Plant compressor cooling system

Reduced penalty for higher heat rejection temperatures. The capital costs of dry cooling systems can be reduced by rejecting heat at a higher temperature but with the penalty of lower plant efficiency. That penalty becomes smaller as the peak temperature of the power cycle increases. For the AHTR Brayton cycle with a minimum helium temperature of 35°C, the losses in efficiency for a 10°C rise in the compressor inlet temperature were calculated to be 1.5, 1.3, and 1.1%, respectively, for AHTR peak coolant temperatures of 705, 800, and 1000°C. 

Plant maintenance. Quality of air filtration system maintenance, frequency of compressor blade washing (deposition leads to higher surface blade rou mess, which in turn leads to faster rate of degradation), prevention of potential bearing seal oil leaks into air inlet stream, periodic water quality control in closed-loop evaporative cooling systems, etc., are all measures that can positively influence compressor fouling and their rate of fouling. 

We concentrate here on open loop cooling in which compressor air mixes with the mainstream after cooling the blade row, the system most widely used in gas turbine plants (but note that a brief reference to closed loop. steam cooling in combined cycles is made later, in Chapter 7). For a gas turbine blade row, such as the stationary entry nozzle guide vane row where most of the cooling is required, the approach first described here (called the simple approach) involves the following ... 

---