A heat engine has three quarters the thermal efficiency of a carnot engine operating between temperatures of 65°C and 435°C if the heat engine absorbs heat at a rate of 44.0 kW, at what rate is heat exhausted?

Respuesta :

Answer:

The value is  [tex]P_e = 31275.2 \ W[/tex]

Explanation:

From the question we are told that

   The efficiency of the carnot engine is  [tex]\eta[/tex]

    The efficiency of a heat engine is [tex]k = \frac{3}{4} * \eta[/tex]

    The operating temperatures of the carnot engine is  [tex]T_1 = 65 ^oC =338 \ K[/tex]  to  [tex]T_2 = 435 ^oC = 708 \ K[/tex]

    The rate at which the heat engine absorbs energy is  [tex]P = 44.0 kW = 44.0 *10^{3} \ W[/tex]

Generally the efficiency of the carnot engine is mathematically represented as

          [tex]\eta = [ 1 - \frac{T_1 }{T_2} ][/tex]

=>       [tex]\eta = [ \frac{T_2 - T_1}{T_2} ][/tex]

=>       [tex]\eta = 0.3856[/tex]

Generally the efficiency of the heat engine is

           [tex]k = \frac{3}{4} * 0.3856[/tex]

=>        [tex]k = 0.2892[/tex]

Generally the efficiency of the heat engine is also mathematically represented as

          [tex]k = \frac{W}{P}[/tex]

Here W is the work done which is mathematically represented as

        [tex]W = P - P_e[/tex]

Here [tex]P_e[/tex]  is the heat exhausted

So

       [tex]k = \frac{P - P_e}{P}[/tex]

=>    [tex]0.2892 = \frac{44*10^{3} - P_e}{44*10^{3}}[/tex]

=>   [tex]P_e = 31275.2 \ W[/tex]