Boiler efficiency and fuel consumption

• CR1310
In summary, the problem is to calculate the amount of fuel oil that will be consumed in one hour by a boiler producing 6250 kg/h of superheated steam at a pressure of 2.1 MN/m2 and a feedwater temperature of 50 oC. The boiler has a thermal efficiency of 70% and the fuel oil used has a calorific value of 45000 kJ/kg. The question also asks for the enthalpy of the feedwater and the reason for given specific heat capacity. After some help from a university lecturer, the problem was solved using the formula for boiler efficiency and not using thermodynamic tables.
CR1310

Homework Statement

A boiler is to produce 6250 kg/h of steam superheated by 40 oC at a pressure of 2.1 MN/m2. The temperature of the feedwater is 50 oC. If the thermal efficiency of the boiler is 70%, how much fuel oil will be consumed in one hour? The calorific value of the fuel oil used is 45000 kJ/kg, cp of superheated steam is 2.093 kJ/kg K.

for pressure 2.1 Mn/m2
Hfg = 1880 kJ/kg
Hf = 920 kj/KG
sat temp - 214.9

Homework Equations

I want to know how to calculate the enthalpy of the feed water to put back into the boiler efficiency question.
why am i given cp?

The Attempt at a Solution

using the formula : boiler efficiency = m x (H2-H1) / fuel consumption x calorific value

H1 is the feed water enthalpy and i am told not to use thermodynamic tables

I got some help from a university lecturer and solved it.

Last edited:
how did you solve this?

0drt9 said:
how did you solve this?
The OP posted this problem 3 and a half years ago and never was seen again. I don't think you're going to get a response.

Chestermiller

1. What is boiler efficiency and why is it important?

Boiler efficiency refers to the percentage of energy in the fuel that is converted into heat by the boiler. It is important because a more efficient boiler means less fuel consumption and lower energy costs.

2. How is boiler efficiency measured?

Boiler efficiency is typically measured using the heat loss method, which takes into account the energy input (fuel consumption) and output (heat produced) of the boiler. It is expressed as a percentage, with higher percentages indicating a more efficient boiler.

3. What factors affect boiler efficiency?

Some factors that can impact boiler efficiency include the type and quality of fuel being used, the size and condition of the boiler, the combustion process, and the operation and maintenance of the boiler. Proper maintenance and regular tune-ups can help improve boiler efficiency.

4. How can I improve boiler efficiency and reduce fuel consumption?

There are several ways to improve boiler efficiency and reduce fuel consumption, such as ensuring proper insulation and sealing of pipes and valves, using high-efficiency burners, and implementing a regular maintenance schedule. It is also important to properly size the boiler for the specific heating needs of the building.

5. What is the relationship between boiler efficiency and emissions?

A more efficient boiler generally results in lower emissions, as less fuel is needed to produce the same amount of heat. However, it is important to note that other factors, such as the type of fuel being used and the combustion process, also play a role in emissions. Regular maintenance and proper operation can help reduce emissions from a boiler.

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