Water Boiling test ( WBT )

Water Boiling Test is ussualy used for Stove Performance Test ( SPT ). This type of SPT is a lab-based test designed to explore the most basic aspects of stove performance in a controlled environment. As it is a short test and the results are not highly variable, relatively few tests can give useful and quick feedback in laboratory and simulated settings to test, for example, the effect of changes in stove design, fuel quality, and other physical variables. It is also useful in field tests to determine whether stoves have been built to faithfully match their design criteria

The water boiling test determines stove efficiency by comparing the energy delivered to the water ( energy used to heat water and energy used to vaporize water ) with the energy released from the fuel during combustion . The effective calorific value of the fuel is used to determine how much energy is released during combustion, taking into account energy used to evaporate water in the fuel.

Efficiency can be calculated by :




Where:

• Mi, mass of the water (kg )
  
• Cp, specific heat of the water (J/kg K)
• T_b, boiling temperature of the water (K)
• T_i, initial temperature of the water (K)
• m_e, evaporated amount of water (kg)
• l, specific heat of evaporation (J/kg)
• m_f, mass of fuel burnt (kg)
• B_w, combustion value of the Fuel (J/kg)