A flow detector for detecting flow rates of fluid in pipes by measuring the temperature of the pipe and the ambient temperature and determining from the signals whether there is a flow in the pipe,by the shape of the temperature signals without providing any heat input to the pipe or fluid.

Flow detection device

The present application generally relates to fluid flow detection apparatuses and methods for detecting a water leak in a pipe system of a building. A method may: determine that a low flow is present, if absolute values of temperature differences between ambient and pipe temperatures of respective samples of a first monitoring period are above a difference threshold;and performa high flow test by estimating a temperature profile of water entering the pipe, based on identifying at least one temperature difference maximum of a second monitoring period, wherein each said difference maxima is a maximum temperature difference between ambient and pipe temperatures of a received sample, and determining that a high flow is present by detecting, based on the received pipe temperatures of the second monitoring period, if the pipe temperature is approaching the estimated water temperature profile.

Fluid flow detection apparatus

A location (100) is including an installation (120) associated with a site (102). At the site (102) is a house. A water main (110) forms part of a water distribution network and is buried approximately 1 m below the surface (112) of a road. A ferrule (114) extends from an upper part of the water main pipe and is in fluid communication with a first portion (116) of a service pipe at depth of typically approximately 0.75 m and which extends from the water main (110) to underneath a pavement (118). An outside stop-tap or meter chamber (122) is provided below pavement (118) and includes a pilotable cover (124), which can be opened to provide access to the interior of the chamber (122). A first connector (126) is provided on an upstream side of the chamber and a second connector (128) is provided on a downstream side of the chamber. A stop-tap or stop-tap and meter assembly (130) is provided within the chamber and in fluidic communication with the first and second connectors. An insulating member (134), for example in the form of a piece of polystyrene, extends across the interior of the chamber (122) and acts to insulate the lower part of the chamber from the environment above. A temperature logging device (160) is located on the insulating member (134) and includes a first temperature sensor (162). Optionally the temperature logging device may also include a second temperature sensor (164). The temperature of a part of a water supply system between a water main (110) and the site is recorded as a function of time. The recorded temperature as a function of time is analysed to determine a property indicative of the water consumption at the site.

Water flow analysis

Thermal flowmeter (1), in particular for determining and/or monitoring the mass flow (Φ Μ ) and/or the flow velocity (v D ) of a flowable medium (3) through a pipeline (2), having at least three sensor elements (4a, 4b, 4c) and an electronic unit (9), wherein each of the at least three sensor elements (4a, 4b, 4c) is at least partially and/or occasionally in thermal contact with the medium (3) and comprises a heatable temperature sensor (5a, 5b, 5c), and wherein the electronic unit (9) is configured to heat each of the three sensor elements (4a, 4b, 4c) with a heating power (P1, P2, P3), to record the temperature (T1, T2, T3) thereof, to heat at least two of the at least three sensor elements (4a, 4b, 4c) at the same time, to determine the mass flow (Φ Μ ) and/or the flow velocity (v D ) of the medium (3), to make a statement on a change in the thermal resistance of at least one of the at least three sensor elements (4a, 4b, 4c) from a paired comparison of the temperatures (T1, T2, T3) and/or heating powers (P1, P2, P3) of the at least three sensor elements (4a, 4b, 4c) and/or at least one variable derived from at least one of the temperatures (T1, T2, T3) and/or heating powers (P1, P2, P3), to make a statement on a change in the internal thermal resistance of the at least one sensor element from a step response to a sudden change in the supplied heating power ΔΡ at at least one of the at least three sensor elements, and, if a change in the internal and/or external thermal resistance occurs at at least one of the at least three sensor elements (4a, 4b, 4c), to correct the measured value for the mass flow (Φ Μ ) and/or the flow velocity (v D ) and/or to generate and output a message relating to the state of the at least one sensor element.

Thermal flowmeter with a diagnostic function

A method for correcting offset drift effects of a thermal measurement device (10) which comprises at least one temperature sensor (15 a, 15 b) arranged at a defined distance from a heating device (12) for a fluid to be measured, for measuring at least one measurement variable describing the temperature and/or temperature profile during operation of the heating device (12), in which a reference measured value (35) is measured at a reference time in a first measurement of the measurement variable with the heating device (12) turned off, in which a drift measured value (36) is measured at at least one later time in a second measurement of the measurement variable with the heating device (12) turned off, and in which a drift correction is carried out during the measurement by using the heating device (12) on the basis of a difference between the drift measured value (36) and the reference measured value (35).

Method for correcting offset drift effects of a thermal measurement device, thermal measurement device and gas flow meter

A thermal mass flow meter is disclosed for determining a material flow through a vessel. In this case, a sensor arrangement is mounted on a holder immersed into a vessel with a flowing medium. It is proposed that the sensor arrangement comprises a first and a second measuring element, with one of the respective measuring elements being heated while the other respective measuring element is not heated and that the two measuring elements can be heated alternately.

Thermal mass flow meter and method for its operation

Thermischer Massendurchflussmesser mit mindestens einer auf einen Halter montierten Sensoranordnung, die in ein Gefas mit stromendem Medium eingetaucht ist, dadurch gekennzeichnet, dass die Sensoranordnung ein erstes und ein zweites Messelement umfasst, von denen jeweils eines der Messelemente beheizt ist wahrend das jeweils andere Messelement unbeheizt ist und dass die beiden Messelemente in zwei Betriebsarten alternierend beheizbar sind, dass durch bauliche Massnahmen fur eine unterschiedliche Verschmutzungsgeschwindigkeit der Messelemente gesorgt wird, und dass die Stromung des Mediums an den Messelementen verschieden gefuhrt ist.

Huck, Ralf, Dr.-Ing.

Papers

Thermal mass flow meter and method for its operation

Thermischer Massendurchflussmesser und Verfahren zu seinem Betrieb