The cycle thermal efficiency (net power/heat input) for a supercritical vaporgenerator will exceed that for a subcritical cycle.

A possible advantage to using the recuperative preheaters is that they reducethe heat load on the condenser and cooling tower. The lower capital cost for asmaller condenser and cooling tower must be compared to the extra cost for therecuperators; over the long haul, the resulting higher efficiency should meanlower operating cost

The features that distinguish the Kalinacycles (there are several versions) from other binary cycles are as follows

Given thesmall size of turbines using organic working fluids, practical considerations maylead to an alternative design using two separate turbines; see Figure 8.13.

Dual-pressure binary plant: pressure-enthalpy process diagram

Dual-pressure binary plant: Simplified schematic flow diagram

The Carnot efficiency is the highest possible efficiency

therefore the gases should be removed from the condenser. This can be achieved byinstalling vacuum pumps, compressors, or steam ejectors. The condenser heat removalis done either by using a cooling tower or through cold air circulation in the condenser.The condensate forms a small fraction of the cooling water circuit, a large portion ofwhich is then evaporated and dispersed into the atmosphere by the cooling tower. Thecooling water surplus (blow down) is disposed of in shallow injection wells. In singleflash condensation system, the condensate does have direct contact with the coolingwater.

Single flash power plants are classified according to their steam turbines types, i.e., theturbine exit conditions. Two such basic types are the single flash with a condensationsystem and the single flash back pressure system. In the first type, a condenser oper-ating at very low pressure is used to condensate the steam leaving the steam turbine.The condenser should operate at low vacuum pressure to maintain a large enthalpy dif-ference across the expansion process of the steam turbine, hence resulting in a higherpower output. The geothermal fluid usually contains non-condensable gases which arecollected at the condenser. Such a collection of gases may raise the condenser pressure,