Ministry of Education of the Republic of Azerbaijan Baku Engineering University Faculty: "Architecture and Construction". Department: "Architecture and Design". Course Title: Engineering communication systems of buildings

MATHEMATICAL EXPRESSION OF THE LAW II OF THERMODYNAMICS

Thermal FIE for the rotating Carnot cycle:

From here or .
we can write. q2 temperature T2 because it is transferred from the working body to a cold environment its sign can be perceived negatively, so or The latter equality while for elementary Carnot cycles should write. Here:

Here - is an integral obtained on all circular contours. According to (1):

^dq  Tds ⁽¹⁹⁾
is taken. This is a mathematical expression of the law of thermodynamics for open processes. (18) and According to (19):

Thermal FIE for non-rotating cycle:
here or .
we can write. If we take into account that the sign of q₂ is negative:
or is being.
İn generally or should be. For a non-rotating cycle:

you can write. For reversible and non-reversible processes according to expressions (18) and (21):
(22)
you can write. If the gas passes through a path that does not return from state 1 to state 2, and a path that changes from state 2 to state 1, then for a non-return cycle, according to expression (21) is got. Dividing the cycle into rotating and non-rotating parts, the last inequality can be written as:

Given the expression (2) for the rotating 2-1 process:
or (24)
we get. If we combine the expressions (2) and (24):

while in differential form . Here

will be taken. Expression (25) is a mathematical expression of the law term of thermodynamics.