초록 ▼

The present invention is a method and apparatus for monitoring in real time the mass and energy flow rate of a gas through a pipeline. The invention determines the mass flow ratio of a pipeline gas flowing through a pipeline compared to sample gas tapped from the pipeline line when the volumetric fl

The present invention is a method and apparatus for monitoring in real time the mass and energy flow rate of a gas through a pipeline. The invention determines the mass flow ratio of a pipeline gas flowing through a pipeline compared to sample gas tapped from the pipeline line when the volumetric flow of pipeline gas through the pipeline is measured by a linear flow meter. Sample gas tapped from the pipeline is flowed to a chamber having a section with a fixed volume until the pressure in the chamber section is substantially equal to the pipeline gas pressure. The sample gas is maintained at substantially the same temperature as the gas in the pipeline while the sample gas is in the chamber section. A timer measures the time interval for the sample gas to flow from the chamber section at a selected rate for a calculated pressure drop the selected rate being controlled by a flow controller. The mass flow ratio is computed using the measured time interval and a signal from the linear flow meter. The energy flow rate of the pipeline gas is determined by measuring the energy flow rate of the sample gas and relating that value to the mass flow ratio of the pipeline gas compared to the sample gas.

대표청구항 ▼

An apparatus to be used with a linear flow meter to measure a ratio of a mass flow rate of a pipeline gas through a pipeline compared to a mass flow rate of a sample gas tapped from the pipeline, the apparatus comprising: a chamber having a section with a fixed volume for containing the sample gas,

An apparatus to be used with a linear flow meter to measure a ratio of a mass flow rate of a pipeline gas through a pipeline compared to a mass flow rate of a sample gas tapped from the pipeline, the apparatus comprising: a chamber having a section with a fixed volume for containing the sample gas, the sample gas being maintained at substantially the same temperature as the pipeline gas in the pipeline when contained in the chamber section; means for routing the sample gas to the chamber section; a valve for controlling the flow of sample gas to the chamber section; a flow controller for flowing the sample gas from the chamber section at a selected rate; a pressure sensor for measuring the sample gas pressure in the chamber section; means for closing the valve when the sample gas pressure in the chamber section reaches the pressure of the pipeline gas in the pipeline; and a timer for measuring a time interval for the sample gas to flow from the chamber section at the selected rate beginning when the sample gas pressure in the chamber section drops below a first pressure, and ending when the sample gas pressure in the chamber section drops below a second pressure, the first pressure being greater than about one-half of the pipeline gas pressure in the pipeline and the second pressure being less than about one-half of the pipeline gas pressure in the pipeline; and a controller which receives a signal from the timer and a signal from the linear flow meter representing the volumetric flow of the pipeline gas through the pipeline and derives the ratio of the mass flow rate of the pipeline gas through the pipeline compared to the mass flow rate of the sample gas. A method for measuring a mass flow ratio [Figure] of a pipeline gas through a pipeline compared to a sample gas tapped from the pipeline, the method comprising the steps of: measuring the volumetric flow rate of the pipeline gas through the pipeline with a linear flow meter; flowing the sample gas to a chamber having a section with a fixed volume; maintaining the temperature of the sample gas at substantially the same temperature as the pipeline gas in the pipeline when the sample gas is in the chamber section; stopping the flow of sample gas to the chamber section when the pressure in the chamber section reaches the pressure of the pipeline gas in the pipeline; flowing the sample gas from the chamber section after the flow of the sample gas to the chamber section is stopped, thereby reducing the sample gas pressure in the chamber section; timing the interval of time tm for the sample gas to flow from the chamber section at a selected rate beginning when the sample gas pressure in the chamber section drops below a first pressure and ending when the sample gas pressure in the chamber section drops below a second pressure wherein the first pressure is greater than about one-half of the pipeline gas pressure in the pipeline and the second pressure is less than about one-half of the pipeline gas pressure in the pipeline; and deriving the mass flow ratio [Figure] of the pipeline gas through the pipeline compared to the sample gas tapped from the pipeline from a signal ft from the linear flow meter that is related to the volumetric flow rate of the pipeline gas, and the time interval tm.