Plate heat exchanger

The present utility model provides a plate heat exchanger comprising: a plurality of heat transfer plates stacked in a first direction, the heat transfer plates having a heat transfer plate edge at one side in a second direction perpendicular to the first direction; first and second fluid passages formed between adjacent heat transfer plates and fluidly isolated from each other; two first ports formed in the heat transfer plate at the one side and the other side thereof, respectively, which are opposite in the second direction, and in fluid communication with the first fluid passage; and a hole formed in the heat transfer plate between one of the two first ports on the one side and an edge of the heat transfer plate in the second direction, in fluid communication with the first fluid passage and in fluid isolation from the second fluid passage. By providing holes in the bottom area of the plate heat exchanger, excessive water remaining in the plate heat exchanger under non-use conditions is avoided to prevent ice formation in the plate heat exchanger.