ENG 312 - Lecture Note 1 PDF

**BENSON IDAHOSA UNIVERSITY, BENIN CITY** **FACULTY OF ENGINEERING** **DEPARTMENT OF MECHANICAL ENGINEERING** LECTURE NOTE ONE **Course Title: Energy Technologies 1** **Course Code: ENG 312** **Credit Hours: 2** **Course Status: Compulsory** **Course Lecturer(s)** +-------------------------...

**BENSON IDAHOSA UNIVERSITY, BENIN CITY** **FACULTY OF ENGINEERING** **DEPARTMENT OF MECHANICAL ENGINEERING** LECTURE NOTE ONE **Course Title: Energy Technologies 1** **Course Code: ENG 312** **Credit Hours: 2** **Course Status: Compulsory** **Course Lecturer(s)** +-----------------------------------------------------------------------+ | **TOPIC:** | | | | **INTRODUCTION** | +=======================================================================+ | **LEARNING OBJECTIVES:** | | | | 1. *To explain the meaning of work, energy and power* | | | | 2. *To explain how the pre-industrial forms of energy* | | | | 3. *To describe early form of hydro and wind energy* | | | | 4. *To explain basic effect of industrial revolution* | +-----------------------------------------------------------------------+ | **LEARNING OUTCOMES:** | | | | 1. Explain the meaning of work, energy and power | | | | 2. Explain the source and use of energy by pre-industrial man | | | | 3. Explain early form of hydro and wind energy | | | | 4. Explain basic aspects of industrial revolution | +-----------------------------------------------------------------------+ | **CONTENT:** | | | | **1.1 Introduction** | | | | Throughout history man has been able to utilize energy in ways no | | other species have been able to grasp. Man's ability to use energy | | has led to increased brain development, granted ability to travel | | great distances, allowed for the manufacturing of a variety of | | products. | | | | It has also helped to power machines that influence everything in | | life from healthcare to communication to science and research. | | Unfortunately this command over energy and the rate at which energy | | has been exploited has led to some disastrous consequences. Rapidly | | dwindling finite resources and carbon emissions continue to cause | | large-scale environmental issues. | | | | **Energy** | | | | Energy is a conservable quantity. However, its value relates to the | | capacity of doing work, which is not conserved because the real | | process are irreversible. Humans master energy by converting it from | | one form to another while producing useful work. As such the chemical | | energy of fuels is converted into high-temperature heat by | | combustion, whereas heat can be converted into work by heat engines. | | Any energy conversion process affects the surrounding environment in | | many ways. | | | | Some basic terms | | | | a. Work | | | | The unit of work or energy in SI is joule which has the symbol J. | | This is the work done when the point of application of a force of 1N | | is displaced in 1m in the direction of the applied force. | | | | *Work = force x distance = (mass x acceleration) x distance = W = m a | | Δx* | | | | *= (kg)(m s^-2^)(m) = (kg m s^-2^)m* | | | | *Work = N m = J* | | | | b. Energy | | | | Energy = work = *force x distance = (mass x acceleration) x distance | | = W = m a Δx* | | | | *= (kg)(m s^-2^)(m) = (kg m s^-2^)m* | | | | *Energy = N m = J* | | | | c. Power | | | | **1.2. Pre-industrial man** | | | | It can be argued that the most influential change in the development | | of modern man was his ability to use energy to complete tasks on a | | scale that was previously impossible. They ate food and used the | | calories within the food to perform work. | | | | Fire led to cooked food and protection from predators, the use of | | animals made agriculture and transportation more efficient, soon | | sailboats and windmills were taking advantages of wind energy for | | transportation and milling. | | | | Regardless of how energy was being used and which source it came | | from, what is clear is that these technologies made what were | | difficult and tedious quicker and easier. | | | | a. Fire and early man | | | | The earliest known exploitation of the natural environment for energy | | production by humans comes in the form of fire may be as far as | | 1.6million years ago. Fire can be described as a chemical reaction | | that occurs between oxygen (air), heat and a fuel source. It is the | | visible oxidation that occurs as a result of rapid combustion. | | | | Fire offered a variety of advantages to early man including | | protection from insects and predators, warmth, as well as providing | | illumination during the night. | | | | Significantly it provided man with the ability to cook food as it | | required between 5.7 to 6.2 hours per day to chew a tough, fibrous | | diet of plants, and raw meat. | | | | Another use of fire was in the form of fire-stick farming. Land was | | cleared for a variety of reasons and burned. The burning process | | increased nutrient availability, which resulted in higher plant | | yields. | | | | In modern times slash and burn or swidden agricultural practices | | continue to be prevalent methods for land clearing in agriculture. | | This process involves cutting down vegetation in an area and setting | | it on fire. | | | | b\. Gunpowder | | | | The active ingredient for gunpowder were discovered when an alchemist | | accidentally dropped charcoal into a bow of potassium nitrate (around | | 9^th^ century AD). The combination of the ingredients caused the | | mixture to deflagrate violently and, thus gunpowder was born. | | | | c.. Metallurgy | | | | The next major advancement in the exploitation of fire was seen in | | metallurgy. Ancient Egyptians utilized the intense heat generated by | | fire to melt and cast pure metals. Metallurgical processes were | | greatly enhanced following the advent of coke. Coke is a coal-based | | product of destructive distillation of coal. Today coke is an | | essential component in the processing of iron ore. | | | | d\. Steam boilers | | | | In modern times, fire sees extensive use in electricity and heat | | generation through the use of steam boilers. Oxygen-fed fires are | | used to boil large quantities of water whose steam in turn drives | | large turbines, generating electricity. Waste heat from this process | | can also be captured and used in a variety of heating processes, this | | is known as co-generation. | | | | e\. Animals | | | | The use of animals for agriculture, transportation, and hunting dates | | back to thousands of years. Animals such as cattle, horses, mules, | | donkeys, elephants, and dogs have all been used for human benefit | | throughout this time. By exploiting the energy of these animals, man | | developed the ability to perform essential tasks quicker and faster. | | This led to greater crop yields, faster and further distances | | travelled. | | | | f\. Agriculture | | | | From the earliest of times animal energy has been used in agriculture | | as plows towed by oxen as means of tiling fields for planting crops. | | An operator would walk behind the plow controlling a pair of handles | | to ensure that the share remains upright and in the soil. In modern | | times this task is performed by engine driven tractors. | | | | g\. Transportation, hunting, warfare | | | | The use of horses for transportation was first observed around 3500 | | BC by the Botai people of what is now modern-day Kazakhstan. These | | people used domesticated horses to gain advantage when hunting wild | | horses for meat and other herding activities | | | | As the use of horses spread across Europe and Asia, we begin to see | | the implementation of a new form of transport; the chariots. Also the | | use of chariots was essential in warfare as it offered | | manoeuvrability and a platform for ranged attacks. The combination of | | animal labour and drawn carts for transportation was a concept that | | extended until the advent of the modern automobile | | | | **1.3 Early Wind and Hydro** | | | | a. Sailboats | | | | | | | | b. Windmills | | | | | | | | c. Waterwheels | +-----------------------------------------------------------------------+ | **SUMMARY:** | | | | In this lecture, we have defined what is work, energy, and power. | | | | Described the pre-industrial development, source and use of energy | | and how it affected their lifestyle. | | | | How the pre-industrial man made use of hydro and wind energy | | | | The coming of industrial revolution. | +-----------------------------------------------------------------------+ | **ASSIGNMENTS:** | | | | **.** 1. Name and explain 5 sources of energy before industrial | | revolution | | | | 2\. Explain the deference between work, energy and power. | +-----------------------------------------------------------------------+