Final control questions on the subject “heat engineering” The purpose and function of the subject. Working parameter. Status parameters. Base words and phrases

 
Base words and phrases: radiation, white , black body, transparent, laws,parallel plates 
 
In the field of high-temperature heat engineering, radiant heat exchange is 
faster than other heat exchange methods. Therefore, when creating aggregates 
working at high temperatures, it is necessary to take into account the high use of 
radiant heat exchange. This applies primarily to boilers and industrial furnaces. Such 
furnaces are widely used in construction materials enterprises, in the production of 
cement, lime, fireclay and other materials. 
Radiation energy mainly depends on the physical properties and temperature of the 
body emitting light. Electromagnetic waves differ in wavelength or frequency of 
vibration. If we denote the wavelength λ and the vibration frequency by N, then the 
velocity in vacuum for all rays is w=λN=3∙10
8
m/s. 

---

A photon is accepted as a particle that carries light energy. A photon (Greek rhos 
(rhotos) - light) has a certain mass when it is moving, and its mass is zero when it is 
at rest. 
A part of all the light energy Q falling on the surface of the body is absorbed by the 
body QA, a part QR returns from it, and the rest QD passes through the body, i.e. 
Q=Q
A
+Q
R
+Q
D
(10.3) 
The totality of the processes of radiation energy distribution, absorption, return and 
transfer is called radiant heat exchange. 
If we divide both parts of the equation (10.3) by the total amount of light energy Q, 
we get the following: 
(10.4)
,
1
Q
Q
Q
Q
Q
Q






D
R
A
D
R
A
here 
Q
Q
,
Q
Q
,
Q
Q
D
R
A
D
R
A



- describe absorption, repulsion, and transmission, 
respectively (Figure 10.1).
(10.4)
The equation is called the radiant energy heat balance equation.