Self-contained regulating valve, and compression type refrigerating machine having the same

#This invention relates to a self-operated regulating valve, and a compression refrigerating machine having it.

#FIG. 9 is a system diagram showing a multistage compression turbo-refrigerating machine according to prior art. As shown in the drawing, in an evaporator 1, a refrigerant liquid (e.g., an organic refrigerant such as a fluorocarbon) is heated with cold water (or brine) 3, flowing in a tube 2, to generate a refrigerant gas. At this time, the cold water 3 is cooled by heat exchange in the evaporator 1, and then delivered to the outside.

#A turbo-compressor 4 having two impellers takes in the refrigerant gas evaporated by the evaporator 1, compresses it at two stages by the two impellers rotated by an electric motor (not shown), and discharges a high temperature, high pressure refrigerant gas. A refrigerant gas from an inter-cooler 5 is also taken into the impeller located at the second stage (intermediate stage). In a condenser 6, the high temperature, high pressure refrigerant gas discharged from the turbo-compressor 4 is cooled with cooling water 8, flowing in a tube 7, to condensate and liquefy it. At this time, the cooling water 8 is heated by heat exchange in the condenser 6, and then discharged to the outside. A refrigerant liquid formed by condensation is accumulated at the bottom of the condenser 6.

#FIG. 1 is a structural drawing showing a self-operated regulating valve according to a first embodiment of the present invention.

#FIG. 2 is a structural drawing showing a self-operated regulating valve according to a second embodiment of the present invention.

#FIG. 3 is a structural drawing showing a self-operated regulating valve according to a third embodiment of the present invention.

#Embodiments of the present invention will be described in detail based on the accompanying drawings.

#<First Embodiment>

#FIG. 1 is a structural drawing showing a self-operated regulating valve according to a first embodiment of the present invention. As shown in the drawing, a valve body 11 of the self-operated regulating valve I forming a cylindrical closed space has an inlet 11a and an outlet 11b formed at opposed positions of a central portion thereof for incoming and outgoing of a fluid. In the inside space, a spool 13 is housed. The self-operated regulating valve I is connected to pipe lines 12 and 12, located above and below it in the drawing, via the inlet 11a and the outlet 11b. The spool 13 has a through-hole 13a opposed to the inlet 11a and the outlet 11b and serving as a passage for the fluid, and is slidable in the internal space of the valve body 11 in the right-and-left direction in the drawing along the axial direction. A predetermined preload is imposed on one end surface of the spool 13 by a preload spring 14. O rings 15, 16 are fitted on the outer peripheral surface at right and left end portions of the spool 13 to form two spaces between the respective end surfaces of the spool 13 and the respective end surfaces of the interior of the valve body 11. These respective spaces serve as pressure transmission chambers 17, 18, which accept one pressure P1 and other pressure P2 via pressure transmission pipes 19, 20 and pressure introduction holes 11c, 11d formed in the valve body 11. FIG. 1 shows a state in which a differential pressure ΔP between the one pressure P1 and the other pressure P2 is at a set value or higher to render the self-operated regulating valve I open. At this time, the left end surface of the spool 13 contacts a stopper 22 to have its position restrained. When the differential pressure ΔP decreases, by contrast, the spool 13 moves rightward in the drawing according to the amount of the decrease, and when its right end surface contacts a stopper 21, its position is restrained to stop the spool 13. As noted from this, at a time when the spool 13 contacts the stopper 21, the self-operated regulating valve I comes to a full-closed state. At a time when the spool 13 contacts the stopper 22, the self-operated regulating valve I comes to a full-open state.