What are the benefits of reciprocating engines for both power generation and cogeneration?

When looking at the different ways in which power can be generated, there are a large array of options available. From combustion engines to rotary engines to Stirling engines and everything in between, the ways in which power can be produced is numerous.

Reciprocating Engine

When it comes to cogeneration however, some engines are better than others to produce the best levels of heat and electricity. That is why we have decided to take a look at the reciprocating engine and its benefits when it comes to both power generation and cogeneration. If cogeneration is something you are considering for your business, read on!

If you have any questions, feel free to give Inoplex a call on 0448 307 282 and we can discuss your queries with you.

Reciprocating engines

Let's take a look at reciprocating engines, what they are and how they work, as well as their pros and cons when it comes to power generation and cogeneration.

What are they?

A reciprocating engine, which is sometimes referred to as a piston engine, is (generally) a heat engine that utilises one or more reciprocating pistons to transform pressure into a circular or rotating motion. There are 3 major types, known as an internal combustion engine, steam engine (type of external combustion engine) and a Stirling engine.

Reciprocating Engine

How do they work?

As mentioned, a reciprocating engine uses one or more pistons to convert pressure into rotational motion, utilising the 'up and down' motion to translate this energy. Some engine block configurations include:

  • In-line: One row of cylinders
  • V-engine: Two rows of cylinders meeting in a point
  • W-engine: A double zigzag of cylinders
  • Opposed engine: Two horizontal rows of cylinders

The type of reciprocating engine will determine the configuration arrangement, and the slightly differing processes which allow for one 'cycle' to be completed. In saying this, there are four general steps that a reciprocating engine takes:

  • Step One : Intake - The first step to commence a cycle is the introduction of fuel inside the cylinder. This is usually a mixture and is delivered through the intake port, which expands the piston all the way to the bottom of the cylinder.
  • Step Two : Compression - Next, the piston gets pushed from the bottom to the top, which compresses the mixture of fuel and allows the spark plug to ignite it.
  • Step Three : Ignition - The ignition then pushes the piston down, providing useful work to the engine.
  • Step Four : Exhaust - Finally, any chemical waste gets released out the exhaust port and the cycle starts again.

Benefits of a reciprocating engine

There are quite a few benefits when it comes to reciprocating engines for both power generation and cogeneration, including:

  • Provide incremental electricity quickly
  • High electrical efficiency
  • Quick start-up capabilities, allowing them to start and stop quickly
  • Low pressure gas fuel
  • Can operate at partial loads, with good part load efficiency
  • The characteristics of the exhaust heat makes them great for producing hot water
  • Range of sizes for differing site requirements
  • Can start up when grid does not have power
  • Use significantly less water to run than traditional methods
Inoplex use the Ford Barra FG straight 6 engine for their cogeneration plants, which is a style of reciprocating engine.

Disadvantages of a reciprocating engine

With benefits also come a few disadvantages for both power generation, cogeneration and reciprocating engines, including:

  • Relatively high emissions
  • Engine cooling produces low grade heat
  • If heat is not used, engine must be cooled
  • High relative maintenance costs ($/MWh)
  • Can have higher levels of low frequency noise
  • Forces require substantial foundations

Who could benefit from a reciprocating engine?

Due to the characteristics of reciprocating engines, they are generally most appropriately suited for sites of a smaller size, that are non-industrial and have a larger demand for hot water.

Inoplex

Your knowledgeable cogeneration specialists

If you have any questions regarding reciprocating engines for cogeneration systems, or would like to speak to one of our friendly team members regarding the utilisation of cogeneration for your business, give Inoplex a call now on 0448 307 282 and we can discuss any available options with you.

Resources:

Pump Industry (The pumps and engines powering cogeneration and trigeneration systems): https://www.pumpindustry.com.au/the-pumps-and-engines-powering-cogeneration-and-trigeneration-systems/

Wikipedia (Reciprocating engine): https://en.wikipedia.org/wiki/Reciprocating_engine

Wikipedia (Cogeneration): https://en.wikipedia.org/wiki/Cogeneration

NSW Government - Office of Environment & Heritage (Energy Saver - Cogeneration feasibility guide): https://www.environment.nsw.gov.au/resources/business/140685-cogeneration-feasibility-guide.pdf

U.S. Energy Information Administration (Natural gas-fired reciprocating engines are being deployed more to balance renewables): https://www.eia.gov/todayinenergy/detail.php?id=37972

Schneider University (Advantages and Disadvantages of different power generation forms): http://energy.schneideruniversities.com/content/lessons/127/Distributed%20Generation/data/downloads/distributed_generation%20attachments.pdf

Energy Education (Reciprocating Engine): https://energyeducation.ca/encyclopedia/Reciprocating_engine