Contrec 515 – HC12

Heat Calculator - Analogue Flow (Mass)

The 515 HC12 application measures the volume, mass and energy content of fluid in a heating or cooling system by using an analog mass flow input in conjunction with analog feed and return temperature inputs.

A selection of fluid types and modes makes it suitable for many heating/cooling applications. The flowmeter input signal can be selected as either 0-5V, 1-5Vor 4-20mA. Minimum and maximum points are programmed and non-linear correction points can be used to better reflect the flowmeters behaviour.

The instrument calculates the mass flow and energy according to the IAPWS Industrial Formulation (1997) when the fluid type is water, while internal enthalpy and density tables are used for the selection of other industry fluids.

CALCULATIONS

The instrument can calculate the mass and energy for the following common industry fluids:

Water
Glycol (35% Solution)
Brine (27% CaC2)
TYFOXIT F20
TYFOXIT F40
Essotherm 500/Thermaloil
THERMINOL 55
User Custom Fluid
Formulas

volume flow = mass flow/ρflow

power = mass flow x (hTF – hTR)

where:

ρflow = density at flow conditions

hTF = Specific enthalpy at feed temperature

hTR = Specific enthalpy at return temperature