15:40
Operational experience II
Chair: Ing. Claudio Spadacini
15:40
20 mins
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ORC PERFORMANCE RATING PROCEDURES AND EQUIPMENT CERTIFICATION
Joost Brasz
Abstract: Potential ORC customers are faced with choosing from an increasing number of equipment manufacturers. Comparing the relative merit of various product offerings is difficult since ORC thermal efficiency and the amount of power being generated are heavily dependent on heat source and heat sink temperature and capacity. To allow an easy comparison between various ORC products the performance data provided by manufacturers should be certified by an independent entity, based on identical and well-defined heat source and heat sink conditions and follow qualified testing methods, specifying maximum allowable measurement deviations. Off-design performance of ORC systems is also critical since the daily and seasonal fluctuations in ambient conditions affect heat sink temperature levels causing large variations in ORC output power.
The air-conditioning industry faced similar problems in the second half of the last century. Like ORC behavior, air-conditioning performance also strongly depends on outdoor weather conditions as well as indoor cooling demands. To allow a fair comparison of competing product offerings the HVAC equipment manufacturers have formed the American Heating and Refrigeration Institute (AHRI). Through the use of industry standards and voluntary participation in AHRI's certification programs, consumers are assured manufacturers' performance claims are accurate and rated uniformly, enabling meaningful comparisons. AHRI provides access to its standards and guidelines, as well as information about how they are developed and advanced globally.
After reviewing some of the performance rating and certification programs that were implemented by AHRI to help the HVAC industry through self-regulation, the paper will focus on potential testing procedures and test conditions to be included in a future standard for ORC equipment qualification.
The objective of this presentation is to see whether there is interest within the ORC community for an independent organization with the authority to certify the performance claims by various manufacturers.
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16:00
20 mins
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OREGEN™ WASTE HEAT RECOVERY CYCLE: DEVELOPMENT AND APPLICATIONS
Matteo Dall'Ara, Matteo Berti, Andrea Burrato, Alberto Scotti Del Greco, Paolo Del Turco
Abstract: The current energy market is pushing to promote the development of more efficient ways of exploitation of energy sources available, achieving at the same time an overall plant reduction in CO2 emissions. This, coupled to the fact that some countries are pushing for emission regulations up to the introduction of carbon taxes, is fostering the interest in increased efficiency embedded in the waste heat recovery systems.
The traditional Rankine Cycle with water/steam has limitations that make difficult its application in systems where the load of the gas turbine over time is variable or where water is not available, or where the temperature of the waste heat source is low.
The ORegen™, Organic Rankine Cycle developed by GE, is a double closed loop system that overcomes the limitations described above. The system is capable of recovering waste heat from gas turbines also operating at load that may vary dramatically over time (like in mechanical drive application) or located in areas where the water is not at hand. The core of the system is a family of high efficiency double stage turbo-expanders, covering the power range up to 17MW.
This article describes the ORegen™ recovery cycle and the design and development of turbo expanders, including the experimental test campaign performed on the Inlet Guide Vane mechanism to validate the positioning accuracy. The most relevant aspects of the first unit commissioning and testing are also given.
Finally, a business case study and the future development for the ORegen™ cycle that demonstrate perspectives for spreading waste heat recovery to new fields of application are presented.
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16:20
20 mins
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FIELD OPERATIONAL ANALYSIS OF AN EXISTING SMALL SIZE BIOMASS-FIRED ORC UNIT
Michel Noussan, Giulio Cerino Abdin, Alberto Poggio, Roberta Roberto
Abstract: The current paper presents the operation analysis of a small size ORC system fired with wood residuals. The system consists of two ORC units of a nominal electric power of 125 kW each, and the available heat is used for the supply of a small district heating network. The results of the field monitoring over almost two years provide information about the system behaviour under different conditions, providing the possibility to correlate different parameters.
Field tests are essential in order to underline some aspects that are usually not taken into account during the design process and the system simulations (e.g. failures, variable environmental conditions, variable fuel properties, etc...).
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16:40
20 mins
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WASTE HEAT RECOVERY VIA ORGANIC RANKINE CYCLE: RESULTS OF A ERA-SME TECHNOLOGY TRANSFER PROJECT
Bruno Vanslambrouck, Sergei Gusev, Tobias Erhart, Michel De Paepe, Martijn van den Broek
Abstract: The main goal of the EraSME project “Waste heat recovery via an Organic Rankine Cycle”, completed by partners Howest (Belgium), Ghent University (Belgium) and University of Applied Sciences Stuttgart (Germany) between 1 January 2010 and 31 December 2012, was to find an entrance in Flanders for the Organic Rankine Cycle (ORC) technology in applications with sufficient amounts of waste heat at high enough temperatures. The project was preceded by a similar study that focused on renewable energy sources.
Several tools were developed to aid in the viability assessment, the selection, and the sizing of ORC installations. With these methods, a fast determination of feasibility is possible. The outcome is based on the size, nature and temperature of the waste heat stream as well as the electricity price. An estimate can be given of the net power output, the investment costs and the economic feasibility. The tool is linked to a database of ORC manufacturer specifications.
Another objective of the project was to keep track of the evolution in ORC market supply, both commercial and precommercial. We also looked beyond the product line of the main manufacturers. Some ORCs are developed for specific applications.
ORC technology was benchmarked against alternatives for waste heat recovery, such as: steam turbines, heat pumps and absorption cooling. ORC in or as a combined heat and power (CHP) system was also examined.
A laboratory test unit of 10kWe nominal power was installed during the project, which is now used in further research on dynamic behavior and control. It is still the only ORC demonstration unit in Flanders and has been very instructive in introducing representatives from industry, researchers and students to the technology.
A considerable part of the project execution consisted of case studies in response to industrial requests from several sectors. Detailed and concrete feasibility studies allowed us to define the current application area of waste heat recovery ORC in a better way. A knowledge center for waste heat recovery (www.wasteheat.eu) was initiated to consolidate the know-how and to advise potential users.
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