Abstract: [Subject] A low-cost and brief method to detect an airtight failure in a working-gas circulating type gas engine with sufficient accuracy and a working-gas circulating type gas engine using the method should be provided. [Means for Solution] In a working-gas circulating type gas engine, an extra predetermined quantity 1 of at least one of fuel gas, oxidizer gas, and working gas is supplied as surplus gas into a circulation passage. Based on the difference between this predetermined quantity 1 and increment of this predetermined quantity 1 and the increment of the quantity of the gas in the circulation passage separately detected by a gas quantity detecting means, the existence of an airtight failure in the engine is judged.

Abstract: A working gas circulation type engine includes a combustion chamber in which a working gas having a ratio of specific heats higher than that of air can be expanded by combustion of a fuel, a circulation path capable of circulating a gas containing the working gas from a gas exhaust side to a gas suction side of the combustion chamber and supplying the gas containing the working gas to the combustion chamber again, and a control device that changes a control parameter for controlling the combustion of the fuel based on a ratio of specific heats of the gas circulating in the circulation path. Therefore, there can be provided the working gas circulation type engine capable of obtaining a stable output.

Abstract: A heat exchanger for a stirling engine 10A of a twin-cylinder ? type includes a heat transfer tube group 70A formed with heat transfer tubes 71A causing a working fluid of the stirling engine 10A to flow between a high-temperature cylinder 20 and a low-temperature cylinder 30 arranged linearly and parallel to each other in the stirling engine. The heat transfer tube group 70A includes a rising section G1 extending upward, a falling section G2 extending downward, and a connecting section G3 connecting the rising section G1 and the falling section G2 in a turn-back manner, where the heat transfer tube group 70A is regarded as extending from one end or the other end thereof.

Abstract: A cooling system 1A includes an internal combustion engine 10, a pump 31, a radiator 32, a main passage section 41, a stirling engine 20, a branch passage section 43 branching from the main passage section 41 at a first connection point P1 and joining a downstream part of the main passage section 41 from the first connection point P1 at a second connection point P2, and a thermostat 33. The first connection point P1 and the second connection point P2 are provided in a part of the main passage section 41 between the radiator 32 and the pump 31. The thermostat 33 is provided in another part of the main passage section 41 between the first connection point P1 and the second connection point P2.

Abstract: In a working gas circulation engine, water vapor contained in exhaust gas after combustion is separated and removed at higher efficiency as compared with the conventional technology, the influence of remaining water vapor is prevented from reducing the ratio of specific heats of working gas and deteriorating the thermal efficiency of the engine. A working gas circulation engine which comprises a circulation passage part which connects an inlet port communicated to a combustion chamber and an exhaust port communicated to the combustion chamber in the exterior of the combustion chamber, supplies fuel, oxygen, and working gas to the combustion chamber to burn the fuel in the combustion chamber, and supplies the working gas contained in the exhaust gas discharged through the exhaust port from the combustion chamber to the combustion chamber through the circulation passage part and the inlet port.

Abstract: In a case of performing a static pressure gas lubrication by a stirling engine provided with a pair of cylinders of a high-temperature-side cylinder 20 and a low-temperature-side cylinder 30, a stirling engine gas lubrication structure is provided with an introduction pipe 70A for introducing a working fluid existing within a low-temperature working space into at least an inside of an expansion piston 21 of the expansion piston 21 and a compression piston 31, the low-temperature working space being included in a working space where the working fluid circulates between the cylinders 20 and 30, a temperature of the working fluid in the low-temperature working space lower than that of the working fluid in a working space of a high-temperature side cylinder 22 in a driving state.

Abstract: An exhaust heat recovery system includes a plurality of Starling engines. Heaters of the Starling engines are disposed in an exhaust passage that is a heat medium passage. An inside of the exhaust passage is partitioned with a partitioning member into a first exhaust passage and a second exhaust passage. The heater of the Starling engine disposed on an upstream side in a flowing direction of exhaust gas is provided in the first exhaust passage, and the heater of the Starling engine disposed on a downstream side in the flowing direction of the exhaust gas is provided in the second exhaust passage.

Abstract: A gas lubrication structure is provided with a high-temperature-side cylinder, an expansion piston lubricated relative to the high-temperature-side cylinder by gas, and a layer provided to the outer peripheral surface of the expansion piston and composed of a material flexible and having a higher linear expansion coefficient than the base material of the expansion piston. The thickness of the layer under normal temperatures is not less than the size of the clearance formed between the layer and the high-temperature-side cylinder. Also, even if the layer is thermally expanded under use conditions, the layer under normal temperatures has a thickness enabling a clearance to be formed between the layer and the high-temperature-side cylinder.

Abstract: An exhaust pipe through which an exhaust port of an internal combustion engine and a catalyst for purifying an exhaust gas of the internal combustion engine are connected to each other includes a porous portion that is provided on at least a part of an inner peripheral face of the exhaust pipe. A thermal conductivity that the porous portion exhibits in a high temperature state where a temperature of the exhaust gas is as high as it is required to radiate a heat of the exhaust gas through the exhaust pipe is at least ten times higher than a thermal conductivity that the porous portion exhibits in a low temperature state where the temperature of the exhaust gas is as low as it is required to warm the catalyst up.

Abstract: [Summary] [Subject] A low-cost and brief method to detect an airtight failure in a working-gas circulating type gas engine with sufficient accuracy and a working-gas circulating type gas engine using the method should be provided. [Means for Solution] In a working-gas circulating type gas engine, an extra predetermined quantity 1 of at least one of fuel gas, oxidizer gas, and working gas is supplied as surplus gas into a circulation passage. Based on the difference between this predetermined quantity 1 and increment of this predetermined quantity 1 and the increment of the quantity of the gas in the circulation passage separately detected by a gas quantity detecting means, the existence of an airtight failure in the engine is judged.

Abstract: A high expansion ratio internal combustion engine includes: a variable compression ratio mechanism that varies a mechanical compression ratio of the internal combustion engine; and a variable valve train in which some valve(s) of a plurality of intake valves is phase-variable and the remaining valve(s) is phase-fixed, the variable valve train being configured such that a working angle of the phase-variable intake valve is larger than a working angle of the phase-fixed intake valve, wherein a valve-open timing of the phase-variable intake valve is retarded after a valve-open timing of the phase-fixed intake valve when the internal combustion engine is under low-load operating state.

Abstract: The working gas circulation engine includes a circulation route capable of circulating gas containing the working gas from an exhaust side to an intake side of a combustion chamber and resupplying to the combustion chamber and provided with a removing device to remove a product generated with a reaction from the circulating gas, a supplying device capable of supplying plural kinds of reactant gas to the combustion chamber or the circulation route, a pressure detecting device capable of detecting pressure in the circulation route, and a control unit that controls supply amount of at least one kind of the reactant gas to be supplied from the supplying device based on the pressure in the circulation route detected by the pressure detecting device, and performs pressure control to adjust the pressure in the circulation route.

Abstract: In a working gas circulation engine, water vapor contained in exhaust gas after combustion is separated and removed at higher efficiency as compared with the conventional technology, the influence of remaining water vapor is prevented from reducing the ratio of specific heats of working gas and deteriorating the thermal efficiency of the engine. A working gas circulation engine which comprises a circulation passage part which connects an inlet port communicated to a combustion chamber and an exhaust port communicated to the combustion chamber in the exterior of the combustion chamber, supplies fuel, oxygen, and working gas to the combustion chamber to burn the fuel in the combustion chamber, and supplies the working gas contained in the exhaust gas discharged through the exhaust port from the combustion chamber to the combustion chamber through the circulation passage part and the inlet port.

Abstract: A cooling system 1A includes an internal combustion engine 10, a pump 31, a radiator 32, a main passage section 41, a stirling engine 20, a branch passage section 43 branching from the main passage section 41 at a first connection point P1 and joining a downstream part of the main passage section 41 from the first connection point P1 at a second connection point P2, and a thermostat 33. The first connection point P1 and the second connection point P2 are provided in a part of the main passage section 41 between the radiator 32 and the pump 31. The thermostat 33 is provided in another part of the main passage section 41 between the first connection point P1 and the second connection point P2.

Abstract: A silica structure includes mesoporous silica spheres; and connection portions each of which includes metal oxide, and each of which connects the mesoporous silica spheres to each other.

Abstract: A Stirling engine is provided with a fluid passage that connects a low temperature-side actuating fluid space and a crankcase inner space, and a passage opening/closing valve that is provided in the fluid passage and that opens and closes the fluid passage. Upon stopping of the Stirling engine, the passage opening/closing valve enables communication through the fluid passage, at a region at which the piston floats in the cylinder. This region is determined based on the pressure of an actuating fluid in the actuating fluid space and the rotational speed of a crankshaft of the Stirling engine.

Abstract: A Stirling engine has a fluid passage that connects a low temperature-side actuating fluid space and a crankcase inner space, and a passage opening/closing valve that is provided in the fluid passage and that opens and closes the fluid passage. The passage opening/closing valve enables communication through the fluid passage upon startup of the Stirling engine, and shuts off communication through the fluid passage when the rotational speed of the crankshaft of the Stirling engine is equal to or greater than a pre-established start-enabling rotational speed.

Abstract: A gas circulation engine includes a combustion chamber to which high-pressure fuel in a first high-pressure fuel supply passage, an oxidant and working gas are supplied; a circulation path that connects an intake-side portion and an exhaust-side portion of the combustion chamber to each other; a fuel bleed-off tank into which the high-pressure fuel in the first high-pressure fuel supply passage is bled off; a fuel bleed-off valve that permits or shuts off communication between the first high-pressure fuel supply passage and the fuel bleed-off tank; and a fuel bleed-off control unit that permits communication between the first high-pressure fuel supply passage and the fuel bleed-off tank by opening the fuel bleed-off valve when the engine is stopped, the communication between the first high-pressure fuel supply passage and the fuel bleed-off tank being shut off during operation of the engine.

Abstract: An internal combustion engine comprises a variable compression ratio mechanism capable of varying the mechanical compression ratio and a variable valve timing mechanism capable of controlling the closing timing of an intake valve. In an engine low-load operation, the mechanical compression ratio is maintained at a maximum mechanical compression ratio. In an engine high-load operation, the mechanical compression ratio is gradually decreased as the engine load increases. In the engine high-load operation, a load at which a predetermined mechanical compression ratio lower than the maximum mechanical compression ratio is obtained is preset, and a throttle valve is closed in the range of loads lower than the preset load.

Abstract: In a case of performing a static pressure gas lubrication by a stirling engine provided with a pair of cylinders of a high-temperature-side cylinder 20 and a low-temperature-side cylinder 30, a stirling engine gas lubrication structure is provided with an introduction pipe 70A for introducing a working fluid existing within a low-temperature working space into at least an inside of an expansion piston 21 of the expansion piston 21 and a compression piston 31, the low-temperature working space being included in a working space where the working fluid circulates between the cylinders 20 and 30, a temperature of the working fluid in the low-temperature working space lower than that of the working fluid in a working space of a high-temperature side cylinder 22 in a driving state.