A cryogenic gas expander system that incorporates a high-performance, high-speed permanent magnet, direct-drive generator and low loss magnetic bearings is described. Flow loop testing to 30,000rpm was completed at the system manufacturer’s facility in January 2005, and field installation is scheduled for October 2005. As part of the system testing, the rotor was dropped onto the backup bearings multiple times at an intermediate speed and at 30,000rpm. Orbit and time-history data from a full speed drop and spin down are presented and discussed in detail. A transient, nonlinear rotordynamic analysis simulation model was developed for the machine to provide insight into the dynamic behavior. The model includes the dead band clearance, the flexible backup bearing support, and hard stop. Model predictions are discussed relative to the test data.

A recent trend in designing naval ships is to improve performance through using more electric equipment. The reliability and quality of the onboard electric power, therefore, becomes critical as the ship functionality would entirely depend on its availability. This paper investigates the possibility of using Flywheel Energy Storage Systems (FESS), similar to those earlier developed for commercial applications, to address issues related to onboard power supplies. A design of a FESS for onboard power backup and railroad electrical stations is presented. The FESSs power output parameters are 500kWx30sec in high-duty mode and up to 2MW in pulse mode. High power output is one of the main advantages of FESS over commercially available electrochemical batteries. The other advantages include essentially an unlimited number of charge/discharge cycles, observable state of charge and environmental friendliness. Designs of the main FESS components are discussed: low-loss magnetic bearings, an energy-storage hub, a high-efficiency motor/generator and power electronics.

A cryogenic gas expander system that incorporates a high performance, high-speed permanent magnet, direct-drive generator and low loss magnetic bearings is described. Flow loop testing to 30,000 rpm was completed at the system manufacturer's facility in January 2005, and field installation is scheduled for October 2005. As part of the system testing, the rotor was dropped onto the backup bearings multiple times at an intermediate speed and at 30,000 rpm. Orbit and timehistory data from a full speed drop and spin down are presented and discussed in detail. A transient, nonlinear rotordynamic analysis simulation model was developed for the machine to provide insight into the dynamic behavior. The model includes the dead band clearance, the flexible backup bearing support and hard stop. Model predictions are discussed relative to the test data.

Installation and performance analysis of Thermapower™ 125MT Organic Rankine Cycle (ORC) System for recovery of waste heat from an existing Molten Carbonate Fuel Cell (MCFC) plant are presented. Over the last three years, about 100 MWe of new FC stationary power plants are in operation in Korea and more FC stationary power plants are on order and planned. The success of these fuel cell plants is their capability to supply both electricity and heat to customers. In order to promote renewable energy in Korea, the Korean Government is enforcing large power plants to supply electricity generated by renewable energy. The Korea Power Exchange (KPX) buys fuel cell generated electricity as renewable energy with higher price than other fossil fuel power plants [1]. Most of these FC plants supply electricity to power companies with their full capability, however valuable heat is wasted due to the limited demand, especially in summer season and off working hours or lack of heat pipe infrastructures. Due to the recent decrease in electricity price for renewable energy in Korea, the need for efficient utilization of waste heat is ever more demanding. In this study, 125 kWe ORC system is installed to 11.2 MWe FC power plant to demonstrate cost saving benefits. This FC Power plant has 4 units of 2.8 MWe fuel cell in operation and has capacity of producing 6.0 ton/h of 167°C steam. In order to install an ORC system to existing FC plant, their Balance of Plant (BoP) has to be modified since only excess steam is allow to be utilized by the ORC system, after supplying steam to their prime customer. Furthermore, site has distinctly hot and cold seasons, thus affecting condensing conditions and therefore ORC performance. Design considerations to accommodate varying ambient conditions as well as steam flow rate variation are presented and discussed.