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74-610: The plant is located at 440 Unwin Avenue in Toronto's Port Lands area, directly south of the foot of Carlaw Avenue, across the shipping channel and next to the recently opened Portlands Energy Centre . The Richard L. Hearn Generating Station, together with the nearby Ashbridges Bay Wastewater Treatment Plant sewage sludge incinerator stack and the Commissioners Street waste incinerator stack, stand as towering landmarks of

148-513: A heat recovery steam generator (HRSG) with a live steam temperature between 420 and 580 °C. The condenser of the Rankine cycle is usually cooled by water from a lake, river, sea or cooling towers . This temperature can be as low as 15 °C. Plant size is important in the cost of the plant. The larger plant sizes benefit from economies of scale (lower initial cost per kilowatt) and improved efficiency. For large-scale power generation,

222-722: A steam power plant (operating by the Rankine cycle ). This is a combined cycle gas turbine (CCGT) plant. These achieve a best-of-class real (see below) thermal efficiency of around 64% in base-load operation. In contrast, a single cycle steam power plant is limited to efficiencies from 35 to 42%. Many new power plants utilize CCGTs. Stationary CCGTs burn natural gas or synthesis gas from coal . Ships burn fuel oil . Multiple stage turbine or steam cycles can also be used, but CCGT plants have advantages for both electricity generation and marine power. The gas turbine cycle can often start very quickly, which gives immediate power. This avoids

296-430: A 50.00 MJ/kg (21,500 BTU/lb) LHV: a 11% increase. Efficiency of the turbine is increased when combustion can run hotter, so the working fluid expands more. Therefore, efficiency is limited by whether the first stage of turbine blades can survive higher temperatures. Cooling and materials research are continuing. A common technique, adopted from aircraft, is to pressurise hot-stage turbine blades with coolant. This

370-634: A backup or supplementary power. It is named after American professor D. Y. Cheng who patented the design in 1976. The efficiency of a heat engine, the fraction of input heat energy that can be converted to useful work, is limited by the temperature difference between the heat entering the engine and the exhaust heat leaving the engine. In a thermal power station , water is the working medium. High pressure steam requires strong, bulky components. High temperatures require expensive alloys made from nickel or cobalt , rather than inexpensive steel . These alloys limit practical steam temperatures to 655 °C while

444-400: A bit taller than the first five. The eight short chimneys were a source of air pollution in local neighborhoods and downtown Toronto and also fly ash and other particulates. The station contributed to Toronto's smog problem. The eight chimneys were demolished and electrostatic precipitators were added for the 200 MW units when the large smokestack was built. The new single tall smokestack

518-415: A business add plant capacity as it is needed. Multiple-pressure reheat steam cycles are applied to combined-cycle systems with gas turbines with exhaust gas temperatures near 600 °C. Single- and multiple-pressure non-reheat steam cycles are applied to combined-cycle systems with gas turbines that have exhaust gas temperatures of 540 °C or less. Selection of the steam cycle for a specific application

592-530: A bygone industrial era in the Portlands area of Toronto (all three facilities are no longer in operation, but their towering smokestacks still stand). The property was sold to Studios of America in 2018. The R. L. Hearn Generating Station was the site of Canada's first 100 MW steam turbo-generator set. The station sits in what was once Ashbridge's Bay , a shallow marsh that was filled in with rubble from downtown construction sites from 1911 to 1950s. The station

666-449: A combined heat and power (CHP) plant. In general, combined cycle efficiencies in service are over 50% on a lower heating value and Gross Output basis. Most combined cycle units, especially the larger units, have peak, steady-state efficiencies on the LHV basis of 55 to 59%. A limitation of combined cycles is that efficiency is reduced when not running at continuous output. During start up,

740-532: A location shoot for the Star Trek: Discovery episode "Brother". Additionally, it was used as a film location for Shazam! . Furthermore, the station was also used as a filming location for Disney Channel original films (DCOM) Zombies 2 , known formally in the Disney trilogy as Seabrook Power and is where the musical number 'Flesh & Bone' takes place. On June 5, 2014, the building was used for

814-520: A marine CCGT safer by permitting a ship to operate with equipment failures. A flexible stationary plant can make more money. Duct burning raises the flue temperature, which increases the quantity or temperature of the steam (e.g. to 84 bar, 525 degree Celsius). This improves the efficiency of the steam cycle. Supplementary firing lets the plant respond to fluctuations of electrical load, because duct burners can have very good efficiency with partial loads. It can enable higher steam production to compensate for

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888-552: A means of load control or load shifting since ice can be made during periods of low power demand and, potentially in the future the anticipated high availability of other resources such as renewables during certain periods. Combustion technology is a proprietary but very active area of research, because fuels, gasification and carburation all affect fuel efficiency. A typical focus is to combine aerodynamic and chemical computer simulations to find combustor designs that assure complete fuel burn up, yet minimize both pollution and dilution of

962-422: A more efficient steam cycle. However, a multi-shaft system is about 5% higher in initial cost. The overall plant size and the associated number of gas turbines required can also determine which type of plant is more economical. A collection of single shaft combined cycle power plants can be more costly to operate and maintain, because there are more pieces of equipment. However, it can save interest costs by letting

1036-407: A percentage of the lower heating value of the fuel consumed, can be over 60% when operating new, i.e. unaged, and at continuous output which are ideal conditions. As with single cycle thermal units, combined cycle units may also deliver low temperature heat energy for industrial processes, district heating and other uses. This is called cogeneration and such power plants are often referred to as

1110-451: A second plant, while nearby residents opposed any kind of power generation plant in the area. A proposal was made by Enwave (the former Toronto District Heating Corporation) and Constellation Energy to install advanced gas turbines and cogeneration inside the station and restore the station's control rooms, turbine hall and building exterior as a historical, filmmaking and education centre. The Minister of Energy, Donna Cansfield rejected

1184-431: A simple cycle, to as much as 64% net for the turbine alone in specified conditions for a combined cycle. Historically successful combined cycles have used mercury vapour turbines , magnetohydrodynamic generators and molten carbonate fuel cells , with steam plants for the low temperature "bottoming" cycle. Very low temperature bottoming cycles have been too costly due to the very large sizes of equipment needed to handle

1258-434: A single electrical generator on a single shaft. This arrangement is simpler to operate, smaller, with a lower startup cost. Single-shaft arrangements can have less flexibility and reliability than multi-shaft systems. With some expense, there are ways to add operational flexibility: Most often, the operator desires to operate the gas turbine as a peaking plant. In these plants, the steam turbine's shaft can be disconnected with

1332-602: A synchro-self-shifting (SSS) clutch, for start up or for simple cycle operation of the gas turbine. Another less common set of options enable more heat or standalone operation of the steam turbine to increase reliability: Duct burning, perhaps with a fresh air blower in the duct and a clutch on the gas turbine side of the shaft. A multi-shaft system usually has only one steam system for up to three gas turbines. Having only one large steam turbine and heat sink has economies of scale and can have lower cost operations and maintenance. A larger steam turbine can also use higher pressures, for

1406-564: A thermodynamic cycle that operates between the gas-turbine's high firing temperature and the waste heat temperature from the condensers of the steam cycle. This large range means that the Carnot efficiency of the cycle is high. The actual efficiency, while lower than the Carnot efficiency, is still higher than that of either plant on its own. The electric efficiency of a combined cycle power station, if calculated as electric energy produced as

1480-626: A typical set would be a 270 MW primary gas turbine coupled to a 130 MW secondary steam turbine, giving a total output of 400 MW. A typical power station might consist of between 1 and 6 such sets. Gas turbines for large-scale power generation are manufactured by at least four separate groups – General Electric, Siemens, Mitsubishi-Hitachi, and Ansaldo Energia. These groups are also developing, testing and/or marketing gas turbine sizes in excess of 300 MW (for 60 Hz applications) and 400 MW (for 50 Hz applications). Combined cycle units are made up of one or more such gas turbines, each with

1554-478: A waste heat steam generator arranged to supply steam to a single or multiple steam turbines, thus forming a combined cycle block or unit. Combined cycle block sizes offered by three major manufacturers (Alstom, General Electric and Siemens) can range anywhere from 50 MW to well over 1300 MW with costs approaching $ 670/kW. The heat recovery boiler is item 5 in the COGAS figure shown above. Hot gas turbine exhaust enters

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1628-430: A water washing procedure. A simpler and less expensive purification system will do the same job for light crude and light distillates. A magnesium additive system may also be needed to reduce the corrosive effects if vanadium is present. Fuels requiring such treatment must have a separate fuel-treatment plant and a system of accurate fuel monitoring to assure reliable, low-maintenance operation of gas turbines. Xcel Energy

1702-508: A wider range of temperatures or heat to electric power. Systems burning low quality fuels such as brown coal or peat might use relatively expensive closed-cycle helium turbines as the topping cycle to avoid even more expensive fuel processing and gasification that would be needed by a conventional gas turbine. A typical single-shaft system has one gas turbine, one steam turbine, one generator and one heat recovery steam generator (HRSG). The gas turbine and steam turbine are both coupled in tandem to

1776-406: Is a simplified form of combined cycle where the steam turbine is eliminated by injecting steam directly into the combustion turbine. This has been used since the mid 1970s and allows recovery of waste heat with less total complexity, but at the loss of the additional power and redundancy of a true combined cycle system. It has no additional steam turbine or generator, and therefore it cannot be used as

1850-471: Is also bled-off in proprietary ways to improve the aerodynamic efficiencies of the turbine blades. Different vendors have experimented with different coolants. Air is common but steam is increasingly used. Some vendors might now utilize single-crystal turbine blades in the hot section, a technique already common in military aircraft engines. The efficiency of CCGT and GT can also be boosted by pre-cooling combustion air. This increases its density, also increasing

1924-419: Is also some development of modified Rankine cycles. Two promising areas are ammonia/water mixtures, and turbines that utilize supercritical carbon dioxide. Modern CCGT plants also need software that is precisely tuned to every choice of fuel, equipment, temperature, humidity and pressure. When a plant is improved, the software becomes a moving target. CCGT software is also expensive to test, because actual time

1998-418: Is determined by an economic evaluation that considers a plant's installed cost, fuel cost and quality, duty cycle, and the costs of interest, business risks, and operations and maintenance. By combining both gas and steam cycles, high input temperatures and low output temperatures can be achieved. The efficiency of the cycles add, because they are powered by the same fuel source. So, a combined cycle plant has

2072-941: Is going to build two natural gas power plants in the Midwestern United States that can mix 30% hydrogen with the natural gas. Intermountain Power Plant is being retrofitted to a natural gas/hydrogen power plant that can run on 30% hydrogen as well, and is scheduled to run on pure hydrogen by 2045. However others think low-carbon hydrogen should be used for things which are harder to decarbonize , such as making fertilizer , so there may not be enough for electricity generation. Combined-cycle systems can have single-shaft or multi-shaft configurations. Also, there are several configurations of steam systems. The most fuel-efficient power generation cycles use an unfired heat recovery steam generator (HRSG) with modular pre-engineered components. These unfired steam cycles are also

2146-479: Is often readily available in rural areas. Gas turbines burn mainly natural gas and light oil. Crude oil, residual, and some distillates contain corrosive components and as such require fuel treatment equipment. In addition, ash deposits from these fuels result in gas turbine deratings of up to 15%. They may still be economically attractive fuels however, particularly in combined-cycle plants. Sodium and potassium are removed from residual, crude and heavy distillates by

2220-482: Is supplied to the low-temperature turbine. A super heater can be provided in the low-pressure circuit. Some part of the feed water from the low-pressure zone is transferred to the high-pressure economizer by a booster pump . This economizer heats up the water to its saturation temperature . This saturated water goes through the high-temperature zone of the boiler and is supplied to the high-pressure turbine . The HRSG can be designed to burn supplementary fuel after

2294-410: Is the gas turbine power plant cycle is the topping cycle. It depicts the heat and work transfer process taking place in the high temperature region. The cycle a-b-c-d-e-f-a which is the Rankine steam cycle takes place at a lower temperature and is known as the bottoming cycle. Transfer of heat energy from high temperature exhaust gas to water and steam takes place in a waste heat recovery boiler in

Hearn Generating Station - Misplaced Pages Continue

2368-480: Is too close to the Portlands natural gas generating plant. The nearly abandoned plant attracted photographers and urban explorers who published their work on websites and in photography exhibits in recent years. On June 15, 2008, Ryan Nyenhuis, an urban explorer trespassing in the plant fell three storeys into a coal chute, and was trapped for three hours when he became pinned under a steel plate. He suffered serious injuries and died two days later in hospital. During

2442-503: The Canadian Union of Operating Engineers and General Workers (CUOE Local 100) in 1960. The Richard L. Hearn plant reached full capacity of 1200 MW for the first time on March 22, 1961. At full load the boilers burned about 400 tonnes of coal per hour, and the turbines and other equipment required about 36 million gallons of cooling water from Lake Ontario per hour. Total construction cost was CA$ 156 million . The turbine hall

2516-541: The Portlands Energy Centre on the site of the Hearn, but the actual plant, opened in 2008 sits next to Hearn. In 2002, Ontario Power Generation announced that Studios of America and Comweb Group (headed by Paul Bronfman ) would be leasing the property of the former generating station and had plans to construct a 28 thousand square metre multipurpose film production studio called Great Lakes Studios on

2590-408: The super heater , then passes through the evaporator and finally through the economiser section as it flows out from the boiler . Feed water comes in through the economizer and then exits after having attained saturation temperature in the water or steam circuit. Finally it flows through the evaporator and super heater. If the temperature of the gases entering the heat recovery boiler is higher, then

2664-417: The working fluid (the exhaust) is still hot enough that a second subsequent heat engine can extract energy from the heat in the exhaust. Usually the heat passes through a heat exchanger so that the two engines can use different working fluids. By generating power from multiple streams of work, the overall efficiency can be increased by 50–60%. That is, from an overall efficiency of the system of say 34% for

2738-464: The 1960s the station employed up to 600 people. Many Ontario Hydro (later Ontario Power Generation) operators, maintainers, technicians and professionals began their careers, and were trained at the station and then went on to work at other plants and Ontario's CANDU nuclear stations. The station at first had four smaller chimneys, one for each of the four boilers. The construction of the four 200 MW units added four more chimneys. The last three were

2812-636: The 1990s the Hearn Generating Station was used as a filming location in many Canadian television productions, including Goosebumps (it served as the Dark Falls Chemical Factory on the Season 2 episode Welcome to Dead House ), Once a Thief and Animorphs . It was usually used to substitute as an industrial factory because of its basic industrial appearance and its iconic tall smokestack. This trend decreased in

2886-674: The City of Toronto's Waterfront Secretariat, or 20 years, according to Studios of America). Subsequent reports indicated that the lease-holders are Paul Vaughan of Studios America and real estate developer Mario Cortellucci, with no reference to Comweb Group. The Ontario government announced in April 2005 that the Portlands Energy Centre would not be part of the approved 2 500 MW of new power production in Ontario coming online in

2960-615: The Toronto Luminato Festival Big Bang Bash, their 2nd annual fundraising gala. It also featured the Yves Saint Laurent Opening Night Party later that evening. In 2015 the building was used for UNSOUND hosted by Luminato Festival. In 2016 Luminato Festival used the building for its festival hub where Sunn O))) performed for the first time. Port Lands, Toronto Too Many Requests If you report this error to

3034-546: The Wikimedia System Administrators, please include the details below. Request from 172.68.168.133 via cp1102 cp1102, Varnish XID 554763759 Upstream caches: cp1102 int Error: 429, Too Many Requests at Thu, 28 Nov 2024 05:54:07 GMT Combined cycle A combined cycle power plant is an assembly of heat engines that work in tandem from the same source of heat, converting it into mechanical energy . On land, when used to make electricity

Hearn Generating Station - Misplaced Pages Continue

3108-399: The addition of scrubbers to the Hearn and proposed to return the station to service. On March 16, 1990, Ontario Hydro announced the restart of two units (7 & 8) to meet demand for the winter of 1991. The restart had a projected cost of $ 69 million . Work on the restart was well underway when the new New Democratic Party government of Premier Bob Rae cancelled the project. The site

3182-514: The bottoming cycle. During the constant pressure process 4-1 the exhaust gases from the gas turbine reject heat. The feed water, wet and super heated steam absorb some of this heat in the process a-b, b-c and c-d. The steam power plant takes its input heat from the high temperature exhaust gases from a gas turbine power plant. The steam thus generated can be used to drive a steam turbine . The Waste Heat Recovery Boiler (WHRB) has 3 sections: Economiser, evaporator and superheater. The Cheng cycle

3256-507: The capital costs of combined cycle power is relatively low, at around $ 1000/kW, making it one of the cheapest types of generation to install. The thermodynamic cycle of the basic combined cycle consists of two power plant cycles. One is the Joule or Brayton cycle which is a gas turbine cycle and the other is the Rankine cycle which is a steam turbine cycle. The cycle 1-2-3-4-1 which

3330-461: The early 2000s but the generating station still appears on TV from time to time, including in 12 Monkeys from 2015 to 2018 as Raritan Valley National Laboratory, the home of a time machine in a post apocalyptic world. In 2010, the station was used as the backdrop for the climactic scene of the movie RED , other scenes of which were shot in the Toronto area. In 2018, the station was also used for

3404-448: The east and west since the R. L. Hearn closed, which are becoming overloaded, especially in the summer. On June 21, 2010, architecture firm Behnisch Architekten presented a proposal for converting the Hearn site into a three-pad arena. This plan did not proceed. The facility remains in the hands of the lease-holders with options that include extensions lasting until 2041. The property is not suitable for residential development because it

3478-600: The energy harvested from solar radiation with another fuel to cut fuel costs and environmental impact (See: ISCC section ). Many next generation nuclear power plants can use the higher temperature range of a Brayton top cycle, as well as the increase in thermal efficiency offered by a Rankine bottoming cycle. Where the extension of a gas pipeline is impractical or cannot be economically justified, electricity needs in remote areas can be met with small-scale combined cycle plants using renewable fuels. Instead of natural gas, these gasify and burn agricultural and forestry waste, which

3552-584: The entire plant was converted to burn natural gas with four units retaining the option to burn coal. In December 1972, Alberta Premier Peter Lougheed called the billion cubic metres of Alberta natural gas the station was burning annually "an appalling waste of natural gas" at the price of about $ 0.035 per cubic metre, and he charged that Ontario was getting a "cheap ride" at Alberta's expense. The station operated burning natural gas until 1983. Units 1–5 were mothballed between 1978 and 1979. Conversion to natural gas reduced pollution but increased operating costs and

3626-400: The expansion ratio of the turbine. This is practised in hot climates and also has the effect of increasing power output. This is achieved by evaporative cooling of water using a moist matrix placed in the turbine's inlet, or by using Ice storage air conditioning . The latter has the advantage of greater improvements due to the lower temperatures available. Furthermore, ice storage can be used as

3700-407: The failure of another unit. Also, coal can be burned in the steam generator as an economical supplementary fuel. Supplementary firing can raise exhaust temperatures from 600 °C (GT exhaust) to 800 or even 1000 °C. Supplemental firing does not raise the efficiency of most combined cycles. For single boilers it can raise the efficiency if fired to 700–750 °C; for multiple boilers however,

3774-470: The flexibility of the plant should be the major attraction. "Maximum supplementary firing" is the condition when the maximum fuel is fired with the oxygen available in the gas turbine exhaust. Combined cycle plants are usually powered by natural gas , although fuel oil , synthesis gas or other fuels can be used. The supplementary fuel may be natural gas, fuel oil, or coal. Biofuels can also be used. Integrated solar combined cycle power stations combine

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3848-407: The gas turbine. Supplementary burners are also called duct burners . Duct burning is possible because the turbine exhaust gas (flue gas) still contains some oxygen . Temperature limits at the gas turbine inlet force the turbine to use excess air, above the optimal stoichiometric ratio to burn the fuel. Often in gas turbine designs part of the compressed air flow bypasses the burner in order to cool

3922-607: The hot exhaust gases. Some combustors inject other materials, such air or steam, to reduce pollution by reducing the formation of nitrates and ozone. Another active area of research is the steam generator for the Rankine cycle. Typical plants already use a two-stage steam turbine, reheating the steam between the two stages. When the heat-exchangers' thermal conductivity can be improved, efficiency improves. As in nuclear reactors, tubes might be made thinner (e.g. from stronger or more corrosion-resistant steel). Another approach might use silicon carbide sandwiches, which do not corrode. There

3996-426: The input temperature to the turbine (the firing temperature), is relatively high (900 to 1,400 °C). The output temperature of the flue gas is also high (450 to 650 °C). This is therefore high enough to provide heat for a second cycle which uses steam as the working fluid (a Rankine cycle ). In a combined cycle power plant, the heat of the gas turbine's exhaust is used to generate steam by passing it through

4070-507: The large mass flows and small temperature differences. However, in cold climates it is common to sell hot power plant water for hot water and space heating. Vacuum-insulated piping can let this utility reach as far as 90 km. The approach is called " combined heat and power " (CHP). In stationary and marine power plants, a widely used combined cycle has a large gas turbine (operating by the Brayton cycle ). The turbine's hot exhaust powers

4144-431: The lower temperature of a steam plant is fixed by the temperature of the cooling water. With these limits, a steam plant has a fixed upper efficiency of 35–42%. An open circuit gas turbine cycle has a compressor , a combustor and a turbine . For gas turbines the amount of metal that must withstand the high temperatures and pressures is small, and lower quantities of expensive materials can be used. In this type of cycle,

4218-427: The lowest in initial cost, and they are often part of a single shaft system that is installed as a unit. Supplementary-fired and multishaft combined-cycle systems are usually selected for specific fuels, applications or situations. For example, cogeneration combined-cycle systems sometimes need more heat, or higher temperatures, and electricity is a lower priority. Multishaft systems with supplementary firing can provide

4292-407: The most common type is called a combined cycle gas turbine ( CCGT ) plant, which is a kind of gas-fired power plant . The same principle is also used for marine propulsion, where it is called a combined gas and steam (COGAS) plant. Combining two or more thermodynamic cycles improves overall efficiency, which reduces fuel costs. The principle is that after completing its cycle in the first engine,

4366-581: The need for separate expensive peaker plants , or lets a ship maneuver. Over time the secondary steam cycle will warm up, improving fuel efficiency and providing further power. In November 2013, the Fraunhofer Institute for Solar Energy Systems ISE assessed the levelised cost of energy for newly built power plants in the German electricity sector . They gave costs of between 78 and €100 /MWh for CCGT plants powered by natural gas. In addition

4440-485: The next few years. The Independent Electricity System Operator warned of rolling black-outs in Toronto if 250 MW are not added by 2008, with an additional 250 MW required by 2010. However, in February 2006 this decision was reversed, a new plan emerged proposing a new plant be built next to the Hearn site. Toronto mayor David Miller lobbied to have Hearn restored in some capacity to provide that power rather than build

4514-482: The plant's efficiency was much lower than today's combined cycle and cogeneration plants. The last three 200 MW units at the plant resumed burning coal along with natural gas but they were phased out of operation in July 1983, due to concerns about increased air pollution in Toronto and an abundant energy supply in the province. The staff level had been reduced to around 180 when power production stopped in 1983. Many of

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4588-664: The proposal. On September 18, 2006, an agreement was signed between the Provincial government, Ontario Power Generation and TransCanada Corp. to construct a gas-fired plant next to Hearn. The Portlands plant may eventually be co-generation, however it is being built as a combined cycle plant due to inability to negotiate contracts for cogeneration energy sales. The Portlands Energy Centre opened in June 2008 with simple cycle production and combined cycle operation scheduled for mid-2009. Extensive demolition of previously preserved areas of

4662-517: The second cycle can take time to start up. Thus efficiency is initially much lower until the second cycle is running, which can take an hour or more. Heat engine efficiency can be based on the fuel Higher Heating Value (HHV), including latent heat of vaporisation that would be recuperated in condensing boilers , or the Lower Heating Value (LHV), excluding it. The HHV of methane is 55.50 MJ/kg (23,860 BTU/lb), compared to

4736-418: The site. Most of the boilers and a large amount of other equipment were removed and sent to the scrapyard. This movie studio project was abandoned in 2006. Although the station did not become a movie studio, the R. L. Hearn interior and grounds were used in a number of movie productions over the years. As of 2010, Studios of America still has long-term lease obligations for the Hearn site (32.5 years, according to

4810-545: The station including the turbine hall began once Studios of America abandoned their plans for a film studio. In 2006, proposal to build a $ 600 million transmission corridor from the Portlands plant to connect with higher voltage transmission lines north of Toronto was being discussed and opposed by resident and other groups. The transmission system that the R.L Hearn station supplied was a 115 kV network of buried and overhead lines and transformer stations in Toronto. The city has been supplied by stepdown transformer stations from

4884-410: The station was not even finished in the 1950s when Hydro officials and the government began to talk about phasing out the plant with nuclear power and closing it. The early years were marked by difficult labour relations and several near strikes. Several unions were involved in conflicts with management and each other during the life of the station. The R. L. Hearn station was one of the founding locals of

4958-428: The temperature of the exiting gases is also high. In order to remove the maximum amount of heat from the gasses exiting the high temperature cycle, a dual pressure boiler is often employed. It has two water / steam drums. The low-pressure drum is connected to the low-pressure economizer or evaporator. The low-pressure steam is generated in the low temperature zone of the turbine exhaust gasses. The low-pressure steam

5032-413: The turbine blades. The turbine exhaust is already hot, so a regenerative air preheater is not required as in a conventional steam plant. However, a fresh air fan blowing directly into the duct permits a duct-burning steam plant to operate even when the gas turbine cannot. Without supplementary firing, the thermal efficiency of a combined cycle power plant is higher. But more flexible plant operations make

5106-407: The workers took early retirement and others were transferred to other sites. Some of the generators were operated as synchronous condensers to improve power quality in Toronto and the electrical control room and switchyard continued to operate until 1995, with a staff of about 10. In October 1985, Premier David Peterson 's Liberal government proposed the re-opening the station using natural gas. It

5180-425: Was almost 300 metres long and was an impressive sight, viewed from the visitor gallery on the west side of the plant where the offices were located. Units 1–4 (100 MW) had one turbine-generator each. The 200 MW units (5–8) had two turbine-generators per unit—an arrangement called tandem cross-compound—so there were a total of 12 turbine-generator sets in the turbine hall. At the peak of the R. L. Hearn's operation in

5254-402: Was built in response to pressure to reduce smog in Toronto by the emerging environmental movement in the late 1960s. It stands 215 metres tall and was one of the tallest in the world, costing $ 9 million when it was completed in 1971. Air pollution in Toronto from the station was greatly reduced and the area around the plant became known as a good fishing and recreation spot. By the end of 1971,

5328-527: Was designated as protected for future electricity development by the Mike Harris - and Ernie Eves -led Ontario Progressive Conservative Party. This was also done with all other existing publicly owned electrical generating stations during the deregulation of the Ontario electrical power system. The plant had all of the asbestos insulation removed and site remediation work was done in the 1990s. Former premier Mike Harris later mentioned his plans to build

5402-698: Was officially opened on October 26, 1951, by Leslie Frost , Premier of Ontario, with the first two units in service. Four units were in operation by 1953. The plant originally burned coal which was transported on ships through the Saint Lawrence Seaway . The station was designed by Stone & Webster . The turbine generators were built by Parsons in England and the boilers were made in Canada by Babcock & Wilcox (Cambridge, Ontario) and Combustion Engineering (Montreal, Quebec). Construction on

5476-504: Was only the first of numerous proposals to restart the plant, involving cogeneration , tri-generation, garbage incineration and eventually gas turbine combined cycle plants as new technologies were developed. In June 1987, Ontario Progressive Conservative Party (PC) energy critic Philip Andrewes pushed the governing Liberal government to have the Hearn re-opened as a "non-polluting" natural gas power plant. In October 1988, PC member of provincial parliament Donald Cousens called for

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