Hydraulic Analysis of Oil Spill Control Systems in Transformer Stations

Electrical transformer stations use transformer oil to increase the efficiency of the electrical voltage transfer and to reduce the moisture and air in an electrical transformer. Each year, there is a high probability of spilling the transformer oil accidentally into the environment. Some spill events contain large volume of transformer oil. The objective of this thesis is to investigate oil spill control systems for spilled transformer oil during all operating and weathering conditions at a Hydro One's transformer station near the city of Burlington. This thesis examines the design of (1) oil trap systems which trap the spilled transformer oil and (2) the oil back-up systems thick back up the transformer oil spills to the transformer station. This research focuses primarily on Hydro One's transformer stations and the normal operation conditions in Ontario.

Control of oil spills in urban areas

The City of Toronto has experienced about 300 oil spills per year (Li 1997). Traditionally, the city recommends that businesses and industries practise pollution prevention and install on-site oil separators. Currently, the sizing criteria for these devices are not well defined and the draft code of practices for oil separators by the Canadian Petroleum Product Institute (1994) has not yet been approved by the Ministry of the Environment (Li 2000). Thus, the city is currently investigating the possibility of installing oil separators at spill prone sewer outfalls. The new application of oil separators at sewer outfalls requires that the devices be operable under high flow conditions and that their capacity should reflect the land use characteristics in the associated sewershed. This study has developed an innovative spill control device for the Humber Creek outfall and a Geographic Information System (GIS)-based analysis technique for urban oil spill management. First, a flow diversion structure was designed to capture the dry weather flow at the outfan and to transport the captured flow into an oil/water separator designed in accordance to the American Petroleum Institute's manual (1990). The designs of the flow diversion structure and the oil/water separator were evaluated by a physical model study using the National Water Research Institute's Hydraulics Laboratory at the Canada Centre for Inland Waters in Burlington, Ontario. Then, the GIS-based analysis technique was used to identify potential treatment options for spill-prone sewer outfall in the Town of Richmond Hill. It was found that (I) the spill event characteristics should be analyzed in order to develop design criteria for oil spill control systems; (2) the preliminary design of the oil spill control system at Humber Creek was different from the API's methodology; and (3) the physical model investigation confirmed the conveyance capacity of the diversion channel and the general behaviour of the tilted-plate separator. A database of oil spill records in the Greater Toronto Area from 1988 to 2000 were compiled and geo-referenced. By overlaying the spill characteristics and other GIS data layers, such as woodlots, wetlands and watercourses, spill prone areas were identified. In order to increase the accuracy of the analysis, the percentage of georeference oil spill locations should be increased.

Control of oil spills in urban areas

The City of Toronto has experienced about 300 oil spills per year (Li 1997). Traditionally, the city recommends that businesses and industries practise pollution prevention and install on-site oil separators. Currently, the sizing criteria for these devices are not well defined and the draft code of practices for oil separators by the Canadian Petroleum Product Institute (1994) has not yet been approved by the Ministry of the Environment (Li 2000). Thus, the city is currently investigating the possibility of installing oil separators at spill prone sewer outfalls. The new application of oil separators at sewer outfalls requires that the devices be operable under high flow conditions and that their capacity should reflect the land use characteristics in the associated sewershed. This study has developed an innovative spill control device for the Humber Creek outfall and a Geographic Information System (GIS)-based analysis technique for urban oil spill management. First, a flow diversion structure was designed to capture the dry weather flow at the outfan and to transport the captured flow into an oil/water separator designed in accordance to the American Petroleum Institute's manual (1990). The designs of the flow diversion structure and the oil/water separator were evaluated by a physical model study using the National Water Research Institute's Hydraulics Laboratory at the Canada Centre for Inland Waters in Burlington, Ontario. Then, the GIS-based analysis technique was used to identify potential treatment options for spill-prone sewer outfall in the Town of Richmond Hill. It was found that (I) the spill event characteristics should be analyzed in order to develop design criteria for oil spill control systems; (2) the preliminary design of the oil spill control system at Humber Creek was different from the API's methodology; and (3) the physical model investigation confirmed the conveyance capacity of the diversion channel and the general behaviour of the tilted-plate separator. A database of oil spill records in the Greater Toronto Area from 1988 to 2000 were compiled and geo-referenced. By overlaying the spill characteristics and other GIS data layers, such as woodlots, wetlands and watercourses, spill prone areas were identified. In order to increase the accuracy of the analysis, the percentage of georeference oil spill locations should be increased.

Hydraulic Analysis of Oil Spill Control Systems in Transformer Stations

Electrical transformer stations use transformer oil to increase the efficiency of the electrical voltage transfer and to reduce the moisture and air in an electrical transformer. Each year, there is a high probability of spilling the transformer oil accidentally into the environment. Some spill events contain large volume of transformer oil. The objective of this thesis is to investigate oil spill control systems for spilled transformer oil during all operating and weathering conditions at a Hydro One's transformer station near the city of Burlington. This thesis examines the design of (1) oil trap systems which trap the spilled transformer oil and (2) the oil back-up systems thick back up the transformer oil spills to the transformer station. This research focuses primarily on Hydro One's transformer stations and the normal operation conditions in Ontario.