Stirling Engine System Research Articles

Cost Comparison of Constant and Tracking System PV Panels with Stirling Motor-Operated Systems

At the present days, quick consumption of fossil-basic sources and damages that fossil fuels give to environment have caused people to tend towards alternative energy sources. As energy need has been increasing constantly, renewable energy sources are needed in the event that energy bottleneck does not occur in the future. One which is most and easily found among renewable energy sources is solar energy and our country has got high potential in terms of sun potential. On this study, as solar energy potential over world and in Turkey, methods to produce energy from sun and literature information have been mentioned, the relation of cost and efficiency-performance for electric production of sun from past to today has been analyzed,.various stable FV panel systems, sun tracker systems and SMGTS sample designs have been examined. Suggestions to increase yield with electrical basic have been made as cost analysis has been made for SMGTS's with stable and moving FV systems. Consequently, it has been determined that electric production capacity from sun would be increased much more in regions with high temperature average as using intensive solar energy systems such as Stirling engine system which its application is made.

Integration of a wood pellet burner and a Stirling engine to produce residential heat and power

The integration a Stirling engine with a pellet burner is a promising alternative to produce heat and power for residential use. In this context, this study is focused on the experimental evaluation of the integration of a 20 kWth wood pellet burner and a 1 kWe Stirling engine. The thermal power not absorbed by the engine is used to produce hot water. The evaluation highlights the effects of pellet type, combustion chamber length and cycling operation on the Stirling engine temperatures and thermal power absorbed. The results show that the position of the Stirling engine is highly relevant in order to utilize as much as possible of the radiative heat from the burner. Within this study, only a 5 cm distance change between the Stirling engine and the pellet burner could result in an increase of almost 100 °C in the hot side of the engine. However, at a larger distance, the temperature of the hot side is almost unchanged suggesting dominating convective heat transfer from the hot flue gas. Ash accumulation decreases the temperature of the hot side of the engine after some cycles of operation when a commercial pellet burner is integrated. The temperature ratio, which is the relation between the minimum and maximum temperatures of the engine, decreases when using Ø8 mm wood pellets in comparison to Ø6 mm pellets due to higher measured temperatures on the hot side of the engine. Therefore, the amount of heat supplied to the engine is increased for Ø8 mm wood pellets. The effectiveness of the engine regenerator is increased at higher pressures. The relation between temperature of the hot side end and thermal power absorbed by the Stirling engine is nearly linear between 500 °C and 660 °C. Higher pressure inside the Stirling engine has a positive effect on the thermal power output. Both the chemical and thermal losses increase somewhat when integrating a Stirling engine in comparison to a stand-alone boiler for only heat production. The overall efficiency of the pellets fired Stirling engine system reached 72%.

Challenges in Developing a Domestic Solar Thermal Electricity System Using a Stirling Engine

This paper investigates the challenges in developing a domestic scale solar thermal electricity system using a Stirling engine. All the system components, the parabolic troughs, the heat transfer fluid and the Stirling engine are individually analyzed and described. The analysis includes a market survey and performance assessments of the various components. In this paper a mathematical analysis for a gamma type Stirling engine is carried out. The mathematical analysis demonstrates how such a low/medium temperature engine can be developed. The design is based on an atmospheric air as the working fluid. The market survey reveals that low/medium temperature Stirling engines are not currently readily available. The few that are mentioned in literature are still in their development stage. The size of the presently available parabolic troughs is too large for domestic rooftop installations but can be easily installed on industrial rooftops. On the other hand a range of heat transfer fluids suitable for domestic Stirling engine systems are quite readily available from the present market. All these factors present a real challenge for developing a domestic Stirling engine system for generating enough energy to make it feasible to feed into the electricity grid. Some comments are further given in the conclusions’ section of the paper in which the wider implications of the study are discussed in relation with photovoltaic systems.

Simulation, design and thermal analysis of a solar Stirling engine using MATLAB

This paper presents the modeling and simulation fora prototype of the solar-powered Stirling engine working at the low temperature range. A mathematical model for the thermal analysis of the solar-powered low temperature Stirling engine with heat transfer is developed using Matlab program. The model takes into consideration the effect of the absorber temperature on the thermal analysis like as radiation and convection heat transfer between the absorber and the working fluid as well as radiation and convection heat transfer between the lower temperature plate and the working fluid. Hence, the present analysis provides a theoretical guidance for designing and operating of the solar-powered low temperature Stirling engine system, as well as estimating output power from the solar Stirling engine using Matlab program. This study attempts to demonstrate the potential of the low temperature Stirling engine as an option for the prime movers for Photovoltaic tracking systems. The heat source temperature is 40–60°C as the temperature available from the sun directly.

Investigations to Conduct a Study about Possibilities to Use Small Scale Solar Dish Stirling Engine System in Thailand

This research studies the possibilities of generating electricity by using small scale solar dish Stirling engine system in Thailand. A solar dish Stirling engine system was evaluated and designed as prototypes for Thailand. The performance of system for electricity generation was also simulated under Thai climate condition. The results of the study can be structured in two parts. First is testing the existing Stirling engine and second is simulation the electricity generation by solar dish Stirling engine system prototype in Thailand. The existing Stirling engine at the Komplexlabor of the FH – Stralsund University, Germany was tested to understand the characteristics of the operating system. Stirling engine was operated at temperature of about 800 o C in the combustion chamber, being its nominal rotational speed 1,517rpm. Finally, the average Stirling engine efficiency was established in 22%. The results of simulation on solar dish Stirling engine were that the main components for a prototype of a solar dish Stirling engine system in Thailand shall consist of a Stirling engine with a nominal power of 25kW, and a 131 m2 dish concentrator. It can generate electricity about 27,946 kWh/year of electricity under Thai climate condition. During the working process, the heat lost on dish concentrator was 22% and heat lost within the Stirling engine was 60.84%. The system efficiency of this solar dish Stirling engine system was 17%.

A06 30kW級スターリングエンジン発電システムの耐久性評価(スターリングエンジン及び関連要素と応用システム(2))

Woody biomass such as the thinned wood is widely distributed in the mountain-ringed region and the field, and it is difficult economically to collect and to transport it. Therefore, small-scale power generation is suitable in many cases. Development of small-scale power system based on the biomass gasification is under going. But because of so complicated system and high cost, the commercialization is not progressing as expected. Small-scale system which has high thermal efficiency and low cost is requested. So, in this study we develop small-scale power system, in which stirling engine power system is combined with biomass combustion furnace. We aim at high thermal efficiency and low cost of the biomass power system through this development. In this paper, the demonstration plant of 30kW-class stirling engine system using biomass is evaluated about the durability. Especially, secular change of the plant performance and condition of heater tubes are reported.

Finite time thermodynamic analysis and optimization of solar-dish Stirling heat engine with regenerative losses

The present study investigates the performance of the solar-driven Stirling engine system to maximize the power output and thermal efficiency using the non-linearized heat loss model of the solar dish collector and the irreversible cycle model of the Stirling engine. Finite time thermodynamic analysis has been done for combined system to calculate the finite-rate heat transfer, internal heat losses in the regenerator, conductive thermal bridging losses, and finite regeneration process time. The results indicate that exergy efficiency of dish system increases as the effectiveness of regenerator increases but decreases with increase in regenerative time coefficient. It is also found that optimal range of collector temperature and corresponding concentrating ratio are 1000 K~1400 K and 1100~1400, respectively, in order to get maximum value of exergy efficiency. It is reported that the exergy efficiency of this dish system can reach the maximum value when operating temperature and concentrating ratio are 1150 K and 1300, respectively.

Field Test of 30kW-Class Stirling Engine Power Generating System Using Biomass

Woody biomass such as the thinned wood is widely distributed in the mountain-ringed region and the field, and it is difficult economically to collect and to transport it. Therefore, small-scale power generation is suitable in many cases. Development of small-scale power system based on the biomass gasification is under going. But because of so complicated system and high cost, the commercialization is not progressing as expected. Small-scale system which has high thermal efficiency and low cost is requested. So, in this study we develop small-scale power system, in which stirling engine power system is combined with biomass combustion furnace. We aim at high thermal efficiency and low cost of the biomass power system through this development. In this paper, our field tests of a 30kW-class stirling engine is reported. Moreover, the demonstration plant of stirling engine system using biomass is intrduced and typical results of the field test of the plant are reported.

An analysis of beta type Stirling engine with rhombic drive mechanism

Stirling engine system is one of the options for electrifying a remote community not serviceable by the grid, which can operate on energy input in the form of heat. Major hurdle for the wide-spread usage of rhombic drive beta type Stirling engine is complexity of the drive and requirement of tight tolerances for its proper functioning. However, if the operating and geometrical constraints of the system are accounted for, different feasible design options can be identified. In the present work, various aspects that need to be considered at different decision making stages of the design and development of a Stirling engine are addressed. The proposed design methodology can generate and evaluate a range of possible design alternatives which can speed up the decision making process and also provide a clear understanding of the system design considerations. The present work is mainly about the design methodology for beta type Stirling engine and the optimization of phase angle, considering the effect of overlapping volume between compression and expansion spaces. It is also noticed that variation of compression space volume with phase angle remains sinusoidal for any phase difference. The aim of the present work is to find a feasible solution which should lead to a design of a single cylinder, beta type Stirling engine of 1.5 kW e capacity for rural electrification.

A07 30kW級バイオマス利用スターリングエンジン発電システムの性能評価(スターリングエンジン及び関連要素と応用システム(2))

Woody biomass such as the thinned wood is widely distributed in the mountain-ringed region and the field, and it is difficult economically to collect and to transport it. Therefore, small-scale power generator is suitable in many cases. Development of small-scale power system based on the biomass gasification is under going. But because of so complicated system and high cost, the commercialization is not progressing as expected. Small-scale system which has high thermal efficiency and low cost is requested. So, in this study we develop small-scale power system, in which stirling engine power system is combined with biomass combustion furnace. We aim at high thermal efficiency and low cost of the biomass power system through this developement. In this paper, the demonstration plant of 30kW-class stirling engine system using biomass is introduced and typical results of the field test of the plant are reported. Moreover, the possibility of the optimization of the system is reported.

Application of Infra-Free Motherboard (IFM) in a Decentralized Community for a Customized Real-time Processing Multidirectional Energy Supply Network

Decentralized resource management is a promising field as it has the ability to lessen impact on Earth′s climate change, assist with renewable technology development, increase equity in the distribution and consumption of resources, decrease vulnerability and enable participation of local people and businesses in the supply of technologies. Alternative energy and water resources are widely researched to provide self-sufficiency in scales of single houses to communities, but are still limited to demographical, technological, economical and social factors, which vary around the globe. Infra-Free (IF) is an academic research that seeks a synergy between relevant research fields to promote different decentralization scenarios for combined energy and water technologies with best-performance. The Infra-Free Motherboard (IFM) is a proposal for a standardized platform, where installed technologies integrate within a household as robotic systems that evolve into a self-aware artificial platform to provide customized resource management. It addresses a multidirectional, real-time processing artificial resource management system that could develop its own skills by close interaction with the environment and the user. The system is enhanced with algorithms and dynamic systems to provide communication between different co-evolving systems that plug-in, adapt, evaluate and finally, customize themselves to dynamically changing environments due to resource availability, local needs, technology readiness and individual choices. The multidirectional real-time processing system further extends into a community application, where intelligent self-learning systems are aware of the amount and availability of resources in the whole network (community) and control the distribution between subsystems (houses) using best performance principles. Finally, this provides a dynamically transforming community that learns, adapts and redesigns itself. In this paper; at first, we introduce the standardized IFM and modular sub-system architecture. Next, we describe the hardware (platform) and software (self-learning process) architecture for the purpose to realize a customized real-time energy management system in a community of interconnected houses with a special focus on energy equation strategies. Next, we study a scenario to apply IFM in a small-scale community (100 people) in Masdar in 2012; integrated with a plug-in car concept, CO2recycle, evaporative cooling and Stirling engine system. Finally, we analyze the energy equalization potential of IFM in a computer simulation for a 6-household cluster (25 people).

New technology for coalbed methane power generation based on Stirling engine driven by porous burner

The development of coalbed methane (CBM) power generation is restricted by the gas source instability. The existing technologies such as steam turbine, gas turbine, and gas engine are not suitable for the instability. So a new technology of CBM power generation is put forward which is a Stirling engine system driven by porous burner. The Stirling engine is an external-combustion engine and its working fluid is not involved in combustion. Stirling engine works as long as heat supply is guaranteed, and therefore it is not conditioned by the gas source instability in itself. Porous burner is a premixed combustion technology in porous medium based on the excess enthalpy combustion. The porous medium is characteristic of the strong heat storage capability and the small combustion pore diameter, and accordingly it adapts well to the gas source instability. So the new CBM power generation technology, which combines the external-combustion distinction of Stirling engine and well adaptability to the gas source instability of porous burner, will agree with the coalbed gas source instability.

Multiphase Stirling Engines

Analysis, design, fabrication, and experimental assessment of a symmetric three-phase free-piston Stirling engine system is discussed in this paper. The system is designed to operate with moderate-temperature heat input that is consistent with solar-thermal collectors. Diaphragm pistons and nylon flexures are considered for this prototype to eliminate surface friction and to provide appropriate seals. In addition, low loss diaphragm pistons, etched and woven-wire screen heat exchangers, and plastic flexures, as the main components of the system, are outlined. The experimental results are presented and compared with design analysis. Experiments successfully confirm the design models for heat exchanger flow friction losses and gas spring hysteresis dissipation. Furthermore, it is revealed that gas spring hysteresis loss is an important dissipation phenomenon for low-power Stirling engines and should be carefully addressed in design. Analysis shows that the gas hysteresis dissipation is reduced drastically by increasing the number of phases in a multiphase Stirling engine system. It is further shown that for an even number of phases, half of the engine chambers could be eliminated by utilizing a reversing mechanism within the multiphase system. The mathematical formulation and modal analysis of multiphase Stirling engine system are then extended to a system that incorporates a reverser. By introducing a reverser to the fabricated prototype, the system successfully operates in engine mode. The system proves its self-starting capability and validates the computed start-up temperature.

A plausible forecast of the energy and emissions performance of mature-technology Stirling engine residential cogeneration systems in Canada

Building performance simulation has been used to provide a plausible estimate of the operational performance that could be expected from a mature-technology version of a Stirling engine (SE) residential cogeneration system. This was accomplished by applying lessons learned from investigating the actual performance of a prototype SE system. Simulation results show that if this mature technology system were to be applied in a single detached house with average heat demand in the province of Ontario, it would reduce both GHG and NOx emissions and would have lower primary energy input, even in comparison to a reference system consisting of the best available technology for a condensing forced-air furnace and a high-efficient water heater, and the most efficient fossil-fuels based central power production technology (natural gas fired combined cycle). It must therefore be concluded that the mature technology SE system has real potential to improve efficiencies and reduce emissions in Ontario.

Exergy analysis of the woody biomass Stirling engine and PEM-FC combined system with exhaust heat reforming

The woody biomass Stirling engine (WB-SEG) is an external combustion engine that outputs high-temperature exhaust gases. It is necessary to improve the exergy efficiency of WB-SEG from the viewpoint of energy cascade utilization. So, a combined system that uses the exhaust heat of WB-SEG for the steam reforming of city gas and that supplies the produced reformed gas to a proton exchange membrane fuel cell (PEM-FC) is proposed. The energy flow and the exergy flow were analyzed for each WB-SEG, PEM-FC, and WB-SEG/PEM-FC combined system. Exhaust heat recovery to preheat fuel and combustion air was investigated in each system. As a result, (a) improvement of the heat exchange performance of the woody biomass combustion gas and engine is observed, (b) reduction in difference in the reaction temperature of each unit, and (c) removal of rapid temperature change of reformed gas are required in order to reduce exergy loss of the system. The exergy efficiency of the WB-SEG/PEM-FC combined system is superior to EM-FC.

21503 多段式スターリングエンジンを用いた内航船舶用排熱回収システムの性能特性(船舶の環境関連技術の新しい展開(1),OS.14 船舶の環境関連技術の新しい展開,学術講演)

When a freight ship is in a harbor, a Diesel engine generator is operated to supply electric energy in the ship. Exhaust gas from the Diesel engine causes air pollution in the harbor area. We have tried to develop a heat recovery system with a Stirling engine generator. In this paper, we report the performance of a Stirling engine system. Three Prototype Stirling engines were operated with the exhaust gas from a Diesel engine, and got generated power of 1.3 kW with the temperature of the exhaust gas of 400 C.

Thermal Model of the EuroDish Solar Stirling Engine

One parabolic dish—Stirling engine system—has been in operation at the Engineering School of Seville since March 2004. The unit, based on the Eurodish system, is one of the several Country Reference Units of the EnviroDish project. The system has achieved a maximum thermal efficiency (solar to electricity) close to 20% during operation. The analysis of the different parameters suggests a high potential for improvement. A thermal model of the main components of the engine package (cavity, receiver, and Stirling engine) can help to evaluate possible modifications of the system and identify the most promising ones. The development of such a thermal model and its comparison with experimental data gathered during this period are reported in this work. Model results exhibit a good qualitative agreement with the available measurements. However, the validation of the model will require measuring more parameters at the cavity, receiver, and engine.

Fuel and emissions properties of Stirling engine operated with wood powder

From viewpoints of the environment and fuel cost reduction, small-scale biomass combined heat and power (CHP) plants are in demand, especially wood-waste fueled system, which are simple to operate and maintenance-free with high thermal efficiency similar to oil fired units. These are requested by wood and other industries located in mountainous region. To meet these requirements, a Stirling engine CHP system combined with simplified biomass combustion process with pulverized wood powder was developed. In an R&D project started in 2004 considering wood powder properties as a fuel, combustion performance and emissions in combustion flue gas were tested using combustion test apparatus with commercial size units. The wood powder combustion system was modified and optimized during the combustion test results, and the design of the demonstration plant combined with 55 kW e Stirling engine power unit was considered. The demonstration plant was finally completed in March of 2006, and test operation has been progressed for the future commercial CHP system. In the wood powder combustion test, wood powder of less than 500 μm is mainly used, and a combustion chamber length of 3 m is applied. In these conditions, the air ratio can be reduced to 1.1 without increasing CO emission of less than 10 ppm and combustion efficiency of 99.9%. In the same conditions, NO x emission is estimated to be less than 120 ppm (6% O 2 basis). Wood powder was confirmed to have excellent properties as a fuel for Stirling engine CHP system. This paper summarizes the wood powder combustion test, and presents the evaluation of the burner design parameters for the biomass Stirling engine system.

多種熱源に対応したスターリングエンジンの開発(スターリングエンジン及び関連要素と応用システム(1))

多種熱源に対応したスターリングエンジンの開発(スターリングエンジン及び関連要素と応用システム(1))

Submarine Power Systems Using the V4-275R Stirling Engine

The Stirling power module V4-275R, integrated with a liquid oxygen system, is currently built for submarines for the Royal Swedish Navy and for the offshore company Comex in France. Since mid 1985 the Stirling engine system for the Swedish Navy has been successfully tested in a full-scale submarine test section. The next step in this programme will be an integration of the Stirling system into an operational Swedish submarine. A contract has been signed having Kockums as the main contractor. The French programme means a 500 ton manned diver lock-out submarine, the SAGA I, which is under final construction at Comex in Marseille. The energy system for the SAGA submarine consists of two V4–275R Stirling engines of maximum 100 kW power each. The oxygen storage, manufactured by AGA Cryo in Gothenburg, consists of two liquid oxygen tanks providing a total capacity of 10000 kWh, allowing the submarine to perform missions of up to 14 days submerged.