The study of cooling water discharge into British Waterways canal

Abstract

The current architectural trend is to build large complexes and manage them centrally. Numerous commercial organisations occupy small spaces in large office blocks where computing facilities are common – all generating heat. To control overall building temperatures it is a necessity to include a cooling system in the building plans at the outset. Traditional air conditioning makes use of chillers to cool the system but if the building is located in close proximity to a British Waterways canal then an environmentally friendly alternative may be available. BW estimates an additional 1000 businesses on canal sites could use canal water for cooling purposes. According to British Waterways official web site this will result in a saving of £100 million on annual energy bills and a reduction of carbon dioxide emissions by 1 million tonnes each year. This value is equivalent to 400,000 family sized cars being taken off the roads. New applications for proposed abstraction and discharge licenses are assessed and authorised by BW and are regularly monitored by the local Environmental Agency for compliance with the license and other appropriate environmental regulations. This Study uses a thermography technique to predict heat diffusion profile of thermal water discharge into rivers and canals using thermal camera. It’s provided thermal images for the surface of receiving water showing clearly the mixing zone, shape of plume and edge of plume which have been difficult to predict by mathematical models. The process applied on number of real canal sites and in laboratory to observe the actual thermal discharge. To verify the accuracy of the thermal images, the obtained data are compared with temperature measured by thermocouples on canal sites. In addition a laboratory experimental tank is built to replicate the canal sites that allow the study to be taken under variable conditions. The centerline temperature decay obtained from thermal images agreed with temperature measured by the thermocouples. This paper will be of interest to practicing engineers who deal with environmen