FLOW RATE MEASUREMENT VALVE
A flow rate measurement valve calculates the flow rate of the fluid flowing in a valve body from the differential pressure of the fluid pressure in a flow route upstream from a valve element arranged in the valve body and the fluid pressure in a flow route downstream from the valve element. The downstream fluid pressure is detected without the influence of dynamic pressure by detecting the pressure of fluid stopped in a fluid stagnation part formed in part of the flow route downstream from the valve element. The downstream fluid pressure is measured through a downstream fluid pressure conduction route that passes through an inner peripheral surface of the valve body facing the fluid stagnation part and an outer peripheral surface of the valve body where a downstream fluid pressure detection means is mounted.
1 : A flow rate measurement valve comprising:
a valve element that is arranged inside the valve body and adjusts the flow rate of fluid passing through the interior of said valve body;
a first pressure detector for detecting the fluid pressure in the flow route upstream from said valve element;
a second detector for detecting the fluid pressure of the flow route downstream from said valve element;
a valve openness detector for detecting the amount of openness of said valve element;
a flow rate calculation means for calculating the flow rate of fluid flowing inside said valve body based on the various detection signals of said first and second pressure detectors and said valve openness detector;
a fluid stagnation part that produces fluid stagnation near said valve element in the flow route downstream from said valve element in the valve body, and
a downstream fluid pressure conduction route that passes through an inner peripheral surface of said valve body bordering said fluid stagnation part and through an outer peripheral surface of the valve body,
wherein said second pressure detector is mounted on the outer peripheral surface of said valve body and is connected to said downstream fluid pressure conduction route.
2 . The flow rate measurement valve according to claim 1 , wherein:
said valve comprises a globe valve that adjusts the flow rate of the fluid that passes through the interior of said valve body by changing the position of said valve element at the interior of said valve body by moving a valve spindle that is mounted in said valve element; and
said fluid stagnation part is an open space formed by portions of an outer peripheral surface of said valve element and the inner peripheral surface of said valve body.
3 . The flow rate measurement valve according to claim 1 , wherein:
said valve element is mounted with a valve spindle that is orthogonal to an axial direction of the flow routes of said valve body;
said valve element is supported on said valve spindle so as to freely rotate inside the surface orthogonal to said valve spindle;
said valve element is formed into a roughly hemispherical body having a through hole through which the fluid passes, and
said fluid stagnation part is a space formed by portions of an outer peripheral surface of said valve element and the inner peripheral surface of said valve body.