Turbine motor design

Figure 4-190. Basic turbine motor design principie. (Courtesy Smith International, Inc.)...

Figure 4-191. Downhole turbine motor design. (Courtesy Eastman-Christensen Co.)...

There are of course variations on the downhole turbine motor design, but the basic sections discussed above will be common to all designs. 

The pressure drop Ap (psi) through a given turbine motor design is usually obtained empirically. Once this value is known for a circulation flowrate and mud weight, the pressure drop for other circulation flowrates and mud weights can be estimated. 

If the above performance parameters for a turbine motor design are known for a given circulation flowrate and mud weight (denoted as 1), the performance parameters for the new circulation flowrate and mud weight (denoted as 2) can be found by the following relationships ... 

The downhole turbine motor designed to be activated by the flow of incompressible drilling mud cannot operate on air, gas, unstable foam or stable foam drilling fluids. These downhole turbine motors can only be operated on drilling mud or aerated mud. 

An alternative type of downhole mud motor is the mud turbine, (multistage axial flow turbine) which directly drives the bit. The tool consists of an upper section containing the turbine blades and lower section with bearings. As mud is pumped through the upper section the blades are turned. Turbines are designed to rotate at higher speed than the displacement motor. The higher rotation speed requires diamond or composite bits. 

In this section the design and the operational characteristics and procedures of the most frequently used downhole motors will be discussed. These are the downhole turbine motor and the downhole positive displacement motor. 

The major reason most turbine motors are designed with various add-on motor sections is to allow flexibility when applying turbine motors to operational situations. 

The last column in Tables 4-110 and 4-111 show the thrust load associated with each circulation floWrate (i.e.,-pressure drop). This thrust load is the result of the pressure drop across the turbine motor rotor and stator blades. -The magnitude. of this pressure drop, depends. on the individual internal design details of the turbine motor (i.e., blade angle, number of stages, axial height of blades and The radial width of the blades) and the operating conditions. The additional pressure. drop results in thrust, T (lb), whicit is... 

Communication. A 3D presentation of the data representing simulated flow phenomena, is considered to be much easier to understand, especially for non-experts. As a consequence, the design of a newly developed turbine, motor or in our case an extruder can be communicated to customers, project partners etc. Also, interdisciplinary discussion of CFD results within a company, which today becomes more and more important in the product development process, can be improved by means of Virtual Reality. 

RCT are designed to successfully solve a whole number of tasks in nuclear power when testing fuel elements, in aviation and space industry when testing construction materials, nozzles and engine units, turbine blades and parts, in electromechanical industry-cables switching elements, electric motors in defense sphere- charges, equipment in prospecting for research of rock distribution and detection of precious stones in samples. 

Backup systems which depend upon the action of automatic cut-in devices (e.g., a turbine-driven standby spare for a motor-driven cooling water pump, with PLCI control) would not be considered an acceptable means of preventing a utility failure for normal pressure relief design purposes, even though their installation is fully justified by improved continuity and reliability of plant operations. 

Figure 12-5F. Lubricated and nonlubricated balanced opposed process reciprocating compressors, designed to API 618 code. Fixed- and variable-speed drives using gas or diesel engines, steam or gas turbines, or electric motor. Note power drive to connect to right side of cross-head box in center. (Used by permission Bui. PROM 635/115/95-11. Nuovo Pignone S. P. A., Florence, Italy New York Los Angeles and Houston, Texas. All rights reserved.)...

No matter the duty (utilities excepted), most boiler plant systems employ electric motor-driven, single-stage or multistage centrifugal pumps to supply FW. These may be of conventional design or derivations such as a turbine pump. However, steam-driven reciprocating FW pumps (steam pumps) are still employed in some countries and for certain smaller applications. 

Gas turbines require a start-up device, which is usually an electric motor. The power of the start-up device can be up to 15% of the gas turbine power, depending on the size and design of the machine. 

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