A method and system for adsorbed phase activity coefficients for mixed-gas adsorption includes: providing one or more processors, a memory communicably coupled to the one or more processors and an input/output device communicably coupled to the one or more processors; calculating a first gas activity coefficient ?.sub.1 for a first gas using the one or more processors and a first equation; calculating a second gas activity coefficient y.sub.2 for a second gas using the one or more processors and a second equation based on a bulk mole fraction of the first gas; providing the first gas activity coefficient y.sub.1 for the first gas and the second gas activity coefficient y.sub.2 for the second gas to the input/output device; and using the first gas activity coefficient y.sub.1 for the first gas and the second gas activity coefficient y.sub.2 for the second gas in the gas adsorption system.

A method of determining density of a fluid within a system includes actuating a piston of a hydraulic cylinder at a target velocity. Additionally, the method includes determining differential pressure and volumetric flow rate of the fluid flowing through an orifice under actuation of the piston. The density of the fluid is determined based on the first differential pressure and the volumetric flow rate of the fluid, which is used by the system to regulate a mass flow rate of fluid within the system.

The present disclosure provides a method for modifying a gas density relay and a gas density relay having an online self-check function and a check method therefor. The gas density relay having an online self-check function is used for high-voltage and medium-voltage electrical devices, and includes a gas density relay body, a gas density detection sensor, a gas path blocking pressure regulation mechanism, an online check contact signal sampling unit and an intelligent control unit. The intelligent control unit controls a blocking member of the gas path blocking pressure regulation mechanism to move, so as to block a gas path between a first interface and a second interface. Moreover, a volume of a sealed cavity changes, a gas pressure of the gas density relay body slowly falls, thereby generating contact action, the contact action is transmitted to the intelligent control unit by means of the online check contact signal sampling unit, and the intelligent control unit detects an alarm and/or blocking contact signal action value and/or return value according to a density value during the contact action, such that check can be completed without maintenance personnel on site, and the reliability and efficiency of a power grid are greatly improved while cost is lowered.

Systems and methods for calculating gas densities within a fluid enclosure are disclosed. In an example embodiment, a system includes a temperature probe for measuring an enclosure temperature in a fluid enclosure filled at least in part with a fill gas, an atmospheric pressure sensor for measuring the atmospheric pressure outside the fluid enclosure, a gas sensor for measuring an enclosure pressure within the fluid enclosure, and a controller for calculating a fill gas density within the fluid enclosure based at least in part on the enclosure temperature, the atmospheric pressure, the enclosure pressure, and a gas coefficient of the fill gas.

Mechanical, electronic, algorithmic, and computer network facets are combined to create a highly integrated advanced sensor that monitors the gas density, state-of-repair, and events associated with switchgear. Measurements of gas pressure, atmospheric pressure, gas temperature, are used with models of the non-ideal behavior of a particular gas to realistically estimate gas density. A hierarchical system of signal processing optimizes measurements working within high-frequency, real-time, short-term, medium-term, diurnal, long-term, and historical timeframes and overcomes measurement errors present in real-world applications. The time at which a condition such as gas density will reach a particular level is calculated. Events such as threshold attainments and switchgear operation are detected. A large memory stores all raw data values allowing flexible re-processing and verification at any future time. Instantaneous as well as logged information is communicated in convenient formats over a selected digital network. An embedded web server provides a familiar graphical user interface.

A monitoring device is provided having a temperature-compensated pressure-measuring system, in which an electrical notification is output to the outside with use of a plurality of settable threshold values. Also, a high-performance switching system is provided that includes at least one monitoring device.

A gas densimeter for monitoring a pressure or density of a gas in a gas chamber with a housing having a first housing chamber and a measuring chamber, a first coupling, via which the measuring chamber can be connected to the gas chamber, at least one reference bellows, which is connected directly or indirectly in particular to a transmission element, and at least one transmitting and/or monitoring unit, which is or can be operatively connected directly or indirectly to the transmission element. In this regard, the measuring chamber has a gas-permeable connection to the gas chamber via the first coupling and the reference bellows forms a reference chamber filled with a constant amount of a reference gas. A surface section covering the reference chamber is provided or reachable at least partially within the first housing chamber or measuring chamber as a measuring surface for the gas from the gas chamber.

In order to mechanically monitor a gas density of a greenhouse gas in a more climate-friendly and cost-effective manner, the invention provides a density monitoring method for monitoring the gas density of a noxious gas (10), comprising: a) providing a closed reference volume (26) with a partition wall (28) movably disposed between the reference volume (26) and the noxious gas (10) to be monitored, b) providing a reference gas (56) which has a lower global warming potential relative to the noxious gas (10) by at least a factor of two in the reference volume (26) at a reference gas pressure which is higher than the filling pressure of the noxious gas (10), c) compensating, by means of a spring device (32), for a force acting on the separation wall (28) due to the increased reference gas pressure in the reference volume (26), and d) detecting a deflection of the partition wall (28) for monitoring the gas density. A gas density monitor (14), its use in such a method and an electrical system provided therewith are also proposed.

The application provides a gas density relay with online self-check function and its check method, including a gas density relay body, a first pressure sensor, a second pressure sensor, a temperature sensor, a gas chamber, a pressure regulating mechanism, an online check contact signal sampling unit and an intelligent control unit. The air path of the pressure regulating mechanism is connected to the gas pressure chamber and the second pressure sensor; Pressure rise and fall can be regulated through the pressure regulating mechanism to make the gas density relay body contact action. The contact action is transmitted to the intelligent control unit through the online check contact signal sampling unit. The intelligent control unit detects the action value and/or return value of the contact signal of the gas density relay body according to the density value when the contact acts, and completes the check work without requiring maintainer to go to the site for check. At the same time, because the pressure regulating mechanism is not connected to the SF6 gas path of the gas density relay body or electrical equipment, its sealing requirements are reduced, the reliability of the power grid is improved, and the manufacturing cost is reduced.

A method for estimating a specific gravity of a gaseous fuel is described. The gaseous fuel may power an engine and the engine may include a cylinder, a gas valve configured to supply an intake port of the cylinder with the gaseous fuel, a gas rail configured to deliver the gaseous fuel to the gas valve, and a microprocessor adapted to perform the method. The method may comprise establishing a pressure wave in the gas rail by opening and closing the gas valve, wherein the pressure wave travels at the speed of sound in the gaseous fuel. The method may further comprise determining a frequency of the pressure wave in the gas rail, and estimating the specific gravity of the gaseous fuel based on the frequency of the pressure wave.