Since the amount of steam delivered varies with temperature and pressure, a common expression of the boiler capacity is the heat transferred over time expressed as British Thermal Units per hour. A boilers capacity is usually expressed as kBtu/hour (1000 Btu/hour) and can be calculated as. W = (hg - hf) m (1)
Calculation Details
- Blowdown Mass Flow = Feedwater Mass Flow * Blowdown Rate.
- Steam Mass Flow = Feedwater Mass Flow - Blowdown Mass Flow.
- Steam Mass Flow = Feedwater Mass Flow - Feedwater Mass Flow * Blowdown Rate.
- Feedwater Mass Flow = Steam Mass Flow / [ 1 - Blowdown Rate ]
Boiler water consumption
- The water consumption consists on the control of the make-up water, the blowdown water and the condensed water quantities.
- This equation doesn't take account of the process leaks, the windage and drift which are just forms of uncontrolled blowdown.
- B=S x (1 - r) x m / b - m.
- B = Blowdown.
- S = Steam rate.
Total coal consumption of AY and BY can be calculated by the GCV, GHR and generation. By comparing the GCV of AY and BY and multiplying it with the BY coal consumption, we can get the normalized coal consumption.
In order to calculate boiler efficiency by this method, we divide the total energy output of a boiler by total energy input given to the boiler, multiplied by hundred.
The boiler evaporation ratio is expressed as follows: Evaporation ratio = quantity of steam generation/quantity of fuel consumed. For example quantity of steam Is 310 ton/hr and fuel is 55 ton/hr then the evaporation ratio is 5.63. ? Evaporation ratio is also known as steam fuel ratio.
How much fuel required for 1TPH boiler?
- For 1 tph wood fired boiler. Formula for calculating fuel:Fuel Consumption = steam quantity* latent heat / Efficiency * Calorific Value.
- For 1tph coal fired boiler. But generally speaking,1tph=1000kg/ hr= 5/18 kg/sec.
- For 1t /h Bagasse steam boiler.
1. We measure steam flowrate in kg/h for small flowrate of tph for bigger flowrate. The kg/cm 2 is the steam pressure, not the flowrate.
When water is heated at atmospheric pressure, its temperature rises until it reaches 212°F, the highest temperature at which water can exist at this pressure. Additional heat does not raise the temperature, but converts the water to steam.
Using the equation Q=mcΔT we can calculate the amount of energy for heating the water to 100 degrees. c=4187 Joules per kilogram- the specific heat capacity of water. ΔT = 100-43=57, how many degrees we must increase the water by to make it boil and turn into steam.
As the latent heat of steam at atmospheric pressure is 2257 kJ/kg the amount of flash steam produced will be 299/2257 = 0.133 kg/kg of condensate. Flash steam can be piped to an evaporator, calorifier or vat or can be used for heating in a contact heater.
Steam is water that has been heated to above 100 degrees Centigrade. It has taken in enormous amounts of energy to pass into the vapour state. The steam's heat is transferred to the condensation surface, or into the air. Upon condensation, you get pure water and heat.
Significant fuel savings occur as most returned condensate is relatively hot (130°F to 225°F), reducing the amount of cold makeup water (50°F to 60°F) that must be heated. A simple calculation indicates that energy in the condensate can be more than 10% of the total steam energy content of a typical system.
Condensate is the liquid formed when steam passes from the vapor to the liquid state. In a heating process, condensate is the result of steam transferring a portion of its heat energy, known as latent heat, to the product, line, or equipment being heated.
Multiply the air conditioner's flow rate, measured in gallons per minute, by the air's specific humidity, measured in pounds of water per pound of dry air. If 12 gallons flow through the unit per minute, and the air has a specific humidity of 0.0065 pounds of water per pound of dry air: 12 x 0.0065 = 0.078.
Enthalpy and Phase ChangesAn exothermic processes involves a negative change in enthalpy, or a loss of heat. As water vapor condenses into liquid, it loses energy in the form of heat. Therefore, this process is exothermic.
Saturated steam is pure steam in direct contact with the liquid water from which it was generated and at a temperature of water at the existing pressure. For example, saturated steam at 50 PSIG has a temperature of 298°F. Latent heat varies with temperature (see table above).
