초록 ▼

A moisture flow meter is provided in the air at negative pressures in the drying of transformers by means of a vacuum process for water extraction, causing a differential of pressure through a device of orifice plate and the continuous measurement of the dewpoint. The meter includes a pipeline, a co

A moisture flow meter is provided in the air at negative pressures in the drying of transformers by means of a vacuum process for water extraction, causing a differential of pressure through a device of orifice plate and the continuous measurement of the dewpoint. The meter includes a pipeline, a continuous dewpoint meter able to support negative pressure, as well as the use of a orifice plate and two vacuum meters (vacuum meters) capable of measuring the pressure of condensable steam as well as a orifice which, allow a pressure drop. The signals on both sides of the orifice plate and the one from the dewpoint temperature are sent to a data acquisition card, which allows to measure, with the help of an algorithm, the amount of water in weight that flows per time unit.

대표청구항 ▼

1. A device to continuously measure an extraction rate of water steam from a transformer tank, the device comprising: A pump operating at sub-atmospheric pressure;a pipeline extending between the vacuum pump and the transformer tank;an orifice plate mounted between two flanges inside the pipeline;fi

1. A device to continuously measure an extraction rate of water steam from a transformer tank, the device comprising: A pump operating at sub-atmospheric pressure;a pipeline extending between the vacuum pump and the transformer tank;an orifice plate mounted between two flanges inside the pipeline;first and second pressure meters, disposed on opposite sides of the orifice plate-and configured to measure a pressure drop across the orifice plate;a dewpoint meter operably coupled to an inside of the pipeline; anda temperature meter operably coupled to an inside of the pipeline. 2. The device of claim 1, wherein the orifice plate, the first and second pressure meters, the dewpoint meter, and the temperature meter are in direct contact with a fluid flow through the pipeline during a process of drying a transformer. 3. The device of claim 1, wherein the temperature meter comprises a type RTD temperature sensor. 4. The device of claim 1, wherein each pressure meter comprises a thermocouple type pressure bulb disposed inside a heavy duty enclosure of stainless steel with a mechanical connection of type ⅛″ NPT. 5. A method of continuously measuring a moisture flow through a pipeline during a vacuum process for drying of power transformers, using a device connected in series between a vacuum pump and a transformer tank; the device including: an orifice plate mounted between two flanges inside the pipeline; first and second pressure meters disposed on opposite sides of the orifice plate and configured to measure a pressure drop across the orifice plate; a dewpoint meter operably coupled to an inside of the pipeline; and a temperature meter operably coupled to an inside of the pipeline, the method comprising: determining an air flow expressed in units of mass per time units based on a power of the vacuum pump and the differential pressure caused by the orifice plate;determining a partial pressure of a water steam based on a measured dewpoint temperature of the moist air, considering that the partial pressure is equal to a steam pressure to the dewpoint temperature;determining a mole fraction of water in gas phase (yH20) by dividing the partial pressure of the water steam and a total pressure within the pipeline;determining a mass fraction by multiplying by respective molecular masses; andmultiplying the mass fraction of water by a moist air flow, in order to obtain a speed of water removal. 6. The method of claim 5, wherein the vacuum process for drying is complete when a speed of water removal is less than 3 g/h by mega gram in weight of the insulation.