| 摘要 |
With the disclosed method it is to be ensured that a relatively long pipe network for heated up or warmed up fluids which is connected downstream of the measuring device does not cool down during relatively long rest periods. This can only be achieved if the line lengths connected downstream of the measuring device are also involved in circulation. In conventional water meters, the circulation throughflow is also measured as consumption so that this method can only be used when a second water meter is used in the circulation line so that the differential consumption is then counted as consumption. Unfortunately, this method has the disadvantage that in the case of unfavourable tolerance measurement incorrect values are obtained which have proven unacceptable in practice. The disclosed method is intended to eliminate these losses, this being achieved in that, as a result of the special design of the measuring chamber, in each case the preliminary flow and feedback are directed in parallel into the measuring chamber, specifically in the same flow direction so that when circulation throughflow occurs a pressure compensation is achieved which brings the measuring wheel to a standstill. The pressure difference does not change in favour of the first runnings until a downstream tapping valve opens so that the impeller carries out a precise measurement. The application comprises two embodiments, specifically on the one hand an embodiment with a dividing web in the measuring chamber and on the other hand an embodiment as a separate measuring chamber with the volume flow being diverted by means of corresponding non-return valves into the actual measuring chamber and being removed from the downstream tapping valves. Both versions are provided with a control device which serves to compensate the pressure loss in the pipe network connected downstream of the measuring device.
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