Power transmission

In nearly all mechanical power applications in the oil and gas industry it is necessary to transmit the power generated by a prime mover to an operation (e.g., drawworks of a drilling rig, or a production pumping system). The transmission of rotary power to such operation elements is carried out by a power transmission system. Mechanical power transmission is typically carried out by power betting systems, chain systems, gear systems and by hydraulic systems, or some combination of these three [1,5]. 

There are basically four general categories of power betting [8]. These are  

In general, the choice of power belt drive depends upon such faster or speed, reduction ration, positive-drive requirements, and center distances, shaft relationship (i.e., magnitude of skew and load). 

Ribbed belts Toothed or timing plot link bell 

Formed-steet, light-duty sheave with integral hub 

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Between the bit and the surface, where the torque is generated, we find the drill string (Fig. 3.9). While being mainly a means for power transmission, the drill string fulfils several other functions, and if we move up from the bit we can see what those are. 

Open-Arc Furnaces. Most of the open-arc furnaces are used in melting and refining operations for steel and iron (Fig. 1). Although most furnaces have three electrodes and operate utilizing three-phase a-c power to be compatible with power transmission systems, d-c furnaces are becoming more common. Open-arc furnaces are also used in melting operations for nonferrous metals (particularly copper), slag, refractories, and other less volatile materials. 

Alkylated aromatics are used as the base fluid ia engine oils, gear oils, hydrauHc fluids, and greases ia sub2ero appHcations. They also are used as the base fluid ia power transmission fluids and gas turbine, air compressor, and refrigeration compressor lubricants. 

Link-Suspended Basket Centrifuges In centrifuges with diameters larger than 762 mm (30 in), the basket, curb, curb cover, and drive form a rigid assembly flexibly suspended from three fixed posts (also known as a three-column centrifuge). The three suspension members may be either chain hnks or stiff rods in ball-and-socket joints and are spring-loaded. The suspended assembly has restrained freedom to oscillate to compensate for a normal out-of-balance condition. The drive is vertical with more efficient power transmission compared to the base-bearing type. 

Process machinery usually involves a driver and a driven machine, and these machines are connected by power-transmission equipment. Such equipment can either be mechanical or hydrauhc. 

Although power-transmission equipment is generally simpler than the machines it connects, it nevertheless fails in seivdce as often as—if not more often than—motors, turbines, pumps, and the like. Care must be given to the proper selection and maintenance of power-transmission equipment otherwise, the best process machines cannot perform as expected. 

This segment will discuss the more commonly used power-transmission equipment also discussed will be the machineiy bearings, which not only support the rotors of machineiy, but the power-transmission equipment as well. 

To provide a reference for those working on power projects or at sites, we provide some important data on different types of LT and HT power cables in this appendix. The cables described here are in use for all kinds of power distribution applications. Of these, XLPE cables are also used for power transmission applictiiions. To help a user to select the most appropriate types of cables, we also provide a brief comparative chart of the various types of cables being manufactured. Tables giving the technical particulars of such cables in all voltage ratings have also been provided. 

In the earlier installations sensitive to such iiuerfercnces (he normal practice was coordination between the generating and power transmission agencies and the authorities of essential services (such as public telephones, defence serv ices and railways), who prov ide (heir (wvn communication systems, lo relocate iheir telephone lines to mitigate this problem at the planning stage,... 

Series and shunt capacitors both provide the same degree of compensation. But it is the correct reactive support that provides a more stable system less prone to load and voltage lluctuations. Thus i Judicious choice between the shunt and the series capacitors is required. In the following our main thrust is to arrive at the most appropriate type and extent of reactive support to achieve a higher level of utilization of a power transmission or distribution system, on the one hand, and more stability, on the other. 

In the first case, if we had considered a safe line length of 250 km, this would become 500 km for a symmetrical line. Figure 24.18 illustrates such a condition. Depending upon the length and type of line, a line length compensation may be required. Most transmission lines are seen to be within permissible lengths and only a few may require such a compensation. Nevertheless, it may be worth reducing the phase displacement between E, and to less than 15° electrical, to further iinprove the quality and stability level of power transmission. 

To decide on the best reactive control one should choose the most appropriate electrical line length from the load characteristics drawn already. Choose the one that can transmit the optimum power, and then compensate this to obtain the required line length. For the 400 kV, 50 Hz system considered, we can choose a radial line with an electrical line length of 200-250 km. The compensation is provided so that the P ,aj point, which lies far from the natural power transmission point Pq, shifts within a stable region, i.e. near the Pq region. Then from equation (24.8),... 

Central Board of Power and Irrigation, India (Indian National Commiliee for Cigre), Electric Power Transmission at voltages of WOO kV and Above. Oct. (1984). 

Industrial power engineering and applications handbook I Electrical power transmission - Handbooks, manuals, etc. 

Series unalloyed Al > 99 Al Weak but ductile and o good electrical conductor power transmission lines, cooking foil. 

We say that the motor generates horsepower (HP), and that the pump consumes brake horsepower (BHp). The difference between HP (output) and BHp (input) is what is lost in the power transmission the bearings, shaft, and coupling between the motor and the pump. 

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