heat exchange

Дослідження впливу випаровування і конвекції на процес відведення тепла з поверхні пластини

Побудовано нелінійну модель процесу теплообміну в плоскій пластині, з поверхні якої в навколишнє середовище розсіюється теплова енергія за рахунок випаровування рідини і конвекції. Нелінійну модель зведено до лінійної. Отримано аналітичний розв’язок лінійної модельної задачі. Здійснено порівняння кількості відведеного тепла за рахунок випаровування та конвекції.

Thermoeconomic Model of Air Conditioning System

The mathematical model of the air conditioning system has been developed. It is based on the analysis of thermoeconomic energy efficiency indicators and it is solved in a complex way: by defining the optimal parameters taking into account the non-stationary heat of the tides and by determining the optimal device for optimizing the operating modes of the refrigeration system. When designing an air-conditioning system, a thermoeconomic analysis was made for an object being created.

MATHEMATICAL MODELS OF HEAT TRANSFER IN ELEMENTS OF TURBOGENERATORS

Se­pa­ra­te mat­he­ma­ti­cal mo­dels for de­ter­mi­ning the tem­pe­ra­tu­re distri­bu­ti­on in the ele­ments of tur­bo­ge­ne­ra­tors ha­ve be­en de­ve­lo­ped, which are descri­bed ge­omet­ri­cally by an isot­ro­pic half-spa­ce and a he­at-sen­si­ti­ve spa­ce with lo­cally con­centra­ted so­ur­ces of he­ating. For this pur­po­se, using the the­ory of ge­ne­ra­li­zed functi­ons in a con­ve­ni­ent form, we wri­te the ini­ti­al dif­fe­ren­ti­al eq­ua­ti­ons of ther­mal con­duc­ti­vity with bo­un­dary con­di­ti­ons.

STUDY OF THE TEMPERATURE FIELDS IN THERMOTRANSDUCER’S CASE

The choice of ways of obtaining information about the temperature of the surface layers of a moving object is the crucial in determining  the  type of  temperature transducers. This choice depends on  the  row of specific  factors:  the speed of movement of the measured object relative the object, the state of the surface, the presence of related agents in near-surface layers, the presence of disturbing factors - noise, vibration, etc. The major factor seems to be the value of the heat carried out from the diagnosed object with the help of intermediate substance. 

Heat Exchange between Thermometer Well and Pipe Wall in Natural Gas Metering Systems

This paper deals with the accuracy of gas flow temperature measurement in natural gas metering systems. The effect of heat exchange between thermometer well and the pipe wall on the accuracy of gas flow temperature measurement is investigated. A mathematical model is proposed to calculate the additional systematic error of gas flow temperature measurement caused by heat exchange between thermometer well and the pipe wall. Calculation results were compared to the corresponding experimental values of this error.