Doherty Engineering provided engineering services relating to the installation of a new feedwater economizer. Doherty was required to determine the viable location for installation of a new economizer on a boiler flue gas stack. The services provided included a feasibility study, detailed design and tender documents, and tendering services.

Doherty Engineering completed an energy management plan (EMP) looking at the benefits of adding a cogeneration system with a thorough comparison between gas turbines and steam turbines as the prime mover. The services provided included a review of the energy plan information, energy management policy and best practices, energy baseline, identified conservation capital projects, operation savings and employee awareness plan, energy opportunity identification and analysis, and implementation budget.

Doherty Engineering was retained for a 25 MW biomass plant in Ajax, ON. DEI prepared preliminary and detailed feasibility studies for the biomass cogeneration plant and district energy system, comparing business-as-usual versus business with biomass district energy. Subsequent to the studies, DEI completed the front-end engineering and design (FEED) documentation, developed the tender packages under an EPC framework, managed the turnkey tender process and performed the role of Owner’s Engineer during the detailed engineering design and construction phases, which includes the full complement of contract administration services. The plant generates high pressure superheated steam (550 psig) from wood-fired stoker type combustors. Steam passes through a back pressure turbine, followed by two condensing turbines, each producing approximately 9 MW. The facility includes all balance of plant equipment, such as deaerator, boiler feed, condensate, chemical treatment, steam condensers, cooling towers, lube oil, hydraulic power, wood fuel conveying systems, and wood fuel storage. This facility is one of the few biomass-fired power plants in Ontario and provides steam to an expansive district steam-heating system in the surrounding area. Highlights of the project include: • Three (3) nominal 9 MW steam turbine generators; • Two (2) biomass combustor trains; • Flue gas heat recovery (near condensing); • One (1) 300 MMBTU/hr, 20,000 GPM, 8 cell cross flow cooling tower; • Connection to existing steam distribution network

Doherty Engineering was retained to transition a nuclear plant from its prior electricity generating operation into a Safe Storage State (“SSS”), where the plant is to remain in SSS for 30 years. The project scope involved determining and analyzing future heating and ventilation loads and identifying heating and ventilation technologies. Heating options analyzed included: Natural gas auxiliary boilers; diesel fired auxiliary boilers; cogeneration/combined heat and power; auxiliary boilers (propane fired); auxiliary boilers (electric); water sourced heat pumps; electrical resistance heating; ethanol fired boilers; biomass boilers; solar thermal; geothermal; biomass combined heat and power. High level capital cost estimates were developed for each technology as well.

Doherty Engineering Inc. (“DEI”) conducted a preliminary study on a University campus’ heating systems, which are supplied by a central heating plant steam distribution network. The study involved completing a condition assessment of the existing building heating systems, modelling current heating loads based on metering steam and condensate data, developing a conceptual design for heating the buildings, estimating energy savings and reductions in greenhouse has emissions (GHGs), life cycle costing analysis and completing a preliminary cost estimate for implementation of the project. Work culminated in the preparation of a report summarizing the results of the study, including conceptual drawings for a new central heating plant. The preliminary study led to the detailed engineering design for this new central heating plant. Engineering work included the design of hot water distribution piping, as well as retrofit work in existing buildings to facilitate the conversion from steam to hot water heating, including hydronic heating systems and domestic hot water. DEI prepared all design, development and construction documents, assisting the University in the management of the tender process and completing contract administration services throughout construction.

Doherty Engineering conducted a detailed feasibility assessment and recommendation development of a Campus Energy Centre Roadmap, hereinafter the “Roadmap”, as well as full engineering design services for the development of a new “Chiller Centre”. The Roadmap will serve to inform the college on future projects to meet requirements of projected campus growth.

Doherty Engineering Inc. (“DEI”) was engaged to provide recommendations regarding a new chiller plant of 170 Tons. The existing chilled water plant was installed with the original building and was approximately 30 years old. The existing chiller was a CFC based refrigerant and asbestos surrounding the existing piping. The cooling tower was in need of repair and all existing equipment operated with low efficiency. DEI provided the detailed design, managed the tendering process, construction inspections and final acceptance of the new chiller plant. In addition, DEI located funding for a portion of the capital expense. Overall, the project was executed on time with the mechanical contractor and under budget.

Doherty Engineering Inc. (“DEI”) assisted with works and field surveillance associated with an auxiliary boiler procurement and installation. DEI took on the role of Owner’s Engineer and managed the boiler’s procurement, erection, tie-in, and start-up cycle. As Owner’s Engineer, DEI provided project management services, and supported the work across several aspects throughout project completion by providing recommendations and problem resolution on technical matters. DEI reviewed boiler inspection and test plans to ensure consistency and compliance between the two. DEI coordinated with contractors and sub-contractors to verify that procedures and work practices were conducted in accordance with technical requirements specified. A detailed final report and comprehensive project turnover document set was provided to the client.

Doherty Engineering designed the steam and condensate connection of two buildings to their district energy system. Each project was an extension of their steam distribution system into new buildings that were being constructed on site. The projects involved redesigning the manholes to take new connections, designing the shallow inverted trench distribution system according to the standards required and looking at the requirements of each of the buildings and extending the systems into the buildings’ heat exchanger and condensate return systems. The projects both required coordinating documents with the building contractor.

Doherty Engineering Inc. (“DEI”) provided engineering services related to the design and implementation of a tower free cooling system to offset chilled water use at a Toronto commercial building. DEI reviewed the existing cooling tower system and conducted a survey of the mechanical room and contained equipment in order to prepare a construction budget estimate and calculate potential energy savings. DEI prepared drawings and specifications to issue for tender. Once tendered, DEI initiated and oversaw the contract bidding process, bidding close-out and tender review. Additionally, DEI provided project management services, issued supplementary details and instructions during the construction period, reviewed process schedules, shop drawings, samples, reports, and manuals submitted by the contractor and processed change orders and payment requests. DEI attended site meetings and assisted in the coordination of, and inspection of the work in progress. A final inspection was arranged and performed, including issuing a deficiencies list and certificate of acceptance upon deficiencies rectification.