Heat Distribution Point

an equipment complex used in allocating heat from a heat supply net among customers according to the required form (hot water or steam) and characteristics (such as pressure and temperature) of the heat-transport medium. Heat distribution points contain equipment to regulate and meter the flow of heat. In systems that furnish steam to customers, the heat distribution points usually contain equipment to reduce the steam temperature and pressure to required levels, as well as equipment to collect and return condensate to the heat supply source.

In systems that distribute hot water for public and residential use, the heat distribution points are usually fitted with a mixing device that lowers the temperature of the water from the heat supply net to the value prescribed for such uses as comfort heating. The most widely used mixing devices in the USSR are ejectors, although centrifugal pumps are also found. Heat distribution points in independent heat supply systems contain water-to-water heat exchangers for comfort heating. Heat distribution points of closed systems contain water-to-water heat exchangers for hot-water supply systems. These are usually two-stage heaters that allow the amount of water in the heat supply net to be kept at a minimum. Heat distribution points in open systems are usually provided with valves for diluting the water entering the hot-water supply system from the delivery and return lines of the heat supply net; after dilution, the water is automatically maintained at a prescribed temperature.

Heat distribution points may serve a single building or part of a building, in which case they are normally located in the building’s basement. Other types serve groups of buildings and are usually housed in a separate structure; in closed heat supply systems, these distribution points are called district heat distribution points. They contain heaters (heat exchangers) and circulation pumps to maintain the hot-water supply at the required temperature and pressure at points where the water is tapped. When necessary, district heat distribution points have pumps for the coldwater supply, fire pumps, and other equipment for the district served.