A

Note that while physically, the expansion ratio is essentially the same as the compression ratio, the focus here is on the adiabatic portion of the expansion ratio. The ratio of compression to expansion is known as the cut-off ratio (rc.o.) and is expressed as If these relationships are used in Equation 9-11, the equation for thermal efficiency becomes

Interviews with Operating Personnel

Extensive interviews with knowledgeable management and front-line engineering, operating, and maintenance personnel are a critical aspect of the study process. System operators can provide valuable and timesaving detail on how and when equipment operates, the control parameters used, equipment capabilities, known problems that require solutions, and how and where operating records are kept. The personnel that have daily responsibility for the facility's systems should always be considered an...

Combined Cycles

The fact that a gas turbine exhausts large quantities of air gases at temperatures around those of a fairly efficient steam cycle (1,000 F or 538 C) allows for significant enhancements in overall cycle efficiency. As shown in Figure 3-5, if the exhaust from a gas turbine is fed to a heat recovery steam generator (HRSG), the steam that is raised can drive a steam-powered cycle. The steam cycle converts about 15 to 20 of the rejected heat energy into additional electric power, resulting in a...

W

Where subscripts c and t indicate ideal compressor and turbine, respectively, and ca and ta indicate actual compressor and turbine work, respectively. The actual work requirement of the compressor as a function of temperature (T) or enthalpy (h) change can be expressed as where T2< and h2< represent the actual temperature and enthalpy, respectively. Actual compressor efficiency, in relation to the isentropic process, can be expressed as Correspondingly, actual turbine work can be expressed...

OMR Training Manuals

Implementation of individual OM& R and training programs is typically the responsibility of the on-site OM& R Supervisor, who will report to the OM& R Team Leader. The OM& R Supervisor will develop operating manuals that comprehensively cover the total operation of each new system brought on line. The manuals will contain step-by-step methods for operating systems and individual components, detailing the location of the items, their function, and characteristics, as well as...

Control Systems

Modern combustion gas turbines are equipped with programmable logic controllers (PLCs) using proprietary software. The system provides required control sequences and monitors the functions required to safely start, load, Fig. 10-37 Reduction Drive Assembly. Source Solar Turbines Fig. 10-37 Reduction Drive Assembly. Source Solar Turbines and operate the unit. The control system warns of out-of-specification conditions and processor, with completely automated start-up and extensive monitoring,...

C

kwitchgear is an assembly of switching, interrupting, regulating and protective devices, control logic circuitry, instrumentation, and metering devices required for the safe distribution of electric power. With localized on-site electric generation applications, generator switchgear manages one or more generators in a prearranged control strategy to safely meet the needs of the host facility and, where applicable, the requirements of the utility grid. Figure 27-1 shows switchgear for an...

Absorption Cycle and Engine Driven Heat Pumps

While almost all of the heat pumps currently in commercial operation use electric motor-driven vapor compression systems, the compressor itself is indifferent Fig. 36-24 Geothermal Heat Pump Loop System. Source The Trane Company Fig. 36-24 Geothermal Heat Pump Loop System. Source The Trane Company NH3-H2O based GAX cycle, which are discussed in Chapter 38. While the basic GAX cycle is an excellent heat producer, it is not as thermally efficient in the cooling mode as other cooling system...

Molten Carbonate Fuel Cell MCFC

Molten carbonate electrolyte development is proceeding to commercial system development with prototype capacities of 2 MW and smaller. Commercialization is currently under way. MCFC design studies predict electric generation efficiencies ranging from 50 to 60 when operating on natural gas and just under 50 when operating on coal gas. Operating temperatures of approximately 1,200 F (650 C) allow for in-situ reforming of methane to hydrogen-rich gas directly without catalytic fuel processing. The...

40

10 30 50 70 90 Percent relative humidity Fig. 39-18 Representative Capacities of Various Desiccants. Source Munters Cargocaire and Mason Grant Company 10 30 50 70 90 Percent relative humidity Fig. 39-18 Representative Capacities of Various Desiccants. Source Munters Cargocaire and Mason Grant Company remove water from a fast-moving airstream. Regeneration energy requirement consists of the sum of the heat required to raise the desiccant's vapor pressure higher than that of the surrounding air,...

2 4 6 8 10 12 14 16 18 20 22 24 2 4 6 8 10 12 14 16 18 20 22

Fig. 23-4 On-Site Power Production vs. Purchased Power for Electrically Baseloaded Plant. n I I I I I I I I I I r 4 6 8 10 12 14 16 18 20 22 24 2 Weekday 1 I I I I I I I I I I 4 6 8 10 12 14 16 18 20 22 24 Weekend n I I I I I I I I I I r 4 6 8 10 12 14 16 18 20 22 24 2 Weekday 1 I I I I I I I I I I 4 6 8 10 12 14 16 18 20 22 24 Weekend Purchased Power I_I Exported Power Fig. 23-5 Cogeneration System Matched to Thermal Baseload Requirement. potential buyer. The long-term logic for efficient,...

Supplementary Fired Systems

As discussed in Chapter 8, supplementary firing of gas turbine or reciprocating engine exhaust can be used to efficiently increase thermal output. Because a relatively small portion of the oxygen in an open gas cycle is used for combustion, the remainder can be used for supplementary firing in the exhaust duct or the HRSG. Increasing exhaust gas temperatures can improve steam turbine cycle efficiencies, depending on engine and system type. Also, since the capacity of the gas turbine or...

Info

The two major classes of modern hydraulic turbines are the impulse and reaction types. Hydraulic conditions at dams, waterfalls, and river runs determine, in large part, the class and type of turbine that will be most effective for a given application. Impulse turbines, which achieve rotation through the acceleration of water through supply nozzles, tend to be employed for water resources with high heads and low flow rates. The most widely used type of impulse turbine is the Pelton turbine (or...

Synchronous Generators

A synchronous generator (or alternator) is the machine used to generate most of the ac power used today. A three-phase generator consists of a stator with a three-phase winding and a salient-pole rotor, which carries a dc field. The rotor (rotating winding or element) is driven by a prime mover at synchronous speed. As the magnetic flux of the dc-field winding crosses the stator windings, a three-phase voltage and current is induced. Most synchronous generators are revolving field generators in...

Waukesha Engine Oil Cooler

When it is based on the brake power delivered, it is termed brake sfc (bsfc). Engine thermal fuel efficiency is the ratio of the work produced per cycle to the amount of fuel energy supplied per cycle that can be released by combustion. The fuel energy supplied that can be released by combustion is the product of the mass flow of fuel supplied to the engine and the heating value or energy intensity of the fuel. This may be expressed on a higher heating value (HHV) or lower heating value (LHV)...

Chilled Water Temperature and Flow

Chilled water supply and return temperature are a function of the cooling load and flow rate, commonly measured in gallons per minute (gpm) or liters per minute (lpm). The temperature differential (AT) between supply and return temperature can be calculated in English units 8.33 lbm galx 60 min h x gpm x SGx Cp 1 kg liter x 60 min h x lpm x SG x Cp SG Specific gravity of fluid, which is assumed to be 1 Cp Specific heat of fluid in Btu lbm F, kJ kg C or kWh kg C it is assumed to be 1 Btu lbm F...

Hot Gas Bypass

Hot gas bypass is a technique to eliminate problems with systems that must be operated at evaporator loads below the minimum stage of compressor unloading. Hot gas bypass adds heat load to the system to stabilize suction pressure. It is used to eliminate surging and frost build-up on evaporator coils. Under very low loads, the relatively small mass flow of refrigerant, produced by the less than minimum acceptable load, can cause a gas-cooled motor to heat up and the suction and discharge line...

Energy Fuel and Cost ChargeabletoPower

An important distinction needs to be made in comparing prime mover applications, which use rejected heat (or pass on thermal energy to useful processes), with typical simple-cycle processes. Whereas simple cycle thermal efficiencies refer to a single energy product, thermal efficiency measurements of cogeneration-type applications refer to combined production of prime energy and thermal energy. When a facility is considering an investment in some type of prime mover system, the investment...

S

Load Balancing Thermostatic Control Valve Fig. 8-4 Schematic of Reciprocating Engine Standard Temperature Water System with Series Exhaust Heat Recovery. Source Caterpillar Engine Division Fig. 8-7 Schematic of Reciprocating Engine High-Temperature Water-Steam Heat Recovery System. Source Caterpillar Engine Division Fig. 8-7 Schematic of Reciprocating Engine High-Temperature Water-Steam Heat Recovery System. Source Caterpillar Engine Division Fig. 8-8 Schematic of Reciprocating Engine Ebullient...

Xcb

Fig. 36-17 Illustration of Approach Temperature. Fig. 36-20 Tower Performance as Function of Fan Power (with Single-Speed Motors). Source Marley Tower Company Fig. 36-18 Tower Size Factor vs. Approach. Source Marley Tower Company Fig. 36-18 Tower Size Factor vs. Approach. Source Marley Tower Company Fig. 36-19 Relationship of Fan Power Requirement to Wet-Bulb Temperature. Source Marley Tower Company Fig. 36-19 Relationship of Fan Power Requirement to Wet-Bulb Temperature. Source Marley Tower...

Manufactured Gases

There are several gases made from either coal or oil that are classified as manufactured gas. Generally, these gases are of relatively low heating values and have a high percentage of free hydrogen. These gases are either produced for use as fuel or result as by-products of other processes. All manufactured gases must be cleaned to reduce dust and solid impurities. Tar and ammonia also must be removed by washing or scrubbing the gases. Sulfur is often present and is sometimes removed by passing...

Combined Cycle Applications

The primary use of conventional combined-cycle generation in the United States today is in medium- and large-scale power plants ranging from 100 MW to greater than 1,000 MW In most discussions of future utility, nonutility, or independent power producer power plants, the gas-powered combined-cycle plant is considered state-of-the-art technology. This is due to the high efficiency of combined-cycle plants versus conventional power plants and the reduced societal cost resulting from pollution and...

W T

The steam tables or Mollier chart can be used to determine the difference in throttle and exhaust enthalpy or the heat per lbm (or kg) of steam actually converted into shaft work. Actual expansion is not represented by a vertical (constant entropy) line on a Mollier diagram, but a line sloping downwards to the right. Actual water rate is calculated as follows (hc - hd)actual actual heat drop, in Btu lbm. Similarly, actual power output (W) in terms of kW is expressed as Actual water rate is...

Exhaust Gas Treatment NOx Controls

Exhaust gas treatment technologies can be used as the sole basis of control, or with reductions achieved upstream by combustion operation or equipment modifications. Exhaust gas treatment systems are classified as selective or non-selective, depending on whether they selectively reduce nox or simultaneously reduce nox, unburned hydrocarbons, and CO. Selective catalytic reduction (SCR) is used for nox reduction in exhaust gas from systems operating with a X of greater than 1.0, meaning to the...

Spray Injection Technology

Whereas historically water injection was used only for NOX emissions control, water spray injection is now used for capacity and performance enhancement. This is Fig. 12-15 Gas Turbine Applied to Combined-Cycle System with Fired Boiler. accomplished by injecting a mist of atomized water into the high-pressure (and in some cases also the low-pressure) compressor inlets. Spray intercooling increases mass flow by cooling the air during the compression process. The LM6000 gas turbine, shown in...

Control Lags and Governor Designs

All control systems include time lags. In particular, a time lag inherent to prime movers results from the relationship between speed and acceleration. A torque imbalance is proportional to acceleration, not speed, although speed is the desired control parameter. Since acceleration is the first derivative of speed (rate of change of speed), acceleration at any time is the angle of the tangent of the speed curve at that point. When speed is at a minimum, acceleration is zero. When acceleration...

Low Temperature Absorption Applications

For low-temperature applications, ammonia-water absorption technology has long been an effective option. Some of the newly developed advanced cycles are already being applied. Recently, an absorption ice maker, based on Fig. 38-31 1,400 Ton Single-Effect Absorption Chiller Operating on Heat Recovery-Generated Steam, Providing Inlet Air Cooling for 48 MW Gas Turbine-Generator Set. Source The Trane Company and The American Gas Cooling Center Fig. 38-32 12 Ton Day Recovered Heat-Powered Absorption...

Experience Under PURPA

The QF concept was developed from a 1970s emphasis on conservation, and, therefore, it does not necessarily recognize the benefits associated with peak-shaving, load shifting, and capital cost avoidance. Although it is now generally recognized that strategic peak shaving may, at times, be as beneficial to society as cogeneration, the statutory definitions and requirements for QF status remain in effect. Utilities are thus still permitted to discriminate against non-qualifying facilities,...

100

Fig. 11-36 Percent of Theoretical Efficiency vs. Throttle Flow for Condensing Induction Extraction Turbine. Source Cogen Designs, Inc. Fig. 11-36 Percent of Theoretical Efficiency vs. Throttle Flow for Condensing Induction Extraction Turbine. Source Cogen Designs, Inc. Fig. 11-37 Percent of Theoretical Efficiency vs. Throttle Flow for Back-Pressure Turbine with Extraction. Source Cogen Designs, Inc. Fig. 11-37 Percent of Theoretical Efficiency vs. Throttle Flow for Back-Pressure Turbine with...

Packaged Versus Field Erected Boilers

Shop-assembled packaged boilers are available in capacities as large as several hundred thousand lbm (or kg) of steam per hour. Sizes and mechanical features are often Fig. 7-20 Labeled Cutaway View of Packaged Watertube Boiler Shown in Fig. 7-19. Source Donlee Technologies Fig. 7-20 Labeled Cutaway View of Packaged Watertube Boiler Shown in Fig. 7-19. Source Donlee Technologies limited by transportation considerations. Generally, they are designed to burn liquid or gaseous fuels and are less...

0system Cop Incl Absorption

Fig. 37-42 Two 49 Ton Gas-Fired Reciprocating Engine-Driven, Air-Cooled Chillers with Reciprocating Compressors in Sound Attenuating Enclosures. Source Alturdyne Energy Systems and The American Gas Cooling Center Fig. 37-43 4,150 Ton Gas-Fired Reciprocating Engine-Driven Chiller with Centrifugal Compressor. Source Waukesha Engine Division

Solar Radiation

Fig. 14-43 Solar Wavelength, Frequency, and Photon Energy. Source NREL photons, while the lower-energy photons are absorbed by the lower band gap materials below. In addition to the various layers, PV cell construction includes a transparent cover plate to protect the cell from the outside environment. PV modules, or panels, are then made by connecting numerous cells in series and in parallel to achieve useful levels of current and voltage. They are then mounted in a frame. These panels may...

Boiler Operation

Water is the working fluid in the boiler, as well as the product, and provides the heat sink for cooling boiler components. The overall flow-path of water in the boiler is an open system. A regulating valve is used to maintain the required water level in the boiler and control entering feedwater. When heat is added, the water temperature rises and its volume increases slightly. At the boiling temperature, the water begins to boil isothermally (at constant temperature) while the volume increases...

Solid Desiccant Tower Mixed Beds

Solid towers use desiccants, such as silica gel or molecular sieve, loaded into a vertical tower. Figure 39-10 illustrates a representative solid packed tower system and shows an equilibrium diagram. In the sorption process (1-2), the dry desiccant picks up moisture from the process air that flows through the tower. After the desic-cant has become saturated with moisture, the process air is diverted to a second drying tower for the desorption process (2-3). The first tower is then heated and...

Ammonia Water Absorption Cycles

Ammonia-water (NH3-H2O) based absorption machines have been used for most of this century, notably in residential refrigerators and air conditioners. Presently, the technology is used in custom-designed systems for low-temperature industrial applications and in small-capacity, direct-fired air-cooled units. Typical units are 3, 4, or 5 tons (10, 14, or 17 kW ) capacity, with up to five units assembled on a single skid. Figure 38-23 shows a 50 ton (166 kWr) system featuring two 25 ton (88 kWQ...

Absorption Chiller Technologies

Currently, the two absorption cycles in widespread use are the lithium bromide (LiBr) cycle and ammonia-water (NH3H2O) cycle. In the LiBr cycle, water acts as the refrigerant and LiBr is the absorbent. In the ammonia-water cycle, an Fig. 38-2 Illustration of Single-Effect Absorption Cooling Cycle. Source The American Gas Cooling Center ammonia-water solution acts as the refrigerant with water as the absorbent. Most of the large capacity units on the market today use the LiBr cycle. The...

Reciprocating Engine Driven Electric Generation Systems

Recip Engine Cogen Schematic

Internal combustion reciprocating engines are commonly used to provide standby (or emergency) power, as well as primary power. They offer many attractive features, including leadership in small unit, simple-cycle thermal fuel efficiency. There are many types of reciprocating engine-driven electric generation systems with capacities ranging from 1 to 70,000 kW. Defining engine characteristics can include Otto, Diesel or other cycles. Atmospheric pressures or supercharged turbocharged elevated...

St

Work produced by combustion engine (e.g., gas turbine or reciprocating engine) Work produced by steam turbine Heat energy input to combustion engine If additional heat is added via after-firing or supplemental firing in the HRSG, thermal efficiency can be expressed as In a cogeneration application in which a portion of the recovered heat is passed on to process (QP), either directly from the HRSG or via extraction from the steam turbine, efficiency can be expressed as The net fuel rate, or FCP...

Types of Service Applications

Industrial steam turbines may be applied in generator or mechanical drive applications. Generator drives can be direct-drive applications, but more often the turbine drives the generator through a speed reduction gear, which allows the turbine to be designed for optimum speed and efficiency. Figures 11-10 and 11-11 show steam turbinegenerator set applications. Mechanical drives can be applied in numerous applications, including compressors, fans, blowers, pumps, mills, crushers, cutters, and...

Gen

Where the on-site generation capacity is small (less than 50 ) compared with the utility grid on the load side of the nearest utility sectionalizer or recloser, the relaying illustrated here could be sufficient. Where the local on-site generation is equal to or larger than that section of the grid, further study would be needed to determine the extent of required protective relaying. Figure 28-20 represents a protective scheme for the generators in this power system. These generators will...

Actual Rankine Cycle

Ideal simple Rankine cycle efficiency assumes isen-tropic expansion through the turbine or expansion that is carried out reversibly and adiabatically. This means that all enthalpy between the turbine inlet steam hc and exhaust steam hd is converted to work output at maximum possible thermal efficiency. As with any power cycle, actual cycle efficiency is less than ideal. Under actual conditions, inefficiencies occur and the expansion process is not carried out at constant entropy. The factors...

Nh

I echnologies that provide mechanical drive service JL include a broad range of options for application, under a wide range of loads at constant or variable speed. Largely due to their low first-cost, relative ease of installation, simplicity of operation, and low maintenance requirement, electric motors continue to serve most mechanical drive applications. However, thermal efficiency improvements to reciprocating engines and gas turbines over the past few decades and the advent of packaged...

Primary Secondary Distribution Systems

In a typical primary secondary system, there are two separate pumping loops a primary loop for the chillers and a secondary loop for distribution to various facility loads. The chillers, operating on the primary system, can be cycled, staged, and loaded in the most efficient configuration. The primary circulator pumps are matched to the individual flow and head of each chiller, and when a chiller in a multiple unit configuration is inactive, its pump is off. The secondary distribution system...

Qfb

Fig. 38-8 Schematic Diagram Showing Components of an LiBr Double-Effect Absorption Machine. Fig. 38-9 Large-Capacity, Double-Effect, Steam-Powered LiBr Absorption Chiller. Source Carrier Corp. Fig. 38-9 Large-Capacity, Double-Effect, Steam-Powered LiBr Absorption Chiller. Source Carrier Corp. effect units is reduced when operated at lower than design temperature. Figure 38-11 demonstrates typical capacity output versus steam pressure. Figure 38-12 shows part-load performance curves for a...

Depreciation

Depreciation of assets is a principal tax consideration in most projects. Depreciation may be considered from different perspectives. The perspectives used in capital budgeting are physical depreciation and tax depreciation as it affects cash flows. Physical depreciation is a loss of ability to produce future cash flows because of obsolescence or deterioration resulting from wear. As a result of time and use, the value of the asset erodes. Installed energy systems have varying useful lives....

P

For air at standard density, fan velocity pressure can be expressed as where K is a dimensionless compressibility factor defined as the ratio of fan total pressure that would be developed with an incompressible fluid. Fan static pressure (Ps ) is the difference between fan total pressure and fan velocity pressure and, therefore, the difference between the static pressure at the fan outlet and the total pressure at the fan inlet. Thus q Volumetric flow rate p Total fan pressure K Compressibility...

WECS Technology

The prime mover in a modern WECS is the wind turbine. Wind turbine operation may be viewed simply as opposite that of a propeller type fan. Instead of using power to increase air velocity (produce wind) with a fan, wind turbines use wind to produce power. The wind imparts a force that turns the rotor blades, which spins a shaft that drives a generator or other mechanical device. Wind turbines thus change the horizontal movement of the wind into a rotational force turning a shaft. There are two...

Condensing Process

In condensing turbines, steam expands to a deep vacuum with the specific volume of the steam at exhaust equal to about 1,000 times its inlet volume. Steam is then condensed or changed to liquid form in the following stage, where thermal energy is extracted. Condensing turbines are exhausted to a vessel, or condenser, in which thermal energy is rapidly and continuously removed through direct or indirect contact with cooling water. Heat rejection systems are generally classified as once-through...

Metering Throttling Devices

Another critical component of a vapor compression system is the throttling (or expansion or metering) device. Just as the condenser and evaporator are counterparts, the throttling device is the counterpart of the compressor. The compressor and throttling device prepare the refrigerant for the phase change by manipulating the pressure and flow rate, while the evaporator and condenser actually cause the refrigerant to change phase through heat transfer processes. The throttling device is located...

04017 05525

Fig. 17-6 Effects of Fuel-Bound Nitrogen on NOx Emissions for Fuel Oils. Source Cleaver Brooks Fig. 17-6 Effects of Fuel-Bound Nitrogen on NOx Emissions for Fuel Oils. Source Cleaver Brooks control regulations require lower NOx emissions levels in summer months when ground level ozone is most problematic. Dual-fuel boilers and gas turbines can operate exclusively on natural gas and dual-fuel Diesel engines, which feature injection of natural gas, can be operated at the highest gas injection...

Hydrogen

Hydrogen, the simplest element, is composed of one proton and one electron. It is an abundant resource, making up more than 90 of the composition of the universe and is the third most abundant element in the earth's surface. More than 30 of the mass of the sun is atomic hydrogen and water is mostly composed of hydrogen. Under ordinary (earthly) conditions, hydrogen is a colorless, odorless, tasteless, and nonpoisonous gas composed of diatomic molecules (H2). It is a clean-burning fuel with an...

VOC Controls

VOCs contain combinations of carbon and hydrogen and may also include traces of oxygen, sulfur, nitrogen, and halogens, such as fluorine and chlorine (methane, ethane, and few other compounds are excluded from the definition of VOCs). VOC emissions result from incomplete combustion and vaporization from substances such as paint, fuel, solvents and other coatings that use an organic carrier. Typically, major sources of VOCs include synthetic chemical manufacturers, coaters, and other industrial...

11540 18300 23700 28720

*Average Engine at Generator Terminals (2.5 on LM1600 Gen, 2.0 on all others Gen, 1.5 GB included) Table 12-2 Capacity, Performance and Steam Flows of Various GE Steam Injection Cycle Models Source General Electric Company. injection is provided to reduce NOX emissions, the changes in performance are fairly small. Chapter 17 provides a discussion of steam injection for NOX control. Steam injection can provide the flexibility to operate effectively under an extremely wide range of varying load...

Chilled Water Piping and Distribution Systems

The most common multiple chiller systems involve parallel piping configurations designed for constant flow. Chilled water flows through all chillers whenever the system is operating and an identical AT is maintained across each machine. Typically, three-way control valves are used at terminal units to maintain constant system flow by bypassing coils during periods of part-load. There are several limitations with this configuration Pump energy is wasted due to system operation at constant full...

Is

Variable Flow J Drive Auto Switch Over Fig. 35-9 Indirect Free Cooling Configuration, with Heat Exchanger. Source The Trane Company Fig. 35-9 Indirect Free Cooling Configuration, with Heat Exchanger. Source The Trane Company units are generally used. The pumping energy requirement is also greater with indirect free cooling, since both condenser water and chilled water pumps are required and the heat exchanger presents additional head to be overcome by the pumps. The transition between chiller...

Electric Rate 1 TOU

Electric rate 1 is a seasonal TOU rate. The basic tariff is summarized in Figure 22-5. Under this rate, shoulder and off-peak demand charges are assessed only for demand levels that exceed that of the peak periods. For example, if summer peak usage was 1,000 kW and shoulder Fig. 22-4 Rate Structure Profile 4. Peak and Shoulder Summer Usage Monday through Friday. Fig. 22-4 Rate Structure Profile 4. Peak and Shoulder Summer Usage Monday through Friday. usage was 1,500 kW, the demand charge would...

Pf

It can be seen that when voltage is held constant as PF decreases, more current is required to produce the same value of kW. As current flow through the winding increases, voltage drop increases and more power is dissipated in the form of heat. Operation of the generator outside its PF rating can cause overheating of its rotor or stator. This is typically not a problem for isolated operation, but merits special attention during parallel operation with the utility. In this case, a PF controller...

Pump Types

Two Stage Centrifugal Pump

Figure 31-1 provides a comprehensive listing by category and subcategories of types of pumps. Pumps are broadly classified as positive-displacement types (which include reciprocating and rotary pumps) and kinetic or centrifugal types. I Includes radial mixed flow and axial flow designs Horizontal Single-acting Piston Vertical Double-acting Plunger Blade, bucket roller or slipper r Axial Flexible tube Flexible vane Flexible liner Single Close-coupled Single & two stage L Frame mounted...

180 200 220 240 260 5 15

Fig. 39-6 Small Packaged LiCl Liquid System. Source Kathabar Systems Fig. 39-7 Regenerator Capacity in Moisture Removed vs. Temperature Pressure. Source Kathabar Systems absorbed in the conditioner is released in the regenerator to maintain solution concentration. A small amount of the concentrated solution is then transferred back to the condenser. Liquid systems typically range in capacity from 1,000 to 85,000 cfm (28 to 2,400 m3 m). RH levels ranging from 90 to 18 can be achieved by...

Heat Recovery Applications

Steam Turbine Inlet And Letdown

Often, a limiting factor to the economic performance of cogeneration-cycle technology applications is the availability of an adequately sized baseload requirement for the heat output. Often, the capacity of a cogeneration system will be limited by low cooling season thermal loads as compared with the heating season. Absorption cooling technology is thus commonly specified as a means to balance annual thermal loads, thereby improving cogener-ation application project economics. Double-effect...

Watertube Boilers

Boiler Water Tube

Watertube boilers are generally larger than firetube units and have a completely different construction. They generally contain about 75 less water than comparable firetube boilers, can handle higher pressures (well in excess of 1,000 psi or 69 bar), and generally range in capacity from 10,000 lbm (4,500 kg) to several million lbm (or kg) of steam per hour. Watertube boilers use individual water and steam drums with a multitude of connecting tubes through which a steam and water mixture...

Fuel Nozzle Snecma

Pnmary Zone AS ion Recirculation Zone Ports Fig. 17-22 Lean Pre-Mixed Combustor Concept. Source Solar Turbines Fig. 17-23 Lean Pre-Mixed Gas Turbine Low-NOx Combustor Liner. Source Solar Turbines Fig. 17-24 12,400 hp (9,250 kW) Heavy-Duty Industrial Gas Turbine with Dual Silo-Type DLN Combustors. Source MAN GHH Fig. 17-23 Lean Pre-Mixed Gas Turbine Low-NOx Combustor Liner. Source Solar Turbines end. Pre-mix burners are subject to limited operating ranges, since pre-mix flames are extinguished...

Localized Onsite Electric Power Generation vs Centralized Power Plant

In applications of conventional-cycle steam plants and advanced combined-cycle gas turbine plants for intermediate and baseload operation, the centralized plants enjoy several distinct advantages over smaller systems. As noted previously, these include economy of scale, preferential fuel costs, relatively lower staffing levels, potential for higher generation efficiency, and reserve capacity. However, localized on-site conventional and advanced cycle plants also enjoy certain benefits over Fig....

WECS Components

Figure 14-19 provides an exploded cutaway illustration of a pitch-controlled upwind HAWT. While there are many different designs and configurations, this figure illustrates most of the basic components found in a modern wind turbine applied to electric generation. Following is summary detail on each of the main components. Fig. 14-19 Labeled Illustration of Modern Pitch-Controlled, Three-Blade Upwind Turbine Applied to Electric Generation. Source U.S. DoE Fig. 14-20 Cutaway Illustration of the...

Control Governors

Woodward Steam Governor

A governor is a device that controls the speed, or some other parameter, of a prime mover. All prime movers are rotating machines that derive their power from the flow of some energy input, such as fuel or steam. Most commonly, prime mover speed is controlled by varying the flow of the energy input. In all governing systems, at least two components are required a speed sensing element and a device to operate the energy input valve. In the simplest governors, these may be one and the same....

Lw

Fig. 9-68 Fairbanks Morse Six-Cylinder, Two-Stroke-Cycle, Compression-Ignited, Dual-Fuel Opposed Piston Engine. Source Fairbanks Morse Engine Div. Btu bhp-h (8,630 kJ kWh) on a LHV basis, with a NOX emissions rate of about 4 gram bhp-h (5.4 gram kWh). The low-emissions model achieves a NOX emissions rate of about 1 gram bhp-h (1.3 gram kWh), but does so at a slightly higher heat rate of about 6,250 Btu bhp-h (8,810 kJ kWh). Figure 9-69 is a Fairbanks Morse Colt-Pielstick 18-cylinder,...

Assembly Of Piston And Connecting Rodin Four Stroke Engine

Connecting Rod Attached The Piston

Thus, in the ideal Diesel cycle, efficiency is a function of the compression ratio and the expansion ratio. For example, with k held constant at a value of 1.4, a compression ratio of 16 1, with a cut-off ratio of 2 1, would yield the following ideal thermal efficiency k (rc.o. 1). 0.614 (i.e., 61.4 ) There are dramatic differences between ideal cycle efficiencies and those achieved in practice. In addition to the fact that engines do not actually operate on these ideal cycles, there are...

90c

Fig. 27-14 Protective Relay Scheme for Parallel Operation of Generator and Utility-Derived Power Sources. Source Automatic Switch Company Fig. 27-14 Protective Relay Scheme for Parallel Operation of Generator and Utility-Derived Power Sources. Source Automatic Switch Company In this example, there are two utility service connections and an on-site generator system composed of four prime mover generator sets. The on-site power system can provide either peaking power, or operate as a baseloaded...

Desiccant Applications

Generally, the potential benefits achieved with desic-cant systems include energy savings, increased productivity, equipment and product protection, and improved environmental conditions. In industry, desiccant technology has been widely used for several decades for applications that require very low specific humidity in the range of 45 gr lbm (0.0064 kg kg) and less such as the case with clean rooms and other specialty operations. Given recent improvements in desiccant technologies, desiccant...

Combustion and Fuel Firing Systems

The combustion control system regulates the fuel and air input, or firing rate, to the furnace in response to load demand. Fuel-firing systems provide safe, controlled conversion of the chemical energy into heat energy that is transferred to the heat-absorbing surfaces of the boiler. To accomplish this, the fuel-burning system introduces the fuel and air for combustion, mixes these reactants, ignites the combustible mixture, and distributes the flame envelope and the products of combustion. The...

Equipment Classifications

Evaporative cooling towers are the most commonly applied heat rejection technology for large refrigeration-cycle systems. In a typical cooling tower, a pump delivers water to the top of the tower where it is sprayed, or cascaded, over a series of baffles and agitated by contact with moving air. As a small portion of the water evaporates, it cools the air and the remaining water. The water then collects in a sump at the bottom of the tower and returns to the refrigeration or process heat...

Steam Injection Cycles

Steam injection-cycle systems augment gas turbine power output by increasing mass flow. As discussed in Chapter 10, the gas turbine compressor section typically requires about two-thirds of turbine power output, and simply increasing the size of the system increases power output only one-third as fast as mass flow. However, increasing mass flow downstream of the compressor by direct injection of high- or intermediate-pressure steam produces a direct increase in power output. Figure 12-8 shows...

Rotary Screw Compressors

Rotary Compressor Roller

In a rotary screw compressor, air enters the compressor and is trapped between mating male and female rotors and compressed to the required discharge pressure. In the basic single-stage design, the compressor consists of a pair of rotors meshing in a one-piece, dual-bore cylinder. Oil lubricates, seals, and cools the compressor. Oil-flooded rotary screw compressors are typically available in capacities ranging from 25 to 3,000 cubic feet per minute (cfm) or 0.7 to 85 cubic meters per minute (m3...

Steam Turbine Components and

Steam Turbine Blades and Flow Path Design The shape and arrangement of nozzles (stationary blades) and moving blades is perhaps the most important element of steam turbine design. It is the shape of the blades that determines the form of the flow passages and the energy transferred from the fluid (steam) to the rotor. A sufficient number of blades must be provided to ensure well-defined flow passages yet too many blades may result in high resistance to flow. Since the arrangement of the flow...

Steam Properties

When heating water and steam at constant pressure, as in a boiler, one of five conditions exist When heat is added to water in a boiler at constant pressure, the temperature of the water increases. The continued addition of heat will cause the temperature to increase until the pressure of the vapor generated is equal to the boiler pressure (the pressure boost of the boiler feed pumps). At this point, the liquid and vapor are said to be saturated. Boiling point is the temperature at which water...

R717

85.5 (55.2) 70.9 (45.8) 97.3 (62.9) 81.8 (52.8) 83.9 (54.2) 68.8 (44.4) 94.1 (60.8) 79.4 (51.3) 90.7 (58.6) 586.9 (379.1) 90.6 (58.5) 78.1 (50.4) 87.5 (58.6) 80.5 (52.1) 64.2 (41.5) 86.7 (56.0) 76.7 (49.5) 84.0 (54.3) 536.2 (346.4) Table 37-2 Latent Heat of Vaporization at Various Saturation Temperatures in Btu lbm (W-h kg). Table 37-2 Latent Heat of Vaporization at Various Saturation Temperatures in Btu lbm (W-h kg).

Towers Heat Pumps and Heat Recovery

Heat absorbed in the refrigeration cycle, including both the heat extracted in the evaporator and the energy used to drive the cycle (i.e., work of compression), must be rejected to the outside environment. The heat exchanger that rejects heat from condensing refrigerant to an external medium is known as the condenser. This is sometimes referred to as the hot-, high- (pressure) or discharge-side of the cycle. The heat rejection may occur directly from the condenser to ambient air, as is the...

Heat Balance Of Marine Diesel Engine Drawing

Heat Balance Diagram

Fig. 26-26 Heat and Material Balance for 1,100 kW Gas Turbine-Driven Electric Cogeneration System. Source Cogen Designs, Inc. operation on natural gas. The full load simple-cycle heat rate for this unit is 10,400 Btu kWh (10,972 kJ kWh) on an LHV basis. The unit features a five-stage turbine, as well as an eighteen-stage compressor that achieves a pressure ratio of 13.3 1. The exhaust mass flow is 699 lbm s (317 kg s) at a temperature of 941 F (505 C).The generator is driven at a shaft speed of...

1

Fig. 10-59 Recuperated Gas Turbine Efficiency. Source Solar Turbines Fig. 10-60 Simplified Diagram of Gas Turbine Reheat Cycle. through which air exiting the low-pressure compressor passes before entering the high-pressure compressor. Typically, compressor discharge temperatures are about 900 to 1,000 F (482 to 538 C). By cooling the air at an intermediate point in the compression cycle, the outlet temperature is reduced by a few hundred degrees, air density is increased, and compression power...

Design and Provisions for Solid Refuse Wood and Biomass Fuel Boilers

Stoker Boiler Rdf Fuel

For use of solid refuse, wood, and biomass fuels, boiler component design varies considerably from traditional fossil fuel units, but is generally more similar to systems designed for coal than for gas or oil. Similar to coal units, they are larger, more costly, and more maintenance intensive than standard gas or oil burning units. Provisions for fuel handling, combustion, emissions control, and disposal are key design considerations with these fuels. The wide variation in energy density and...

Electric Motor Driven Systems

Chiller Compression Type

Electric motors are by far the most common drivers selected for vapor compression systems. They typically are the lowest first-cost driver option. They are also usually the smallest and easiest to install and offer simplicity of operation and minimal maintenance requirements. Electric motors are abundantly available in capacities ranging from fractional hp (kW) to very large capacities, either as part of pre-engineered, pre-packaged vapor compression systems, or built-up, application-specific...

Examples Based on 250 Psig Saturated Steam

Examples 1 through 3, which are illustrated in Figures 11 -46 through 11 -49, are based on the following Inlet condition (hc) 1,201.7 Btu lbm (250 psig - saturated steam) Exhaust condition (hd) 867.7 Btu lbm - ideal (3 in. HgA)* (condensing example) Exhaust condition (hd) 1,056.3 Btu lbm - ideal (25 psig) (back-pressure examples) Turbine efficiency (n-j-) 70 (condensing example) Turbine efficiency (n-) 50 (back-pressure examples) Steam (mass) flow (nri) 20,000 lbm h Condensate (ha) 83 Btu lbm...

Six Cylinder Of Spark Ignition Engine

Engin For Strok Diy Gram Ful

Derating an engine below its prime power rating produces less wear, greater reliability, and longer engine life. Because energy savings are based on output, derating reduces short-term savings, although the strategy can improve life-cycle economics. A thorough routine or preventative maintenance program should always be required. Routine maintenance includes filters, oil, oil sampling, water treatment, water-side and combustion-side deposit buildup inspections, plugs, and wires or injectors....

Reciprocating Compressor Capacity Control

Capacity is controlled in reciprocating compressors through cycling, cylinder unloading, speed control, or a combination of these techniques. Small reciprocating compressors often simply cycle on and off to meet varying load requirements an inefficient process. Larger compressors, starting at 10 or 20 tons (35 to 70 kW ), typically use cylinder unloading devices to reduce total displacement or compression action. Cylinder unloading helps to control the compressor pumping capacity as evaporator...

Reciprocating Engine Drives

Waukesha Engine Division

Vapor compression chiller systems driven by reciprocating engines generally range in capacity from 20 tons (70 kWr) to several thousand tons (more than 10,000 kWr). Basic engine type distinctions include cycle (i.e., Otto or Diesel), aspiration (i.e., atmospheric or supercharged turbocharged), fuel type, air-fuel ratio (i.e., lean or rich), operating pressures, coolant systems, and methods used to control emissions. Over the past two decades, reciprocating engine-driven chillers have become a...

Examples of Prime Mover Control Systems

Governor Woodward

Figure 13-15 is a block diagram of a Woodward Governor comprehensive multi-engine control system, a family of modules that include speed control, load control, engine control, monitoring, and sequencing. This system may be used with gas, Diesel, and dual-fuel engines in mechanical drive and power generation applications. The digital control application program is created in application block language software (ABLS), designed to be programmed by non-software engineers. The graphical application...

Wind Energy Conversion Systems

Similar in many ways to hydropower, wind is one of the oldest sources of power production, having been used for more than 1,000 years throughout the world. Early windmills were designed with a vertical shaft with paddlelike sails radiating outward and were located in a building with diametrically opposed openings for the inlet and outlet of the wind. Most of these wind devices were patterned after early waterwheels. Over the next several centuries, numerous advancements were made for grain...

Refuse Derived Fuels

In addition to the various waste-related biomass sources used for methane-based gas production, solid waste is a useful direct fuel source that allows for the production of useful thermal energy to be combined with the elimination of the solid waste. Typically, three-quarters of most solid waste is combustible, composing as much as 90 of the waste volume. Solid waste is a commonly used fuel source in centralized plants for steam production. The steam is used for central distribution as a...

Definitions

The following definitions are useful for understanding the properties of steam and the use of steam tables in performing various computations that relate to steam applications. These definitions build on some of the basic thermodynamic terms presented in Chapter 2. The temperature of a system (t) indicates the index of the kinetic energy possessed by the molecules of the sub-stance(s) in the system. At standard atmospheric pressure at sea level, the boiling point of water is 212 in the F scale...

Higher and Lower Heating Values of Fuels

The energy density or the heating value of any fuel depends on its specific chemical composition. At one time, heating value was empirically determined by reacting a known quantity of fuel in a calorimeter with enough oxygen to ensure its complete combustion and measuring the heat quantity generated during the combustion. The amount of information available on the chemical compounds comprising the various fuels today allows the heating values to be calculated from fuel composition. The results...

Lbm Molding Machine

Fig. 17-37 Cutaway View of Reactor Converter Featuring Zeolite Ceramic SCR. Source Environmental Emissions Systems, Inc. Steuler Fig. 17-37 Cutaway View of Reactor Converter Featuring Zeolite Ceramic SCR. Source Environmental Emissions Systems, Inc. Steuler reciprocating engine cogeneration system in an industrial facility. When operating in dual-fuel mode (94 natural gas and 6 Diesel fuel), the exhaust gas flow is 71,910 lbm h Fig. 17-38 Functionality Diagram of SCR NOx Abatement System...

18 Cylinder Diesel Generator

Combination Set Mechanical Diagrams

Fig. 23-21 Layout Diagram of Provisions for Reciprocating Engine Cogeneration Plant. Source MAN B& W Fig. 23-21 Layout Diagram of Provisions for Reciprocating Engine Cogeneration Plant. Source MAN B& W Fig. 23-22 View of Mechanical Room Housing Five 1,130 kW Dual-Fuel Reciprocating Engine Cogeneration Units. Source MAN B& W Fig. 23-22 View of Mechanical Room Housing Five 1,130 kW Dual-Fuel Reciprocating Engine Cogeneration Units. Source MAN B& W Fig. 23-23 Mechanical Room for 14 MW...

Developing Fuel Cell Technologies

Ilustrasion Reaktor Pemfc Fuel Cell

While the current generation of fuel cells struggles for market penetration, new technologies and advancements of current technology remain at the forefront of the industry. This includes the use of different electrolyte materials and new fuel cell designs. Alkaline fuel cells have long been used for space applications. These cells are said to be capable of electric power generation efficiencies of up to 70 . They use alkaline potassium hydroxide as the electrolyte. Until recently they were...

Fan Types

Centrifugal Fan Design Illustration

Figure 32-1 illustrates the aerodynamic classification of fans. If fans are classified according to the direction of the flow through the impeller, there are four distinctive types axial-flow and radial-flow fans (the types normally encountered in general service), mixed-flow fans, and cross-flow fans. Axial-flow fans produce flow in a direction parallel to the axis of the rotation, while radial-flow (or centrifugal) fans produce a flow that is parallel to the radius of rotation. The axial-flow...

Currently Available Steam Turbine Designs

Marine Steam Turbine

Following are illustrations and descriptions of several steam turbines and components, including a range of capacities and designs. Figure 11-54 is an open-case view of a single-stage Elliot turbine available in capacities up to about 3,500 hp (2,600 kW). These units range in size up to about 5 ft (1.5 m) long and 3.5 ft (1 m) wide and high, with a weight of about 2,500 lbm (1,100 kg). The turbine has an operating speed range of between 1,000 and 7,000 rpm. To the far right are lubricated steel...

Heat Recovery Boilers

Recovery Boiler Diagram

Heat recovery boilers are used to produce hot water or steam from the heat of passing exhaust gases. The HRSG is essentially a counterflow heat exchanger composed of a Fig. 8-10 Schematic Diagram of Reciprocating Engine Hot Water Heat Recovery System. Source Fairbanks Morse Engine Division Fig. 8-10 Schematic Diagram of Reciprocating Engine Hot Water Heat Recovery System. Source Fairbanks Morse Engine Division series of superheater, boiler, and economizer sections positioned from gas inlet to...

Refrigerants

A refrigerant is any fluid that, usually with a phase change, picks up heat at a low temperature and pressure and gives up heat at a higher temperature and pressure. There are numerous types of refrigerants used in vapor compression machines, each with a different set of characteristics. The type of refrigerant used will affect compressor capacity. Displacement of refrigerant in constant-speed, positive displacement compressors is constant. The capacity will vary, however, as a function of...

Carnot Cycle

The Carnot cycle is of particular importance because its thermal efficiency represents the maximum value obtainable for any heat engine. The Carnot cycle represents a theoretical efficiency that serves as a standard for cycle efficiencies. It is based on the concept that the thermal efficiency of a reversible engine is a function solely of the upper and lower temperatures of the cycle and not a function of the working substances. The Carnot cycle for both vapor and gas cycles typifies ideal...

Refrigeration Units of Measure

Quantitative measures of heat energy are typically the British Thermal Unit (Btu), Calorie, or kilowatt-hour (kWh). As defined, the removal of one Btu of heat from one lbm of water at 61 F will lower the temperature of the water by 1 F. The heat flow rate, or amount of heat that flows from one substance to another within a given time period, is commonly measured in Btu h or kW. In U.S. customary refrigeration engineering units, the standard ton of refrigeration (sometimes referred to as the...

Compressor Driver Options

Drivers produce the shaft rotational power required to operate the air compressor. Following is a discussion of the commonly used compressor drivers. Electric induction motors are by far the most common drivers selected for stationary air compressor applications. Motors are typically the lowest first-cost driver option and offer simplicity of operation and minimal maintenance requirements. Motor-driven air compressors are abundantly available in all required capacity ranges, often as part of...