Fuel equivalent power

The first methanol bus in the world was placed in revenue service in Auckland, New Zealand in June 1981. It was a Mercedes O 305 city bus using the M 407 hGO methanol engine. This vehicle operated in revenue service for several years with mixed results. Fuel economy on an equivalent energy basis ranged from 6 to 17% mote than diesel fuel economy. Power and torque matched the diesel engine and drivers could not detect a difference. ReHabiUty and durabihty of components was a problem. Additional demonstrations took place in Berlin, Germany and in Pretoria, South Africa, both in 1982. 

Summary ol Hybrid Vehicle Fuel Economy Results on the FUDS and Highway Driving Cycles using Various Engines and a Fuel Cell (1) mpg diesel fuel for diesel engine and mpg gasoline equivalent for fuel cell powered vehicles... 

For reformate flow rates up to 400 Ndm3 min-1, the CO output was determined as < 12 ppm for simulated methanol. The reactors were operated at full load (20 kW equivalent power output) for -100 h without deactivation. In connection with the 20 kW methanol reformer, the CO output of the two final reactors was < 10 ppm for more than 2 h at a feed concentration of 1.6% carbon monoxide. Because the reformer was realized as a combination of steam reformer and catalytic burner in the plate and fin design as well, this may be regarded as an impressive demonstration of the capabilities of the integrated heat exchanger design for fuel processors in the kilowatt range. 

Normal spark ignition engines operate over a range of air-fuel mixtures. Maximum power is obtained under fuel-rich conditions while best economy is obtained under fuel-lean conditions. To make comparisons between fuels, it is necessary to define the air-fuel equivalence ratio,... 

In most cases, Qf ei is calculated based on the lower heating value of fuel. G,- is quantified in different units according to specifications in the marketplace, namely, Btu/h for fuel, Ib/h for steam, and kWh for power. Thus, specific FE factors can be developed as follows based on this general definition of fuel equivalent. Energy are required for making boiler feed water (BFW), condensate and cooling water. The FE factors for these utilities will be discussed in Chapter 3. 

Fuel equivalent for purchased power is assumed to be 9090Btu/kWh compared with the normal conversation factor of 3414Btu/kWh. This assumption implies power generation loss of 5676 (= 9090 — 3414) Btu for each kWh imported. Thus, power generation loss is 17.9MMBtu/h for 3.15 purchased. The rationale for this assumption will be discussed later with the FE calculation given in equation (3.7). 

In previous discussions, some assumptions of fuel equivalent factors were made for power and steam. You may ask What is the basis for making these assumptions How do you determine fuel equivalent values for power and steam in your plant Let us consider the calculation of fuel equivalent for power first. 

By applying equation (3.5), the fuel equivalent factor for power generated from a combined cycle would be... 

Assume fuel equivalent factor for purchased power as 9.09 MMBtu/MWh. Thus,... 

FE fuel equivalent amount of fuel at the source to make a unit of energy utility (power, steam)... 

It is common that steam turbines are connected to steam headers. Therefore, it is logical to take power generation into account when steam price is determined. In reality, when the turbine is offline while the motor is online to run the rotating equipment, the power is imported but fuel for steam is saved. On the other hand, when the turbine is turned online while the motor is offline, import power is saved but at the expense of fuel for steam. To reflect the relative price comparison of fuel and power, the price equivalent efflciency (PEE) for power generation is defined as the price ratio ... 

Thus, the multiplier to fuel equivalence for power defined in equation (3.5) in Chapter 3 can be adjusted based on i/pee... 

To calculate the fuel equivalent for power generation in path 1, ijpee and MFEpo are calculated first as... 

CM maintenance and labor cost CO other costs including environmental control FE fuel equivalent MFE multiplier to fuel equivalence OpEx energy operating expenditure PEE power equivalent efficiency Q heat content q specific heat R capital depreciation factor X fraction of costs... 

MMBtu/h, while power import is 9.4 and 14.2 MW for the current and maximal efficient operating modes, respectively. The heat rate for imported power is 9.09 MMBtu/MWh. Thus, the fuel equivalent for both cases can be calculated as... 

There is only 2% (63%-61%) improvement from the steam system operation in Figure 18.4. The net fuel equivalent for the improved steam system with power import of 12.7 (20-7.3) mw is... 

FE fuel equivalent Q heat duty R power to heat ratio W power r] efficiency... 

To reflect the relative price comparison of fuel and power, the concept of price equivalent efficiency (PEE) for power generation defined in Section 17.5 is used here to express the price ratio of fuel to power ... 

The fuel equivalence for power import can be ealeulated based on equation (17.11) with a revised version as... 

In the power industry, the fuel equivalent for power generation is also ealled heat rate for power generation. Since the fuel and power prices are market driven, the expression in equation (19.3) ean be named as market heat rate for power import. With the market heat rate defined as sueh, it can be compared to heat rates for on-site... 

This implies that importing power requires fuel equivalent of 22,460 Btu to produce 1 kWh of power. 

Cf marginal fuel price Cp imported or exported power price Cy valve orifice coefficient / objective function FE fuel equivalent h enthalpy m, M mass flow... 

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