An engine operates on gasoline (LHV=44 MJ/kg) with a brake thermal efficiency of 37.9 % What is the brake specific fuel consumption with units of gkW/hr?

Respuesta :

Answer:

[tex]s =0.21\ kg/Kw.hr[/tex]

Explanation:

Given that

Calorific value (CV) = 44 MJ/Kg

CV= 44,000 KJ/kg

Brake thermal efficiency(η) = 37.9 %

We know that

[tex]\eta =\dfrac{BP}{\dot{m_f}\times CV}[/tex]

Where BP is the brake power

[tex]\eta =\dfrac{BP}{\dot{m_f}\times CV}[/tex]

[tex]0.379 =\dfrac{BP}{\dot{m_f}\times 44000}[/tex]

[tex]\dfrac{BP}{\dot{m_f}}=16676[/tex]

Brake specific fuel consumption (s)

[tex]s =\dfrac{\dot{m_f}}{BP}[/tex]

[tex]s =\dfrac{3600\times \dot{m_f}}{BP}[/tex]

[tex]s =\dfrac{3600}{16,676}\ kg/Kw.hr[/tex]

[tex]s =0.21\ kg/Kw.hr[/tex]