摘要:
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. With this structure, only by subjecting the outer pipe to simple working such as press working, it is possible to increase the turbulent flow of fluid flowing between the inner pipe and the outer pipe, and to facilitate heat transfer from fluid flowing in the inner pipe to fluid flowing between the inner pipe and the outer pipe.
摘要:
A modular shelving unit includes at least three upright posts spaced apart from each other for supporting a shelf between them. At least one of the at least three posts includes at least two tubular members and at least one interconnecting member for detachably interconnecting adjacent, tubular members via attaching means. The at least two tubular members each have opposite edges and an inner circumferential wall defining annular inclined surfaces. The annular inclined surfaces are radially and outwardly inclined, as they advance to adjacent edges of the opposite edges. The interconnecting member has an outer circumferential wall with opposite end portions and a flange-like stopper radially and outwardly projecting from the outer circumferential wall. The adjacent tubular members are interconnected to the interconnecting member via the attaching means with mutually facing edges of the adjacent tubular members abutting each other. The annular inclined surfaces of the adjacent tubular members together form a positioning groove continuously extending along The abutting edges of the adjacent tubular members, and the flange-like stopper is fitted into the positioning groove with the flange-like stopper resting on the inclined surfaces of the positioning groove.
摘要:
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.
摘要:
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.
摘要:
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. With this method, when the compression mechanism 2 is started, the pressure difference can be generated upstream and downstream of the expansion mechanism 5 for a short time, the operation of the expansion mechanism 5 does not become unstable, vibration and noise can be prevented, and the refrigeration cycle apparatus can swiftly be started.
摘要:
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. A determining method of a high pressure of a refrigeration cycle apparatus in which a refrigeration cycle uses carbon dioxide as refrigerant and has a compressor, an outdoor heat exchanger, an expander and an indoor heat exchanger, and the refrigeration cycle including a bypass circuit provided in parallel to said expander, and a control valve which adjusts a flow rate of refrigerant flowing through said bypass circuit, said compressor being driven by power recover by said expander, wherein if an optimal high pressure of a first refrigeration cycle flowing through said expander and a second refrigeration cycle flowing through said bypass circuit is defined as Ph, and a bypass amount ratio flowing through said bypass circuit in said Ph is defined as Rb0, and a maximum refrigeration cycle efficiency of said first refrigeration cycle in said Ph is defined as COPe, and a maximum refrigeration cycle efficiency of said second refrigeration cycle in said Ph is defined as COPb, the optimal high pressure Ph which maximizes (1−Rb0)×COPe+Rb0×COPb is determined.