Abstract: A liquid circulation heating system performs air-heating by heating a liquid to produce a heated liquid and releasing heat of the heated liquid from a heating radiator. This liquid circulation heating system includes: a heat pump circuit for circulating a refrigerant, having a radiator for heating the liquid by radiating heat from the refrigerant; and a solar heating apparatus for heating the liquid by solar heat. In this liquid circulation heating system, a first passage passing through the radiator and a second passage passing through the solar heating apparatus are formed as passages through which the liquid flows to produce the heated liquid.

Abstract: A liquid circulation heating system includes a heat pump for producing a heated liquid and a heating radiator. The heat pump has a heat pump circuit for circulating a refrigerant to heat a liquid. The refrigerant contains tetrafluoropropene and difluoromethane as main components. According to the liquid circulation heating system having such a configuration, a negative impact on global warming can be reduced.

Abstract: A liquid circulation heating system performs air-heating by heating a liquid to produce a heated liquid and releasing heat of the heated liquid from a heating radiator. This liquid circulation heating system includes: a heat pump circuit for circulating a refrigerant, having a radiator for heating the liquid by radiating heat from the refrigerant; and a solar heating apparatus for heating the liquid by solar heat. In this liquid circulation heating system, a first passage passing through the radiator and a second passage passing through the solar heating apparatus are formed as passages through which the liquid flows to produce the heated liquid.

Abstract: A liquid circulation heating system includes a heat pump for producing a heated liquid and a heating radiator. The heat pump has a heat pump circuit in which a compressor, a radiator, a decompressor, and an evaporator are connected in series. The heat pump circuit is charged with a zeotropic refrigerant mixture of at least two refrigerants having different boiling points. The system is configured so that the composition ratio of a higher boiling point refrigerant in the refrigerant circulating through the heat pump circuit increases when the liquid supplied to the radiator has a relatively high temperature.

Abstract: In a refrigeration cycle apparatus having an expansion mechanism, a method to swiftly generate a pressure difference upstream and downstream of the expansion mechanism of, thereby enhancing the starting performance of the refrigeration cycle apparatus The apparatus has a compression mechanism, a utilizing-side heat exchange, an expansion mechanism for recovering power, and a heat source-side heat exchanger. The revolution number of the heat source fluid transfer means is made smaller than a target revolution number or the heat source fluid transfer means is stopped during a predetermined time after the compression mechanism is started. When the compression mechanism is started, the pressure difference can be generated upstream and downstream of the expansion mechanism for a short time, the operation of the expansion mechanism does not become unstable, vibration and noise can be prevented, and the refrigeration cycle apparatus can swiftly be started.

Abstract: In a refrigeration cycle apparatus having an expansion mechanism, a method to swiftly generate a pressure difference upstream and downstream of the expansion mechanism of, thereby enhancing the starting performance of the refrigeration cycle apparatus. The apparatus has a compression mechanism, a utilizing-side heat exchange, an expansion mechanism for recovering power, and a heat source-side heat exchanger. The revolution number of the heat source fluid transfer means is made smaller than a target revolution number or the heat source fluid transfer means is stopped during a predetermined time after the compression mechanism is started. When the compression mechanism is started, the pressure difference can be generated upstream and downstream of the expansion mechanism for a short time, the operation of the expansion mechanism does not become unstable, vibration and noise can be prevented, and the refrigeration cycle apparatus can swiftly be started.

Abstract: In a refrigeration cycle apparatus in which carbon dioxide is used as refrigerant and refractory oil is used as lubricating oil in a compressor, it is an object of the present invention to reduce influence of adhesion of lubricating oil to the internal heat exchanger, and to enhance the heat exchanging efficiency of the internal heat exchanger.

Abstract: In a refrigeration cycle apparatus having an expansion mechanism, it is an object of the present invention to swiftly generate a pressure difference upstream and downstream of the expansion mechanism of, thereby enhancing the starting performance of the refrigeration cycle apparatus. In a control method of a refrigeration cycle apparatus comprising a compression mechanism 2, a utilizing-side heat exchanger 3, an expansion mechanism 5 for recovering power, a heat source-side heat exchanger 6, and heat source fluid transfer means 9 for transferring a heat source fluid to the heat source-side heat exchanger 6, revolution number of the heat source fluid transfer means 9 is made smaller than target revolution number or the heat source fluid transfer means 9 is stopped during a predetermined time after the compression mechanism 2 is started.

Abstract: In the case of gas injection, a discharging temperature is not reduced sufficiently, and if an amount of injection is increased, a liquid refrigerant flows into a cylinder and the liquid is compressed, and the reliability can not be ensured. A refrigerator wherein at least a compressor, a radiator, a first throttle apparatus and an evaporator are connected to one another in an annular form to constitute a main circuit of a refrigeration cycle, a refrigerant which can be brought into a supercritical state by the radiator during operation is charged into the refrigeration cycle, the refrigerator comprises an injection pipe for injecting the refrigerant on the side of an outlet of the radiator into a cylinder of the compressor.

Abstract: A fuel injection valve protecting apparatus for an LPG injection type engine operates when an excessive current passes through the fuel injection valve, or when an abnormality of the fuel injection valve occurs. An electrical fuse is inserted in a driving current supply line of the fuel injection valve. An electronic control apparatus has an abnormality diagnostic unit to detect any abnormality of the fuel injection valve by monitoring a check signal sent back from a fuel injection valve driving circuit, to thereby close a fuel shutoff valve and shut off the liquefied petroleum gas. Relief valves are connected in parallel between a petroleum gas supply line and an intake manifold so as to directly discharge any petroleum gas in the petroleum gas supply line into the intake manifold when the pressure difference between the petroleum gas supply line and the intake manifold reaches a set differential pressure.

Abstract: A refrigeration cycle apparatus using carbon dioxide as a refrigerant has a compressor, an outdoor heat exchanger, an expander, an indoor heat exchanger and an auxiliary compressor. The auxiliary compressor is driven by power recover by the expander. When refrigerant flows using the indoor heat exchanger as an evaporator, a discharge side of the auxiliary compressor becomes a suction side of the compressor, and when refrigerant flows using the indoor heat exchanger as a gas cooler, a discharge side of the compressor becomes a suction side of the auxiliary compressor.

Abstract: It is an object of the invention to provide an inexpensive double-pipe heat exchanger having high performance and comprising an inner pipe and an outer pipe which constitute a double pipe without adding a heat-transfer facilitating material such as an inner fin. In the double-pipe heat exchanger having the inner pipe and the outer pipe, the outer pipe is dented from its outside toward its inside, thereby forming a plurality of projections which are dented toward the inner pipe. Examples of shapes of the projection are substantially conical shape, substantially truncated shape, substantially spherical surface shape, substantially cylindrical shape, substantially elliptic cylindrical shape and the like. The projections are disposed helically or in a staggered configuration such as to surround the inner pipe.

Abstract: It is an object of the present invention to reduce the constraint that the density ratio is constant as small as possible, and to obtain high power recovering effect in a wide operation range. A refrigeration cycle apparatus uses carbon dioxide as refrigerant and has a compressor, an outdoor heat exchanger, an expander and an indoor heat exchanger. An injection circuit for introducing high pressure refrigerant is provided in a halfway of an expansion process of said expander.

Abstract: It is an object of the invention to provide an inexpensive double-pipe heat exchanger having high performance and comprising an inner pipe and an outer pipe which constitute a double pipe without adding a heat-transfer facilitating material such as an inner fin. In the double-pipe heat exchanger having the inner pipe and the outer pipe, the outer pipe is dented from its outside toward its inside, thereby forming a plurality of projections which are dented toward the inner pipe. Examples of shapes of the projection are substantially conical shape, substantially truncated shape, substantially spherical surface shape, substantially cylindrical shape, substantially elliptic cylindrical shape and the like. The projections are disposed helically or in a staggered configuration such as to surround the inner pipe.

Abstract: It is an object of the present invention to reduce the constraint that the density ratio is constant as small as possible, and to obtain high power recovering effect in a wide operation range by using an expander which is operated in accordance with a flowing direction of refrigerant.

Abstract: A fuel injection valve protecting apparatus in an LPG injection type engine is disclosed which operates when an excessive current passes through a fuel injection valve, or when an abnormality of the fuel injection valve occurs. Also disclosed is a fuel pressure increase preventing apparatus which can release an excessive pressure of petroleum gas so as to avoid a failure in parts of the engine and an engine malfunction. An electrical fuse is inserted in a driving current supply line of a fuel injection valve. An electronic control apparatus has an abnormality diagnostic means incorporated therein to detect an abnormality of the fuel injection valve by monitoring a check signal sent back from a fuel injection valve driving circuit, to thereby close a fuel shutoff valve and shut off the liquefied petroleum gas supplied to a vaporizer from a liquefied petroleum gas cylinder as appropriate.

Abstract: In the case of gas injection a discharging temperature is not reduced sufficiently, and if an amount of injection is increased, a liquid refrigerant flows into a cylinder and the liquid is compressed, and the reliability can not be ensured.

Abstract: It is an object of the present invention to reduce the constraint that the density ratio is constant as small as possible, and to obtain high power recovering effect in a wide operation range by using an expander which is operated in accordance with a flowing direction of refrigerant.

Abstract: A scale removing operation of the heat exchange means or a regenerating operation of ion removing means is carried out using electrolytic water, thereby reducing the water processing amount. The present invention provides a water heater capable of preventing deterioration of performance caused by adhesion of scale, capable of preventing a trouble caused by clogging, and capable of increasing the lifetime. The water heater comprising a heat source, heat exchange means for heating supplied water, and electrolytic water generating means, wherein a removing operation of scale having salt as main ingredient deposited in a water pipe of the heat exchange means is carried out using produced water of the electrolytic water generating means.

Abstract: It is an object of the present invention to reduce the constraint that the density ratio is constant as small as possible, and to obtain high power recovering effect in a wide operation range. A refrigeration cycle apparatus uses carbon dioxide as refrigerant and has a compressor, an outdoor heat exchanger evaporator, an expander and an indoor heat exchanger a radiator. An injection circuit for introducing high pressure refrigerant is provided in a halfway of an expansion process of said expander.