Two surge tanks are used to dampen pressure fluctuations caused by erratic operations of a large air compressor. (See Figure)

(a) If the discharge pressure of the compressor is Pd(t) and the operating pressure of the furnace is Pf (constant), develop a dynamic model for the pressures in the two surge tanks as well as for the air mass flows at points a, b, and c. You may assume that the valve resistances are constant, that the valve flow characteristics are linear, that the surge processes operate isothermally, and that the ideal gas law holds.

(b) How would you modify your model if the surge tanks operated adiabatically? if the ideal gas law were not a goodapproximation?

Transcribed Image Text:

Ry R. Air Ra Compressor Pa P2 Process furnace supply Pf V2 V1 Wa