YOKOHAMA, JAPAN (May 31, 2011) - Ulvac-RIKO is proud to announce a new breakthrough in renewable energy research - efficiently converting hot water of 90°C into 3 kilowatts (100 V, 30 A) of electricity using a (patented) compact and portable power generation system.
With the world facing global warming and an ever reducing supply of oil resources, there is a clear and present need for new technology research in renewable energy. Furthermore, in light of the recent great east Japan earthquake, the shutdown of thermal and nuclear based power plants has created brand new demands not only for energy efficient technologies, but also for the immediate utilization of brand new, yet untapped alternative sources of energy. Once such source, underutilized but in abundance, is low temperature heat source below 150°C, which commonly exists in the form of waste heat from factories, solar heat, or hot springs. Modern attempts to utilize such heat source is limited scales in the 50+ kilowatts range, and only to sites able to meet restrictive requirements such as high volume heat, large space, expensive upfront costs
§ Abstract of Results
ULVA-RIKO has developed a breakthrough small scale solution to generate 3~12 kilowatts of power from low temperature heat sources below 150°C. This one of a kind system is small enough to fit in a small truck, and its low noise operation makes it the ideal solution to be used at sites previously enable to meet the high requirements posed by existing solutions. The power output of this solution, between 3 to 12 kilowatts, is well capable of meeting the power demands of 5 to 20 average households. By directly converting heat energy into electric energy, this breakthrough technology is aiming to be an integral part of future power demands in our society.
This development project consists of two components, the construction of the Rankine cycle1) based (figure 1) portable power generator system (figure 2), and the power generation tests using hot and cooling water (figure 3). In the example shown, using hot water of 91°C with a flow rate of 43 L/min, at temperature difference of 69?C, the system was able to generate 3.8kW of power output, at a high energy regeneration efficiency of 7.2 %2).
At the heart of the power generator system is the one of a kind, ECcentric Orbiting scroll expander generator (Ecoscroll Expander)3), 4), developed using our proprietary technology. The Ecoscoll Expander is compact, highly efficient with quiet operation, which makes it the ideal solution not only for our power generator system, but also HEV, EV car electric compressor, fuel cell air blowers5), vacuum pumps, and many other purposes.
Parts of this project were made possible by the 2009 and 2010 Local Innovation Research and Development Commission of Kanto Bureau of Economy, Trade and Industry, Richstone Inc., and the joint research efforts with The National Institute of Advanced Industrial Science and Technology.
- Generate electricity from hot water at temperatures of 75~100°C.
- Light and portable. Can be transported by a light truck and deployed with virtually no construction cost.
- Compact size and quiet operation. Can be deployed at sites previous unsuitable for big and noisy machines.
- Scalable depending on heat source to generate a maximum of 12 kW.
§ Application of low temperature heat source
- Factory waste heat
- Automobiles, ships
- Fuel cell
- Hot springs
- Solar heat and others...
Case of compact and portable power generation system between 3 to 6 kW
Body size： W1100 mm x D800 mm x H1400 mm
Body weight： About 200 kg
§ Future Plans
Having realized the viability of its target performance, the system will be field tested for durability, and will be commercially available thereafter.
§ Explanation of technical term
1) Rankine cycle : One process transferring heat energy into mechanical energy by using working medium existing in both liquid and gas phases. Ex.) thermal and nuclear based power plants
2) Energy regeneration efficiency : Ratio of the efficiency power to the input energy.
3) Scroll expander : Composition of a pair of the same spiral pattern, one pattern is fixed and the other is made oscillating movement. Increasing expansion room volume, the gas volume is expanded.
4) ECO scroll expander : Scroll expander by ECcentric Orbiting method [ECcentric Orbiting scroll expander].
5) air blower : Discharge machine of middle pressure between pressure fan and compressor.
Figure 1. Schematic figure of compact and portable power generation system(Rankine cycle)
Figure 2. compact and portable power generation system(test model).
Figure 3. View of electric power examination of compact and portable power generation system.
Table 1. electric power examination test result of compact and portable power generation system.
Max. value of actual performance
Total adiabatic efficiency
Energy regeneration efficiency