STUDY OF THE INFLUENCE OF COVERINGS OF EXTENDED RADIATING PIPES ON THEM HEAT RADIATION, WHEN HEATING LARGE OBJECTS AND HEATING INDUSTRIAL ROOMS

Autor: V.S. Pikashov, V.A. Velikodny, T.V. Vinogradova, L.N. Trotsenko
Rok vydání: 2020
Předmět:
Zdroj: Energy Technologies & Resource Saving. :19-26
ISSN: 2664-3561
2413-7723
DOI: 10.33070/etars.2.2020.03
Popis: It is shown that for heating rooms and objects large in length and volume, the use of extended emitting pipes is most appropriate. A method for heating extended objects is described, in which the principle of radiation from radiating pipes with a length of more than 30 m is used in a garage-defroster of railway cars. The heating system of the garage-defroster includes a firebox-heat generator, long pipes of 90 m along the wagons, the control and instrumentation system A. The firebox and the control and instrumentation cabinets are installed in a separate room. The defrost system circuit is essentially a large emitter. The entire heat-radiating circuit is a closed system of direct and return pipes through which a low-temperature (300–400 °C) coolant circulates. The industrial operation of such a system at one of the Ukrainian factories has confirmed the advantages in comparison with the known defrosting systems: reliability, easy operation, high efficiency, safety and environmental friendliness, low capital costs, a minimum of instrumentation and automation, minimal thermal inertia. Ways of increasing the uniformity of temperature and heat radiation from pipes are considered: recirculation of the coolant in the working circuit and applying coatings with different emissivity to the pipe surface. So, with a recirculation rate of the coolant in the working circuit of the industrial defrosting system from 3 to 5, the temperature difference between the surface of the emitting pipes at the first and distant cars was 100 or more degrees. Therefore, cars that are closer to the coolant entrance to the system defrosted faster than others. Two new methods for controlling the radiation intensity of long pipes along their length are proposed: coating coatings with different emissivity on the surface of pipes and coating with maximum and minimum emissivity, which alternate between themselves, around the perimeter of the rings. The results of laboratory experiments on the dependence of the heat radiation of pipes on the methods of applying special coatings to them are shown, which showed that coating in a certain order allows you to change the nature of the distribution of temperatures and heat radiation on surrounding surfaces, significantly reducing their decrease along the length of the radiating pipe. Ref. 18, Fig. 4.
Databáze: OpenAIRE
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