The utilization of waste heat energy has become all attractive attention from the viewpoint of energy security. Many research and development of stirling engine have been carried out as an one of most effective way in recent year. In this study, the development of a thermodynamic model for α type stirling engine which has two control volumes and is considered a heat exchange in the flow passage between both volumes has been down. It has been possible to analyze detail engine performance and heat transfer performance.

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The pressure drop and heat transfer in the regenerator channel were investigated numerically and experimentally. FLUENT, CFD software, was used for the numerical work. The pressure drop calculated was coincident well with the analytical solution over all range investigated. The pressure drop measured took about one half of analytical value for lower reciprocal frequency where acceleration term negligible and approached to the analytical value for high frequency. There remain problems when the heat transfer coefficient is defined by average heat flux divided by the average temperature difference between the channel wall and the fluid.

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In this paper, it is reported that the study of the energy system which is complete independence with power supply using the Stirling engine. This system uses burning wooden biomass as a heat source and uses alpha+ type low temperature difference Stirling engine as electrical power generatioh. The heat obtained from the wooden biomass boiler is used for room heating, hot water supply, cooking heater and so on, using heat as much as possible. And a part of the heat is used for the generation of electricity by the Stirling engine. And the electricity is covered with solar panel and a battery especially in the summer.

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The volume variations of Stirling engines depend on the designs of piston drive mechanisms. A good design of the piston drive mechanism should yield such volume variations that are close to the ideal ones to make the indicated work as large as possible. In the present study, the effects on the P-V diagram of the Stirling engine are firstly separated by using the iVV cycle which has ideal volume variations, and then the P-V diagrams and indicated works yielded, respectively, by two different piston drive mechanisms are compared with those of the iVV cycle to show the characteristics of these mechanisms.

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This paper describes the external combustion engine (named KAIHO II) which improved KAIHO I engine reported in the symposium in last year. KAIHO II is composed of a pair of engines with different function. The first one has two roles ofgenetating pressure difference between heater and cooler and output simultaneously, which is named "pressure difference generator". The other is ordinary power piston. Present engine is set up by couple of KAIHO II engines, whereby the plate heat exchanger is applicable . The theoretical performance of KAIHO II was examined comparing with that of KAIHO I, as a result, it is shown that the former thermal efficiency is about 1.8 times the latter, and the output become large about 1.3〜1.4. Further, the goal of output is 20kW at initial gas pressure=2MPa, T_h=300℃. Manufacture of the engine is in progress and test operation is started in the near future.

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From a viewpoint of energy saving and environmental problem, a LNG fueled ship is noticed in the marine fleld. The LNG (Liquid Natural Gas) is needed to vaporize in the ship. In order to develop the energy saving equipment for the LNG fueled ship, we have discussed to apply a Stirling engine generator system using latent heat of LNG, which has -160 degrees centigrade. In this paper, we discuss about the cold energy used Stirling engine, and calculate the engine performance with an isothermal simulation model.

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From a viewpoint of energy saving and environmental problem, a waste heat recovery system is noticed and developed in industrial and marine fields. We have tried to develop a marine heat recovery system with a 3 kWe Stirling engine generator, and installed it to an electric propulsion ship in 2011. In this paper, we discuss a new-type heat recovery system using the Stirling engine generator and thermoelectricity generating modules to have more high performance system.

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In this laboratory, to raise the performance characteristic of double, acting type (DA type) six cylinder Stirling engine, it researches. Towards practical application of the Stirling engine, must be to improve the current situation better output than the problem. Include mechanical loss as a problem, we measured the mechanical loss output shaft, yoke, connecting rod, piston and piston ring. We show improvements towards the improvement of the output report data to measure the mechanical loss of the Stirling engine time, was obtained. We will explore how you can easily create a large number of improvements as much as possible also.

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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 to utilize woody biomass. 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, we are developing 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, based on basic performance, durability, economical efficiency, etc. which were acquired through the verification test of the demonstration plant, it makes a comprehensive evaluation of the biomass power plant with 30kW-class stirling engine.

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As a power source for emergency power supply, a Stirling engine has received a keen interest due to its high thermal efficiency as well as its fuel diversity. In this study, a tubular name burner has been developed for heating the head of a Stirling engine. Results show that stable combustion can be obtained for a wide range in equivalence ratio from stoichiometric to near lean-limit mixtures, and that the head temperature, the electric power generation as well as the thermal efficiency of the Stirling engine are increased with decreasing the equivalence ratio under a constant heat input condition. This seems due to an increase of air now rate, and hence, due to an increase of heat transfer rate. In this study, a self-recirculation type tubular flame burner has been adopted to increase the head temperature, and the maximum thermal efficiency of 12% has been achieved.

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A new method to measure heat transfer between the working gas and the regenerator matrix has been proposed. Since the change in internal energy of working gas is calculated from its pressure and volume, heat added to the working gas is estinated from the lot law of thermodynamics with measured pressure history. The validity of the method has been confirmed as Well as the effect of measurement error and the ways to reduce the effect of noise have been examined.

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In this laboratory, to raise the performance characteristic of double-acting type (DA type) six cylinder Stirling engine, it is researched. We required strict airtightness of cooler because this engine is required 6 cooler. Therefore, we developed leak-free cooler to solve. that problem. Two different type coolers were manufactured and tested that one of them was block type, other was composite type cooler. Composite type cooler has two kinds, straight groove cooler and helical groove cooler, and they consist of core and single tube. In this study, we introduce three kinds of coolers was manufactured and report the compared result about performance of the manufactured cooler.

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The pulse tube engine consists of one piston in one cylinder, cooler with orifice, pulse tube, heater and gas damper with stacked wire gauzes. The pulse tube has the work source in this engine. The gas damper has the function breaking the thermodynamic symmetry. For this research, the engine replaced a gas damper with a sudden expansion tube is proposed. A simple prototype engine, using air at normal atmospheric pressure as the working gas, was fabricated. Effects of expansion tube shape on the engine performance were examined experimentally. The effect of sudden expansion tube was confirmed.

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The working gas flow in a rectangular pulse tube refrigerator was visualized using the Schlieren technique in order to understand characteristics of a gas piston. The experiments were conducted with inertance tube lengths of 700mm, 1350mm, 2100mm. One side of the gas piston end that was the boundary of a jet from a regenerator was observed. The lowest cool-down temperature was -19℃ at the condition of the inertance tube length 1350mm. At this condition, it was found that the gas piston end was just reached at the regenerator when the direction of a compression piston was changed from expansion to compression.

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Thermoacoustic phenomenon is the energy conversion between heat and sound. For example, when wire meshes are inserted in a tube and temperature gradient is given in there, working gas becomes unsteady and begins spontaneous oscillation. But, there are uhclear points in the process of the energy conversion from heat to sound. In this work, the characteristics of the conversion are revealed from the viewpoint of fluid dynamics by visualizing in now channel of parallel-plate stack with Particle Imaging Velocimetry (PIV). And, the effect of aperture ratio on sound pressure in thermoacoustic prime mover became obvious.

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The prime mover for the traveling wave thermoacoustic refrigerator driven by solar heat was developed. The sunlight collected by the parabolic thermal collector with the diameter of 1600[mm] was introduced to the mesh (D=30[mm]) located at the end of the stack. Temperature distribution on the end of the stack was measured, and the uniformity of heating by solar heat was confirmed. As the sunlight came into the mesh, the oscillation of the sound wave was confirmed with the temperature difference of 150[℃]. The performance was evaluated with the collected heat temperature and the pressure of the generated acoustic wave.

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A multistage thermoacoustic engine with multiple regenerators needs regenerators installed not only at the peak of acoustic impedance distribution in real part, and therefore is generally inefficient. In this report, we suggest a composition of a multistage thermoacoustic engine by numerical calculation, so that high acoustic impedance and traveling-wave are realized at all regenerator positions, and traveling-wave with acoustic impedance ρ_mc is realized at positions other than the regenerators.

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We masured a thermal efficiency of a multistage thmoacoustic engine by a forced oscillation method. In the forced oscillation method, we can arbitrarily change the operating frequcncy and the acoustic power, independently of the temperature difference. As a result of the experiment we found that the themal efficiency of the thermoacoustic engine unit reached 6.58% which is 21.4% of Carnot effaaiciency when the operating frequency was 35 Hz and a hot end temperature was 150 ℃.

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We study a problem of acoustic wave propagation in a periodic field created by the array of thermoacoustic engines. Possibility of acoustic power amplification is examined through the eigenvalue and eigenvector of the transfer matrix related to the unit cell of the system.

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Thermoacoustic devices are composed of tubes whose radii are usually different each other. There are two joint conditions of the tubes: they are jointed directly or via a tapered tube. In this study, acoustically lost power was measured at the joint position under the two conditions.

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Thermoacoustic heat pump is expected high reliability and long life because it has no-moving parts at a heating section. We build a thermoacoustic heat pump and measured its coefficient of performance (COP) circulating water in a hot heat exchanger. Working gas was 0.5 MPa nitrogen, and frequency was 50 Hz. The COP was defined as the ration of heating power over acoustic power delivered to the heat pump. The measured value of COP was 1.1 at 79℃.

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For the purpose of cooling high-temperature superconductor (HTS) devices, superconducting motors, SMES and fault current limiters, a large cooling capacity Stirling-type Pulse tube cryocooler (SPTC) has been developed by Sumitomo Heavy Industries, Ltd (SHI). The design concepts of cryocooler are high efficiency, compact size, light weight, and high reliability. We have developed a cryocooler with a design target of producing a cooling capacity of 200W at 77K. As the experimental results show, the cooling performance of the In-line type expander achieved a cooling capacity of210W at 77K, a minimum temperature of 37K with a compressor input power 3.8kW, an operating frequency of 48Hz〜60Hz, and a compressor efficiency of 74%. Moreover, for miniaturization a U-type expander was tested and the performance is about 10% less than that of an In-line type expander. The cooling capacity degradation caused by inclination to the expander was within 3%. The experimental results of the high power SPTC will be reported in this paper.

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Wastes are defined as a new energy and desired to utilize an energy source beneficially. The authors present a waste incineration and power generation system constructed by an incinerator and a Stirling engine generator. The incinerator has a maximum incineration capacity of 49kg/h and is cooled by circulating water in the side walls in order to enable a long life and supply heat by a hot water. The Stirling engine generator is built up as a 2 piston type engine with driving mechanism including a PM synchronous generator. It is installed in a secondary combustion chamber of the incinerator and heated by combustion gas and an auxiliary kerosene burner. This paper discribes the examination results of the system using firewoods of a cherry tree and a black locust as fuel. The power generation of 2kW and the heat supply capacity of 33kW are obtained by average.

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We had designed and prototyped original gamma-type circulating flow stirling engine (CFSE) with lead valves. It has the power piston in the expansion volume of hot part. This structural characteristics is also effective for binary operating fluid including condensable vapor, as a partial Ranking cycle or Stirling-Ranking complex operation. Using condensable operating fluid, heat recovering is increased and effective for waist heat recovering, low temperature differential operation. On the other hand, the structure and operating fluid flow is more complex, dead volume is larger than the conventional type. To prevent the shortage, oval-gear drive, hypo-cycloid linear drive are adopted.

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