The Steam Turbine: The Steam Engine of Maximum Simplicity and of Highest Thermal Efficiency

1901 ◽  
Vol 51 (1307supp) ◽  
pp. 20953-20956
Author(s):  
Robert H. Thurston
Author(s):  
Kazutaka Hayashi ◽  
Hiroyuki Shiraiwa ◽  
Hiroyuki Yamada ◽  
Susumu Nakano ◽  
Kuniyoshi Tsubouchi

A prototype machine for a 150 kW class two-stage radial inflow condensing steam turbine system has been constructed. This turbine system was proposed for use in the bottoming cycle for 2.4 MW class gas engine systems, increasing the total electrical efficiency of the system by more than 2%. The gross power output of the prototype machine on the generator end was 150kW, and the net power output on the grid end which includes electrical consumption of the auxiliaries was 135kW. Then, the total electrical efficiency of the system was increased from 41.6% to 43.9%. The two-stage inflow condensing turbine system was applied to increase output power under the supplied steam conditions from the exhaust heat of the gas engines. This is the first application of the two-stage condensing turbine system for radial inflow steam turbines. The blade profiles of both high- and low-pressure turbines were designed with the consideration that the thrust does not exceed 300 N at the rated rotational speed. Load tests were carried out to demonstrate the performance of the prototype machine and stable output of 150 kW on the generator end was obtained at the rated rotational speed of 51,000 rpm. Measurement results showed that adiabatic efficiency of the high-pressure turbine was less than the design value, and that of the low-pressure turbine was about 80% which was almost the same as the design value. Thrust acting on the generator rotor at the rated output power was lower than 300 N. Despite a lack of high-pressure turbine efficiency, total thermal efficiency was 10.5% and this value would be enough to improve the total thermal efficiency of a distributed power system combined with this turbine system.


1997 ◽  
Vol 119 (4) ◽  
pp. 250-256 ◽  
Author(s):  
H. Jin ◽  
M. Ishida ◽  
M. Kobayashi ◽  
M. Nunokawa

Two operating advanced power plants, a supercritical steam plant and a gas-steam turbine combined cycle, have been analyzed using a methodology of graphical exergy analysis (EUDs). The comparison of two plants, which may provide the detailed information on internal phenomena, points out several inefficient segments in the combined cycle plant: higher exergy loss caused by mixing in the combustor, higher exergy waste from the heat recovery steam generator, and higher exergy loss by inefficiency in the power section, especially in the steam turbine. On the basis of these fundamental features of each plant, we recommend several schemes for improving the thermal efficiency of current advanced power plants.


Author(s):  
M. Stastny ◽  
J. Kucera ◽  
Z. Hrdina ◽  
D. Hanus

The paper deals with the IGCC for brown coal (BC) with simultaneous improvement of the steam cycle by the usage of supercritical steam parameters. Two gasifiers with a fluidized bed are used with outlet syngas temperature about 900°C. Main part of the paper is focused on the arrangement and optimization of the IGCC with net total electrical output 454.7 MW and with supercritical inlet parameters 260 bar, 580°C/600°C of steam turbine. The energy sources for the steam part of the cycle are HRSGs downstream of two gas turbines at 122.6 MW each and two raw gas coolers downstream of two gasifiers. The thermal efficiency of this IGCC is on LHV basis about 49.0%. Utilization of brown coal (BC) energy in described IGCC is by 4.7% higher than in steam power station with the same parameters. This IGCC enables reduction of CO2 emission by around 44% compared with existing power stations with thermal efficiency 34%.


Author(s):  
Mohammad Almajali ◽  
Omar Quran

Abstract This paper deals with aspects of the combined power and power (CPP) plants. Such plants consist of two major parts; the steam turbine and gas turbine plants. This study investigates the efficiency of CPP under the effect of several factors. CPP plants can achieve the highest thermal efficiency obtained with turbomachinery up to date. In this cycle, the anticipated waste thermal energy of the exhaust of gas turbine is used to generate a high pressure steam to empower the steam turbine in the steam cycle. By systematically varying the main design parameters, their influence on the CPP plant can be revealed. A comprehensive parametric study was conducted to measure the influence of the main parameter of the gas and steam cycles on the performance of CPP. The results exhibit that the overall plant thermal efficiency is significantly greater than that of either the two turbines. Due to the high thermal efficiency, a significant reduction in the greenhouse effect can be achieved. It is found that regenerative steam cycle will reduce the overall efficiency of combined cycle. On the other hand, using reheat steam cycle in the CPP plant will lead to an increase in both the thermal efficiency of the plant and the dryness factor of steam at exit of the steam turbine.


1948 ◽  
Vol 158 (1) ◽  
pp. 52-65 ◽  
Author(s):  
G. H. Martin

The advent of the gas turbine and its effect on the position of the steam turbine for the central power station is briefly discussed. In the opinion of the author the steam turbine will hold the field for large power generation for many years to come, and there is no immediate prospect of any other form of prime mover becoming a serious competitor for the generation of electricity in the central power station. Data are given indicating the gain in thermal efficiency that can be expected from increased steam conditions up to 2,000 lb. per sq. in., and 1,000 deg. F. with and without reheating. The advantages of reheating as a means of obtaining higher efficiency are strongly emphasized. Methods of operation to enable quick starting are discussed. Some of the principal constructional problems created by high steam conditions are briefly discussed and methods of overcoming the difficulties are indicated. The essence of the paper is to examine, in as simple a manner as possible, the means available for improving the efficiency of the central power station; and in an effort to achieve this, detailed methods of calculation are not included, as it is considered they would detract from a clear appreciation of the results. The minimum of assumptions have been made, so that the curves represent a true picture of the actual gains that could be obtained in practice.


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