Base loads

Petroleum. Thermal cracking (pyrolysis) of petroleum or fractions thereof was an important method for producing gas in the years following its use for increasing the heat content of water gas. Many water gas sets operations were converted into oil-gasification units (55). Some of these have been used for base-load city gas supply, but most find use for peak-load situations in the winter. 

Table 5. Cost Distribution for MHD—Steam Base Load Power Plants ...

Gas turbine-based power plants, particularly natural gas-fired cogeneration and combined-cycle faciUties, have proven to be highly rehable, efficient, and environmentally attractive. Advances in machine design, more efficient plant integration, and optimistic forecasts for the availabiUty of affordable natural gas worldwide have boosted the appeal of these systems for both base-load and peaking service. 

In May of 1995, one gas turbine manufacturer introduced a new engine series expected to push the achievable net efficiency ratings for base-load... 

Electric power generation using biomass as a fuel is economic in situations where the cost of the fuel is competitive with that of fossil fuels. The cost of a commercially available biomass steam—electric power plant is about 1500/kW for a wood-fired facility. If wood can be obtained at a cost of 2.00/GJ ( 2.10 X 10 /Btu), the total cost of power for base-load operation would be about 0.05/kWh. If wood or agricultural wastes are available at... 

Continuity and reliahility of this energy source was required if it were used as base load, which required standby equipment, spares, and appropriate operator attention. 

Use for base load or partial flaring ratas if noise and visual pollution are critical. 

Failure rate questionnaires were sent to 35 companies which operate LNG base loading or satellite facilities. These operators had previously expressed an interest in participating in the study. Twenty-five companies returned questionnaires which covered failures at 27 separate LNG facilities. Approximately 1,626,000 hours of plant operating time were represented by the returned questionnaires. 

About 2.5 million tons (2.3 million tonnes) of coal arc burned daily in U.S. power plants. This is equivalent to roughly 21,000 railcars in transit, so it is apparent that coorditiatiiig production and cotistimp-tioii is no easy task. Accidents, rail strikes, natural disasters (e.g., floods that take out bridges and rail lines) and severe weather (e.g., deep river freezes that halt barge traffic) can all severely disrupt deliveries for utility customers dependent on a reliable coal supply for base load plants. Nonetheless, to reduce costs U.S. utilities have significantly reduced typical inventory levels over time. Wliereas a coal inventory of ninety days of supply was once typical, inventories now frequently run in the range of thirty to forty-five days. 

Simpson, S. W. Many, S. M. and Messerle, H. K. (1989). Open-Cycle Disk Generators Lahoratoiy Experiments and Predictions for Base-Load Operation. MHD An International Journal 2(l) 57-63. 

Since the early 1960s, advanced steam conditions have not been pursued. In the 1960s and early 1970s there was little motivation to continue lowering heat rates of fossil-fired plants due to the expected increase in nuclear power generation for base-load application and the availability of relatively inexpensive fossil fuel. Therefore the metallurgical development required to provide material X for advanced steam conditions was never undertaken. 

Diesels are used in many industrial applications (for example, for base-load generation in mines, cement plants and in remote regions of the world). In addition, they are often utilized to provide standby power for hospitals, telecommunications, banks, computer centers and office complexes that must have full independent power capability. The diesel can be started rapidly, making it ideal for peak lopping duties to meet maximum load demands, or for emergency use in cases of power supply interruptions. 

The gas turbine is widely used by electrical supply authorities for peak lopping and standby generation. Additionally, it is often employed for base-load operation when the fuel costs are low. 

Energy-management systems will form an important part of a multi-boiler installation, whether on steam or hot water. Boiler(s) for base load will be selected and further boilers brought on- or taken off-line as required. The important feature of these systems is that the selection of boilers coming either on- or off-line will be ahead of the load and programed to anticipate rising or falling demands. 

Because of their cantilever design and pinion rotating speeds, bullgear compressors are extremely sensitive to variations in demand or down-stream pressure changes. Because of this sensitivity, their use should be limited to base load applications. 

Helical-lobe compressors are best suited for base-load applications where they can provide a constant volume and pressure of discharge gas. The only recommended method of volume control is the use of variable-speed motors. With variable-speed drives, capacity variations can be obtained with a proportionate reduction in speed. A 50 per cent speed reduction is the maximum permissible control range. 

Rotary positive-displacement compressors should be operated as base loaded units. They are especially sensitive to the repeated start-stop operation required by load-following applications. Generally, rotary positive-displacement compressors are designed to unload about every six to eight hours. This unload cycle is needed to dissipate the heat generated by the compression process. If the unload frequency is too great, these compressors have a high probability of failure. 

Since the system may fall short of intended performance under extreme conditions, heat pumps should not be designed to provide all the heat required. They should give a base load, to the best of their ability, as conditions permit, and the balance provided with top-up heat from a conventional fuel. 

NOTE As a consequence of the different kinds of operational and management problems associated with raising steam in industrial boiler plants, it often requires a different mindset than that needed for a base-load utility power house, where personnel strive to maintain steady-state (but knife-edge) operating conditions. The differences between industrial plants and power generators is also reflected in the waterside chemistries and monitoring and control objectives of their respective boiler plant systems. 

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