HPRATE manual        Air Conditioner performance rating

The HPRATE simulation package is a graphical interface to the ORNL MkV heat pump model developed by the Oak Ridge National Laboratory Tennessee for the USA Department of Energy. The program predicts the steady state performance of electrically driven, vapour compression, air-air heat pumps in both heating and cooling modes.

The features of the model adopted within the HPRATE graphical front end allow the user to specify:

System operating conditions

·       Indoor and outdoor air wet and dry bulb temperatures

·       The arrangement of the compressor and fans in the air flow stream.

Compressor characteristics

Refrigerant flow control devices

·       Specified refrigerant sub-cooling at the condenser exit

·       A capillary tube or TX valve

Fin and tube heat exchangers

·       Tube size, spacing, number of rows and parallel circuits

·       Fin pitch, thickness, material and type of fin (smooth, wavy or louvered)

·       Air flow rates

Refrigerants                CFC  :  R12, R114, R502

HCFC : R22, R123, R124

Single component HFC : R134a, R32, R125, R143a, R152a

Azeotropic mixtures : R32/R125 (60/40), R143a/R125 (55/45), R410a, R507, R404a

Hydrocarbon : R290 (propane)

Refrigerant lines

·       Lengths and diameters of interconnecting pipes

·       Measured pressure drops in pipes and coils (if available)

·       Heat losses from suction, discharge and liquid lines

The main restriction in the current model is that the user cannot specify the refrigerant charge, instead it is assumed that the system is charged with the correct amount of refrigerant for the specified operating conditions. This is a satisfactory model for systems having a suction line accumulator which can store excess refrigerant and maintain a low compressor inlet superheat.  For charge sensitive systems, the performance for a given refrigerant charge cannot be accurately modelled for different operating conditions unless the level of compressor inlet superheat is known for each operating point.

The output from HPRATE includes

·       Capacity and COP

·       Compressor power consumption

·       Output dry and wet bulb air temperatures

·       Refrigerant pressure drops

·       Refrigerant states throughout the cycle.

·       Sensible and latent heat capacities

COMPUTER REQUIREMENTS  IBM compatible PC

The program is available from

Em Prof Graham Morrison
Thermal Design Pty Ltd
Phone 0425 212 218
t_design@tpg.com.au

HPRATE manual