Heat Condenser Evaporator

Overview

Engineering reference data for Heat Condenser Evaporator in thermodynamics.

Key Formulas

First Law

$\Delta U = Q - W$

Energy is conserved — heat added minus work done.

Ideal Gas Law

$PV = nRT$

Relates pressure, volume, and temperature of an ideal gas.

Heat Transfer

$Q = mc\Delta T$

Sensible heat transfer.

Carnot Efficiency

$\eta = 1 - T_C/T_H$

Maximum efficiency between two temperatures.

Variables

Symbol	Description	Unit
$U$	Internal energy	J
$Q$	Heat	J
$W$	Work	J
$P$	Pressure	Pa
$V$	Volume	m³
$T$	Temperature	K

Heat Load and Flow Rate Equations

The total heat load ($h$) for water systems can be calculated using the basic heat transfer equation:

$h = c_p \rho q \Delta t = 500 \cdot q \cdot \Delta t$

where:

• $h$ = heat load (Btu/h)
• $c_p = 1$ (Btu/lb·°F) - specific heat of water
• $\rho = 8.33$ (lb/gal) - density of water
• $q$ = water volume flow rate (gal/min)
• $\Delta t$ = temperature difference (°F)

Evaporator Water Flow Rate

The required water flow rate through the evaporator ($q_{evap}$) is determined by the air conditioning load:

$q_{evap} = \frac{24 \cdot h_{evap}}{\Delta t}$

where:

• $q_{evap}$ = evaporator water flow rate (gpm)
• $h_{evap}$ = air conditioning load (refrigeration tons)

Condenser Water Flow Rate

The required water flow rate through the condenser ($q_{cond}$) accounts for the additional heat of compression:

$q_{cond} = \frac{30 \cdot h_{cond}}{\Delta t}$

where:

• $q_{cond}$ = condenser water flow rate (gpm)
• $h_{cond}$ = chiller tonnage/condenser heat rejection

Refrigeration Unit Conversions

Note: The condenser heat rejection ($h_{cond}$) is approximately 1.25 times the evaporator cooling effect ($h_{evap}$), reflecting the compressor's work input. This relationship is:
$h_{cond} = h_{evap} \times 1.25$

Interactive Charts

References

• Original Source