The flow transmitter or flow sensor in the steam metering system is the core part, mainly including the vortex flowmeter, differential pressure flowmeter, split rotor steam flowmeter, etc., which are collectively referred to as the steam flowmeter.

1. Vortex Flowmeter

The Karman vortex street principle is used to measure the volume flow of steam, which is composed of a sensor, converter, and display instrument. During operation, the steam fluid impacts the triangular cylinder-type vortex generator, and the regular Karman vortex is generated alternately from both sides of the vortex generator. The vortex frequency has a linear relationship with the average speed of steam, so as to know the steam flow.

2. Differential Pressure Flowmeter

Based on the Bernoulli equation and flow continuity equation, the differential pressure generated by the throttling device installed in the steam pipeline, the size of the differential pressure, and the steam flow has a definite numerical relationship. Common differential pressure flowmeters include orifice flowmeters, nozzle flowmeters, V-cone flowmeters, balance flowmeters, wedge flowmeters, etc.

3. Split Rotor Steam Flowmeter

After the steam enters the throttling fluid of the flowmeter, part of it passes through the throttling orifice of the main pipe, and part of it flows through the nozzle through the splitter pipe and jets onto the impeller, forming a torque on the impeller, so that the impeller drives the wheel shaft to rotate, and the impeller speed is proportional to the flow.