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Micro-Combined Heat and Power Systems

Lee Layton, P.E.


Course Outline

Beginning with an overview of the electric power system in the United States, this course explores the application of a distributed generation power system known as a micro-combined heat and power system.

The concept of micro-combined heating and power systems are reviewed and then the various types of prime movers for the system are discussed.  The prime movers may include reciprocating engines, Stirling engines, micro-turbines, Rankine cycle engines, or fuel cells.

A key component of a m-CHP system is heat recovery and the various methods of heat recovery are reviewed such as recuperators and Transmural heat transfer systems.

The basic operation of absorption chillers is discussed and how it might be applied in a m-CHP system.  Dehumidification methods for use with m-CHP are also discussed.

This course includes a multiple-choice quiz at the end, which is designed to enhance the understanding of the course materials.

Learning Objective

After taking this course you will:

Intended Audience

This course is intended for engineers, architects, and others who want to understand how this exciting new technology may be used to generate power.

Benefit to Attendees

The course is intended to be an introduction to a new concept in distributed power generation.  By taking this course you will understand the benefits – and drawbacks – of a micro-combined heating and power system.

Course Introduction

A product that is just emerging in the residential sector is micro-combined heat and power systems.  A micro-combined heat and power system (m-CHP) is a power source that will simultaneously generate useful heat, cooling effects, and power for residential or small commercial applications.  Micro-CHP systems are generally considered to be systems of 15 kW electrical demand or smaller.

Combined heat and power (CHP) generation systems are not new.  In fact, they have been around for well over a century.  In the late 1800’s steam was the prime mover for mechanical equipment in industrial plants and the steam was also used to generate electricity for lighting.  In the early 1900’s steam driven equipment was replaced with electric motors, but combined heat and power systems, also known as co-generation systems, continued to be used in industrial plants and, in fact, co-generation is still a popular concept for industry.   Building on the success of co-generation in the industrial sector, products are now appearing in the residential sector that will supply both the heat and power needs of a residential home. 

The components of a m-CHP system include a prime mover, a heat exchanger for hot water, a heat exchanger for building heat, an electrical generator, and maybe an absorption chiller, and a desiccant dehumidifier.  The prime mover may be a reciprocating engine, turbine, fuel cell, or some other type of energy source that can be used to produce electricity.  The waste heat from the prime mover is then used to ‘fuel’ the other components of the m-CHP system.

A major distinction between industrial CHP systems and m-CHP systems is that industrial CHP systems generate electricity and heat is the useful by-product for other functions.  However, with a m-CHP system, the systems are primarily driven by the heat demand of the home and electricity is a by-product.  This difference is significant, because if there is not a major heat load, then the system cannot economically generate a useful amount of electricity.  This may mean that m-CHP systems will only find a niche market in predominately cold climates.

In this course, we will look at the various components of a micro-combined heat and power system including the prime movers that are the back-bone of the system, heat exchangers, absorption chillers, and desiccant dehumidifiers.  But, first let’s begin with an overview of m-CHP systems.

Course Content

This course content is in the following PDF document:

Micro-Combined Heat and Power Systems

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Course Summary

Micro-combined heat and power (m-CHP) systems hold promise as an efficient means to deliver heating, cooling, and electric power to residential buildings.  Some of the barriers to m-CHP systems include the selection of a prime mover that can efficiently generate electricity and deliver waste heat that is sufficient for heating needs, absorption chillers, and desiccant dehumidifiers.  Another major barrier is that, in many parts of the country, the heating need is not sufficient to use all of the waste heat available from the prime mover, which will negatively impact the total system efficiency of the m-CHP system.

As development continues and the technology evolves, m-CHP systems may be able to convert up to 90% of the fuel input into useful energy, which may help the country reduce greenhouse gases.

Quiz

Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.

DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDH Center or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered architect and/or professional engineer/surveyor. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.