Moriaki Tsukamoto

Test Results From the Advanced Humid Air Turbine System Pilot Plant: Part 2—Humidification, Water Recovery and Water Quality

The AHAT (advanced humid air turbine) system has been studied to improve thermal efficiency of gas turbine power generation. This is an original gas turbine power generation system which substitutes the WAC (water atomization cooling) system for the intercooler system of the HAT cycle. A pilot plant was built to verify feasibility of the AHAT system, which is composed of a gas turbine, a humidification tower, a recuperator and a water recovery system. Firstly, characteristics of the humidification tower were examined. The experimental results of the humidification rate agreed with the calculation results within a deviation of 1%. Humidification increased the heat recovery, and the electrical efficiency exceeded 40%. Secondly, characteristics of the spray-type water recovery system were examined. 95% of water consumed by the humidification tower was recovered, and a significant reduction of the make-up water for the HAT cycle was confirmed. Thirdly, concentrations of impurities within the circulating water of the AHAT system were measured when the recovered water was recycled without any purification process.Copyright

Study of the Effects of Sodium Aerosol Behavior on the Characteristics of the Sodium Ionization Detector

Effect of the supplied voltage on the characteristics of a sodium ionization detector (SID) has been studied. Platinum wire and tantalum plate have been used as electrodes. The supplied voltage and the sodium concentration in gas range from 0 to 1600 V and from 0.5×10-4 to 20×10-4 w/o, respectively. It was found that the ion current decreased with increasing supplied voltage over the saturation voltage. This effect can be explained in terms of the behavior of sodium aerosol in the SID. Sodium particles, charged by adhesion of sodium ions, are moved away from filament under the influence of the electrostatic field. Therefore, because re-evaporation from the sodium aerosol is repressed when the supplied voltage is high, the ion current decreases.