Energy Engineering

Coal Production in the U.S. (Energy Engineering)

Abstract U.S. coal production is historically important. Coal is now used principally as a fuel for electricity generation and other industrial processes. Coal mining practices and technologies have become more productive due to geographic changes in mining areas and increased mine sizes that produce coal at competitive prices. Coal prices respond to occasional surges in […]

Coal Supply in the U.S. (Energy Engineering)

Abstract The United States has approximately 275 billion tons of coal resources in the ground, enough to last more than 200 years at current rates of consumption. Coal ranks in the United States are (from lowest to highest) lignite, subbituminous, bituminous, and anthracite. Estimated recoverable reserves of coal are located in 32 states, and mining […]

Cold Air Retrofit: Case Study (Energy Engineering)

Abstract The first-cost focus of new construction can often result in buildings that do not work—particularly the Heating Ventilation and Air Conditioning (HVAC) systems. This article presents an innovative cold air retrofit that corrected designed-in HVAC inadequacies in an office building. By utilizing cold air, the retrofit overcame insufficient airflow and insufficient cooling capacity at […]

Coal-to-Liquid Fuels (Energy Engineering)

Abstract A chemical process used for turning coal into liquid fuels that has the potential for producing hundreds of thousands of barrels per day of hydrocarbon liquids and other byproducts—including electricity—is described. The key to converting coal to liquids is the Fischer-Tropsch (FT) process, which was invented in Germany in the 1920s. This process is […]

Combined Heat and Power (CHP): Integration with Industrial Processes (Energy Engineering)

Abstract This entry discusses the integration of combined heat and power (CHP), otherwise known as cogeneration, with industrial processes. It builds on other entries in this topic that discuss the basics of CHP or cogeneration. INTRODUCTION This section discusses the integration of CHP, also referred to as cogeneration, with industrial processes. Topics discussed in this […]

Commissioning: Existing Buildings (Energy Engineering)

Abstract Commissioning an existing building is referred to by various terms, including recommissioning, retrocommissioning, and continuous commissioning® (CC®). A comprehensive study of 182 existing buildings totaling over 22,000,000 ft2 in floor area reported average energy savings of 18% at an average cost of $0. 41/ft2 after they were commissioned, producing an average simple payback of […]

Commissioning: New Buildings (Energy Engineering)

Abstract Commissioning is the methodology for bringing to light design errors, equipment malfunctions, and improper control strategies at the most cost-effective time to implement corrective action. The primary goal of commissioning is to achieve optimal building systems performance. There are two types of commissioning: acceptance-based and process-based. Process-based commissioning is a comprehensive process that begins […]

Commissioning: Retrocommissioning (Energy Engineering)

Abstract This entry examines the practice of commissioning in existing buildings, or retrocommissioning. It provides a definition and a practical understanding of the retrocommissioning process, outlines the energy and nonenergy benefits that result, and examines the link between retrocommissioning and maintenance activities. It also explains the relationship between retrocommissioning and the U.S. Green Building Council’s […]

Compressed Air Control Systems (Energy Engineering)

Abstract This Compressor Control Systems entry provides an outline of the strategies used to manage compressed air generation at a typical manufacturing facility and discusses the components of a compressed air system, typical control methodology, and energy saving strategies. Compressed air distribution, metering, and monitoring is also reviewed. This entry is meant to give the […]

Compressed Air Energy Storage (CAES)

Abstract Compressed-air energy storage (CAES) is currently being deployed as an alternative to lead-acid batteries for uninterruptible power supplies. These systems use compressed air supplied from either transport cylinders delivered by local gas services, or from stationary cylinders refilled from on-site compressors to drive a variety of economical expansion engine topologies. Several factors make these […]