A release of hot water/steam may result in persons in the vicinity sustaining burns and, depending on the burn-degree and amount of skin being burned, ultimately become fatality injured. With (district) heating networks being increasingly applied to transport residual heat from industry to users, our client required insight in associated risks. With no regulatory guidance on determining the risk due to contact with hot water/steam, we had to define criteria for this specific type of accident ourselves.
We performed a desktop study on the sustained degree of burns when the skin temperature becomes elevated for a certain period of time (based upon publicly available information on heat transfer to the skin surface in case of exposure to heat radiation or conduction). Based on this information and information on expected response from persons confronted with a release, we derived acceptance criteria for the degree of burns and related fatality. We determined effect distances in terms of vapour (cloud) temperature in relation to distance from the leak source. By combining this information with statistics on the frequency of a leak we were able to present a risk profile of the district heating network under study.
Our client gained insight in the course of a release, the response of persons when confronted with a release & associated injury, and the risk profile for this specific heat distribution network.