V O L . 7 , D O C . 6 0 a C A L C U L A T I O N S O N C O O L E R 2 1
Vol. 7, 56b. Professor Einstein on the Proposed Hebrew
University of Jerusalem
[before 3 April
1921][1]
[See documentary edition for English text.]
Vol. 7, 60a. Calculations on a Cooler
[July 1921– March
1922][1]
Given to Mr. Müller &
Nernst[2]
In isothermal compression there must be supplied:
1) work
;
2) heat
.
Hence .
The negative thereof is the total energy (per unit mass of the
working
fluid[4]
) discharged from the compressor, therefore,
according to the equation of energy, also the heat extracted or cold
discharged from the other component, if the effect of heat conduc-
tion between exchanger and compressor is neglected, which is not
always permissible. (If heat flows from exchanger to compressor,
then the amount of heat discharged outwards by the latter is con-
served, that is, also the cold discharged by the other component.) If one ignores
this, then
.
According to the second law,
hence also
and
[3]
A –pν p Δp) + ( ν Δν) + ( pΔν + νΔp = =
W Δu pΔν +=
A W + Δ( u pν) + =
K A W) + –(
∂u
∂p
----- -– ν p-----
∂ν
∂p
- Δp = =
∂u
∂p
----- -– p-----
∂ν
∂p
- T------
∂ν
∂T
=
K T------
∂ν
∂T
ν Δp =
Previous Page Next Page