Engineering Contexts and Challenges

1
Engineering Contexts and Challenges Renewable
Energies Biomass Generation The Engineering
Scenario Biomass Energy Generation slides
2-3 The Main Branches of Engineering slide 4 The
Systems Approach slides 5 -7 Making Biogas /
Energy Transformations / Mechanisms slides
8-9 Modelling solutions slide 10 Energy
generation systems slide 11-14 Presentation
slide 15 Biogas Generator Extension Work
slides 16-
2

• The Engineering Scenario.
• A Scottish based distillery company plans to
  install a biomass generator that produces energy
  by burning the large amount of used grain (waste)
  produced in the distilling process. They want to
  build the biomass plant on their existing site.
• Many companies are considering using renewable
  means to generate energy. The main reasons for
  this are
• to comply with laws and regulations meant to help
  the environment
• to improve the companys reputation by showing
  they are a responsible company and
  environmentally friendly
• to save money by not having to buy electricity or
  generate electricity by other less
  environmentally friendly means
• to make their energy supply reliable and reuse
  cheap and available materials
• Activity. Find out about biomass generation and,
  through discussion, suggest other advantages of
  using this form of energy generation.

3

• In this activity we will consider some of the
  engineering tasks and activities required to
  build an engineering plant of this type. Once
  we understand how the systems work we will design
  and model some of the systems necessary to
  create movement and produce or convert energy.
• Activities.
• Through group and class discussion, internet
  research and, where possible, by discussion with
  practicing engineers.
• identify the
• main branches of engineering likely to be
  involved in building this plant.
• types of engineer responsible for each of these
  stages the planning, designing, construction,
  testing and maintenance of the new plant
• Biofuel and biomass are forms of renewable energy
  generation. List four types of renewable energy
  sources and three fossil fuels used in
  electricity generation and comment on the
  environmental implications of each.
• The main branches of engineering are shown in the
  following slide.
• Examples of engineering sub branches are
  included on separate slides 18-23.

4
Engineering is a combination between the abstract
of science and the beauty of art (Martin
Bercovici)
Activity. Consider one main branch of
engineering and the note some of the most
important activities and products involved. Other
engineering sub branches are included on
slides18-23.
5

• The Systems Approach
• Large engineering projects such as the biomass
  generator are complex. To make them easer to
  understand a Systems Approach is used. One
  feature of the systems approach is to use Input
  gt gt process gtgt output
• (what goes in) gt (what happens inside the
  machine for example) gt (what comes out)
• From the overall system diagram engineers can
  then decide what sub-systems will deal with each
  of the inputs and which will produce each of the
  required outputs. This gives a clearer picture of
  what the complete system will look like including
  how the sub-systems are connected together.
• Activity. For a simple system, such as the
  kettle identify the inputs, processes and
  output.
• The next slide shows some of the important inputs
  and outputs of the distillery.
• Activity. By discussing the main inputs and
  outputs identify some of the possible
  environmental impacts from such a plant.
• Supplementary questions on environment issues are
  included in extension slide 17.

6
System Diagram
Activity. By discussing the main inputs and
outputs identify some of the possible
environmental impacts from this plant.
7
Sub-system diagram showing biomass energy
generation
Super grain feed hopper
Belt presses
Used grain (waste)
Grain cake
Distillery
Biogas
Anaerobic Digester
Electricity
Steam Turbine
Bio fuel Boiler
Export electricity
Natural gas
Existing Boilers
Steam
8
How it Works Making Biogas
Making Biogas. The video clip shows how biogas is
produced. The movement of the products around the
system is controlled by various mechanisms.
Activity watch the clip and identify mechanisms
used in this system. Mechanisms are used to open
and close the gates and valves to allow the
products to flow from one part of the system to
another. The gate in the Shed is opened using an
electric motor, which is connected to a mechanism
known as a rack and pinion. Mechanisms change
the size and direction of force produced at the
output of the mechanism compared to the input
force.
9

• Mechanisms can also covert one type of motion to
  another.
• Electric motors produce what is known as rotary
  motion at their output shaft. As you saw in the
  video clip the gate has to move in a straight
  line up and down. Motion in a straight line is
  called linear motion and straight line motion
  which repeats over and over is known as
  reciprocating motion. Types of Motion
• The system diagram for a rack and pinion
  mechanism is shown below. This mechanism converts
  rotary motion to linear reciprocating motion.
• This example of a control is shown as a
  simulation model in the slide 10.
• Activity Extensions.
• A number of other modelling challenges of
  control systems, based on the Biogas Generator ,
  can be found in the extension materials. Slides
  24-27.
• Study the mechanisms in a bicycle and explain how
  motion is converted.

10

• Electronic simulation software ,such as YENKA as
  shown here, allows mechanisms and electrical
  circuits to be combined and the resulting system
  simulated.
• Activity Shed Gate control.
• Draw up a sub-system diagram for the system shown
  for opening and closing the shed gate.
• Build the circuit shown using suitable electronic
  simulation circuit software.

11
How it Works - Biogas Plant
The video clip shows how grain, and other
materials can be used to produce biogas.
Activity How many examples of rotary motion
converted to linear motion, or vice versa, are
shown in the video clip? Activity Extension. A
number of other modelling challenges can be
found in the extension materials. Slides 25-27.
12
How it Works - Micro-hydro Process

• Activity
• Watch each of the following three videos.
• Micro-hydro power
• Wave Power
• Combined heat and power plant
• Choose one to discuss in more detail and then
  draw up a sub-system diagram showing the energy
  transformations in the process.

13
How it Works - Wave Power Process
Activity Choose one video/audio clip to discuss
in more detail and then draw up a sub-system
diagram showing the energy transformations in the
process. For background to energy generation
from the ocean please click.
14
How it Works - Heat and Power Process
Activity Choose one video/audio clip to discuss
in more detail and then draw up a sub-system
diagram showing the energy transformations in the
process. Extension Activity. Find out how a
steam turbine works and compare its complexity to
a wind turbine or tidal power turbine.
15

• Presentation
• Prepare a presentation which demonstrates your
  understanding of the importance of engineers to
  society.
• The presentation should last around 5 minutes.
• The presentation could be based on a historical
  contribution made by engineering, a current
  product or project, or a future development.
• A historical contribution could be a description
  of an invention or inventor, or a civil
  engineering project from the pyramids to castles,
  roads, bridges and so on.
• A current contribution should focus on the role
  of one particular engineer in the development of
  an important product or project.
• A future contribution should look at how an
  emerging technology could be developed to provide
  benefits to individuals or society as a whole.

16
Engineering Contexts and Challenges Extension
work based on the Biogas Generator The social
and environmental impact of engineering slide
17 Engineering Sub Branches slides 18-23 Systems
Modelling slides 24-27
17

• The social and environmental impact of
  engineering.
• Activity
• There are many benefits for the distillery
  company from the biomass project. List four of
  these benefits and explain them.
• This project would help to reduce the need for
  energy generated from finite (fossil fuel)
  sources. What benefits would a power generation
  plant of this type have for society as a whole?
• The project would also have some advantages and
  disadvantages to the local community, especially
  those living close to the plant.
• What social and economic benefits would the
  project bring to the local community?
• What disadvantages would there be for those
  living around the plant, both during the building
  phase and afterwards?
• In terms of the health and wellbeing of society
  - discuss the pros and cons of supporting a
  company that produces alcohol?

18

• Engineering Sub- branches
• Mechanical Engineering slide 19
• Civil Engineering slide 20
• Electrical Engineering slide 21
• Chemical Engineering slide 22
• Hybrid Engineering slide 23

19
Activity Which of these sub branches could be
involved in the Biomass Project and what would be
their role?
20
Activity Which of these sub branches could be
involved in the Biomass Project and what would be
their role?
21
Activity Which of these sub branches could be
involved in the Biomass Project and what would be
their role?
22
Activity Which of these sub branches could be
involved in the Biomass Project and what would be
their role?
23
There are many others, including industrial
engineering, nuclear engineering, agricultural
engineering and applied engineering.
Activity Which of these sub branches could be
involved in the Biomass Project and what would be
their role?
24

• Systems Modelling
• The following modelled examples are based on
  the systems, controls and mechanisms found in the
  Biomass generator and similar engineering
  systems.
• Grain filling warning system. Slide 25
• Grain hopper sensing system. Slide 26
• Temperature sensing system. Slide 27
• Activity. Using appropriate modelling systems and
  or boards design, assemble, test and evaluate
  your solutions.

25

• Challenge Grain filling warning system.
• Design a system which will light a red LED while
  the substrate tank is filling. Once a float
  switch detects that the tank is full a solenoid
  should close the filler pipe and the red LED
  should go off.
• Draw a system diagram
• Draw a sub-system diagram
• Build and test the simulated circuit shown.

26

• Challenge Grain hopper sensing system.
• Design a system that will spin a mixing paddle
  once a light sensor detects it is dark (showing
  that the grain tank is full) or when a test
  switch is pressed.
• Draw a system diagram
• Draw a sub-system diagram
• Build and test the simulated circuit shown.
• Suggest other uses for this type of system.

27

• Challenge. Temperature sensing system.
• Design a system that will switch on a heater
  (simulated by a lamp) when the temperature in the
  fermenting tank falls and the heater switch is
  on.
• Draw a system diagram
• Draw a sub-system diagram
• Build and test the simulated circuit shown.
• Comment on the success of the design and suggest
  other uses for this type of system.