Reciprocating compressor for a cooling device

Abstract

A reciprocating compressor for a cooling device provided with a closed circuit (C) having a main branch (M), in which a first flow rate (X) of circulating coolant enters in the compressor, and a first economizer branch, or secondary branch (E), in which a second flow rate (X1) of coolant circulates under a pressure different from the pressure of the first flow rate (X) of coolant, the compressor being provided with a cylinder and a piston reciprocatingly moving in the cylinder, between a top dead center (S) and a bottom dead center (I), and having a suction duct for the entrance of the first flow rate of coolant, and a port obtained in the wall of the cylinder for the entrance of the second flow rate of coolant, in such a way that the piston exposes at least in part the first inlet port, at least during its inlet stroke, and covers the port at least during its compression stroke, wherein the first inlet port has a slit shape with the main dimension substantially transverse to the axis (A) of the cylinder.

Description

FIELD OF THE INVENTION[0001]The present invention relates to a reciprocating compressor for a cooling device.KNOWN PREVIOUS ART[0002]In particular, the present reciprocating compressor is used in those cooling devices comprising a closed circuit in which a determined flow rate of coolant circulates and that is provided with a main branch and at least one economizer and / or secondary branch. In such branches of the closed circuit two defined fractions of the overall flow rate of the coolant circulate, then exiting from the compressor. Such an economizer, or secondary, branch is fluidically connected to a section of the closed circuit comprised between the condenser and the expansion valve, on the one hand, and to the cylinder of the reciprocating compressor for the re-injection, into the compressor itself, of the fraction of flow rate crossing the secondary branch, on the other hand. Still in a known way, along such a closed circuit a condenser, an expansion valve, an evaporator and t...

AI Technical Summary

Benefits of technology

The patent text describes a compressor design that allows a high flow rate of coolant to enter the cylinder without affecting the dimensions of the compressor. This is achieved by a slit-like inlet port located next to the bottom dead centre of the piston, which allows coolant to flow in the same very short time as the piston stroke. The compressor also includes a valve that helps prevent excessive loss of compressor displacement and compression work at the side port. The use of a deformable reed valve makes the compressor more compact, while avoiding complicated elements for synchronizing the opening or closing of the side ports.

Problems solved by technology

Unfortunately, with respect to reciprocating compressors having the same displacement, but free from side port, a remarkable reduction of the possible compressor work is obtained, since a part of the piston stroke is used to allow the inflow fraction of the flow rate of coolant coming from the economizer, or secondary, branch.

In particular, in cases where such a fraction of flow rate is considerable, up to 50% of the overall flow rate value, the use of compressors having the same displacement as those employed in cooling devices free of economizer, or secondary, branch, becomes highly difficult.

In fact, in such cases, the inlet port for the flow rate of coolant has remarkable dimensions along the axis of the cylinder with the result that a compressor having a displacement greater than those normally used, and thus with an increase of overall costs, has to be employed.

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