Volume flow controller
A volume flow controller (VSR ) , also called volume flow stabilizer (VSK) , is a component of a closed or an open system through which a fluid usually flows. In the line in which it is installed, it keeps the volume flow constant, even with fluctuating environmental influences , by automatically activating a built-in throttle device (i.e. by changing the pressure loss ) .
The free inflow length specified by the manufacturer must be observed for correct functioning. Mounting directly behind bends or branches means that the flow to the controller is not even, which causes inaccuracies in the volume flow.
A distinction is made between constant and variable volume flow controllers.
Constant volume flow controllers are set to a fixed setpoint (volume flow). Many models work purely mechanically without the need for additional drive energy.
Volume flow controllers for variable volume flow usually work electronically and receive setpoints for the air volume from a higher-level controller , which correspond to the changing requirements and which the controller automatically ensures.
Volume flow controller in ventilation systems
When installing volume flow controllers, attention should be paid to accessibility. This is particularly important for variable volume flow controllers.
A silencer should be provided directly behind a volume flow controller to reduce flow noise.
Differential pressure volume flow controller
The differential pressure volume flow controller is a component from control technology and is one of the proportional controllers .
The controller is used to change a volume flow (e.g. the water flow in a pipe ). For this purpose, the pressure is determined at two suitable points in the line and compared with a specified value. The resulting difference (differential pressure) controls a suitable actuator.
Commercially available differential pressure volume flow controllers in heating circuits do not require any auxiliary energy and are based on the differential pressure between the flow and return. These regulators consist of a control valve and two actuators with operating diaphragms that work independently of one another. Increasing differential pressure generates a positioning force when the set maximum volume flow is exceeded on the upper operating diaphragm, which slowly closes the valve against the pressure of the positioning springs with the help of the valve plug stem. The respective control pressures are generated by the heat transfer medium (regulator without auxiliary energy) and transferred to the diaphragm housing via a control line attached to the valve housing. The larger signal (larger actuating force) has priority and intervenes in the control. The nominal value of the differential pressure can be adjusted via the nut and the maximum volume flow via the adjustable throttle screw.
Individual evidence
- ↑ Jens Knissel; Max Giesen; Tobias Klektiven : Planning guide for semi-central ventilation - decentralized fans in central air conditioning systems . 1.1 edition. kassel university press GmbH, Kassel 2018, ISBN 978-3-7376-5070-0 , p. 34 ( google.de ).
- ↑ MIETZSCH GmbH Lufttechnik Dresden: Volume flow stabilizer (without auxiliary energy), type VSK . ( mietzsch.de [PDF; 141 kB ]).