Development Of Non-magnetic Heat Meter Based On Enthalpy

With the development of heat energy measurement reformation, we have made great progress in heating project. Traditional mode of charging expense by area has become more and more unreasonable and unscientific. The thought of heating together and charging separately has gone deep into people's heart. In order to fulfill the need of heat energy measurement, heat meter should be developed.Heat meter developing in our country is very late, the technology is falling behind with Europe's. In addition, the price of heat meter is a problem, the flow sensor of European heat meter such as electromagnetic flow sensor, ultrasonic flow sensor are hard to be used widely in our country. So it's very necessary to develop a kind of heat meter that suits national conditions. Earlier, dry reed sensor and hall sensor are used in our country for flow detection, but they are both based on magnetic fields, which brings some deadly disadvantages. They are easy to be disturbed by any other magnetic fields, they are prone to fade magnetism and trend to absorb scrap irons. These characteristics can affect the precision of flow detection. So the non-magnetic flow sensor becomes a new trend.So, this paper designs a non-magnetic heat meter based on enthalpy, the theory will be narrated in five parts as follows.First, this paper derives the formula of heat integral by the analytical method of thermodynamics and introduces other related arithmetic of heat integral, and then chooses a suitable arithmetic by contrast.Second, this paper does a research on the theory of temperature measurement, and puts forward a good method to measure temperature by platinum resistance sensor. This method can handle nonlinear of platinum and electrical bridge by looking up tables and linear interpolation. In addition, density and enthalpy need to be acquired through temperature, so this paper introduces how to make the tables of temperature and enthalpy and the detail about how to look up tables in detail and then shows the specific hardware circuit and makes a detailed interpretation on them.Third, this paper studies the theory of non-magnetic flow detection, analyses the oscillation decaying theory and the effect of eddy current in detail, and then studies the non-magnetic flow detection IC TMS3723B and shows the specific hardware circuit.Fourth, this paper introduces the thought of heat meter software programming and resisting interfere design.Fifth, this paper introduces low-power design of heat meter and precision experiment.