The VRF curve system model in energyplus has a specific performance curve to modify the EIR as a function of the part-load ratio (PLR) when the PLR is greater than 1.
However, actually the PLR will never be greater than 1 during the simulation, because the algorithm limits the indoor units capacity to match PLR=1 (as described in Engineering reference v9.5, page 1183). In fact, the outdoor unit can't provide more capacity than its maximum available capacity. So in practice, this performance curve is never used.
I thought that this performance curve was useful to introduce power input data for a Combination Ratio (CR) greater than 100%. But in this situation the PLR isn't greater than 1 as well, since the maximum available capacity of the outdoor unit already includes the Combination Ratio correction (page 1179, equation 16.449). However, the cooling power calculation (page 1186, equation 16.461) modifier curves doesn't include any correction as a function of CR.
Am I right about the PLR calculation? And if so, is there any specific input that I'm missing for taking into account the change in the reference power input when CR>100%? Something similar to the Combination Ratio correction factor, but applied to the power input calculation.
