Injecting steam into the gas turbine has been a strategy adopted by turbine users for a long time to increase its power output. The increased mass flow coupled with the higher thermal conductivity and specific heat of the exhaust gases (due to the higher percent by volume of water vapor) generates more power in the […]

Gas turbine plants operate in both combined cycle and cogeneration mode (Fig. 1.9). Figure 1.10 Shows the arrangement of an unfired HRSG used in such plants. Large combined cycle plants with thousands of megawatts in capacity are being built today. Chemical plants, refineries, and process plants use HRSGs in cogeneration mode to supply steam for […]

The Rankine cycle is a thermodynamic cycle used to generate electricity in many power stations and is the practical approach to the Carnot cycle. Superheated steam is generated in a boiler, then expanded in a steam turbine. The turbine drives a generator to convert the work into electricity. The remaining steam is then condensed and […]

A 3 MW plant has been in operation in California for more than a decade. In this plant, 31,450 lb/h of ammonia vapor enters the turbine at 1600psia, 960°F and exhausts at 21 psia. The ammonia concentration varies throughout the system. The main working fluid in the HRVG is at 70% concentration, whereas at the […]

A recent development in power generation technology is the Kalina cycle, which basically follows the Rankine cycle concept except that the working fluid is 70% ammonia-water mixture. It has the potential to be 10-15% more efficient than the Rankine cycle and uses conventional materials of construction, making the technology viable. Figure 1.4 Shows the scheme […]

A discussion on boilers would be incomplete without mentioning the Rankine cycle. The steam-based Rankine cycle has been synonymous with power generation for more than a century. In the United States, utility boilers typically use subcritical parameters (2400 psi, 1050/1050°F), whereas in Europe and Japan, supercritical plants are in vogue (4300 psi, 1120/1120°F). The net […]

Basic human needs can be met only through industrial growth, which depends to a great extent on energy supply. The large increase in population during the last few decades and the spurt in industrial growth have placed tremendous burden on the electrical utility industry and process plants producing chemicals, fertilizers, petrochemicals, and other essential commodities, […]

The role of boilers and heat recovery steam generators (HRSGs) in the industrial economy has been profound. Boilers form the backbone of power plants, cogeneration systems, and combined cycle plants. There are few process plants, refineries, chemical plants, or electric utilities that do not have a steam plant. Steam is the most convenient working fluid […]