermal efficiency of the boiler.

Secondly, it may cause overheating and low strength of the metal, endangering safety. The steel used for the heating surface of industrial boilers is generally carbon steel. During use, the metal wall temperature is allowed to be below 450 ℃; when the boiler is in normal operation, the metal wall temperature is generally below 280 ℃. When there is no scale on the heating surface of the boiler, the metal can quickly transfer heat to the water after being heated. At this time, the temperature difference between the two is about 30 ℃. However, if scale accumulates on the heated surface, the temperature difference between the two will increase. For example: when the heating surface of a boiler with a working pressure of 1.25Mpa has 1 mm thick scale (mixed scale), the temperature difference between the metal wall and the boiler water will reach about 200 ℃; when the scale reaches 3 mm, the metal wall temperature will rise to 580 ℃, far exceeds the allowable temperature of steel. At this time, the tensile strength of the steel will be reduced, and the pressure components of the boiler will overheat, bulge, deform, leak, and even explode under the action of internal pressure. The measured data shows that the metal wall temperature increases as the scale thickness increases. The thicker the scale, the higher the metal wall temperature, and the greater the probability of accidents.

The water circulation of industrial boilers has two forms: natural water circulation and forced water circulation. The natural water cycle is a water cycle that relies on the pressure difference caused by the difference in the specific gravity of soda and water in the riser pipe and the down pipe. Forced water circulation depends on the mechanical power of the water pump to force the circulation. Regardless of which form of water circulation, it is designed and calculated, which means that there is enough circulation cross-sectional area. When scale builds up on the inner wall of the furnace tube, the circulation area in the tube is reduced, the flow resistance increases, the normal water circulation is destroyed, and the metal wall temperature toward the fire surface rises. When the pipeline is blocked by scale, the water circulation is completely stopped, and the metal wall temperature is higher, and pipe burst accidents will occur for a long time.

Once the industrial boiler scales, it must be removed quickly, so as to ensure the safe and economical operation of the boiler. The later the scale builds up, the more medicine is consumed, and the more money is invested. For example, if the average fouling of a 1t/h boiler is 3 mm, 0.5 tons of chemicals are required to remove the fouling once. After increasing according to the different boiler tonnage, the required reagent will increase by one-third, and the investment capital will increase accordingly.

The service life of general industrial boilers can run continuously for about 20 years under normal use conditions. However, most of the boilers of the current use units have not reached this life. There are many reasons for this, one of which is the influence of scale. The drum has a bulge, and after digging and repairing it, it should be properly reduced in pressure to ensure safety. In this way, for units that require high steam pressure, they have to replace a new boiler.