What is Fuel-To-Steam Efficiency For boilers?

Fuel-to-steam efficiency is the core index to measure boiler performance, which reflects the ability of boiler system to convert input fuel energy into usable steam. In industrial production, as an energy conversion device, boiler's operating efficiency directly affects the operating cost and environmental performance of enterprises. The higher the fuel-to-steam efficiency, the higher the fuel utilization rate and the more stable the steam output efficiency, which can not only reduce fuel costs, but also reduce energy waste and pollutant emissions.

Boiler is widely used in food processing, chemical industry, textile, power generation and other industries, and it is the core equipment of energy supply in these industries. Especially in the industrial field where energy consumption accounts for a large proportion of the total cost, optimizing the fuel-to-steam efficiency of boilers is not only a technical upgrade, but also a strategic choice for enterprises to improve their profitability in the fierce market competition.

EPCB Boiler will deeply discuss the concept, calculation method, influencing factors and optimization strategy of fuel-to-steam efficiency. Through the systematic analysis and interpretation of practical cases in this paper, you will fully understand the far-reaching impact of fuel-to-steam efficiency on the production and operation of enterprises, and at the same time master effective strategies to optimize boiler efficiency, providing feasible guidance for enterprises to achieve energy saving and green development.

What is Fuel to Steam efficiency?

Definition of Fuel to Steam Efficiency

Fuel-to-steam efficiency refers to the ability of a boiler to effectively convert fuel energy into steam energy, usually expressed as a percentage. It is an important indicator of boiler performance, indicating how much chemical energy in fuel is converted into steam energy during combustion, rather than being wasted as heat loss or other forms of energy loss.

 Why is the fuel-to-steam efficiency a key performance index in boiler operation?

Fuel-to-steam efficiency is a comprehensive embodiment of boiler operation efficiency, which directly affects the energy cost and production efficiency of enterprises. The higher the efficiency, the more fully the fuel is used, and the less the heat loss, which directly reduces the operating cost of enterprises. At the same time, the fuel-to-steam efficiency can also reflect the operating state of the boiler. By monitoring the change of efficiency, problems can be found and solved in time to ensure the stability of the system. Efficient boilers not only realize the double optimization of cost and emission, but also enhance the competitiveness and sustainable development ability of enterprises.

The impact of fuel-to-steam efficiency on energy saving and environmental protection of enterprises

Improving the efficiency of fuel-to-steam conversion can significantly reduce the operating costs of enterprises, and reduce the fuel procurement expenditure by converting fuel into steam more efficiently, which is especially suitable for industries with high energy costs such as chemical industry, textile industry and power generation. At the same time, optimizing combustion process and heat management can minimize energy waste and maximize boiler energy utilization. Higher combustion efficiency can also effectively reduce the emissions of carbon dioxide, nitrogen oxides and particulate matter, help enterprises meet strict environmental protection regulations and contribute to the global carbon neutrality goal.

How to Calculate Fuel-To-Steam Efficiency?

The calculation formula of fuel-to-steam efficiency is as follows:

Calculation formula of fuel to steam efficiency

Fuel-to-steam efficiency is an important index to measure boiler performance, and its calculation formula is:

Fuel-to-steam efficiency = (energy input by fuel/energy output by steam) ×100%

This formula evaluates the efficiency of the boiler by comparing the total energy of fuel with the energy actually converted into steam by the boiler, usually expressed as a percentage.

Formula analysis: energy input (fuel) and energy output (steam)

Energy input (fuel):The energy input by fuel depends on the consumption of fuel and the calorific value of fuel (usually expressed in BTU or kilojoule).

The formula is:Fuel input energy = fuel consumption × fuel calorific value

Energy output (steam):The energy output of steam is determined by the flow rate, pressure and temperature of steam, which usually includes sensible heat and latent heat.

The formula is:Steam output energy = steam flow × (steam enthalpy and feed water enthalpy)

Among them:The enthalpy of steam and feed water can be found by thermodynamic table.Steam flow is the amount of steam output by the boiler per hour.

Calculation example:A boiler burns 100 cubic meters of natural gas per hour (calorific value is 35,000 kJ/cubic meter) and produces 4 tons of steam. The steam pressure is 1.6 MPa (corresponding enthalpy is 2,783 kJ/kg) and the feed water temperature is 80°C (corresponding enthalpy is 335 kJ/kg).

Calculate the fuel-to-steam efficiency of boiler:

Step 1: Calculate the fuel input energy

Fuel input energy =100m3×35,000kJ/m3=3,500,000kJ.

Step 2: calculate the steam output energy

The steam mass is 4 tons = 4,000 kg.

Steam output energy = 4,000 kg× (2,783,335) kJ/kg = 4,000× 2,448 = 9,792,000 kJ.

Step 3: Calculate the fuel-to-steam efficiency

Fuel-to-steam efficiency = (fuel input energy and steam output energy) × 100 = (3,500,0009,792,000 )× 100 = 280%.

Factors Affecting Fuel-To-Steam Efficiency

The fuel to steam efficiency reflects the effect of boiler energy utilization. Many factors will directly or indirectly affect the efficiency, from fuel type to boiler design, operating conditions, heat loss and maintenance.

Fuel type

The fuel type of the boiler directly determines the calorific value and efficiency of the combustion process. Different fuels have different chemical characteristics, which have the following effects on the fuel-to-steam efficiency:

Natural gas: clean and efficient

Natural gas stands out for its high calorific value (about 35,000 kJ/m3) and complete combustion. The flue gas quantity is small, the heat loss of flue gas is obviously reduced, and the sulfur content is low, which will not cause scaling or corrosion to the heat exchanger and help to maintain the long-term efficient operation of the boiler.

Coal: high calorific value but large heat loss

The calorific value of coal varies with the type of coal (about 20,000-30,000 kJ/kg), but the combustion efficiency is lower than that of natural gas, which may produce unburned carbon particles and affect the efficiency. When coal is burned, the flue gas contains a large amount of dust, which is easy to accumulate dust on the heat exchange surface and increase the heat transfer resistance, thus reducing the efficiency of the boiler.

Oil: high calorific value but high maintenance cost

Fuel oil has good combustion efficiency and high calorific value, but the flue gas contains more sulfides, so it is necessary to clean the heat exchange surface regularly to prevent scaling and maintain the efficient operation of the boiler. At the same time, the cost of fuel is high, so it is necessary to balance economy and efficiency in fuel selection.

Boiler design

The design of boiler determines the mixing effect of fuel and air and the heat transfer efficiency;

Fire tube boiler: simple structure and low efficiency.

Fire-tube boiler heats water by gas flowing through the pipeline in the boiler, which is relatively simple in structure and suitable for small boilers. However, the heat transfer area is limited and the thermal efficiency is low, which is usually suitable for medium and low pressure steam demand.

Water tube boiler: suitable for high pressure and high temperature conditions, with high efficiency.

Water-tube boiler flows through the pipeline through water, and the surrounding gas heats the water. This design has larger heat transfer area, can withstand higher pressure and temperature, and has higher thermal efficiency, which is suitable for scenes with high steam demand in industry.

Waste heat boiler: using waste heat to improve efficiency

Using industrial waste heat or flue gas waste heat to produce steam is an effective means to improve the efficiency of fuel to steam.

Operating conditions

Pressure and temperature

Higher pressure and temperature are helpful to improve steam quality, but at the same time, it will also increase heat loss, especially flue gas and radiation loss. Unreasonable operating parameters may lead to incomplete fuel combustion or waste of heat energy, reducing the overall efficiency.

Fuel to air ratio

Insufficient air (high fuel to air ratio): resulting in incomplete combustion, resulting in unburned fuel and high carbon emissions.

Excess air (low fuel-to-air ratio): excessive flue gas takes away heat, increases heat loss and reduces fuel utilization.

Heat loss

The heat loss of boiler is the main factor affecting the efficiency of fuel to steam, including the following two forms:

Smoke loss:High temperature flue gas discharge takes away the unused heat, which is the main source of boiler heat loss. If the flue gas temperature is too high or there is no waste heat recovery device (such as economizer), the fuel-to-steam efficiency will be significantly reduced.

Radiation loss:Heat is lost to the environment through the surface of the boiler, especially when the heat preservation measures are not in place, the radiation loss will increase significantly, further weakening the efficiency of the boiler.

Maintenance

Cleaning and maintenance of boiler system is very important for maintaining efficient operation:

Fouling of heat exchanger and pipeline:Dust and dirt produced by fuel combustion will cover the heat exchange surface, increase heat transfer resistance and reduce boiler efficiency. Especially the scale problem, will significantly reduce the heat transfer efficiency and lead to increased fuel consumption.

Poor burner calibration:Long-term uncalibration of burner will lead to uneven mixing of fuel and air, reduce combustion efficiency and increase fuel waste.

Preventive maintenance:Regular cleaning of burners, heat exchangers and pipelines, and timely inspection of equipment status can effectively avoid the problem of efficiency decline caused by fouling and aging, and ensure the efficient operation of boilers.

How to Optimize the Fuel-To-Steam Efficiency of Boilers?

Optimizing the fuel-to-steam efficiency of boilers is a key measure to improve energy utilization, reduce operating costs and reduce environmental impact. How to effectively improve the boiler efficiency is described in detail from several angles.

Improve combustion efficiency

Calibrating burner:The fuel-air ratio of burner is the core of combustion efficiency. By calibrating the burner regularly, the mixture of fuel and air can be ensured to reach the best state, which can effectively reduce unburned fuel and emissions and improve combustion efficiency.

Adopt advanced burner:Choosing a burner with low nitrogen combustion technology and intelligent adjustment function can optimize the combustion process and reduce fuel waste and pollutant emission.

Recovery of waste heat

Install economizer:Energy saver is a kind of equipment that uses waste heat of flue gas to preheat water supply, which can significantly reduce the loss of flue gas and improve the utilization rate of heat energy. Through the economizer, the flue gas temperature is greatly reduced, thus improving the overall efficiency of the boiler.

Condensed water recovery system:Recovering steam condensate and reintroducing it into boiler system not only saves energy, but also reduces the consumption of fresh water and treatment cost. This method is especially suitable for industries with high steam consumption.

Choose high-efficiency boiler

Replace the old boiler:Boilers with long service life usually have the problem of reduced efficiency. Replacing it with a new boiler equipped with advanced heat transfer technology and efficient control system can significantly improve the efficiency of fuel to steam.

Select the boiler type that meets the requirements:Choose well-designed and efficient equipment such as water tube boiler or fire tube boiler according to industrial needs to ensure that the boiler can meet the production needs while maintaining high efficiency.

Adopt automatic control system

Using PLC/DCS system:PLC (Programmable Logic Controller) or DCS (Distributed Control System) can realize real-time monitoring and accurate adjustment of boilers, keep the operating parameters in the best state all the time, and avoid fuel waste and efficiency decline.

Integrated internet of things (IoT) technology:The Internet of Things technology is used to monitor the boiler operation state, collect and analyze data, and realize predictive maintenance and efficiency optimization. With the support of big data, the stability and energy-saving effect of boilers can be further improved.

Regular maintenance

Clean the heat exchange surface:The fouling on the heat exchange surface will significantly reduce the heat transfer efficiency. Regular cleaning and removal of scale or dust can restore the heat transfer performance of equipment and reduce energy waste.

Check and replace aging parts:Timely inspection and replacement of aging burners, seals and sensors can avoid the efficiency decline caused by equipment failure and prolong the service life of the boiler.

Technology and Innovation to Improve Fuel-To-Steam Efficiency

Optimizing the boiler's fuel-to-steam efficiency is the core goal to improve the industrial energy utilization efficiency. By adopting advanced technologies and innovative solutions, enterprises can significantly reduce energy consumption and emissions, and achieve a win-win situation of economic benefits and environmental benefits. The following four aspects are elaborated in detail: energy-saving technology, boiler transformation, intelligent monitoring system and green energy.

Energy saving technology

Low nitrogen combustion technology:Low-nitrogen combustion technology can not only reduce pollutant emissions, but also improve fuel combustion efficiency by optimizing the combustion process and reducing the combustion temperature and the amount of nitrogen oxides (NOx). This technology is particularly important in the context of increasingly stringent environmental regulations, which can help enterprises achieve cleaner production and save fuel costs.

Energy-saving heat exchange system:Installing advanced energy-saving heat exchange equipment (such as condensing heat exchanger or high-efficiency economizer) can recover flue gas waste heat and use it to preheat feed water or air, thus significantly reducing heat loss. This technology improves the overall thermal efficiency of the boiler and is an effective method to reduce energy waste.

Boiler transformation

Equipment upgrade:Retrofitting the key components of the existing boiler system, such as installing variable frequency drives (VSD) for pumps and fans. Variable frequency drive can dynamically adjust the running speed of equipment according to the actual load demand, reduce power consumption and mechanical wear, and then improve the overall efficiency.

Reconstruction of heat energy recovery system:In view of the old boiler system, adding waste heat recovery device or improving burner design can further reduce fuel waste and increase the output ratio of steam energy.

Intelligent monitoring system

Internet of things (IoT) technology:Real-time data collection and analysis of boiler system are realized through Internet of Things technology, and key indicators (such as pressure, temperature, fuel consumption and steam output) are monitored. This can not only help enterprises to optimize operating parameters, but also provide predictive maintenance to avoid efficiency decline caused by failures.

Artificial intelligence platform:The artificial intelligence platform is introduced to analyze and optimize the boiler operation state through machine learning algorithm. For example, AI can predict the changing trend of combustion efficiency according to historical data, and actively adjust the fuel-air ratio to improve efficiency.

Automatic control system:Intelligent control system (such as PLC/DCS) can quickly respond to load changes and realize fine management of combustion process. Combined with intelligent monitoring, the boiler operation is always kept in the best state, and the fuel utilization rate is maximized.

Green energy

Biomass boiler:Biomass boilers take agricultural and forestry wastes or biofuels as raw materials, which are not only renewable, but also reduce dependence on fossil fuels. Its net carbon dioxide emission is close to zero, which meets the goal of carbon neutrality and is an ideal choice for sustainable development.

Solar assisted heating:Integrating solar water heater or heating system in boiler system can use renewable energy to replace some fossil fuels, further improve the overall efficiency and reduce operating costs and carbon emissions.

Case study: an example of successfully optimizing boiler efficiency

Case 1

The boiler system in a food processing factory has low operating efficiency and serious energy waste, especially the waste heat in flue gas is not fully utilized, which leads to high fuel consumption and high operating cost.

Optimization measures:

The enterprise installed a set of high-efficiency economizer for the boiler, and used the residual heat in the flue gas to preheat the feed water. The design of economizer can recover the heat of high-temperature flue gas, reduce the exhaust temperature of flue gas and reduce the heat loss.

Results:

· The fuel-to-steam efficiency is improved by 8%.

· Save fuel costs by $50,000 a year.

· The emission of unused heat in flue gas is reduced and the environmental performance is improved.

Waste heat recovery is one of the most direct and economical ways to improve boiler efficiency, especially suitable for industries that need continuous steam supply.

Case 2

A textile enterprise has a large demand for steam in the production process, but the boiler system uses a traditional burner, which is inefficient and the emission exceeds the standard, so it is difficult to meet the increasingly strict environmental protection regulations.

Optimization measures:

Enterprises upgrade the boiler burner to a Low-NOx Burner, and readjust the ratio of fuel and air to make the combustion process more complete and reduce the generation of nitrogen oxides (NOx).

Results:

· The emission has been reduced by 15%, significantly reducing the emission of nitrogen oxides.

· The fuel-to-steam efficiency is improved to 90%, and the fuel utilization rate is greatly improved.

Revelation:

Low-nitrogen combustion technology can not only help enterprises meet environmental regulations, but also directly reduce fuel costs by improving combustion efficiency, especially for industries with strict emission requirements.

Case 3

A chemical enterprise uses a traditional boiler, the operation efficiency fluctuates greatly, and it depends on manual monitoring, so it is difficult to accurately grasp the real-time state of the boiler, which leads to energy waste and fuel consumption problems.

Optimization measures:

Enterprises adopt the Internet of Things (IoT) monitoring system, install multiple sensors for boilers, and collect real-time operation data (such as pressure, temperature, steam output and fuel consumption). By analyzing the data through the artificial intelligence platform, the system automatically optimizes the operation parameters and carries out predictive maintenance.

Results:

· The operation efficiency is improved by 12%, and the fuel waste is obviously reduced.

· Predictive maintenance is realized, and the equipment failure rate and maintenance cost are reduced.

· The overall energy cost of the enterprise is significantly reduced and the operation is more efficient.

Revelation:

Internet of Things technology can optimize the boiler operation state in real time, and it is a powerful tool to realize intelligent management and improve efficiency, which is suitable for industries that need refined management.

Conclusion

Fuel-to-steam efficiency is the key index of boiler's economy and environmental protection performance. High-efficiency boilers can not only reduce fuel consumption and save costs, but also reduce pollutant emissions and help enterprises achieve environmental protection goals. Through reasonable design, technological innovation and refined management, such as selecting high-efficiency boilers, adopting low-nitrogen combustion technology and introducing intelligent monitoring system, combined with regular cleaning and maintenance, the boiler efficiency can be significantly improved and the energy utilization rate can be maximized. Efficient boilers not only optimize production and operation, but also promote enterprises to achieve energy conservation, emission reduction and sustainable development, which has both economic benefits and social responsibilities. Choosing EPCB boiler and its optimization solution will help you realize efficient and reliable boiler operation and make the best use of every fuel.

FAQ

1. What is the standard value of fuel-to-steam efficiency?

The efficiency of boiler fuel to steam is usually between 70% and 90%, and the specific value depends on the boiler type, fuel characteristics and daily maintenance level.

Efficient boiler design (such as water-tube boiler) and high-quality fuel (such as natural gas) help to improve efficiency. Regular maintenance and optimization of operation parameters is an important guarantee to maintain efficiency.

2. How to judge whether the boiler needs to optimize efficiency?

Boiler efficiency is a key factor affecting the operating cost and production stability of enterprises. To judge whether the boiler needs to optimize efficiency, we can start from the following aspects, focusing on the abnormal performance in boiler operation, such as excessive fuel consumption, unstable steam output and excessive emissions. These problems often reflect the decline of boiler efficiency, and optimization measures need to be taken in time.

3. What factors will lead to the decline of boiler efficiency?

The reasons for the decline of boiler efficiency include unreasonable design, poor fuel quality, high heat loss, aging equipment and insufficient maintenance. By taking measures such as design optimization, fuel selection, reducing heat loss and regular maintenance, enterprises can effectively prolong the service life of boilers and improve the efficiency of fuel-to-steam conversion, thus achieving the goals of energy saving and environmental protection.