Peak Load Power Research Articles

Scaling of divertor conditions in next step devices with divertor depth and upstream plasma conditions

From 2-D modelling of the scrape-off plasma of a next step device, the scaling of key divertor parameters with density, power, transport coefficients and geometry (pitch, size) is derived. In high-recycling conditions, both power density and electron temperature at the divertor plate decrease strongly with increasing upstream density and decreasing input power. When the upstream density is adjusted to obtain constant, low electron temperature at peak power load, the peak power per unit area is proportional to the input power, and the scaling with connection length and transport coefficients is relatively benign. When divertor depth increases, the temperature still increases strongly with decreasing upstream density and both electron temperature and peak power per unit area decrease. Only for a very short divertor, a thermally unstable region is found (i.e. the upstream density is a multivalued function of plasma temperature at the divertor plate).

Scaling of divertor conditions in ITER/NET with density, power, SOL transport, pitch, size, and particle throughput

Scaling laws for the divertor conditions to be expected in a next step device, ITER, are derived from 2D modelling. Model calculations are carried out for varying density, power, transport coefficients, pitch, size and particle throughput. In the low temperature, high recycling domain, the peak power, the electron temperature, and the particle density at the plate are found to be extremely sensitive to upstream parameters, especially to upstream density. Low density, high power operation therefore remains very demanding for the divertor. For operation at a critical density, for which the electron temperature at the point of peak power load is a fixed low value, the peak power load scales more gently, proportional to the power density flowing into the scrape-off layer. Precise control of the density is required to maintain this temperature

Central station thermal energy storage for peak and intermediate load power generation

The application of thermal energy storage to central station power plants allows baseload power-generating technologies to provide peak and intermediate load electric power. DOE has provided funding for a study to investigate the technical and economic feasibility of using molten nitrate salt thermal energy storage in conjunction with pulverized-coal-fired and integrated gasification combined-cycle power plants. The results suggest that the use of thermal energy storage is technically feasible and can reduce the cost of generating peak and intermediate load electric power from coal by between 5% and 20%.

High-voltage, high-power operation of the plasma erosion opening switch

A plasma erosion opening switch (PEOS) is used as the opening switch for a vacuum inductive storage system driven by a 1.8-MV, 1.6-TW pulsed power generator. A 135-nH vacuum inductor is current charged to ∼750 kA in 50 ns through the closed PEOS which then opens in <10 ns into an inverse ion diode load. Electrical diagnostics and nuclear activations from ions accelerated in the diode yield a peak load voltage (4.25 MV) and peak load power (2.8 TW) that are 2.4 and 1.8 times greater than ideal matched load values for the same generator values.

Start-Up and Shut-Down of Large Size Turbo Sets

This paper briefly deals with the problems associated with start-up and shut-down of large size turbo sets and possible solutions to these problems. Desirable characteristics of start-up & shut-down procedures have been indent If ied and present practices discussed. Importance of stress monitoring during start-up and shut-down has been discussed in brief. Necessity of employment of “Automatic Control” has been emphasised in view of high complexity of Operation and operator fatigue. Starting up and shutting down of turbo sets is one of the most critical operations of large thermal power plants. This assumes added importance in case of peak load power plants where the turbo sets are required to be started and stopped, frequently depending upon the occurance of the peak load demand.

Characteristics of superconducting magnetic energy storage (SMES) energized by a high-voltage SCR converter

A small-scale Superconducting Magnetic Energy Storage(SMES) unit was constructed using small magnets and a high-voltage converter, and the characteristics of this unit were examined. The high output voltage of the converter makes it possible for even a small magnet to charge and discharge large power. Moreover, converter control provides adequate protection during quenching. AC and DC filters can be eliminated from the converter system, and ripple voltage does not harm the superconducting magnet. These features demonstrated the potential of an SMES unit as a power system stabilizer and a peak load power supply.

Power needs of cooling systems in Kuwait and their effects on the utility

Summer indoor comfortable environmental conditions can be maintained inside the buildings in Kuwait only by employing mechanical cooling systems, owing to the prevailing hot climatic conditions in the country. Cooling systems in Kuwait are, generally, of the vapour compression type that depend solely on electricity. The electric power needs of the cooling systems are quite large and they shape the pattern of load demand in the country. In this paper, the electric power needs of the cooling systems in Kuwait are investigated. It is shown that these needs account for an average of 43% of the total annual power consumption. It is also shown that during the month of highest power demand, the cooling systems' needs account for about 67% of the total power consumption. The paper also investigates the effect of the cooling systems on the size of the installed power generation facilities. Finally, the effects of introducing energy conservation measures in future buildings in Kuwait on the projected growth rates of the annual peak load and total power consumption are investigated.

Strong Tl–Hg band emission at 4590 and 6560 Å via electron beam initiated discharges in TlI and Hg mixtures

Very strong Tl–Hg excimer band emission at 4590 (B 2Σ1/2–X1/2) and 6560 Å (B 2Σ1/2–X3/2) has been observed from stable glow discharges produced in TlI and Hg mixtures via a 20 nsec electron beam pulse. Hg densities up to 5×1019/cm3 and peak TlI densities of 1017/cm3 were used at a maximum operating temperatures of 550°C. Peak power loading of 34 kW/cm3 at 7 A/cm2 and E/N values up to 3×10−16 V⋅ cm2 have been achieved in a 60 cm3 active volume. The discharges are much more stable and repeatable than similar discharges in TlI and Xe mixtures. The Tl–Hg band emission totally dominates the spectrum that also exhibits Tl and Hg atomic emission plus weaker HgI (B 2Σ1/2–X1/2) emission at 4430 Å. A plausible kinetic model for the dominant processes is presented and the potential of this systme as a TlHg laser at 4590 and 6560 Å are discussed.

Stored air handles peak power loads

Stored air handles peak power loads

Major Pumped Storage Projects in the United States

Pumped storage hydroelectric projects are assuming an important role in the supply of electric power in the United States. Their operating characteristics are ideally suited for serving peak power loads, and to complement the base load power being derived from today's large efficient fossil and nuclear fueled steam-electric plants. Development of the reversible pump turbine has enhanced the feasibility of pumped storage projects. Six major projects have been placed in operation since 1961; seven are under construction; and applications for 10 projects are pending before the Federal Power Commission. The pumped storage capacity of these installations totals more than 12,000,000 kw. Large amounts of new peaking capacity will be needed in supplying the country's growing electric power loads. Much of this capacity will be provided through development of pumped storage hydroelectric projects at the many favorable sites that are available. Plans for developing a number of new sites are already under way.

Remote automatic control for line capacitors

STEADILY DECREASING peak-load power factor has amplified the problem of providing a supply for the ever-increasing reactive load on the Baltimore Gas and Electric Company system. The location of new generation in more remote areas has increased the attractiveness of static capacitors located near the load for reactive supply. However, in order to avoid excessive voltage and generator instability at light loads, suitable switching provisions for these capacitors must be available. Capacitors located on substation busses, so as to facilitate this switching, are a step in the right direction, but do not provide relief to the most costly element of the system — the distribution facilities. Pole-mounted line capacitors provide maximum feasible system relief, but the switching must be accomplished by automatic means. Time clocks, voltage, current, temperature, and other types of control are available for this function, and each type has its place. However, the extensive use of these controls presents a substantial co-ordination problem if excessive voltage changes are to be avoided. Considerable maintenance can be expected, and lack of operation supervision would indicate that some routine inspection may be deemed essential.

Kilovar Supply in Bulk-Power Transmission Systems

The principal results of this study are shown in Figs. 5-7. The data as presented permit a broad range of application as far as system operating voltages are concerned, since circuit kw loading is expressed in per-unit of 2.5 (kv)2, where kv is the actual operating voltage in kv at the sending-end of the transmission line. For reference, 1.0 per-unit circuit kw load for several operating voltages is shown in Table I. Approximate economic kvar transmission limits are shown in each figure as a function of circuit kw loading for several transmission distances as well as fox two different values of transformer impedance, i.e., 10 and 15%. For convenience, optimum kvars are expressed as a ratio of kw load received. Figs. 5, 6, and 7 apply to conductor sizes of 1,272-, 636-, and 266.8-MCM ACSR respectively. Also, Figs. 5(A), 6(A), and 7(A) apply to future design cases where differences in transformer kva, generator reactive capacity, and power and energy loss are evaluated. Data for existing facilities, where only energy and power demand differences are considered, are given in Figs. 5(B), 6(B), and 7(B). Indications of the normal peak-load generator power factors and receiving system load-bus voltages which correspond to the economic kvar transmission limits are also given in Figs. 5-7. It should be clear that the load-bus voltages are expressed in per cent as seen from the highvoltage sending-end bus, and reflect the actual operating turns ratio of the receiving-end step-down transformer.