Associated Gas Utilization Using a Reheat Gas Turbine – Part 1: The Impact of Engine Degradation on the Optimized Power, Energy, and Revenue From Sold Electricity

This study presents a methodology for optimizing the power from a fleet of engines that use associated gas as fuel. The effects of engine degradation on optimized power, energy, and electricity revenue have been evaluated. The Cranfield University TURBOMATCH has been used to simulate a 296MW reheat gas turbine. Four scenarios were considered — clean, optimistic, medium, and pessimistic. Genetic algorithm was used in optimizing the power generated from the fleets. In the sequence of clean, optimistic, medium, and pessimistic fleets, the optimization results show that the total optimized power values are 7324.6, 7245.1, 7164.0, and 7074.4MW respectively. In the same sequence, the total energy generated is 64.2, 63.5, 62.8, and 61.9 billion kWh. In a similar sequence still, the electricity revenue is 8.487, 8.390, 8.298, and 8.192 billion US dollars respectively. In comparison with the clean, engine degradation resulted in a 1.09%, 2.19%, and 3.42% decrease in energy for the optimistic, medium, and pessimistic degraded fleets respectively. In the same sequence as the decrease in energy, degradation resulted in a 1.15%, 2.23%, and 3.48% decrease in electricity revenue. The methodology and results presented in this paper would serve as a guide for associated gas investors in the economic utilization of this fuel resource. This is innovative; it has not been done with the Alstom GT-26 engine.

Mathematical Modeling of the Polytropic Process Using the Sequential Cubic Polynomial Approximation

The polytropic process is used to signify the effect of “energy degradation” associated with the equipment losses, which is as an inherent irreversibility in a compression process. The polytropic process is path dependent, which entails the irreversibility associated with the system. The change of gas composition and operating conditions affect the energy degradation. In this paper the polytropic process of real gas is explained and thermodynamics and mathematical model used in Taher-Evans Cubic Polynomial Method [1], [2] is presented. The elegance of Taher-Evans Cubic Polynomial Method is its rapid solution technique and high precision for calculating polytropic efficiency as required for compressor performance testing by the ASME PTC-10 [3].

Transmission improvement options via local energy degradation at a cyclotron driven ocular tumor treatment facility

The goal of this work is to increase the beam transmission from the cyclotron to the patient location of ocular tumor treatment facility Optis 2 at the Paul Scherrer Institute and thus to reduce the patient treatment times. The examined options for such transmission increase were the installation of local degraders in the patient treatment room and modification of the energy selection collimator settings. The experiments have shown that an improvement of the beam transmission is possible to achieve, however on a cost of an increase in lateral or distal penumbra of the beam. The benefits and drawbacks of the examined options are discussed.