Advanced Diploma of Mechanical Engineering Technology

Advanced Diploma of Mechanical Engineering Technology

Answer 1

At the time of writing, five mainstream energy sources are:

1. Coal – Coal fuels approximately 25% of the total primary energy needs for the world, with the current reserves may last up to 200 years. Coal is easy to recover, and technologies for conversion are well established. Coal is a significant source of pollution during burning, storage, and transportation. Coal emits CO2, CO, SO2, NOx, and particulate matter.
2. Crude oil – Crude oil currently fuels approximately 35 – 37% of the total energy needs for the world. Crude oil reserves are only expected to last another 45 – 50 years, with Saudi Arabia having the largest share of reserves of 25%. Crude is expensive to extract from deepwater reserves. Cruse produces pollution from vehicle exhausts consisting of CO, benzene, 1-3, and nitrogen oxides.
3. Hydroelectric power – Hydroelectric power provides about 15% of global energy. Water resources where available are renewable and hydroelectric power plants can only be placed in specific locations, and require substantial initial investments. This form of power generation produces no pollution; however, it can create significant environmental destruction.
4. Solar energy – Solar is inexhaustible and readily available as a source of energy. Solar has been used as a first energy source for ages in applications such as clothes drying. Since 2002, solar energy has grown by approximately 35%. Solar energy can be in either large scale solar farms, or on a smaller scale on residential homes and buildings to provide a power source.
5. Wind energy – The kinetic energy of the wind can generate electricity, charge batteries, and pump water. When there are several wind turbines in a single area, this is called a wind farm. These wind farms can generate electricity on a large scale. Wind turbines are available that produce from 1000 watts up to 2.2 Megawatts. The cost of wind generation has come down by about 85% in the past 20 years; it is also a renewable and non-polluting form of energy.

Three ways energy is produced from energy conversions are:

1. Energy is converted in hydroelectric dams when the dam is filled with water, which then uses potential gravitational energy as the water falls through the turbine, causing the turbine to spin, transferring motion energy to a generator which creates electricity.
2. Energy is produced similarly in wind farms when the wind speed passing onto the wind turbine blades causes them to spin, in turn rotating a generator, producing electricity. These turbines produce more power as the turbine spins faster in higher winds.
3. Energy is produced in coal-fired power plants where coal is burned creatingthermal energy, which heats water from a reservoir, pumped through a boiler, creating steam. The steam is then directed to a turbine through pipes at high pressure, causing the turbine to spin, which then transfers energy to a generator, producing electricity.

Answer 2

An energy audit is a systematic way of identifying all the possibilities of energy conservation and environmental protection.

Steps involved in conducting an energy audit are:

1. Identify all the major types of energies being used, all the energy consuming units and wastages.
2. Segregate energy forms such as heating, cooling, etc.
3. Assess the efficiency of current usage
4. Identify wastages
5. Recommend measure for improving efficiency, reducing wastes
6. Estimate the savings potential, investment budgets, payback periods and return on investments
7. Implement a system for continuous recording, monitoring, and reporting of energy data types.

Three phases involved in an energy audit are:

1. An analysis of existing consumption identifies where, how, and how much energy is being used in the plant. It also identifies trends in the consumption data.
2. A main or walk through an audit will document where the main areas of energy consumption exist within the plant. This phase identifies any apparent areas of wastage along with the areas of the most evident savings.
3. A detailed analysis phase takes the data from the initial analysis and walk through steps and compiles detailed plans for energy savings options. These plans will include details on the energy use and cost of each stage of the production process as well as costs along with estimated payback periods for the various options submitted.

Answer 7