Pumps performance analysis

Motivation Unit tests require a substantial investment in time and resources to complete successfully. This is the case whether the test is a straightforward analysis of pump performance or a complex analysis of an integrated reactor and separation train. The uncertainties in the measurements, the likelihood that different underlying problems lead to the same symptoms, and the multiple interpretations of unit performance are barriers against accurate understanding of the unit operation. The goal of any unit test should be to maximize the success (i.e., to describe accurately unit performance) while minimizing the resources necessary to arrive at the description and the subsequent recommendations. The number of measurements and the number of trials should be selected so that they are minimized. 

In this study, a closed BTES using boreholes at UOIT is described and its technical details are presented, along with an illustrative example providing a performance analysis of the heat pumps. 

Kato, Y., and C. L. Pritchard, 2000. Energy performance analysis of isobutene/water/tert-butanol chemical heat pump, Trans. IChemE, 78 (2), 184-191. 

Chen, L., Sun, F., and Wu, C., Performance analysis of a closed regenerated Brayton heat pump with internal irreversibility. International Journal of Energy Research, 23, 1039-1050, 1999. 

We have seen how the screw extruder pump is synthesized from a simple building block of two parallel plates in relative motion. We have also seen how the analysis of the screw extruder leads in first approximation back to the shallow channel parallel plate model. We carried out the analysis for isothermal flow of a Newtonian fluid, reaching a model (Eq. 6.3-27) that is satisfactory for gaining a deeper insight into the pressurization and flow mechanisms in the screw extruder, and also for first-order approximations of the pumping performance of screw extruders. 

Gommed, K., and Grossman, G. (1990) Performance Analysis of Staged Absorption Heat Pumps Water-Lithium Bromide Systems, ASHRAE Transactions, Vol. 96(1), pp. 1590 - 1598. 

A typical laboratory setup includes a column, fraction collector, and peristaltic pump connected with flexible tubing. In some cases an on-line spectrophotometer may be useful, but generally the large number of UV-absorbing compounds in the feed results in data that has a weak, or no, correlation with product adsorbance. The standard practice is to collect the column-effluent fractions and perform analysis by methods such as HPLC to determine product concentration in the effluent. 

Automatic macromodel extraction that takes advantage of high-fidelity device simulations (e.g., FEM, FVM, and BEM) to extract RLC values in irregular microchannel geometries has also been reported. Turowski et al. [11] approximate the microfluidic Tesla valve as an/ L circuit (serial connection of a resistor R and an inductor L in Fig. 5) and performed both steady and transient analysis to extract its fluidic resistance and inductance. The macromodels are then stitched together for an overall system simulation on the pumping performance. 

The reactor coolant pumps are sized to deliver flow that equals or exceeds the design flow rate utilized in the thermal hydraulic analysis of the Reactor Coolant System. Analysis of steady-state and anticipated transients is performed assuming the minimum design flow rate. Tests are performed to evaluate reactor coolant pump performance during the post-core load hot functional testing to verify adequate flow. 

Safety Factors for Performance When specifying pump performance, safety factors should not be applied to both capacity and head without careful graphical analysis of pump and process dynamics. It is normally adequate to specify pumps as below ... 

The compressor is modeled with either the new RELAP5-3D compressor component or a pump component. The RELAP5-3D compressor component is used for all steady state and transient runs except for the complete loss of electrical load (overspeed) transient in which the pump component was used, The compressor component requires compressor data that covers the range of flow rates and shaft speeds that occur during a transient. Since the overspeed transient takes shaft speed well beyond the available compressor data, the necessary data extrapolation introduced too much error into the calculation and in many cases made the compressor unstable. The pump model, on the other hand, is able to calculate performance at the very high shaft speeds, and the pump performance curves were extrapolated to the necessary operating points. More compressor data would have been required to refine the analysis of the overspeed transient had the design continued. 

It is noteworthy, however, that traces of sulfur can have beneficial effects on the anti-wear resistance of fuel injection pumps. It is thus undesirable to reduce the sulfur content to extremely low values unless additives having lubricating qualities are added. Independently from total sulfur content, the presence of mercaptans that are particularly aggressive towards certain metal or synthetic parts is strictly controlled. The mercaptan content is thereby limited to 0.002% (20 ppm) maximum. The analysis is performed chemically in accordance to the NF M 07-022 or ASTM D 3227 procedures. 

Liquid chromatography was performed on symmetry 5 p.m (100 X 4.6 mm i.d) column at 40°C. The mobile phase consisted of acetronitrile 0.043 M H PO (36 63, v/v) adjusted to pH 6.7 with 5 M NaOH and pumped at a flow rate of 1.2 ml/min. Detection of clarithromycin and azithromycin as an internal standard (I.S) was monitored on an electrochemical detector operated at a potential of 0.85 Volt. Each analysis required no longer than 14 min. Quantitation over the range of 0.05 - 5.0 p.g/ml was made by correlating peak area ratio of the dmg to that of the I.S versus concentration. A linear relationship was verified as indicated by a correlation coefficient, r, better than 0.999. 

During the PHEA stage, the analyst has to identify likely human errors and possible ways of error detection and recovery. The PHEA prompts the analyst to examine the main performance-influencing factors (PIFs) (see Chapter 3) which can contribute to critical errors. All the task steps at the bottom level of the HTA are analyzed in turn to identify likely error modes, their potential for recovery, their safety or quality consequences, and the main performance-influencing factors (PIFs) which can give rise to these errors. In this case study, credible errors were found for the majority of the task steps and each error had multiple causes. An analysis of two operations from the HTA is presented to illustrate the outputs of the PHEA. Figure 7.12 shows a PHEA of the two following tasks Receive instructions to pump and Reset system. 

Los Alamos National Laboratory performed separate statistical analyses using the Failure Rate Analysis Code (FRAC) on IPRDS failure data for pumps and valves. The major purpose of the study was to determine which environmental, system, and operating factors adequately explain the variability in the failure data. The results of the pump study are documented in NUREG/CR-3650. The valve study findings are presented in NUREG/CR-4217. 

If a simple pump is considered, it is possible to state that there must be a working relation between the power input, and the flow rate, pressure rise, fluid properties, and size of the machine. If a dimensional analysis is performed, it can be shown that a working relation may exist... 

It is very simple to perform batch fermentation in a small flask with a volume of say 200 ml. Now our target is to use a 2 litre B. Braun fermenter. All accessories are shown in Figure 10.5. The fermentation vessel only, as shown in Figure 10.6, with about 250 ml of media without any accessories but with some silicon tubing attached with a filter for ventilation is autoclaved at a 131 °C for 10 minutes at 15psig.9 After that, the system is handled with special care and all accessories attached. Media is separately sterilised and pumped into the vessel. Inoculum is transferred and the batch experiment is started right after the inoculation of seed culture. An initial sample is withdrawn for analysis. 

The schematic diagram of the experimental setup is shown in Fig. 2 and the experimental conditions are shown in Table 2. Each gas was controlled its flow rate by a mass flow controller and supplied to the module at a pressure sli tly higher than the atmospheric pressure. Absorbent solution was suppUed to the module by a circulation pump. A small amount of absorbent solution, which did not permeate the membrane, overflowed and then it was introduced to the upper part of the permeate side. Permeation and returning liquid fell down to the reservoir and it was recycled to the feed side. The dry gas through condenser was discharged from the vacuum pump, and its flow rate was measured by a digital soap-film flow meter. The gas composition was determined by a gas chromatograph (Yanaco, GC-2800, column Porapak Q for CO2 and (N2+O2) analysis, and molecular sieve 5A for N2 and O2 analysis). The performance of the module was calculated by the same procedure reported in our previous paper [1]. 

Liquid feed was fed by hydrostatic means gas feed was accomplished from a reservoir with the aid of a syringe pump [7]. The gas pressure was held nearly constant by passing a gas stream into a non-absorbing liquid. Analysis was performed both by visual means using a microscope and camera and by chemical analysis of the liquid output solution (Figure 5.33). 

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