Introduction to Reciprocating Internal Combustion Engines and CHP

2.1 Introduction

Reciprocating internal combustion engines are a well-established and widely used technology.

Worldwide production for reciprocating internal combustion engines is over 200 million units per year. Reciprocating engines include both diesel and spark-ignition configurations. They are important for both transportation and for stationary uses. Their sizes range from fractional horsepower engines to 5-story tall marine propulsion systems weighing over 5 million pounds and producing over 80 megawatts (MW) of power. The long history of technical development and high production levels have contributed to making reciprocating engines a rugged, reliable, and economic choice as a prime mover for CHP applications.

Reciprocating engine technology has improved dramatically over the past three decades, driven by economic and environmental pressures for power density improvements (more output per unit of engine displacement), increased fuel efficiency, and reduced emissions. Electronic Power Control Modules (PCMs) have made possible more precise control and diagnostic monitoring of the engine process. Stationary engine manufacturers and worldwide engine R&D firms continue to drive advanced engine technology, including accelerating the diffusion of innovative technology and concepts from the automotive market to the stationary market.

 

2.1 Introduction

Reciprocating internal combustion engines are a well-established and widely used technology.

Worldwide production for reciprocating internal combustion engines is over 200 million units per year.7 Reciprocating engines include both diesel and spark-ignition configurations. They are important for both transportation and for stationary uses. Their sizes range from fractional horsepower engines to 5-story tall marine propulsion systems weighing over 5 million pounds and producing over 80 megawatts (MW) of power. The long history of technical development and high production levels have contributed to making reciprocating engines a rugged, reliable, and economic choice as a prime mover for CHP applications.

Reciprocating engine technology has improved dramatically over the past three decades, driven by economic and environmental pressures for power density improvements (more output per unit of engine displacement), increased fuel efficiency, and reduced emissions. Electronic Power Control Modules (PCMs) have made possible more precise control and diagnostic monitoring of the engine process. Stationary engine manufacturers and worldwide engine R&D firms continue to drive advanced engine technology, including accelerating the diffusion of innovative technology and concepts from the automotive market to the stationary market. 

System is designed to satisfy the baseload electric needs of the facility. Approximately 1.6 MW of thermal energy (MWth), in the form of hot water, is recovered from engine exhaust and engine cooling systems to provide space heating and domestic hot water to the facility as well as to drive absorption chillers for space conditioning during summer months. Overall efficiency of this type of CHP system can exceed 70 percent.

A typical industrial application for engine CHP would be a food processing plant with a 2 MW natural gas engine-driven CHP system comprised of multiple 500 to 800 kW engine gensets. The system provides baseload power to the facility and approximately 2.2 MWth low pressure steam for process heating and washdown. Overall efficiency for a CHP system of this type approaches 75 percent.

 

2.2.2 Emergency/Standby Generators

Reciprocating engine emergency/standby generators are used in a wide variety of settings from residential homes to hospitals, scientific laboratories, data centers, telecommunication equipment, and modern naval ships. Residential systems include portable gasoline fueled spark-ignition engines or permanent installations fueled by natural gas or propane. Commercial and industrial systems more typically use diesel engines. The advantages of diesel engines in standby applications include low upfront cost, ability to store on-site fuel if required for emergency applications, and rapid start-up and ramping to full load. Because of their relatively high emissions of air pollutants, such diesel systems are generally limited in the number of hours they can operate. These systems may also be restricted by permit from providing any other services such as peak-shaving.

2.2.3 Peak Shaving

Engine generators can supply power during utility peak load periods thereby providing benefits to both the end user and the local utility company. The facility can save on peak power charges and the utility can optimize operations and minimize investments in generation, transmission, and distribution that are used only 0-200 hours/year. In a typical utility peak shaving program, a utility will ask a facility to run its on-site generator during the utility’s peak load period, and in exchange, the utility will provide the facility with monthly payments