Multiphase Free-Piston Stirling Engine for Solar-Thermal-Electric Power Generation Applications

Due to their high relative cost, solar-electric energy systems have yet to be exploited on a widespread basis. It is believed in the energy community that a technology similar to photovoltaics, but offered at about $1/W, would lead to widespread deployment at residential and commercial sites. This paper addresses the feasibility study of a low-cost solar-thermal electricity generation technology, suitable for distributed deployment. Specifically, we discuss a system based on nonimaging solar concentrators, integrated with free-piston Stirling engine devices incorporating integrated electric generation. We target concentrator collector operation at moderate temperatures, in the range of 120°C to 150°C. This temperature range is consistent with the use of optical concentrators with low-concentration ratios, wide angles of radiation acceptance which are compatible with no diurnal tracking and no or only a few seasonal adjustments. Therefore, costs and reliability hazards associated with tracking hardware systems are avoided. This paper further outlines the design, fabrication, and test results of a single-phase free-piston Stirling engine prototype. A very low loss resonant displacer piston is designed for the system using a very linear magnetic spring. The power piston, which is not mechanically linked to the displacer piston, forms a mass-spring resonating subsystem with the gas spring, and has a resonant frequency matched to that of the displacer. The design of heat exchangers is discussed, with an emphasis on their low fluid friction losses. Only standard low-cost materials and manufacturing methods are required to realize such a machine. The fabricated engine prototype is successfully tested as an engine, and the experimental results are presented and discussed. Extensive experimentation on individual component subsystems confirms the theoretical models and design considerations. Based on the experimental results and the verified component models, an appropriately dimensioned Stirling engine candidate is discussed.

Download Full-text

Low-cost distributed solar-thermal-electric power generation

10.1117/12.509785 ◽

2004 ◽

Cited By ~ 3

Author(s):

Artin Der Minassians ◽

Konrad H. Aschenbach ◽

Seth R. Sanders

Keyword(s):

Power Generation ◽

Electric Power ◽

Low Cost ◽

Solar Thermal ◽

Electric Power Generation

Download Full-text

Optimization of the Midterm Electricity Generation Mix Considering the Effects of Water, Land and Carbon Footprints

10.29007/vpvk ◽

2018 ◽

Author(s):

Mohsen Bozorg ◽

Hamed Mazandarani Zadeh ◽

Dragan Savic

Keyword(s):

Power Generation ◽

Power Consumption ◽

Electric Power ◽

Electricity Generation ◽

Optimization Problem ◽

Solar Thermal ◽

Series Data ◽

Electric Power Generation ◽

Advantages And Disadvantages ◽

Generation Capacity

Electric energy plays a key role in the development of modern societies. Each of the electric power generation technologies (e.g., hydroelectric, wind, solar, thermal, etc.) has some advantages and disadvantages with respect to the fundamental resource indicators, including water footprint, land footprint, carbon footprint, as well as electricity generation costs. Due to the shortage and frequent crisis associated with the above resources, optimal selection of the mix of electricity generation technologies is very important and the share of each technology in the capacity expansion of the generation system must be carefully defined. Iran is in an arid and semi-arid region, with less than one third of the average world precipitation. Moreover, the available water resources are restricted due to the water crises in the Middle-East region. In this paper, we first estimated the peak power consumption of Iran in 2024, based on the time-series data from 2004 to 2014. Then, we formulated an optimization problem to find the share of each electric power generation technology to cover the required extra generation capacity for supplying the power consumption in the target year 2024, considering the effect of the four aforementioned performance indicators. The optimization problem is solved using Genetic Algorithm. Numerical results show that in the target year, 20 GW of electricity should be added to the generation capacity. The results also show that, solar thermal and solar photovoltaic are the best electric generation technologies regarding the available resources.

Download Full-text

Biogas-fuelled Stirling engine for electric power generation

E3S Web of Conferences ◽

10.1051/e3sconf/20186702015 ◽

2018 ◽

Vol 67 ◽

pp. 02015

Author(s):

Ardiyansyah Yatim ◽

Ade Luthfi ◽

Raden Chemilo

Keyword(s):

Power Generation ◽

Electric Power ◽

Combustion Engine ◽

Combustion Process ◽

Stirling Engine ◽

Hot Water ◽

Electric Power Generation ◽

Fuel Distribution ◽

Local Farm ◽

External Combustion

The Stirling engine is an external combustion where the fuel combustion process takes place outside the cylinder. It offers flexibility of fuel used for the power generation, hence is a potential substitute to fossil fuelled internal combustion engine and contribute toward more sustainable power generation. In this study a Gamma V2-6 Stirling engine is used in a biogasfuelled power generation system. The engine has maximum capacity of 10kW. The required fuel input is 60,000BTU/hr or equivalent to 17 kW. The fuel is a biogas which comes from a biodigester. The system requires constant heat from the combustion chamber, hence a novel fuel distribution control is introduced. A specific burner is also designed to fulfil the purpose. In this study, a biogasfueled Stirling engine for electric power generation is designed and developed. The system has 5 kW capacity fuelled by 165 kg/day solid waste (biowaste) from local farm. The biodigester needed is 20 m3. Based on empirical model, the estimated energy efficiency of the system is 36%. In addition, the system offers potential utilization of hot water as by side product.

Download Full-text