Shaft power formula for turbine

Horsepower is the imperial British unit of power. A horsepower is the ability to do work at the rate of. Note that Power is "Work per unit time" and work is "Force through distance".

In gravity systems the Force is Weight - mass multiplied with gravity. The total horsepower developed by water falling from a given height is the product of the mass flow rate in pounds per minute times the falling height in feet divided by and can be expressed as:. SG for water is 1. Q gal - Volume Flow imp gpm. The brake horsepower is the amount of real horsepower going to the pump, not the horsepower used by the motor.

In the metric system kilowatts kW is used. Due to hydraulic, mechanical and volumetric losses in a pump or turbine the actual horsepower available for work on or from the fluid is less than the total horsepower supplied. Horsepower can be converted to other common units as:. Together with the equations above it's possible to express 4 in many common combinations - such as:. Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro.

We don't collect information from our users. Only emails and answers are saved in our archive. Cookies are only used in the browser to improve user experience. Some of our calculators and applications let you save application data to your local computer. These applications will - due to browser restrictions - send data between your browser and our server. We don't save this data.

Google use cookies for serving our ads and handling visitor statistics. AddThis use cookies for handling links to social media. Please read AddThis Privacy for more information.Hot Threads. Featured Threads. Log in Register.

Pelton Wheel: Parts, Working, Efficiency, Advantages, Disadvantages, Applications [With PDF]

Search titles only. Search Advanced search…. Log in. Forums Engineering Mechanical Engineering. JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding. How to calculate the power generated by a turbine steam? Thread starter clurt Start date Oct 28, Tags mass flow power generated pressure steam steam power steam quality temperature turbine.

Firstly, lets assume the expansion is isentropic. Related Mechanical Engineering News on Phys. SteamKing Staff Emeritus. Science Advisor. Homework Helper. Eduardo Almeida. Eduardo Almeida said:. SteamKing said:. Unless you know the enthalpy of the inlet and exhaust steam, yes, you need to refer to steam tables. For your exhaust condition, knowing the pressure is often not enough information. However, since you have specified a turbine operating isentropically, then using a Mollier diagram a special diagram of enthalpy versus entropythe state line of this turbine will be a single vertical line running from the inlet point down to the exhaust pressure of 30 kPa.

Since Mollier diagrams are hard to find on the web, you can also use steam tables. Hi, everyone I have question about turbine and pressure.

Pump Power Calculation Formula | Specific speed of a centrifugal pump

Hi, asdarw Unfortunately, you have not provided enough information to calculate pressure in the turbine. A turbine extracts work between an inlet pressure and an exhaust pressure, so you'll need to specify one or the other of these pressures. Also, if you want to ask a question, don't hijack another user's thread, especially one which is months, if not years, old. Make a thread for your own question.

It's easy to do, and you can make as many different threads as you need. If your question is for home work or course work, be sure to fill out the HW Template and post in the appropriate HW forum.

I know how to open new thread, but i didnt know where. Yes its about test in School. I know Q, N, and H, and the answer is Good job on the first question, SteamKing. Good old thermo As for the second question, I'm thinking that perhaps the pressure is a change in pressure, or what I always call the delta P of the flow work.

That being said, there is enough to calculate the delta P but not a static inlet or outlet pressure as you pointed out without having all the other information. Let's make sure I understand the variables first: Q is volume flow rate h is isentropic efficiency N is power output?The Pelton wheel or Pelton wheel turbine is a tangential flow impulse turbine used for high heads of water. The energy available at the inlet of the turbine is only kinetic energy. The pressure energy at the inlet and outlet of the turbine is atmospheric.

This is a hydraulic turbine and the main uses of these turbines are in the hydropower plant to generate electricity. It is a flexible source of electricity and also the cost of electricity generation is relatively low. The amount of water striking the buckets of the runner is controlled by providing a spear in the nozzle. The speed is a conical needle which is operated either by a hand wheel or automatically in an axial direction depending upon the size of the unit.

When the spear is pushed forward into the nozzle and the amount of water striking the runner is reduced. On the other hand, if the sphere is pushed back, the amount of water striking the runner increases. The runner or blade consists of a circular disc on the Periphery of which several buckets evenly spaced are fixed. The Shape of the bucket is of a double hemispherical cup or bowl. Each bucket is divided into two symmetrical parts by a dividing wall which is known as a splitter.

The jet of water strikes on the splitter. The splitter divides the jet into two equal parts and the Jets come out at the outer edge of the bucket. The bucket is shaped in such a way that the jet gets deflected through degrees or degrees. The bucket is made of cast iron, cast Steel bronze or stainless steel depending upon the head at the inlet of the turbine. The function of the casing is to prevent the splashing of the water and to discharge water to the tailrace.

shaft power formula for turbine

It also acts as a safe ground against accidents. It is made of cast iron or fabricated steel plates. The casing of the Pelton wheel does not perform any hydraulic function. When the nozzle is completely closed by moving the spear in the forward direction, the amount of water striking the runner reduces to zero. But the runner due to inertia goes on revolving for a long time.

To stop the runner in a short time, a small nozzle is provided which directs the jet of water on the back of the vanes. This jet of water is called breaking jet. From there it comes through the penstock and reaches the nozzle of the Pelton turbine.

The nozzle increases the kinetic energy of the water and directs the water in the form of the jet. Now, the jet of water from the nozzle strikes the buckets vanes of the runner. So that the runner rotates at very high speed and the quantity of water striking the vanes or buckets is controlled by the spear present inside the nozzle and then the main important process is the generator is attached to the shaft of the runner which converts the mechanical energy rotational energy of the runner into an electrical energy.

It is the ratio of power generated by the runner of the turbine to the water-energy supplied to the bucket of the runner. It is a ratio of the actual quantity of writing on the runner blades per second to the net quantity of water supplied by the jet to the turbine per second is known as volumetric efficiency.

It is defined as a ratio of the power available at the shaft to the net power available at the base of the nozzle. Pelton wheel is the preferred turbine for hydropower when the available water source has a relatively high hydraulic head at low flow rates. In a hydroelectric power plant, This is used to drive the generator of the turbine and that generator generates the mechanical energy of the turbine into electrical energy. So this is the overview of the Pelton Wheel Turbine, I tried my best to describe the whole thing, I hope you got the concept of Pelton Wheel.

Still, if you have any doubt ask in the comment section, I will get back to you as soon as possible. And as always do share this article on your favorite social media and spread the knowledge globally. See you in another article, until then enjoy the rest of your day.Power is in general rated in watt W or horsepower hp.

The old imperial unit horsepower is equal to watts 0. The unit of electric power - 1 watt - is equal to the power produced by an electrical current of 1 amp at a potential difference of 1 volt. Shaft power produced from a direct current DC electrical motor:. Shaft power produced from an alternating current AC electrical motor:. Shaft power as horse power :. The shaft power as hp. Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro.

We don't collect information from our users. Only emails and answers are saved in our archive. Cookies are only used in the browser to improve user experience.

Some of our calculators and applications let you save application data to your local computer. These applications will - due to browser restrictions - send data between your browser and our server. We don't save this data.

Google use cookies for serving our ads and handling visitor statistics. AddThis use cookies for handling links to social media. Please read AddThis Privacy for more information. If you want to promote your products or services in the Engineering ToolBox - please use Google Adwords. Privacy We don't collect information from our users. Citation This page can be cited as Engineering ToolBox, Electrical Motor Shaft Power. Modify access date. Scientific Online Calculator. Make Shortcut to Home Screen?In this article discussed about pump basic formulas with examples like pump power calculation formulaspecific speed of centrifugal pump and affinity laws for centrifugal and displacement pumps.

Also provided online calculator for pump power calculation. The work performed by the pump is equal to the weight of liquid pumped in Unit time multiplied by total Head in meters. Pump input BHP is the power delivered to the pump shaft and is designated as brake horsepower. Pump Efficiency is the ratio of pump input and output power. Pump input power calculation formula or pump shaft power calculation formula. Formula — 5 USCS units. For an electric-motor-driven pumping unit, the overall efficiency is.

The specific speed can be used to classify the optimum impeller design. Specific Speed of pump Nq is defined as the speed in RPM at which a geometrically similar impeller would run if it were reduced proportionately in size so as to delivered 75 kg of water per second to the height of 1 m. The specific speed can be made a truly dimensionless characteristic parameter while retaining the same numerical value by using following equation. For multistage pumps the developed head H at best efficiency.

Consider half total discharge in case of double suction impeller. Radial high head impeller — up to approx. Radial medium head impeller — up to approx. Radial low head impeller — up to approx. Mixed flow impeller — up to approx. Axial flow impeller propeller — approx. Affinity laws for pumps — Please go through the below link.

Affinity laws for centrifugal pumps Positive displacement pump affinity laws Pump affinity laws with example. Pump Efficiency is the most important factor while calculating power consumption.

So while selection of the higher rating of pump always choose best efficiency pump set. Click Here. Classification of pumps Types of pumps and their working principles. NPSH calculation Pump suction and delivery lines head loss with online calculator. Thanks for reading this article. I Hope it may fulfill your requirement. In this article explained about centrifugal section and Sugar house equipment capacity calculation for process house of sugar industry In this session discuss about Vacuum Pan design criteria for crystallization process in sugar factory.

Vacuum Pan Design Aspects in Sugar This article discussed about 80 MT capacity batch vacuum pan design calculation of Heating surface, Number of tubes, Dia of the downtake In this article, the concepts of the Graining volume in batch pan and example for calculation of the graining volume are discussed.A free-turbine turboshaft is a form of turboshaft or turboprop gas turbine engine where the power is extracted from the exhaust stream of a gas turbine by an independent turbine, downstream of the gas turbine and is not connected to the gas turbine the exhaust airflow is what spins the turbine that is connected to the shaft hence the term "free".

This is opposed to the power being extracted from the power spool via a gear box. The advantage of the free turbine is that the two turbines can operate at different speeds, and that these speeds can vary relative to each other. This is particularly advantageous for varying loads, such as turboprop engines.

A free-turbine turboshaft ingests air through its intake at the front of the engine. The air passes through an axial compressor into the combustorwhere the compressed air is mixed with fuel and ignited.

The expanded exhaust gases first pass through a compressor turbine, which is used to drive the axial compressor, and then drives the power turbine before being exhausted to the atmosphere.

The compressor blades and compressor turbine blades are connected by a common shaft, and the free power turbine is on a separate shaft. Turboshaft engines are sometimes characterized by the number of spools. This refers to the number of compressor-and-turbine assemblies in the gas generator stage. A drawback to the simple free turbine turboprop is its behaviour if the load suddenly falls to zero.

shaft power formula for turbine

In such a case, the unconstrained free power turbine overspeeds and will be destroyed by centrifugal forces. In the confined space of the Britannia's Bristol Proteus engine, fragments perforated the oil tank and led to a fire, which threatened the integrity of the wing spar.

The pilot, Bill Peggthen made a forced landing on the estuary mud. To avoid such accidents, free turbine engines, including the Proteus, are now commonly fitted with a device to shut off the fuel supply at the HP cock if torque in the power turbine output shaft suddenly falls to zero.

Most turboshaft and turboprop engines now use free turbines. This includes those for static power generation, as marine propulsion and particularly for helicopters. A major market for turboshaft engines is that for helicopters. When turboshaft engines became available in the s, they were rapidly adopted for both new designs and as replacements for piston engines.

They offered more power and far better power to weight ratios.If you have not reviewed these concepts for a while, it would be helpful to do so before studying this article. For example, we have heard engine builderscamshaft consultantsand other " technical experts" ask customers:. And the question is usually asked in a tone which strongly suggests that these "experts" believe power and torque are somehow mutually exclusive.

At the bottom of this page, the derivation of that equation is shown, for anyone interested. Referring to Figure 1assume that the handle is attached to the crank-arm so that it is parallel to the supported shaft and is located at a radius of 12" from the center of the shaft.

In this example, consider the shaft to be fixed to the wall. Let the arrow represent a lb.

shaft power formula for turbine

Because the shaft is fixed to the wall, the shaft does not turn, but there is a torque of pound-feet pounds times 1 foot applied to the shaft.

In the same way that one ton is a large amount of weight by definition, poundsone horsepower is a large amount of power. The definition of one horsepower is 33, foot-pounds per minute. Consider the following change to the handle-and-crank-arm sketch above. The handle is still 12" from the center of the shaft, but now, instead of being fixed to the wall, the shaft now goes through the wall, supported by frictionless bearings, and is attached to a generator behind the wall.

Suppose, as illustrated in Figure 2that a constant force of lbs. In other words, the "arrow" rotates with the handle and remains in the same position relative to the crank and handle, as shown in the sequence below. That is called a "tangential force".

- Power and Torque -

If that constant lb. The point to be taken from those numbers is that a given amount of horsepower can be made from an infinite number of combinations of torque and RPM. In fact, in cars of equal weight, the smaller engine will probably race BETTER because it's much lighter, therefore puts less weight on the front end. AND, in reality, the car with the lighter 2-liter engine will likely weigh less than the big V8-powered car, so will be a better race car for several reasons. A dynamometer determines the POWER an engine produces by applying a load to the engine output shaft by means of a water brake, a generator, an eddy-current absorber, or any other controllable device capable of absorbing power.

Then it applies various factors air temperature, barometric pressure, relative humidity in order to correct the observed power to the value it would have been if it had been measured at standard atmospheric conditionscalled corrected power. In the course of working with lots of different engine projects, we often hear the suggestion that engine power can be increased by the use of a "better" oil pump.

Implicit in that suggestion is the belief that a "better" oil pump has higher pumping efficiency, and can, therefore, deliver the required flow at the required pressure while consuming less power from the crankshaft to do so. While that is technically true, the magnitude of the improvement number is surprisingly small. How much power does it take to drive a pump delivering a known flow at a known pressure? We have already shown that power is work per unit time, and we will stick with good old American units for the time being foot-pounds per minute and inch-pounds per minute.

From there it is simply a matter of multiplying by the appropriate constants to produce an equation which calculates HP from pressure times flow. Since flow is more freqently given in gallons per minute, and since it is well known that there are cubic inches in a gallon, then:.

Since, as explained above, 1 HP is 33, foot-pounds of work per minute, multiplying that number by 12 produces the number of inch-pounds of work per minute in one HPDividingby gives the units-conversion factor of Therefore, the simple equation is:.

When the equation is modified to include pump efficiency, it becomes:. So suppose your all-aluminum V8 engine requires 10 GPM at 50 psi.

Jet Engine, How it works ?

The oil pump will have been sized to maintain some preferred level of oil pressure at idle when the engine and oil are hot, so the pump will have far more capacity than is required to maintain the 10 GPM at 50 psi at operating speed. That's what the "relief" valve does: bypasses the excess flow capacity back to the inlet of the pump, which, as an added benefit, also dramatically reduces the prospect cavitation in the pump inlet line.


thoughts on “Shaft power formula for turbine

Leave a Reply

Your email address will not be published. Required fields are marked *