Ulrich Orth

Design and Operational Aspects of Gas and Steam Turbines for the Novel Solar Hybrid Combined Cycle SHCC

Solar hybrid power plants are characterized by a combination of heat input both of high temperature solar heat and heat from combustion of gaseous or liquid fuel which enables to supply the electricity market according to its requirements and to utilize the limited and high grade natural resources economically. The SHCC® power plant concept integrates the high temperature solar heat into the gas turbine process and in addition — depending on the scheme of the process cycle — downstream into the steam cycle. The feed-in of solar heat into the gas turbine is carried out between compressor outlet and combustor inlet either by direct solar thermal heating of the pressurized air inside the receivers of the solar tower or by indirectly heating via interconnection of a heat transfer fluid. Thus, high shares of solar heat input referring to the total heat input of more than 60% in design point can be achieved. Besides low consumption of fossil fuels and high efficiency, the SHCC® concept is aimed for a permanent availability of the power plant capacity due to the possible substitution of solar heat by combustion heat during periods without sufficient solar irradiation. In consequence, no additional standby capacity is necessary. SHCC® can be conducted with today’s power plant and solar technology. One of the possible variants has already been demonstrated in the test field PSA in Spain using a small capacity gas turbine with location in the head of the solar tower for direct heating of the combustion air. However, the authors present and analyze also alternative concepts for power plants of higher capacity. Of course, the gas turbine needs a design which enables the external heating of the combustion air. Today only a few types of gas turbines are available for SHCC® demonstration. But these gas turbines were not designed for solar hybrid application at all. Thus, the autors present finally some reflections on gas turbine parameters and their consequences for SHCC® as basis for evaluation of potentials of SHCC® .Copyright

Surface Temperature Measurements in an Industrial Gas Turbine Using Thermal History Paints

The measurement of surface temperatures of hot-gas path components of gas turbines under operating conditions provides a considerable challenge because the complexity of measurements under the prevailing conditions is substantial. The results from temperature measurements from an engine test using Thermal History Paint (THP) are presented here. The sensor material in the THP is an oxide ceramic which is doped with lanthanide ions to make the material luminescent. The properties of the luminescence depend on the temperature of exposure. The paper describes the first application of this technology in an extended, rather than dedicated, engine test in which components in both the hot gas path and the secondary air system were coated with THP. During the test campaign the engine components operated below maximum temperature for extended periods of time, which required a novel approach to the calibration of the paint. An overview over the correspondence between the temperatures measured with the THP, thermal paints and CFD calculations is provided for a sideplate and turbine blade. There is very good correlation between the results of the different methods. For the sideplate, the temperature measured with the THP was within 10K of the CFD calculation. Furthermore, the THP exhibited only minor erosion damage after over 50 hours of engine testing. The high durability and measurement accuracy demonstrate the feasibility of using the THP in extended engine tests.

Combustion System Development and Testing for MAN’s New Industrial Gas Turbines MGT 6100 and MGT 6200

This paper describes the development and test results of the low emission combustion system for the new industrial gas turbines in the 6–7 MW class from MAN Diesel & Turbo.The design of a robust combustion system and the achievement of very low emission targets were the most important design goals of the combustor development.During the design phase, the analysis of the combustor (i.e. burner design, air distribution, liner cooling design) was supported with different CFD tools.This advanced Dry Low Emission can combustion system (ACC) consists of 6 cans mounted externally on the gas turbine.The behavior and performance of a single can sector was tested over a wide load range and with different boundary conditions; first on an atmospheric test rig and later on a high pressure test rig with extensive instrumentation to ensure an efficient test campaign and accurate data.The atmospheric tests showed a very good performance for all combustor parts and promising results. The high pressure tests demonstrated very stable behavior at all operation modes and very low emissions to satisfy stringent environmental requirements.The whole operation concept of the combustion system was tested first on the single-can high pressure test bed and later on twin and single shaft gas turbines at MAN’s gas turbine test facility. During the engine tests, the can combustors demonstrated the expected combustion performance under real operation conditions.All emissions and performance targets were fully achieved. On the single shaft engine, the combustors were running with single digit ppm NOx levels between 50% and 100% load.The validation phase and further optimization of the gas turbines and the engine components are ongoing.The highlights of the development process and results of the combustor and engine tests will be presented and discussed within this paper.Copyright

MAN’s New Gas Turbines for Mechanical Drive and Power Generation Applications

MAN Diesel & Turbo recently developed a completely new gas turbine family for the first time in its history. The first product line contains both two-shaft and single-shaft gas turbines in the 6 – 7 MW class. The two-shaft engine was thoroughly tested at MAN’s gas turbine test center, and the first engine has been delivered to a launch customer. For MAN, it constitutes a technology platform that will produce further developments and new models in the coming years.The two-shaft design makes the new gas turbine an ideal mechanical drive for both turbo compressors and pumps. This gas turbine operates to suit the optimum duty point of the driven machine; both in a wide speed and power range. The two stage power turbine design allows for a wide speed range of 45 to 105% while maintaining high efficiency. For power generation a single-shaft version has been created by adding one additional stage to the two stage high pressure turbine. The compressor pressure ratio is 15, which is high enough for achieving the highest potential efficiency for both generator and compressor drive applications. Low pollutant emission levels are achieved with MAN’s DLN combustion technology. The gas turbine exhaust temperature is sufficiently high to reach high heat recovery rates in combined heat and power cycles. Another important feature of the new gas turbine is its unrestricted suitability for taking load quickly and rapid load changes.Service costs have also been significantly improved upon. MAN opted for a sturdy and modular gas turbine construction, while not compromising on efficiency. The objective is to extend service life and shorten down time occurrences. The modular package assembly process helps to reduce routine maintenance and repair time, and ultimately package downtime.Copyright

Component Testing and Prototype Commissioning of MAN’s New Gas Turbine in the 6 MW-Class

MAN Diesel & Turbo has developed a new gas turbine in the 6 MW-class for both mechanical drive and power generation applications. The lay-out of the Gas Turbine has been driven by opportunities in current and future markets and the positioning of the competition, and this has determined the characteristics and technical parameters which have been optimized in the 6 MW design.The design makes use of extremely high precision engineering so that the assembly of sub components to modules is a smooth flowing process and can guarantee both the high standards in quality and performance which MAN Diesel & Turbo is aiming for. Individual components have been tested and thoroughly validated. These tests include in particular the compressor of the gas turbine and the combustion chamber.The commissioning of the gas turbine prototype engine had been prepared with a numerous number of measuring probes and carried out at the Oberhausen plant gas turbine test field. Results of component and the gas turbine prototype tests will be presented and discussed.Copyright