Integration of Kalina cycle in a combined heat and power plant, a case study

Abstract

This paper presents the integration of the Kalina cycle process in a combined heat and power plant for improvement of efficiency. In combined heat and power plants, the heat of flue gases is often available at low temperatures. This low-grade waste heat cannot be used for steam production and therefore power generation by a conventional steam cycle. Moreover, the steam supply for the purpose of heating is mostly exhausted, and therefore the waste heat at a low-grade temperature is not usable for heating. If other measures to increase the efficiency of a power plant process, like feed-water heating or combustion air heating, have been exhausted, alternative ways to generate electricity like the Kalina cycle process offer an interesting option. This process maximizes the generated electricity with recovery of heat and without demand of additional fuels by integration in existing plants. The calculations show that the net efficiency of an integrated Kalina plant is between 12.3 and 17.1 % depending on the cooling water temperature and the ammonia content in the basic solution. The gross electricity power is between 320 and 440 kW for 2.3 MW of heat input to the process. The gross efficiency is between 13.5 and 18.8 %.

Entropy and Exergy Analysis of a Heat Recovery Vapor Generator for Ammonia-Water Mixtures

“…The exergy efficiency of a heat exchanger can be viewed as the net recovered thermal exergy in the cold stream normalized by the available thermal exergy in the hot stream as listed in Equations (13)- (16). Figure 9 shows the exergy efficiencies of pre-heater, evaporator, and superheater for various ammonia concentrations and pressures of working fluid.…”

“…Ammonia and water have similar molecular weights and, thus, traditional design of steam turbines can be employed in the ammonia-water power cycles with only minor modifications. Also, the boiling point of ammonia is substantially lower than that of water, which makes it practically useful to utilize the low-temperature waste heat in the power generation systems [15,16].…”

Exergy Analysis of Absorption Power Cycle Depending on Source Temperatures

“…Ogriseck [14] performed an investigation of the integration of the Kalina cycle process in a combined heat and power generation, while Lolos and Rogdakis [15] investigated Kalina cycle using low-temperature heat sources. Bombarda et al [16] carried out a comparative analysis on thermodynamic performance of Kalina and organic Rankine cycles.…”

Thermoeconomic Analysis and Optimization of a New Combined Supercritical Carbon Dioxide Recompression Brayton/Kalina Cycle

“…Data from the literature are used to verify the models developed for the SCRBC [2] and the KC [28]. For the case of the SCRBC, a validation has been previously reported by the authors [2].…”