Interior Temperature Measurements Research Articles

An observer-based solution of inverse heat conduction problems

An inverse heat conduction problem arises when temperature measurements are taken in the interior of a body, and the temperature and heat flux on the surface are desired. A new approach to the solution of this class of problems is introduced. It relies on the concept of state and disturbance observers which is well-known from systems theory. The complete temperature profile in the heat conducting body as well as the surface heat flux and temperature can be computed from one or several interior temperature measurements by means of a non-linear distributed parameter observer. The technique is introduced and analysed theoretically by means of a simple tutorial example. The approach is finally applied to a difficult inverse problem of technical significance. The time history of local heat flux and temperature oscillations at the inner surface of an evaporator tube are estimated during transition boiling conditions. Experimental results with boiling refrigerant R114 flowing upward in an electrically heated tube are presented.

An Observer-based Solution of an Inverse Heat Transfer Problem in Transition Boiling

An inverse heat conduction problem arises when temperature measurements are taken in the interiour of a body, and the temperature and heat flux on the surface are desired. A new approach to the solution of this class of problems is introduced. It is based on the concept of state and disturbance observers which is well-known from systems theory. The complete temperature profile in the heat conducting body as well as the surface heat flux and temperature can be computed from one or several interior temperature measurements by means of a nonlinear distributed parameter observer. The technique is applied to the estimation of the time history of local heat flux and temperature oscillations at the inner surface of a tube during transition boiling conditions. After discussion of the design methodology and evaluation of the observer scheme, experimental results with boiling refrigerant R114 flowing upward in an electrically heated nickel tube are given.

A convolution method for inverse heat conduction problems

The problem of determining the temperature at one end of a rod by means of interior temperature measurements has considerable practical importance and has been well studied, however, few exact solutions have been found. Most of the applicable results therefore, have been obtained from the (numerical) analysis of discretized systems. In this paper we present an analytic method for obtaining solutions to this problem which does not require differentiation (only integration) of the interior temperature readings and is valid for general finite energy boundary data and for general radiation boundary conditions at the known end of the rod.

A NEW FINITE-DIFFERENCE METHOD FOR THE NONLINEAR INVERSE HEAT CONDUCTION PROBLEM

A new space-marching finite-difference algorithm is developed to solve the nonlinear inverse heat conduction problem. This algorithm uses interior temperature measurements at future times to estimate the surface heat flux. The results of this method are compared on a test case with four other numerical schemes. The method is as accurate as the method developed by Beck [ 1] and uses a smaller computational time. This scheme is also employed to estimate the effects of different types of experimental errors on the estimation of the surface heat flux. Errors due to temperature measurements, thermocouple locations, and material properties are each investigated.

THERMAL CONDITIONS IN THE ANTICLINAL ZONE OF SURAKHANY-KARACHUKHUR-ZYKH-PESCHANYY (APSHERON PENINSULA)

The thermal environments of a number of deposits of the Apsheron Peninsula (the Surakhany, Karachukhur, Zykh, Gousany, Peschanyy deposits are considered. The paper is a result of result of extensive work carried out on the earth interior temperature measurements (by means of maximum mercury thermometers in idle bore-holes). More than 2, 300 temperature measurements were made at depths from 0. 2 km to 4. 0 km. The geothermal sections and maps that were constructed clearly reflect the structural environment of the earth's interior. The principal anticlinal zones as well as the deep-seated Goussan structural unit, confined to a buried uplift, are clearly shown by corresponding anomalies. At the southern end of the high-temperature zone, confined to the eastern limb of the Karachukhur-Zykh fold, in immediate proximity to the Zykh mud volcano, the highest temperature zone is located. The geothermic degree at shallow depths (less than 200-500m) is at minimum values of 20-30 meters per degree centigrade and less; increasing with depth it attains mean values of 40-80 m/°C at depths of 1 to 4 km. The geothermic degree is less in argillaceous deposits of the productive zone than in arenaceous deposits. The geothermal data may be used in, studying tectonic, lithologic and other characteristics of earth's interior structure. — Auth. English summ.