Study and Design of Heat Recovery Steam Generators

Author(s):  
S. Vedanth

In the modern scenario of energy systems, we see that the efficiency of the modern day power plants attain a maximum possible limit of 40%–50% in most cases. This is a result of the wastage’s that are prevalent in the systems in the form of heat loss, friction losses due to flow in pipes and flow in other units. The modern day power plants employ the Heat Recovery Steam Generators ( HRSG) which help in converting the waste heat coming out of the turbine into useful work, thus increasing the overall efficiency of the plant. The application of Gas turbine generator (GT) based co-Generation power plants as a part of the industrial plants is on the rise. These plants are required to meet the industrial plants power and steam demand with variations associated with it. This paper deals with the study of a versatile industrial HRSG with specifications in order to support the design. The study and design is based on the design and production unit “Babcock Borsig power systems”, Chennai, India. The paper focuses on the Heat recovery Steam Generator design inclusive of selecting the parameters like pressure of steam, velocity of fluids at different stages with respect to the conditions, material selection etc. The design of HRSG involves primary inputs such as the Engineering Flow diagrams, Arrangement of Equipment’s at proper elevation and Engineering data (Specifications). The considerations of line sizing with respect to pressure drop, Net positive Suction Head, Pipe line erosion, Water Hammer and noise are taken into account. A well-specified and designed HRSG can substantially help the Industrial Co-Generation plant to meet the demand variation and imbalances without sacrificing the reliability of operation. The study is an important contribution to the exponentially rising population and hence the energy demands in the world.

Author(s):  
Antonio Agresta ◽  
Antonella Ingenito ◽  
Roberto Andriani ◽  
Fausto Gamma

Following the increasing interest of aero-naval industry to design and build systems that might provide fuel and energy savings, this study wants to point out the possibility to produce an increase in the power output from the prime mover propulsion systems of aircrafts. The complexity of using steam heat recovery systems, as well as the lower expected cycle efficiencies, temperature limitations, toxicity, material compatibilities, and/or costs of organic fluids in Rankine cycle power systems, precludes their consideration as a solution to power improvement for this application in turboprop engines. The power improvement system must also comply with the space constraints inherent with onboard power plants, as well as the interest to be economical with respect to the cost of the power recovery system compared to the fuel that can be saved per flight exercise. A waste heat recovery application of the CO2 supercritical cycle will culminate in the sizing of the major components.


Author(s):  
E. Hamid ◽  
M. Newby ◽  
P. Pilidis

One of the key elements of increasing the thermal efficiency of a combined cycle power plant (CCPP) is to improve the design and operation of the heat recovery steam generators (HRSG) utilized in the cycle. Once-through steam generator (OTSG) is a new technology introduced for heat recovery in power systems. It eliminates boiler drums and other components of conventional HRSGs. The simplicity and compactness of an OTSG justifies its application in combined cycle power plants. This paper describes a design principle and an analytical sizing approach that will assist OTSG’s designers to achieve a good design by determining the core dimension, volume of an OTSG for given flow rates and their entering and leaving temperatures as well as the heat transfer area on the smoke side. The developed model has been tested with reference to a scaled model of an existing OTSG that is installed at Manx Electricity Authority and the results were promising. The overall characteristics of heat transfer and pressure drop distributions of the OTSG “scaled model” shows general agreement with the real characteristics of the existing OTSG with error values less than 1%.


2019 ◽  
Vol 150 ◽  
pp. 200-209 ◽  
Author(s):  
Min Yan ◽  
Chunyuan Ma ◽  
Qiuwan Shen ◽  
Zhanlong Song ◽  
Jingcai Chang

Author(s):  
W. V. Hambleton

This paper represents a study of the overall problems encountered in large gas turbine exhaust heat recovery systems. A number of specific installations are described, including systems recovering heat in other than the conventional form of steam generation.


Author(s):  
Akber Pasha

In recent years the combined cycle has become a very attractive power plant arrangement because of its high cycle efficiency, short order-to-on-line time and flexibility in the sizing when compared to conventional steam power plants. However, optimization of the cycle and selection of combined cycle equipment has become more complex because the three major components, Gas Turbine, Heat Recovery Steam Generator and Steam Turbine, are often designed and built by different manufacturers. Heat Recovery Steam Generators are classified into two major categories — 1) Natural Circulation and 2) Forced Circulation. Both circulation designs have certain advantages, disadvantages and limitations. This paper analyzes various factors including; availability, start-up, gas turbine exhaust conditions, reliability, space requirements, etc., which are affected by the type of circulation and which in turn affect the design, price and performance of the Heat Recovery Steam Generator. Modern trends around the world are discussed and conclusions are drawn as to the best type of circulation for a Heat Recovery Steam Generator for combined cycle application.


2013 ◽  
Vol 597 ◽  
pp. 45-50
Author(s):  
Sławomir Smoleń ◽  
Hendrik Boertz

One of the key challenges on the area of energy engineering is the system development for increasing the efficiency of primary energy conversion and use. An effective and important measure suitable for improving efficiencies of existing applications and allowing the extraction of energy from previously unsuitable sources is the Organic Rankine Cycle. Applications based on this cycle allow the use of low temperature energy sources such as waste heat from industrial applications, geothermal sources, biomass, fired power plants and micro combined heat and power systems.Working fluid selection is a major step in designing heat recovery systems based on the Organic Rankine Cycle. Within the framework of the previous original study a special tool has been elaborated in order to compare the influence of different working fluids on performance of an ORC heat recovery power plant installation. A database of a number of organic fluids has been developed. The elaborated tool should create a support by choosing an optimal working fluid for special applications and become a part of a bigger optimization procedure by different frame conditions. The main sorting criterion for the fluids is the system efficiency (resulting from the thermo-physical characteristics) and beyond that the date base contains additional information and criteria, which have to be taken into account, like environmental characteristics for safety and practical considerations.The presented work focuses on the calculation and optimization procedure related to the coupling heat source – ORC cycle. This interface is (or can be) a big source of energy but especially exergy losses. That is why the optimization of the heat transfer between the heat source and the process is (besides the ORC efficiency) of essential importance for the total system efficiency.Within the presented work the general calculation approach and some representative calculation results have been given. This procedure is a part of a complex procedure and program for Working Fluid Selection for Organic Rankine Cycle Applied to Heat Recovery Systems.


2015 ◽  
Vol 36 (3) ◽  
pp. 25-48 ◽  
Author(s):  
Tomasz Kowalczyk ◽  
Paweł Ziółkowski ◽  
Janusz Badur

Abstract The conversion of a waste heat energy to electricity is now becoming one of the key points to improve the energy efficiency in a process engineering. However, large losses of a low-temperature thermal energy are also present in power engineering. One of such sources of waste heat in power plants are exhaust gases at the outlet of boilers. Through usage of a waste heat regeneration system it is possible to attain a heat rate of approximately 200 MWth, under about 90 °C, for a supercritical power block of 900 MWel fuelled by a lignite. In the article, we propose to use the waste heat to improve thermal efficiency of the Szewalski binary vapour cycle. The Szewalski binary vapour cycle provides steam as the working fluid in a high temperature part of the cycle, while another fluid – organic working fluid – as the working substance substituting conventional steam over the temperature range represented by the low pressure steam expansion. In order to define in detail the efficiency of energy conversion at various stages of the proposed cycle the exergy analysis was performed. The steam cycle for reference conditions, the Szewalski binary vapour cycle as well as the Szewalski hierarchic vapour cycle cooperating with a system of waste heat recovery have been comprised.


Sign in / Sign up

Export Citation Format

Share Document