Fred,
I think you will have to modify Type668 to do that. I suggest you take a look at Type666 water-cooled chiller which works at part load by defining a setpoint on outlet load temperature. Instead of calculating part load ratio as a result of desired outlet water temperature, you can directly specify 10%, 50% and so on. You will also need some data on fraction of full load power at given part load ratio, to properly model heat pump performance at part load.
Hope this helps.
Best regards,
Knut Erik Enerstvedt
>Does anyone know of a way to make part load operation work in Type668?
>The performance maps are based on entering conditions on the evaporator and condenser side. However, there is no direct way to >make type668 run at 10%, 50%, etc.
>The work around I have used in the past is dividing the performance map by 50% to reflect two stages of operation and so on. Then >setting up valves and controls to route the flow correctly.
>The HP I am modeling has a 10:1 turn down ratio and I don’t want to make 10 heat pumps each with 10% of the total capacity of a >single unit.
>Please advise,
>Fred