Drill:Convert 2.7g/cm³ to kg/L

Renewable Matter and Energy

Objectives: SWBAT•Understand the concept of energy •Establish a common definition of “renewable energy”•Discuss and write an opinion on renewable energy

Renewable Matter and Energy

Define:Biofuel non-renewable energyBiomass photovoltaic cell Energy power Energy transfer renewable energyGeothermal energy solar energyHydro energy wattJoule wind energywork potential energy Energy source

DiscussionMake a list of1. renewable energy

sources2. non-renewable

energy sources.3. How much of the

energy use in the U.S. comes from each?

Matter and EnergyRenewable energy is a topic of debate in

today’s society and engineering is right in the middle of it. Many people feel we are close to damaging the Earth , permanently, because of our current consumption of non- renewable energies. Others argue that the Earth has always gone through cycles similar to what is presently occurring…

Essay due today 2/3/2014What do you think?Explain your point of view on renewable

energy. What renewables would you consider ?

Why/ How would you implement your ideas?

Are there benefits to using non-renwables? What are they ? Compare and contrast the renewable and non-renewable energy. What are characteristics they both share? Answer these questions in your essay answer.

Drill: 2/4/14

A Serbian track star’s average running velocity is 15 mph what would be his 100 meter time? Do you see an Olympic medal in his future?

Matter and Energy

This course is an introduction to the study of thermodynamics and an investigation of how it can be applied to renewable energy sources.

Thermodynamics comes from the Greek words:

therme (heat) + dynamis (force)=

Thermodynamics“the study of systems and energy

transfer”

Matter and Energy

So what is a thermodynamic system?Thermodynamics - “the study of systems and energy

transfer”

Pressure Cooker

Gas-fired Boiler

Geothermal Power PlantSystem – whatever we choose to study

Systems have a boundary and surroundings.

We could be talking about…

Matter and Energy

So what is a thermodynamic system?Thermodynamics - “the study of systems and energy

transfer”

We can choose to study all…

System – what we choose to study

Boundary – separates system from surroundings

Surroundings – everything outside of system

or some part…of a complex system.Always draw the system and its boundaries before starting

any work!!!

Matter and Energy

Let’s practice drawing system boundaries…Thermodynamics - “the study of systems and energy

transfer”

What’s the boundary if I’m interested in the pressure drop of steam as it passes through the turbine?

What’s the boundary if we’re interested in the efficiency of the cooling tower?We’ve been asked to determine the efficiency of the entire geothermal power plant...what should our boundary be?

Random question

What are the four power cycles in thermodynamics?

Gas cycle: the working fluid remains a gas throughout the entire cycle.� 1)Otto cycle: The ideal cycle for spark-ignition �engines 2) Brayton cycle: The ideal cycle for gas-turbine �engines

Vapor cycle: the working fluid remains is alternatively vaporized and condensed in a cycle

3)Rankine cycle: The ideal cycle for vapor power cycles

Matter and Energy

There are two types of systems…Closed Systems – no mass crosses the boundary

Open Systems – mass crosses the boundary

Thermodynamics - “the study of systems and energy transfer”

Matter and Energy

There are two types of systems…Closed Systems – no mass crosses the boundaryOpen Systems – mass crosses the boundary

Thermodynamics - “the study of systems and energy transfer”

“Energy can cross the boundary of both open and closed systems.”

Energy in… Energy out…

Matter and Energy

How do we describe systems?Thermodynamics - “the study of systems and energy

transfer”

Energy in… Energy out…

Property – a characteristic used to describe a system

What are some properties we could use to describe the system above?

MassVolume

MassVolume

TemperaturePressure

TemperaturePressure

We’ve intentionally placed the properties above into two groups. Why do you think that is?

What’s common to the properties in each group? How would you measure each property?If we removed a small amount of mass from the system, which properties would you expect to change?

Matter and Energy

There are two types of properties:Property – a characteristic used to describe a

system

1) Extensive – the whole equals the sum of its parts

Which set of properties are best described as extensive?

MassVolume

MassVolume

TemperaturePressure

TemperaturePressure

2) Intensive – the whole is the same as any partEXTENSIVE

INTENSIVE

Mass and Volume are both extensive properties.Temperature and Pressure are intensive properties.

Extensive properties usually use capital letters as symbols.Intensive properties usually use lower case letters as symbols.

Drill with a partner

Identify which of the two descriptions of your class is an intensive property and which is extensive:

The number of students in the class.

The grade level of the students in class.

Be able to explain your answer

Matter and EnergyProperty – a characteristic used to describe a

systemProperty Symbol

Definition

Mass m measure of the amount of material present

Volume V amount of space occupied by an object

Energy E the ability to do work or produce heat

Temperature

T measure of the molecular activity of a substance

Pressure P force exerted per unit area on the boundaries of a substance

Density ρ the total mass of a substance divided by the total volumeWhat type of property is

density, ρ?What type of property is energy, E?

IntensiveExtensive

Matter and EnergyProperty – a characteristic used to describe a

system

When an extensive property is made intensive by dividing by mass, we use a lowercase symbol and the prefix “specific”.

In general, an extensive property can be made intensive by dividing by the mass of the system.

Extensive Divide by Mass

Intensive

EnergyE

kilojoules, kJ

Energy/massE/m

kilojoules/kilogram

Specific Energye

kJ/kg

HOMEWORKDefine the following properties:Specific volumeDensitySpecific gravity Humidity

Answers to HomeworkIn thermodynamics, the specific

volume of a substance is the ratio of the substance's volume to its mass. It is the reciprocal of density and is an intrinsic property of matter:

Answers to HomeworkThe mass density or density of a material is

its mass per unit volume. The symbol most often used for density is ρ (the lower case Greek letter rho). Mathematically, density is defined as mass divided by volume:

where ρ is the density, m is the mass, and V is the volume. In some cases (for instance, in the United States oil and gas industry), density is also defined as its weight per unit volume,

although this quantity is more properly called specific weight.

Answers to HomeworkThe specific gravity of a material is defined as

the ratio of its density to the density of some standard material, such as water at a specified temperature, for example, 60°F (15°C), or (for gases) air at standard conditions of temperature and pressure. Specific gravity is a convenient concept because it is usually easier to measure than density, and its value is the same in all systems of units.

Humidity is atmospheric moisture: the amount of moisture in the air