Tuesday, September 27, 2011

How Wind Turbines Work!!!

Wind ENERGY
How Wind Turbines Work!!!

-Wind is a form of solar energy. Winds are caused by the uneven heating of the atmosphere by the sun, the irregularities of the earth's surface, and rotation of the earth. Wind flow patterns are modified by the earth's terrain, bodies of water, and vegetation. Humans use this wind flow, or motion energy, for many purposes: sailing, flying a kite, and even generating electricity.

-The terms wind energy or wind power describes the process by which the wind is used to generate mechanical power or electricity. Wind turbines convert the kinetic energy in the wind into mechanical power. This mechanical power can be used for specific tasks (such as grinding grain or pumping water) or a generator can convert this mechanical power into electricity.

-So how do wind turbines make electricity? Simply stated, a wind turbine works the opposite of a fan. Instead of using electricity to make wind, like a fan, wind turbines use wind to make electricity. The wind turns the blades, which spin a shaft, which connects to a generator and makes electricity. Take a look inside a wind turbine to see the various parts in the following figure.

-This aerial view of a wind power plant shows how a group of wind turbines can make electricity for the utility grid. The electricity is sent through transmission and distribution lines to homes, businesses, schools, and so on.



Types of Wind Turbines
-Modern wind turbines fall into two basic groups: the horizontal-axis variety and the vertical-axis design, like the eggbeater-style Darrieus model, named after its French inventor.

-Horizontal-axis wind turbines typically either have two or three blades. These three-bladed wind turbines are operated "upwind," with the blades facing into the wind.


-Utility-scale turbines range in size from 100 kilowatts to as large as several megawatts. Larger turbines are grouped together into wind farms, which provide bulk power to the electrical grid.

-Single small turbines, below 100 kilowatts, are used for homes, telecommunications dishes, or water pumping. Small turbines are sometimes used in connection with diesel generators, batteries, and photovoltaic systems. These systems are called hybrid wind systems and are typically used in remote, off-grid locations, where a connection to the utility grid is not available.

Inside the Wind Turbine

 Turbine Technical Drawing Enlarged
Anemometer:
Measures the wind speed and transmits wind speed data to the controller.
Blades:
Most turbines have either two or three blades. Wind blowing over the blades causes the blades to "lift" and rotate.
Brake:
A disc brake, which can be applied mechanically, electrically, or hydraulically to stop the rotor in emergencies.
Controller:
The controller starts up the machine at wind speeds of about 8 to 16 miles per hour (mph) and shuts off the machine at about 55 mph. Turbines do not operate at wind speeds above about 55 mph because they might be damaged by the high winds.
Gear box:
Gears connect the low-speed shaft to the high-speed shaft and increase the rotational speeds from about 30 to 60 rotations per minute (rpm) to about 1000 to 1800 rpm, the rotational speed required by most generators to produce electricity. The gear box is a costly (and heavy) part of the wind turbine and engineers are exploring "direct-drive" generators that operate at lower rotational speeds and don't need gear boxes.
Generator:
Usually an off-the-shelf induction generator that produces 60-cycle AC electricity.
High-speed shaft:
Drives the generator.
Low-speed shaft:
The rotor turns the low-speed shaft at about 30 to 60 rotations per minute.
Nacelle:
The nacelle sits atop the tower and contains the gear box, low- and high-speed shafts, generator, controller, and brake. Some nacelles are large enough for a helicopter to land on.
Pitch:
Blades are turned, or pitched, out of the wind to control the rotor speed and keep the rotor from turning in winds that are too high or too low to produce electricity.
Rotor:
The blades and the hub together are called the rotor.
Tower:
Towers are made from tubular steel (shown here), concrete, or steel lattice. Because wind speed increases with height, taller towers enable turbines to capture more energy and generate more electricity.
Wind direction:
This is an "upwind" turbine, so-called because it operates facing into the wind. Other turbines are designed to run "downwind," facing away from the wind.
Wind vane:
Measures wind direction and communicates with the yaw drive to orient the turbine properly with respect to the wind.
Yaw drive:
Upwind turbines face into the wind; the yaw drive is used to keep the rotor facing into the wind as the wind direction changes. Downwind turbines don't require a yaw drive, the wind blows the rotor downwind.
Yaw motor:
Powers the yaw drive.



This Info are from http://www1.eere.energy.gov

Thursday, September 22, 2011

Diesel Generator sizing - How to Determine What Size You Need??

Diesel Generator sizing - How to Determine What Size You Need??

-Getting a generator that can handle all your power generation needs is one of the most critical aspects of the purchasing decision.  Whether you are interested in prime or standby power, if your new generator can't meet your specific requirements then it simply won't be doing anyone any good because it can put undue stress on the unit and even damage some of the devices connected to it.  Unfortunately, determining exactly what size of generator to get is often very difficult and involves a number of factors and considerations.
-Making a choice amongst single phase, three phase, kW, KVA, welder, standby or motor starting generators can be mind-boggling. To prevent such confusion, this article was developed to help you get a better idea of how the sizing process works and some key things to keep in mind.

Generator Size Variations
-With the latest advancements in the field of electrical engineering, generators are now available in a wide range of sizes. Generators with power supply capacities of 5kW to 50kW are readily available in the personal and home use markets, while industrial generators are anywhere from 50kW to over 3 Megawatts.  Handy and portable gen sets are available for homes, RV's and small offices, but larger businesses, data centers, buildings, plants, and industrial applications need to use the much larger sized industrial generators to meet their higher power requirements.

Generator Sizing - How Much Power
-Many people believe smaller generators can be used for standby electric power because they are not running all the time. This is not only a myth but can actually be very detrimental. Unfortunately, generator under sizing is one of the most common mistakes committed by buyers.  Not only does it involve the risks of damaging your new asset (the generator), but it can also damage other assets connected to it, create hazardous situations, and even limit overall productivity of the unit and/or the business relying on it.  If nothing else, the key thing to remember here is that more is always better than less.

Know Your Requirements

Going to a dealer and buying the best or cheapest generator available without any other consideration is clearly not the best approach. It is always better to delve deep into your power generation requirements before making a choice. You can do this in the following ways:

- Make a list of the items that need to be powered by the generator
- Make a note of the starting and running wattage of the respective items
- Calculate the total power requirements in KVA or KW

Advantages of choosing the right size generator
Now that you have an idea on how to choose the appropriate size of generator to suit your needs, here's just a few of the benefits obtained by going through that process:

- No unexpected system failures
- No shutdowns due to capacity overload
- Increased longevity of the generator
- Guaranteed performance
- Smoother hassle-free maintenance
- Increased system life span
- Assured personal safety
- Much smaller chance of asset damage

Tuesday, September 20, 2011

Ingress Protection Codes and Classification IP CODE

Ingress Protection Codes and Classification IP CODE

- The IPCODE (IP code) is used to stipulate the environmental protection applicable for specific equipment enclosures.
-When we purchase any electrical equipment, mechanical devices, household instruments, or enclosures, it is important to identify what degree of IP rating or IP Code (Ingress Protection) the equipment offers. Ingress of solid or liquid particles into the equipment can be dangerous to humans as well as machinery.
-The intention of this rating is to provide consumers and end users clearer details than advertising terminology such as "rainproof" or "waterproof."
-The IP code is used to stipulate the environmental protection used for specific equipment enclosure.
**Normally an IP code has two numbers:
  • Protection from solid particles
  • Protection from liquids
As an example, with the rating "IP 23," the first digit "2" describes the level of protection from solid objects and second digit "3" describes the level of protection from liquids.
  • 2 = Protected against solid objects up to 12mm, e.g. fingers.
  • 3 = Protected against direct sprays of water up to 60° from the vertical.

IP Standards

An engineer working within industry should understand the types of enclosures provided against hazardous parts and the ingress of solid foreign particles for all equipment located in the plant. Also during design of machines, an engineer should take care of IP codes of equipment, considering its application and the surrounding condition of placement.
The applicable European standards for ingress protection are:
  • BS EN 60529 Specification of Degrees of Protection Provided by Enclosures
  • IEC 529 Specification of Degrees of Protection Provided by Enclosures
Both of these provide a numerical code to classify the degree of protection offered. Please click on the following link to view the table.





This information source from ‘’ ContractorsUnlimited.co.uk ‘’.

Monday, September 19, 2011

OPERATION JOB OR TECHNICAL PLANNING ??

HELLO EVERYONE

I want to share with you an important question , and I hope you have a reply for me ?
What would you choose if there are two offers for work and why ?

The first Offer , is to work as an operational Engineer at Electricity Power Generation Utility and you have to make the proper control and optimization for the whole unit.

The seconde Offer , is to work at Technical Planning Engineer for a company in telecommunication Sector , and you have to make proper tenders and recommendation for purchasing and order of Electrical Equipments like Diesel Units , Batteries , Medium Voltage Panels , UPS , INVERTERS , Rectifirers.


I want your replies so soon , please , and thanks for your interest.

Khaled Hamza

Monday, July 18, 2011

BOILER DRUM ROLES

BOILER DRUM ROLES





- Steam drums are used on recirculating boilers that operate at subcritical pressures. The primary purpose of the steam drum is to separate the saturated steam from the steam-water mixture that leaves the heat transfer surfaces and enters the drum. The steam-free water is recirculated within the boiler with the incoming feedwater for further steam generation. The saturated steam is removed from the drum through a series of outlet nozzles, where the steam is used as is or flows to a superheater for further heating. (By definition, saturated steam is pure steam that is at the temperature that corresponds to the boiling temperature at a particular pressure. For example, saturated steam at a pressure of 500 psia has a temperature of 467°F.)

The steam drum is also used for the following:

1- To mix the saturated water that remains after steam separation with the incoming feedwater.
 
2- To mix the chemicals that are put into the drum for the purpose of Corrosion control and water treatment.

3-  To purify the steam by removing contaminants and residual moisture.

4-  To provide the source for a blowdown system where a portion of the water is rejected as a means of controlling the boiler water chemistry and reducing the solids content.

5- To provide a storage of water to accommodate any rapid changes in the boiler load.





- The most important function of the steam drum, however, remains as the separation of steam and water. Separation by natural gravity can be accomplished with a large steam-water surface inside the drum. This is not the economical choice in today’s design because it results in larger steam drums, and therefore the use of mechanical separation devices is the primary choice for separation of steam and water.

- Efficient steam-water separation is of major importance because it produces high-quality steam that is free of moisture.

This leads to the following key factors in efficient boiler operation:

1. It prevents the carry-over of water droplets into the superheater, where thermal damage could result.

2. It minimizes the carry-under of steam with the water that leaves the drum, where this residual steam would reduce the circulation effectiveness of the boiler.

3. It prevents the carry-over of solids. Solids are dissolved in the water droplets that may be entrained in the steam if not separated properly. By proper separation, this prevents the formation of deposits in the superheater and ultimately on the turbine blades.



**(carry-over is the passing of water and impurities to the steam outlet)
**The term critical pressure is the pressure at which there is no difference between the liquid and vapor states of water; i.e., the density is identical. This occurs at 3206 psia.



This information source from ‘’ Steam Plant Operation  8th Ed. - Everett B. Woodruff  ‘’ .

Monday, July 11, 2011

AUTOMATIC VOLTAGE REGULATOR (AVR)

-I will talk today with you about an important equipment used in power system utilities, it is the Automatic Voltage Regulator (AVR). From its name it is a regulator which regulates the output voltage at a nominal constant voltage level.
Role of AVR
AVR (Automatic voltage regulator) has following roles.

1- To regulate generator terminal voltage.
Mainly generator under no-load condition, AVR regulates the generator voltage to voltage setter (90R).






*AVR detects terminal voltage and compare with voltage setter (90R).
*AVR regulates field current via the Exciter.
*Generator terminal voltage is regulated by field current.


Vt < 90R _ Field current will be increase
Vt > 90R _ Field current will be decrease



2-To adjust MVars (Reactive power).
When the generator connected to power grid, AVR adjust reactive power by regulate generator voltage.





MVar (Reactive power: Q) is regulated by generator terminal voltage. Therefore AVR can regulate MVars.

Vt is increased _ MVars will be increase
Vt is decreased _ MVars will be decrease

Hence;

To increase MVars _ 90R raise
To decrease MVars _ 90R lower



3-To improve the power system stability.
There are two stability
-Transient stability …… Improved by AVR
-Dynamic stability ……. Improved by PSS (power system stabilizer)







  * Improve the Transient stability






Transient stability is improved by high initial response characteristic. In the fault condition, Field voltage is increased to keep the generator voltage constantly. If the excitation response is slow, it will not able to keep voltage and the generator cannot keep synchronizing.


 * Improve the Dynamic state stability







Dynamic stability is improved by Power System Stabilizer (PSS). PSS is provided in order to improve the power system dynamic stability. PSS will control the excitation to reduce the power swing rapidly.



4-To suppress the over-voltage on load rejection.
When the load rejection, field current and field voltage should be reduced rapidly to keep terminal voltage constantly and prevent overvoltage.







This information source is MELCO CO. for CEPC generator

Sunday, July 3, 2011

Gas Recirculation Fan ( Structure & Control )


Gas Recirculation Fan

- Gas Recirculation Fan (GRF) draw gas from a point between the economizer outlet and the air heater inlet and discharge it into the bottom of the furnace outlet.

- Recirculation gas introduced in the vicinity of the initial burning zone of the furnace is used for steam temperature control, while re circulated  gas introduced near the furnace outlet is used for control of gas temperature.












-RH outlet steam temperature is normally controlled by regulating the gas recirculation flow. Increased flue gas flow over Reheater of the convection heating surfaces increases the heat absorption and RH temperature is increased.

-The following picture will show the full specification of the GRF ( motor and impeller ).







-Due to large GRF duty , Bearings are equipped with water cooling flexible line , the bearing at the motor side is fixed to the shaft, while at the counter to the motor side is set free for the shaft expansion caused by the heat of high temperature gas in the casing during the continuous operation.






-Because the fan treats the high temperature gas, it is adopted with a turning device, If the fan stopping remain the high temperature gas in the casing, the impeller has the unbalance by heat effect. So the purpose of the no unbalance of the heat effect drive the turning device regular time at about 50 rpm until the economizer heat decreased to a safety limit about 100 centigrade.



Gas Recirculation control

-RH outlet steam temperature is normally controlled by regulating the gas recirculation flow. Increased flue gas flow over Reheater of the convection heating surfaces increases the heat absorption and RH temperature is increased. The amount of gas recirculation flow is controlled by positioning the inlet dampers on the two Gas Recirculation Fans (GRF).

(1)During start -up (approximately < 25% boiler load), GRF inlet damper position is control led by the function generator from Boiler Master. Because RH temperature feedback control is difficult during the start-up due to the slow response.

(2) Dynamic feed forward signal (BIR) is added to GRF inlet damper to improve RH steam temperature control during load change.

(3)High and low limit from Boiler Master for GRF inlet damper are provided. High limit is to avoid the unstable combustion and the over current of GRF. And low limit is to protect the water wall and avoid the high NOx.

Saturday, July 2, 2011

Keeping Control of Drum Levels


Keeping Control of Drum Levels

 “THIS ARTICLE GIVES US DIFFERENT TECHNIQUES ABOUT BOILER CONTROL ESPECIALLY DRUM LEVEL CONTROL,”

-Power plants are designed to operate for decades, provided they undergo regular repair, upgrade and improvement. Much of the time, those maintenance actions are minor. But plant managers expect a few big-ticket expenditures.
-Public Service Electric & Gas Co. (PSEG), for instance, spent $1.3 billion and more than 7 million hours of labor during the 2008 to 2010 period upgrading emissions controls at its Hudson and Mercer, N.J. coal-fired plants. By installing scrubbers, selective catalytic reduction, baghouses and activated carbon injection, PSEG reduced NOX emissions by more than 95 percent, SO2 by more than 94 percent, particulates by more than 99 percent and mercury by more than 90 percent. On a smaller scale, PSEG’s 753 MW Mercer Generating Station experienced problems controlling the water levels in its four Foster Wheeler drum boilers. In that case, it was simply a matter of replacing the original actuators on the feedwater valves with new electraulic actuators.
-“We would have excursions in drum levels and had to wait until it settled down before the operator was comfortable with moving on line,” said PSEG Controls Engineer, Mark Maute. “It’s not a problem anymore. There is no slop in the controls and it runs right where it is supposed to.”

Hitting the Set Point

-Boiler efficiency and overall plant performance depend on being able to accurately control the water levels in the drum. Several problems affect that ability. To begin with, there is the issue of shrink and swell. As steam demand increases, the drum pressure drops initially, causing bubbles to form below the surface of the water and producing a rise in the drum level (swell). When demand decreases, pressure in the drum increases and water levels drop (shrink). This is usually addressed by using a cascade/feed-forward control strategy that takes readings from steam flow, feedwater flow, drum level and drum pressure transmitters and adjusts the feedwater accordingly.
-The feedwater control strategy must also integrate with the combustion control strategy. The firing rate set point demand is calculated as a function of the steam flow and the main steam header pressure. Accurate control of the feedwater loop is necessary to maintain stable combustion flow. If the plant requires steam pressure and flow to remain fairly constant but the feedwater loop is unstable due to poor controllability, the combustion controls will have to continually adjust in attempting to follow unstable changes in the feedwater flow and keep the steam demand at the set point.
-To accurately control the volume of water entering the drum, the feedwater regulator valve needs to accommodate a wide range of operating conditions. During start-up and low-fire conditions, the valve sees high inlet pressures but low flow, so the valve requires anti-cavitation trim to address the full pressure drop across the valve. As the boiler load increases, the valve passes more flow, the inlet pressure drops and the outlet pressure to the drum rises. As a result, the valve must have a large capacity with minimal pressure drop. Some plants use two valves in parallel, one designed for start-up conditions and the other for mid- to full load. The other approach is to use a single valve with a characterized disk stack designed to accommodate varying flow conditions.
-Whichever approach is taken, the feedwater regulator valve must have an actuator that can smoothly and accurately adjust feedwater flow. The valve doesn’t need to be extremely fast, because the digital control system will tune the loop for optimum operation. But the actuator should respond to the command without added delay and execute the command without overshooting or undershooting.
-Pneumatic actuators cannot achieve the highest level of control performance because air is compressible. When the command is given to increase the air pressure and move the valve, there is a lag while the air pressure increases to the point where it is high enough to overcome the static friction of the actuator and start it moving. Pneumatic actuators also tend to overshoot the set point. This dynamic is known as hysteresis, and is a common occurrence in pneumatic control valves. “Smart” pneumatic positioners slow the actuator as it nears the set point to reduce the amount of overshoot, but the adverse affect is that they also increase the “deadtime” in the process loop and ultimately inhibit the controls engineer in optimum loop-tuning. It is common for pneumatic actuators to add seconds of deadtime into the process loop, making them more difficult to tune for high levels of process performance.
-One alternative for improved control is for a plant to use hydraulic actuators. Hydraulic fluids are incompressible by nature, have immediate response and move to position in a stable and repeatable manner without overshooting and without hysteresis. The detriments of electro-hydraulic control systems (EHC’s) are in that they are more expensive than pneumatic systems and require a network of components: an external gravity fed reservoir, constantly running motors/pumps, expensive filtering systems and typically handling of fire retardant oil. Because of these components, EHCs have given maintenance department’s headaches for years. Although the performance of hydraulic systems is undeniably more robust and more accurate, the trade-offs associated with maintaining these systems offset their inherent benefit.

Gaining Control

-To address its feedwater problems, PSEG decided to use an “electraulic” (electro-hydraulic) actuator from Rexa. The Rexa actuators are self-contained units that combine hydraulic, electronic and mechanical technologies. Rexa actuators provide performance commensurate with typical hydraulic systems (0.05 percent resolution and 70mSec deadtime), but eliminate the maintenance-intensive requirements associated with EHCs.
-Electraulic actuators have two main components, a power module and a control enclosure and operate by moving hydraulic fluid from one side of a double-acting cylinder to the other.
-Inside the power module are a motor, gear pump, flow match valve, 60cc thermal expansion/make-up oil reservoir, heater and thermostat. Upon receipt of a control signal, the pump delivers oil at a nominal 2,000 psi to one side or the other of a hydraulic cylinder, causing motion in the desired direction. The hydraulic cylinders come in either linear or a rack-and-pinion rotary design. A position sensor is mounted within or adjacent to the cylinders and provides position feedback to the control electronics.
-The control sub-assembly contains the central processing unit (CPU), power supply and motor drivers. The CPU typically contains a microprocessor, an analog-to-digital converter, a position transmitter, limit switches and warning and alarm systems. The power supply takes the incoming AC power and coverts it to the voltages required by the control components. The motor driver receives commands from the CPU and sends control signals to the motor. Outside of the enclosure (or inside when conditions require) is a two-line display giving actuator status and a five-button keypad to set up and calibrate the actuator.
-When used to control a feedwater regulator valve, the CPU receives a control signal from the DCS and converts it to a target position for the actuator. It then compares current position of the actuator as reported by the feedback assembly with the desired new position. If the difference is outside the preprogrammed range the CPU will send a signal to start the motor, which then drives the reversible hydraulic pump to pressurize one side of the cylinder or the other, moving the piston in the desired direction. Once it reaches the new position, the pump shuts down and check valves close. This locks the hydraulic fluid in the cylinder and maintains the actuator position, without having to keep the motor running, until a new signal is received from the DCS.

By Joe Zwers , freelance writer
----------------------------------------------------------------------------------------------------------------

http://science-hamza.blogspot.com/

Sunday, March 27, 2011

Air Ejectors (2 of 3)


Air Ejectors (2 of 3)

-An air ejector or steam ejector is a device which uses the motion of moving fluid (Motive Fluid) to transport another fluid (Suction fluid). It is has a wide range of application in steam ejector in boiler condenser, fresh water generator and in priming the centrifugal pump.

-It works on the principle of convergent /divergent nozzle as it provides the venturi effect at the point of diffusion as the tube gets narrows at the throat the velocity of the fluid increases and because of the venturi affect it pressure decreases, vacuum will occur in the diffuser throat where the suction line will be provided.





-The operating medium of an air ejector can be either high-pressure gas or liquid. This is passed through a nozzle and the pressure energy is converted into velocity energy. The high-velocity fluid aspirates the air and the non-condensable gases and the mixture is projected into a diffuser which reconverts the velocity energy into pressure energy.






-Steam is suitable operating medium and is used in the steam-jet air ejector. The steam consumption is controlled by the compression ratio of the air and this factor influences the decision to adopt either single or multiple stage ejectors for a particular condition.

-To meet the requirements when raising vacuum a starting ejector is provided. This is high capacity, high steam consumption ejector, of single stage and without an after condenser.

-A main air ejector with standby unit is usually provided for normal operation. The heat in the operating steam is partially recovered in the condensate which flows through the inter and after coolers.


 


-If an installation is to operate with a direct cooling system, as is provided by the sea or a river, vacuum as high as 29.2 in.Hg would be expected during the winter months.

-A cooling tower installation will operate at a slightly poorer vacuum than a direct cooled station and this vacuum can usually be handled by a two-stage ejector.

Saturday, March 26, 2011

CONDENSER – AIR EXTRACTION EQUIPMENT ( 1 Of 3 )


CONDENSER – AIR EXTRACTION EQUIPMENT


- Turbines are designed for a particular operating conditions like steam inlet pressure, steam inlet temperature and turbine exhaust pressure/ exhaust vacuum, which affects the performance of the turbines in a significant way. Variations in these parameters affect the steam consumption in the turbines and also the turbine efficiency. Theoretical turbine efficiency is calculated as work done by the turbine to the heat supplied to generate the steam.

- Higher exhaust pressure/ lower vacuum, increases the steam consumption in the turbine, keeping all other operating parameters constant. Exhaust pressure lower than the specified will reduce the steam consumption and improves the turbine efficiency. Similarly exhaust vacuum lower than the specified, will lower the turbine efficiency and reduces the steam consumption.

- The air extraction equipment must be capable of meeting two conditions; one met during normal operation, the other when raising vacuum on the turbo-generator unit.

- When raising vacuum the air extraction equipment must deal rapidly with a large quantity of air and sufficient capacity must be installed to reduce pressure quickly in the condenser to a level which allows the turbine to be started. The last row blades of a 500 MW turbine will overheat if they run at speed and at low load in a poor vacuum. Thus, a vacuum of 20 in.Hg must be obtained before steam is admitted to the turbine and a vacuum of 26 in.Hg for full speed. It is important that the time taken to bring a turbo-generator on load shall not be increased by sufficient air extraction capacity.

- Under normal operating conditions the quantity of air to be exhausted is lower. It consists of air leakage into the condenser via flanges and glands and also of incondensable gases that are present in the steam exhausting from the turbine. Air and incondensable must be removed from the condenser as their presence in any quantity impairs the heat transfer capability of the condenser and hence its performance. Conversely, excessive air extraction capacity should not be run, as this involves unnecessary running costs and also results in the extraction of an unwanted quantity of water vapor from the condenser steam space.



“We will talk about the equipment for the extraction in the 2 upcoming articles”