photovoltaic systems

In this article I am going to talk about the first type of photovoltaic systems

On-grid system

**The mechanism

The solar panel convert the sunlight to electromotive force And give (DC) current .
This current transferred through the dc wire to the inverter
 Alternating current then this current will injection to the local grid

The components**

-          (The solar panel )
It convert the sun line to electromotive force


 

-          (Inverter )

It convert the direct current to Alternating current






-          Ac breaker 
to provide  the necessary protection for the system





-          Dc and Ac conductor
"Dc"  wire to transfer the dc current from the solar panel to the inverter 
"Ac"  wire to transfer the ac current from the inverter to the grid 


 in the next post we are going to talk about off-grid system and the main differences
 between on and off grid system 
                
 
 



 


 
 
 

Wind Energy

Wind Energy :
we are always looking for ways to protect the earth that we are living on, these ways contains the renewable energy.
We will talk about one of these energies and that will be the wind energy.
We call these type of energy as green energy, because it helps to make our earth still green as we know it.
Wind Energy: is a clean energy source that can be found for a long time I future. Wind energy converts the natural wind in our environment and coverts that wind motion to a mechanical energy.
As we know the different location in the world have different speed or power of wind that is caused by difference in pressure. So there some locations better than other to have a power from the wind there.
Wind Turbines: it’s a big structure with spinning blades. The blades are connected to an electro-magnetic generator that give us the electricity power when the wind makes the blades spin.

advantages of Wind Energy 

1. Clean Source of Power

The production of wind energy is “clean”. Unlike using coal or oil, creating energy from the wind doesn’t pollute the air or require any destructive chemicals. 

2. Renewable Source

Wind is free. In the event that you live in a geological area that gets a lot of wind, it is ready and waiting. As a renewable asset, wind can never be drained like other regular, non-renewable assets. The expense of delivering wind energy has dropped fundamentally lately, and as it becomes more popular with the general population, it will just continue to be cheaper. You will recover the expense of obtaining and introducing your wind turbine over time.

Winds are caused by rotation of the earth, heating of the atmosphere by sun, and earth’s surface irregularities. We can harness wind energy and use it to generate power as long as sun shines and wind blows.

3. Cost Effective

Wind turbines can give energy to numerous homes. You don’t actually have to possess a wind turbine keeping in mind the end goal to harvest the profits; you can buy your power from a service organization that offers wind energy for a specific area. That means, you don’t even necessarily have to invest any cash in order to reap the benefits of wind energy for your home or business.

4. Extra Savings for Land Owners

Land holders who rent area to wind homesteads can make a considerable amount of additional cash, and wind energy likewise makes new employments in this developing engineering field. Government organizations will also pay you if they can install wind turbines on your land. Also, in some cases, the electric company may wind up owing you. If you produce more power than you require from wind power, it may go into the general electric matrix, which in turn will make you some extra cash. A win all around

Boilers

A boiler (or steam generator, as it is commonly called) is a closed vessel in which water, under pressure is transform into steam by the application of heat. Open vessels and those generating steam at atmospheric pressure are not considered to be boilers.

 In the furnace the chemical energy in the fuel is converted into heat, and it is the function of the boiler to transfer this heat to the water in the most efficient manner. thus the primary function of a boiler is to generate steam at pressure above atmospheric by the absorption of heat that is produced in the combustion of fuel .

A boiler should be designed to absorb the maximum amount of heat released in the process of combustion. This heat is transmitted to the boiler by radiation, conduction, and convection, the percentage of each depending on the boiler design. 

Boiler types :

1) Fire-tube boilers : are so named because the product of combustion pass through tubes that are surrounded by water. They may be either internally fired or externally fired. 

2) Water-tube boilers :is one in which the products of combustion pass around tubes containing water.

3) package boiler 

Nomographs in hybrid system

A Nomograph is a kind of chart that conveys the relationship between

different sets of numbers. The hybrid operation nomographs below

convey the relationship between RPM for MG1, MG2 and the engine.

Because MG1, MG2 and the engine are mechanically connected in the

Planetary Gear Set, if one of the components changes rpm, the rpm of

the other components will be affected. So in the nomograph, the rpm

values of the 3 power sources maintain a relationship in which they are

always connected by a straight line.

Figures down below shows nomographs for different  modes of Toyota Prius

1. Ready-on

 

2. Starting out

3. Engine starting

4. Light acceleration with engine

5. Low speed cruising 

6. Full acceleration

7. High speed cruising 

 

8. Maximum speed

9. Braking

10. Reverse 

Stairs

Stairs :

is a set of steps leading from one floor of a building to another, typically inside the building or   a series of steps or flights of steps for passing from one level to another.

An attractive stair  can enhance a location: fascinating, perfectly attuned to the architecture; a show piece. As a beautiful addition to your office, home or shop. Because there are so many options when it comes to style, materials and installation, staircase prices can vary tremendously. 

Stairs may be in a straight run, leading from one floor to another without a turn or change in direction. Stairs may change direction, commonly by two straight flights connected at a 90 degree angle landing. Stairs may also return onto themselves with 180 degree angle landings at each end of straight flights forming a vertical stairway commonly used in multistory and highrise buildings. Many variations of geometrical stairs may be formed of circular, elliptical and irregular constructions.

Step

Each step is composed of tread and riser.

Tread

The part of the stairway that is stepped on. It is constructed to the same specifications (thickness) as any other flooring. The tread "depth" is measured from the outer edge of the step to the vertical "riser" between steps. The "width" is measured from one side to the other.

Riser

The vertical portion between each tread on the stair. This may be missing for an "open" stair effect.

Nosing

An edge part of the tread that protrudes over the riser beneath. If it is present, this means that, measured horizontally, the total "run" length of the stairs is not simply the sum of the tread lengths, as the treads overlap each other.

Types of stairs :

• Straight Stairs.
• Straight Stair with central landing.
• L Shaped Stair.
• L Shaped Winder Stairs.
• Spiral Stairs.
• Curved Staircase.
• Library Ladder.

Geotechnical engineering

The first step to start any construction is the geotechnical investigation studies , these studies include type of soil , types of rock in the site and the it's topography .

Soil : 

There are many things that we have to know about the soil :
1- type of soil
2- physical properties
3- friction coeffecient angle
4- shear stresses
5- normal stresses
6- thermal resistivity

Any factor of these will affect on the excavation and foundation , for an example , for the weak soil may be we should use raft foundation or piles but for strong soil may be we use single footing . It doesn't affect just the type it's affect the thickness and other dimensions .

Rocks : 

The rocks are divided in three types :
1- Igneous rocks
2- sedimentary rocks
3- metamorphic rocks

Each one of these types differ from the others by physical properties , chemical properties , uses , textures and the procedure that resulted from .

Igneous rocks :

The igneous rocks is the result of magma or lava cools or hardens .

*magma is inside earth's interior 

*lava is outside earth crust

Igneous rocks are classified depending on : 

Texture size : texture mean how a rock looks and feels , and its based on the grain size .

Where the rock is made : rocks that cool slowly have larger crystals , but rocks that cools fast have smaller crystals .

Materials that the rock made from : the major silicate rock forming elements are : O , Si , Al , Fe , Mg ,K , Na , Ca . 

*When the silica percentage decrease the rock will become darker .

*Glassy texture means that the rock have no crystal grains .

In the next post we will talk about other types of rocks : sedimentary and metamorphic rocks .

Hybrid system overview

The hybrid system is the wave of the future, and now there are more incentives to purchase one. Owners of the Prius, or any other hybrid gas-and-electric vehicle, may be eligible for a federal income tax deduction. According to the internal revenue service, hybrid vehicles qualify for a long-standing tax deduction that applies to vehicles powered by clean burning fuels. The policy allows a one-minute deduction, which can be claimed by the consumer for claimed by the consumer for the year the car was first put in use.

In its simplest form, a hybrid system combines the best operating characteristics of an internal combustion engine and an electric motor more sophisticated hybrid systems, such the Toyota hybrid system,  recover energy otherwise lost to heat in the brakes and use it to supplement the power of its fuel-burning engine. These sophisticated techniques allows the Toyota hybrid system to achieve superior fuel efficiency and a massive reduction in CO2.

Hybrid system components:-

• IC engine {internal combustion engine}
• Motor generator 1
• Motor generator 2
• Planetary gear set 
• Inverter 
• HV Battery 
• HV ECU

/-Motor generator 1 

MG1

Motor generator 1 operates as the control element for the power splitting planetary gear set. It recharges the HV battery and also supplies electrical power to drive motor generator 2. MG1 effectively controls the continuously variable transmission function of the trans-axle and operates as the engine starter. 

/-Motor generator 2

MG2 is used for motive force at low speeds and supplemental force at high speeds. It provides power assist to the engine output as needed and helps the vehicle achieve excellent dynamic performance. It also function as a generator during regenerative braking.

/-The planetary gear unit

Is a power splitting device. MG1 is connected to the sun gear, MG2 is connected to the ring gear and the engine output shaft is connected to the planetary carrier. These components are user to combine power delivery from the engine and MG2, and to recover energy to the HV battery.

/-Inverter

Current between MG1,MG2 and the HV battery is controlled by the inverter. The inverter converts high voltage battery DC to AC power, and it rectifies high voltage AC from MG1 and MG2 to recharge the HV battery.

/-HV battery 

The battery stores power recovered by MG2 during regenerative braking and power generated by MG1. The battery supplies power to the electric motor when starting off or when additional power is required.

 *THS (2001−2003 Prius)   

 38 Nickel−Metal Hydrid modules 

Total voltage: 273.6V

 *THS−II (2004 and later Prius) 

    28 Nickel−Metal Hydride modules

Total voltage: 201.6V