Gas meter with gas thermal property measurement and auto-compensation
AssigneeWisenstech Ltd.
InventorsLiji Huang, Chih-Chang Chen
Life of this patent
Estimating the term…
Abstract
An electronic utility gas meter using MEMS thermal mass flow sensor to meter gas custody transfer and MEMS gas thermal property sensor to compensate the metering values due to gas composition variations is disclosed in the present invention. The meter is designed to have a MEMS mass flow sensor to meter the city utility gas consumption independent of environmental temperature and pressure while a MEMS gas thermal property or dual gas thermal property sensors to compensate the tariff due to the gas composition variations for compliance with the current regulation requirements of tariff and remove the major concerns for the wide deployment of the thermal mass MEMS utility gas meters.
Claims16
An electronic utility gas meter, the electronic utility gas meter configured for compensation of a tariff due to a composition variation in a gas, comprising:
- a MEMS mass flow sensor for metering the gas, the MEMS flow sensor operating with a calorimetric sensing principle;
- at least one MEMS gas thermal property sensor for measurement of gas thermal properties, the at least one MEMS gas thermal property sensor providing feedback for a mass flow measurement to compensate data such that tariff changes due to the composition variation can be eliminated in the tariff;
- a meter body that comprises a Venturi flow channel, a pair of flanged or threaded mechanical connections, and two component chambers to host a control electronics printed circuitry board and a battery pack;
- the control electronics printed circuitry board configured for acquisition of sensor data from the MEMS mass flow sensor and the at least one MEMS gas thermal property sensor, processing data compensation, performing data communication;
- managing power, providing onboard data storage, displaying metering information, and managing failure events;
- a data communication port with wired and wireless options that enable data transmission, allow manual access to the onboard data storage, enable programming of user specified functions, and enable diagnosis of meter performance;
- a pair of flow conditioning devices that perform flow straightening and flow profiling;
- the pair of flow conditioning devices installed at an inlet of the Venturi flow channel;
- the battery pack provides power to the MEMS mass flow sensor, the at least one MEMS gas thermal property sensor, and the control electronics printed circuitry board;
- and
- a pair of meter covers that seal the two component chambers and that include a display window,
- wherein said MEMS mass flow sensor is located at a tip of an assembly probe and the at least one MEMS gas thermal property sensor is located on a stem of the assembly probe in a space located away from the tip, the space having a window open to the gas, the window having a filter to filter contaminants.
An electronic utility gas meter, the electronic utility gas meter configured for compensation of a tariff due to a composition variation in a gas, comprising:
- a MEMS mass flow sensor for metering the gas, the MEMs mass flow sensor operating with a calorimetric sensing principle;
- at least one MEMS gas thermal property sensor for measurement of gas thermal properties, the at least one MEMS gas thermal property sensor providing feedback for a mass flow measurement to compensate data such that tariff changes due to the composition variation can be eliminated in the tariff;
- a meter body that comprises a Venturi flow channel, a pair of flanged or threaded mechanical connections, and two component chambers to host a control electronics printed circuitry board and a battery pack;
- the control electronics printed circuitry board configured for acquisition of sensor data from the MEMS mass flow sensor and the at least one MEMS gas thermal property sensor, processing data compensation, performing data communication;
- managing power, providing onboard data storage, displaying metering information, and managing failure events;
- a data communication port with wired and wireless options that enable data transmission, allow manual access to the onboard data storage, enable programming user specified functions, and enable diagnosis of meter performance;
- a pair of flow conditioning devices that perform flow straightening and flow profiling;
- the pair of flow conditioning devices installed at an inlet of a flow channel;
- the battery pack provides power to the MEMS mass flow sensor, the at least one MEMS gas thermal property sensor, and the control electronics printed circuitry board;
- and
- a pair of meter covers that seal two component chambers and that include a display window,
- wherein said at least one MEMS gas thermal property sensor utilizes a heated thermistor to measure thermal conductivity and thermal diffusivity,
- wherein said heated thermistor is passivated with a thermally conductive material, the at least one MEMS gas thermal property sensor further comprising another thermistor open to the gas.
Dependencies are inferred from the claim text.