Aiming at reduction of the energy consumed in domestic use, research and development of an energy system corresponding to ZEH (Zero Energy House) is advanced. The authors are developing a hybrid heat source Stirling engine CHP (combined heat and power) system, which uses solar and woody biomass for a heat source and supplies power generation and warm water. This paper describes characteristics of a solar tracking type collector for 1kW class Stiring engine using the Fresnel lens. The test results of the solar collector with a square and a circular concentrating area are presented. The latter are improved in an absorbed heat efficiency.

A shell & tube heater is usually made by joining the heater tubes to the tube-sheet by welding or high temperature brazing such as silver brazing or nickel brazing, which are either high cost or low performances. In order to develop a new method of making such heaters for the alpha-type small Stirling engines, an attempt was made in the present study to join the tubes to tube-sheet by using the electroless nickel plating method. Fundamental investigations were performed to examine the adhesion strength of the plating film, the shear strength between the tube and tube-sheet, the microscale structure of the cross-section of the plating film and that of the junctions.

We focus on the high-porosity characteristics of sintered metal fiber matrix for Stirling engine regenerator. In order to measure its basic characteristics as regenerator, we measured heat transfer characteristics and pressure drop in comparison with stacked wire-mesh matrix. From the measurement results, sintered metal fiber matrix shows lower flow resistance and either equaling or surpassing heat transfer performance than stacked wire-mesh matrix. From the measured data, we obtained the relational expression between the Nusselt and Reynolds numbers and between the friction factor and Reynolds number for each porosity level of the SMF matrix. The estimation of the indicated thermal efficiency using a simple Schmidt model shows a positive performance of the SMF matrix.

The purpose of this study was to understand the more detailed combustion characteristics of wood pellet gasified combustor developed last year. The experiments were carried out and the temperature were measured in own combustor, and O2, CO2, and CO concentrations were measured in the exhaust gas. As a result, gasified combustion has been performed under the condition of fuel flow rate of 2.09[kg/h] and 3.15[kg/h]. In addition, secondary combustion chamber temperature became maximum (1199.9°C) at the fuel supply rate of 3.15 [kg/h], primary air flow rate of 8 [m³/h] and secondary air flow rate of 10 [m³/h].

An oscillating steam engine has been expected as a low cost and efficient energy conversion system at a low operating temperature. In this study,we numerically investigate the oscillating steam engine . It was found, when the total volume of the engine is 4.5cc and hot section is 60mm , it can produce 18.9w. This result is able to reproduce the output of previous research. Then we investigated the change in output when changing the temperature of the heating section. Result of the calculation, the output increased as to increase the temperature of the heating section.

To develop the low temperature type of Stirling engines, conventional design methods are insufficient for the design of working gas displacement. So we developed a new design method. We defined a Stirling cycle as certain premise and defined a ratio of working gas displacement and volume change.

To aim the enhancement of heat transfer on the cylinder wall we have begun CFD simulation in the expansion space. Axi-symmetrical simulation was done with a moving displacer and simulated mass inflow calculated from an isothermal model. Thermal condition on the wall is assumed adiabatic. We present the results of its first step –– a study of flow pattern. It is shown that the inflow from the heater generates a strong vortex covering about 80% of cylinder wall in the transfer process. It delays rapidly by the expansion.

A looped water Stirling engine which has three U-tubes was proposed by West in 1983. This device can be considered as the system composed of three driver, and three water-columns. This can be drive at the temperature difference of 60°C or less, so we can use waste heat or solar heat. We could structure the water Stirling engine and evaluated the output. As the average pressure was increased, the frequency was increased. On the other hand, the displacement amplitude was decreased and the onset temperature was decreased.

To put ZEH (Zero Energy House) into practice until the goal of 2020 is declared in the cabinet decision of April 2014, and so development of practicable technology is urged. ZEH is the prospective model of housings which enables the reduction of energy consumption in domestic uses. The authors are developing a hybrid heat source Stirling engine CHP (combined heat and power) system, which produces electricity and warm water from solar and woody biomass. This paper presents the results of experiments which were carried out to evaluate the basic characteristics of 1kW class Stirling engine generator which is installed in the Solar power generation system.

Introduction of a waste carbonization furnace is advanced as a countermeasure to the global environmental problem. To reduce the power consumption of the carbonization furnace which can carbonize oily waste and recover oil in the oil field, the authors installed the Stirling engine generator into the carbonization furnace and conducted a demonstration. As a result, output of power generation 273W was obtained, and a possibility of the exhaust heat generation of electricity including an interconnection of power system for the carbonization furnace could be proved.

For wide spread of high temperature superconducting devices, such as fault current limiter, magnetic heater, generator and motor, Sumitomo Electric Industries, Ltd. and Sumitomo Heavy Industries, Ltd. have been developing a super-conducting motor for electric vehicles which are used as city bus. In order to realize the efficiency of HTS motor, a compact, high-efficiency and high-reliability cryocooler is required. For these reasons, SHI developed a high-efficiency Stirling cryocooler. In 2015, a prototype HTS motor system was developed and performance tests were conducted but system reliability was not evaluated. In this paper, we evaluate the life time reliability of a prototype cryocooler and report the impact of gas contamination.

In this study, we designed a loop-type thrmoacoustic heat pump driven by a multi stage traveling wave thermoacoustic engine by numerical calculation. In this apparatus, we achieved high impedance in the regenerator and traveling wave field in the ducts by enlarging the regenerator cross-sectional area and incrementing the duct diameter. By achieving both high impedance in the regenerator and traveling wave field in the ducts high efficiency and low temperature oscillation was performed by the loop-type thermoacoustic heat pump. Furthermore, we compared the heat pump performance and the efficiency of the system with and without the increment of the duct diameter. By the increment of the duct diameter the performance and the efficiency of the system was improved.

Generally, Stirling engines have either two pistons in two cylinders or two pistons in a single cylinder, and a heater, regenerator and cooler are installed between the pistons (except for the double-acting type engine). A single-piston Stirling engine, on the other hand, consists of a single piston in a single cylinder, a cooler, a regenerator, a heater and a gas damper. The gas damper has a role equivalent to the expansion piston or the displacer piston. Therefore, a prototype engine has been fabricated using pressurized helium as the working gas. The basic characteristics of this engine have been examined experimentally. In this research, effect of phase control on the engine performance has been examined experimentally. In addition, using an isothermal model assumed this engine with deformed gamma type Stirling engine, the engine performance has been calculated and compared with the experimental results.