The water tank of a steam cleaner (V = 1 liter) is cold with a mass m = 1 kg filled with water, which is isochorically heated from the initial state t1 = 20 C, p1 = 1 bar. When the pressure p2 = 3 bar is reached, the pressure control valve opens (see drawing) and a small part of the water flows at constant pressure and further heat supply off until the boiling state at p3=p2 is reached. Immediately afterwards the pressure control valve closes again. With the supply of further heating power Q, the equilibrium steam can now (State 4) can be removed for cleaning purposes. Druckhalteventil Wasser/ Dampf 3 bar 0 Wassertank des Dampfreinigers 1/ Op 815 V Definition: isochoric stress coefficient: Assumption: Bits beta) = 3.01 K^-1 = const in the relevant pressure and temperature range. Excerpt from the steam table of water: p t v' y" h' h" bar C m3/kg m3/kg kJ/kg kJ/kg 3 133,52 0,00107 0,60576 561,2 2723,2 How big is the mass of water that has to be drained away so that the Water in the holding tank just boiling after isochoric heating present