Abstract: A pulse tube refrigerator is provided. A pulse tube is inserted into a regenerator such that the central axis of the pulse tube parallels the central axis of the regenerator and that a U-shaped working gas channel is formed by the pulse tube and the regenerator. It is possible to refrigerate more members by increasing the available area of a cold head formed in a cold heat exchanger. It is possible to reduce a restriction on the installing space of a refrigerating unit by reducing the length of the refrigerating unit. It is possible to reduce manufacturing cost by reducing the number of sealing members for the combination of a sealed cell.

Abstract: A pulse tube refrigerator is provided. A pulse tube is inserted into a regenerator such that the central axis of the pulse tube parallels the central axis of the regenerator and that a U-shaped working gas channel is formed by the pulse tube and the regenerator. It is possible to refrigerate more members by increasing the available area of a cold head formed in a cold heat exchanger. It is possible to reduce a restriction on the installing space of a refrigerating unit by reducing the length of the refrigerating unit. It is possible to reduce manufacturing cost by reducing the number of sealing members for the combination of a sealed cell.

Abstract: An operation method of an absorption heat pump is disclosed. This method includes a step for measuring a temperature of a refrigerant vapor passed through the above-described rectification process, a step for comparing the measured temperature and a previously set temperature and estimating a refrigerant density passed through the rectification process, and a step for controlling a heat exchange amount between a rich solution and a refrigerant vapor during the rectification process based on the estimated refrigerant density for thereby obtaining a high purity and density of a refrigerant vapor and a high and stable COP even when a load and an outdoor temperature are changed by changing the amount of a heat exchange performed by a rectifier in accordance with the density of a refrigerant estimated by a temperature of a refrigerant vapor flown into a condenser.

Abstract: An ammonia GAX absorption cycle comprising a first pipe allowing a strong solution generated in an absorber to pass through a rectifier to rectify a coolant vapor provided from a generator the rectifier into a highly concentrated coolant vapor, a second pipe allowing the strong solution flowing in the first pipe and heated in the rectifier flow into a GAX-absorber/generator to undergo heat exchange with a weak solution provided from the generator into the absorber, a third pipe allowing the strong solution enter a solution cooling absorber to undergo heat exchange with the weak solution cooled in the GAX-absorber/generator, and a coolant introducer allowing the strong solution flowing in the second and third pipes and heated by heat exchange to flow into the generator and undergo heat exchange with the coolant vapor and weak solution produced in the generator.