Enhancement of performance of gas turbine engines by inlet air cooling and cogeneration system

Different inlet air cooling systems are usually used with gas turbines. A new form of inlet air cooling called the indirect evaporative cooling system (IECS) has been investigated in this work. This system is a combination of a humidifier with a vapor compression or absorption cooling system for part of the total air i.e. the secondary air stream. The net power produced from the gas turbine on a hot day (45 °C) by using combined (IECS) with absorption chillers showed an increase in power and efficiency by 15% and 9%, respectively; its recovery period is suitable for all environmental conditions. For IECS combined with vapor compression mechanical chillers showed an increase in power and efficiency by about 7.81% and 2.24%, respectively, but its recovery period made it suitable only for hot and humid conditions. The IECS has lower chiller's capital cost by about 25% (mechanical chiller) and 40% (absorption chiller).

Indirect evaporative combined inlet air cooling with gas turbines for green power technology

Cogeneration, simply, is the generation of energy for one process from the excess energy supplied to another process. Cogeneration, then, is nothing more than an economically sound method for the conservation of resources [1]. Thus, the benefits from the use of cogeneration may be cited as energy conservation, environmental improvement and financial attractiveness to investors. In the near future energy efficiency must no longer be a choice, but a commitment—hence the timely importance of this review.

Cogeneration with gas turbine engines

Comparison of performance for cogeneration systems using single- or twin-shaft gas turbine engines

Hydrogen fueled and cooled gas turbine engine

Total energy system of gas turbine is a gas turbine powered energy plant which generates the heat output besides the shaft power. In this paper, the basic thermodynamic characteristics of the plant which satisfies two requirements, such as electric power generation and central heating and cooling, are discussed. The high temperature of turbine exhaust causes a lower thermal efficiency than other conventional prime movers, but by recovering the wasted heat by boiler from 60% to 85% of the input energy is converted to shaft power and available heat. And the excess air ratio in gas turbine cycle is so large that supplementary fuel can be fired in the waste heat boiler. Thus, by controlling the supplementary fuel and the by-pass valve of the regenerator, this system shows fine flexibility in its operation. Also, the characteristic chart of this total energy system in part-load is presented for determining the operating conditions.

A Study on the Total Energy System of the Gas Turbine

Gas turbine, generally, has comparatively low value of thermal efficiency and specific power, and the variations of these values are considerably large when the ambient temperature is varied. This paper is intended to present a solution to this problem by adopting a new cycle concept. To increase the temperature ratio of the cycle is one of the most effective ways to improve thermal efficiency and specific power. In this case, the low-temperature absorption-type refrigerating machine, which is operated by using the gas turbine wasted heat as a heating source to the generator, is introduced as one of the cooling devices to lower the intake air temperature to the compressor. The primary goal of our study is to investigate the general thermodynamic characteristics of this combined cycle. It has been made clear that the new cycle can achieve remarkably higher thermal efficiency and specific power thatn the gas turbine running alone. Furthermore, the cycle has a desirable merit of lessening the variation in these values, when the ambient temperature increases.

Thermodynamic Study on the Suction Cooling Gas Turbine Cycle Combined with Absorption-Type Refrigerating Machine Using Wasted Heat

In this paper, a new cycle concept is presented, that is, the suction cooling gas turbine cycle using the bleed air has been devised in order to improve the part-load performance characteristics of gas turbine. Then, the analysis of this cycle has been made thermodynamically from both the design point and the part-load performance. The results of analysis have revealed: (1) at the design point this cycle gives little advantages in both thermal efficiency and specific power for the given conditions over the conventional cycle. (2) The part-load thermal efficiency can be highly improved in the constant speed operation for the fixed turbine inlet temperature owing to application of the higher value of an air bleed rate.

G.Takeshi Sato

Papers

A Study on the Total Energy System of the Gas Turbine

Thermodynamic Study on the Suction Cooling Gas Turbine Cycle Combined with Absorption-Type Refrigerating Machine Using Wasted Heat

A Study on Suction-Cooling Gas Turbine Cycle with Turbo-Refrigerating Machine using the Bleed Air