Freezing apparatus, and expander

Abstract

Provided is a freezing apparatus, which is constituted to make the inlet quantity of a coolant of an expansion mechanism variable while recovering the energy of a high-pressure coolant as a power to the maximum by the expansion mechanism. The expansion mechanism (50) is equipped with two rotary mechanism units (70 and 80) having displacements made different from each other. These rotary mechanism units are connected in series, and the rotary mechanism unit of the smaller displacement has two inlet ports (55 and 56) formed in its cylinder (71). Inlet pipes (24 and 27), as connected to the inlet ports (55 and 56), are equipped with a front throttle valve (60) and a switch valve (61). A bypass pipe (65) for bypassing the expansion mechanism (50) is equipped with a bypass valve (66). These valves (60, 61 and 66) are controlled to attain a balance between the coolant circulation rate of the expansion mechanism (50) and the coolant circulation rate of a compression mechanism (40).

Description

technical field [0001] The present invention relates to a refrigeration device including an expansion mechanism, in particular to a volumetric expansion mechanism that generates power from the expansion of fluid. Background technique [0002] Conventionally, as disclosed in Patent Documents 1 and 2, in a refrigerant circuit performing a refrigerating cycle, a refrigeration device is known in which an expansion mechanism for recovering power from refrigerant is provided together with a compression mechanism. The power recovered from the high-pressure refrigerant by the expansion mechanism is transmitted to the connected compression mechanism through the drive shaft, and is used to drive the compression mechanism. [0003] However, since the refrigerant circuit is a closed circuit, the amount of refrigerant circulating through the compression mechanism per unit time (equivalent to mass flow, the same below) must always be consistent with the amount of refrigerant circulating t...

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Problems solved by technology

[0008] However, as mentioned above, injecting high-pressure refrigerant into the expansion mechanism during the expansion stroke, or making the refrigerant bypass the expansion mechanism, although the refrigerant circulation of the compression mechanism and the expansion mechanism is balanced, it can be recovered to the maximum extent. The energy of the dynamic high-pressure refrigerant can only be partially recovered by the expansion mechanism, which is not the desired configuration from the perspective of recovery efficiency.

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