23 Superheater package total steam pressure drop

Non-uniformity of the steam-assisted gravity drainage (SAGD) steam chamber significantly decreases the development of heavy oil reservoirs. In this study, to investigate the steam conformance in SAGD operations, a wellbore model is developed for fluid flow in dual-string horizontal wells. Then, a three-dimensional, three-phase reservoir model is presented. Next, the coupled wellbore and reservoir model is solved with a fully implicit finite difference method. Finally, the effects of the injector wellbore configuration, steam injection ratio and injection time on the steam conformance are investigated. The results indicate that under different injector wellbore configurations, the closer the differences between the pressure drop from the landing position of the short string to the heel of the wellbore and the pressure drop from the landing position of the short string to the toe of the wellbore, the better is the steam conformance. The smaller the difference in the steam injection rate between the long and short injection strings, the higher is the uniformity of the steam chamber. The injector annular pressure profile uniformity is consistent with the steam conformance. Creating a more uniform steam pressure in the annulus of the injector improves the uniformity of the steam chamber. The steam conformance decreases with increasing injection time, so the optimization method of steam chamber uniformity should be adjusted according to different injection times.

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Experimental investigation of shell-side steam pressure drop in crossflow in a horizontal falling-film tube bundle

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/88/1/012034 ◽

2015 ◽

Vol 88 ◽

pp. 012034

Author(s):

S Q Shen ◽

H Liu ◽

L Y Gong ◽

X S Mu ◽

R Liu

Keyword(s):

Experimental Investigation ◽

Pressure Drop ◽

Tube Bundle ◽

Steam Pressure ◽

Falling Film ◽

Shell Side

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An Experimental Investigation of Pressure Drop During Partial Condensation of Low Pressure Steam

Journal of Thermal Science and Engineering Applications ◽

10.1115/1.4046516 ◽

2020 ◽

Vol 12 (5) ◽

Author(s):

Jacques du Plessis ◽

Michael Owen

Keyword(s):

Pressure Drop ◽

Cooling System ◽

Thermal Power ◽

Steam Pressure ◽

Tube Length ◽

Condenser Tube ◽

Cooling Systems ◽

Frictional Pressure Drop ◽

Wide Range ◽

Experimental Apparatus

Abstract As direct dry-cooling systems are becoming more popular for thermal power plants, there is a demand to increase the flexibility of the application and performance of these cooling systems. A novel hybrid (dry/wet) dephlegmator (HDWD) cooling system is being developed, and at this stage in the development of the HDWD, the performance analysis and optimization of the HDWD is currently subject to uncertainties in a number of parameters. One of the parameters is the confidence in the correlations to predict the steam-side pressure drop over the wide range of full to partial condensation conditions expected in the system as a result of the design. This study makes use of an experimental apparatus to measure steam pressure drop over a range of partial to full condensation inside a circular horizontal tube. The experiment is conducted by measuring the steam flow and steam pressure drop in a horizontal primary condenser tube with the presence of a secondary condenser tube. The primary condenser has a tube length of 2.5 m and an inside tube diameter of 19.3 mm similar to the proposed HDWD design. Existing correlations for pressure drop in condensing flow are compared with the results to assess the applicability of the correlations for the HDWD case. It was found that the correlation of Lockhart and Martinelli’s with the Chisholm parameter fits the experimental data the best with a mean error of ±15.6%. A parametric study also indicated that there is a prominent increase in the frictional pressure drop at low partial condensation ratios (i.e., high steam through flow) as expected with wave drag at the vapor and condensate interface due to the difference in velocity.

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Impact of Instant Controlled Pressure Drop (DIC) Treatment on Drying Kinetics and Caffeine Extraction from Green Coffee Beans

Journal of Food Research ◽

10.5539/jfr.v1n1p24 ◽

2012 ◽

Vol 1 (1) ◽

pp. 24 ◽

Cited By ~ 1

Author(s):

I. Kamal ◽

A. Gelicus ◽

K. Allaf

Keyword(s):

Pressure Drop ◽

Initial Moisture Content ◽

Effective Diffusivity ◽

Steam Pressure ◽

Raw Material ◽

Saturated Steam ◽

Drying Time ◽

Hot Air ◽

Instant Controlled Pressure Drop ◽

The Impact

The present work is directed towards the impacts of Détente InstantanéeContrôléeDIC (French, for instant controlled pressure-drop) in terms of decaffeination and drying of Ethiopian green coffee beans (GCBs).DICconsisted in subjecting the product to a high-pressure saturated steam during some seconds and ended with an abrupt pressure drop towards a vacuum. A conventional aqueous extraction and a hot air-drying took place after DIC treatment. Inthis study, Response Surface Method (RSM) was used withDIC saturated steam pressure P, thermal treatment time t, and initial moisture content W asthe independent variables. Both direct DICextract recovered from the vacuum tank and the aqueous extracts wereanalyzed and quantified using the reversed phase-HPLC. With decaffeination ratiosas dependent variables, P and Wwere the most significant operating parameters; whilet was much weaker.Total decaffeination ratio could reach 99.5% after DIC treatment at specificconditions of W=11.00% db, P=0.1 MPa, and t=35swhile it was only 58% when achieved with untreated raw material. The effective diffusivity and the starting accessibility were calculated from the diffusion/surface interaction kinetic model of hotair drying after DIC treatment. They dramatically increased with P and t while W had a weak impact.Thus, at the optimized DICconditions, and increased from 0.33 to 12.60 10-10m² s-1and from 0.75 to 11.53 g/100 g db, respectively. Drying time needed to reach 5% db became 60 min instead of 528 min for untreated raw material. RSM analysis showed that the DIC saturated steam pressure P and the initial moisture content W were the most significant variables both affecting the decaffeination ratio; the impact of the total thermal processing time t was much weaker. Total decaffeination ratio could reach 99.5% after DIC treatment at specific conditions of W=11.00% db, P=0.1 MPa, and t=35 s while it was only 58% when achieved with untreated raw material. Using diffusion/surface interaction model of hot-air drying kinetics just after DIC treatment, we could observe that DIC expansion dramatically improved the drying kinetic parameters, with P and t as the most significant DIC operating parameters while the impact of W was much weaker. Thus, the optimized DIC treatment allowed the effective diffusivity and the starting accessibility to increase from 0.33 10-10 m² s-1 and 0.75 g/100 g db to 12.60 10-10 m² s-1 and 11.53 g/100 g db, respectively. Drying time needed to reach 5% db became 60 min instead of 528 min for untreated raw material.

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