Experimental Study of Effects of Non-Condensable on Condensation in a Vertical Tube Bundle

2009 ◽  
Author(s):  
Wenzhong Zhou ◽  
Gavin Henderson ◽  
Shripad T. Revankar
Keyword(s):  
Heat Transfer ◽  
Cooling System ◽  
Tube Bundle ◽  
Condensation Heat Transfer ◽  
Forced Flow ◽  
Test Facility ◽  
Flow Mode ◽  
Scaling Analysis ◽  
Condenser Tube ◽  
Air Concentration

One of the engineered safety systems in the advanced boiling water reactor is a passive containment cooling system (PCCS) which is composed of a number of vertical heat exchanger. After a loss of coolant accident, the pressurized steam discharged from the reactor and the noncondensable (NC) gases mixture flows into the PCCS condenser tube. The PCCS condenser must be able to remove sufficient energy from the reactor containment to prevent containment from exceeding its design pressure. The efficient performance of the PCCS condenser is thus vital to the safety of the reactor. In PCCS condenser tube three flow conditions are expected namely the forced flow, cyclic venting and complete condensation modes. The PCCS test facility consists of steam generator (SG), instrumented condenser with secondary pool boiling section, condensation tank, suppression pool, storage tank, air supply line, and associated piping and instrumentation. The specific design of condensing tube is based on scaling analysis from the PCCS design of ESBWR. The scaled PCCS is made of four tubes of diameter 52.5mm and height 1.8 m arranged in square pitch. Steam air mixture condensation tests were carried out in a through flow mode of operation where the mixture flows through the condenser tube with some steam condensation. Data on condensation heat transfer were obtained for two nominal pressures, 225 kPa and 275 kPa and for air concentration fraction from 0 to 13%. Test results showed that with increase in pressure the condensation heat transfer increased. The presence of the air in the steam decreased the condensation heat transfer coefficient from 10 to 45% depending on air fraction in the steam.

Roll Wave Effects on Annular Condensing Heat Transfer in Horizontal PCCS Condenser Tube

2002 ◽  
Author(s):  
Masaya Kondo ◽  
Hideo Nakamura ◽  
Yoshinari Anoda ◽  
Sadanori Saishu ◽  
Hiroyuki Obata ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Annular Flow ◽  
Cooling System ◽  
Condensation Heat Transfer ◽  
Transfer Model ◽  
Condenser Tube ◽  
Condensing Heat Transfer ◽  
Condensation Heat Transfer Coefficient

A horizontal in-tube condensation heat exchanger is under investigation to be used for a passive containment cooling system (PCCS) of a next generation-type BWR. The flow conditions in the horizontal condenser tube were observed both visually and by local void fraction fluctuation. The observed flow regimes at a rated condition were annular flow at the tube inlet, and turned gradually into wavy flow and smooth stratified flow along the length of the tube. It was found further that frequency of the roll waves that appear on the liquid film in the annular flow is closely related to the measured local condensation heat transfer coefficient. Based on the flow observation, the roll wave frequency and measured condensation heat transfer coefficient, a model is proposed which predicts the condensation heat transfer coefficient particularly for annular flows around the tube inlet region. The proposed heat transfer model predicts well the influences of pressure, local gas-phase velocity and film thickness.

Scaling of Passive Condenser System Separate Effect Facility

2008 ◽  
Author(s):  
Shripad T. Revankar ◽  
Seungmin Oh ◽  
Wenzhong Zhou ◽  
Gavin Henderson
Keyword(s):  
Cooling System ◽  
Forced Flow ◽  
Test Facility ◽  
Prototype System ◽  
Scaling Analysis ◽  
Reactor Accident ◽  
Cooling Period ◽  
Separate Effect ◽  
Suppression Pool

The Passive Containment Cooling System (PCCS) of the Simplified Boiling Water Reactor (SBWR) is a passive condenser system designed to remove energy from the containment for long term cooling period after a postulated reactor accident. Depending on pressure condition and noncondensable (NC) gas fraction in drywell (DW) and suppression pool (SP), three different modes are possible in the PCCS operation namely the forced flow, cyclic venting and complete condensation modes. The prototype SBWR has total of six condenser units with each units consist of hundreds of condenser tubes. Simulation of such prototype system is very expensive and complex Hence a scaling analysis is used in designing an experimental model for the prototype PCCS condenser system. The motive for scaling is to achieve a homologous relationship between an experiment and the prototype which it represents. A scaling method for separate effect test facility is first presented. The design of the scaled test facility for PCCS condenser is then given. Data from the test facility are presented and scaling approach to relate the scaled test facility data to prototype is discussed.

Design of Condensation Heat Transfer Experiment to Evaluate Scaling Distortion in Small Modular Reactor Safety Analysis

2021 ◽  
Vol 7 (3) ◽  
Author(s):  
Palash K. Bhowmik ◽  
J. P. Schlegel ◽  
V. Kalra ◽  
C. Mills ◽  
S. Usman
Keyword(s):  
Heat Transfer ◽  
Test Data ◽  
Cooling System ◽  
Safety Analysis ◽  
Nuclear Industry ◽  
Condensation Heat Transfer ◽  
Saturated Steam ◽  
Test Facility ◽  
Working Fluid ◽  
Different Diameters

Abstract Designing a novel scaled modular test facility as a part of an experiment for condensation heat transfer (CHT) in small modular reactors (SMRs) is the main focus of this study. This facility will provide data to evaluate models' scalability for predicting heat transfer in the passive containment cooling system (PCCS) of SMR. The nuclear industry recognizes SMRs as future candidates for clean, economic, and safe energy generation. However, licensing requires proper evaluation of the safety systems such as PCCS. The knowledge gap from the literature review showed a lack of high-resolution experimental data for scaling of PCCS and validation of computational fluid dynamics tools. In addition, the presently available test data are inconsistent due to unscaled geometric and varying physics conditions. These inconsistencies lead to inadequate test data benchmarking. To fill this research gap, this study developed three scaled (different diameters) condensing test sections with annular cooling for scale testing and analysis. This facility considered saturated steam as the working fluid with noncondensable gases like nitrogen and helium in different mass fractions. This facility also used a precooler unit for inlet steam conditioning and a postcooler unit for condensate cooling. The high fidelity sensors, instruments, and data acquisition systems are installed and calibrated. Finally, facility safety analysis and shakedown tests are performed.

Vertical Tube Passive Condenser Under Secondary Pool Water Level Transient

2010 ◽  
Author(s):  
Shripad T. Revankar ◽  
Wenzhong Zhou
Keyword(s):  
Water Level ◽  
Cooling System ◽  
Vertical Tube ◽  
Test Facility ◽  
Flow Mode ◽  
Scaling Analysis ◽  
Water Level Change ◽  
Level Change ◽  
Pool Water ◽  
System Pressure

An experimental work was carried out on a passive containment cooling system (PCCS) test facility where the effect of PCCS pool water level change on the PCCS heat transfer characteristics was investigated. The specific design of condensing tube was based on scaling analysis from the PCCS design of Economic Simplified Boiling Water Reactor (ESBWR). The annulus between the primary condensing tube and the secondary boiling tube is filled with water and serves as water pool. During the test, steam generated in the pool is discharged through three steam exit nozzles located symmetrically at the top of the secondary boiling tube. Transient tests carried out with secondary pool water level change show that the system pressure for complete condensation mode increases with decrease in water level, however rate of condensation is almost constant. However, if the PCCS is operated in through flow mode the system pressure (primary side pressure) is constant, however, the condensate rate decreases indicating that some of the steam does not condense.

Condensation in a Vertical Tube Bundle Operating in Passive Condensation Mode

2009 ◽  
Author(s):  
Gavin Henderson ◽  
Wenzhong Zhou ◽  
Shripad T. Revankar
Keyword(s):  
Heat Transfer ◽  
Flow Rate ◽  
Cooling System ◽  
Tube Bundle ◽  
Condensation Heat Transfer ◽  
Transfer Coefficients ◽  
Transfer Rates ◽  
Single Tube ◽  
Heat Transfer Coefficients ◽  
Condensation Mode

Passive condenser systems are used in a number of industrial heat transfer systems. Passive containment cooling system (PCCS) which is composed of a number of vertical heat exchanger serves as an engineered safety system in an advanced boiling water reactor. The PCCS condenser must be able to remove sufficient energy from the reactor containment to prevent containment from exceeding its design pressure. Experiments were designed to simulate the PCCS condensation with a tube bundle. Scaling analysis was performed to scale down the prototype PCCS with a tube bundle consisting of four tubes. The tubes in the bundle were of prototype height (1.8 m) and diameter (52.5 mm) and the operating conditions and boundary conditions such as the operating pressure, secondary cooling system were designed to represent prototype conditions. Steam condensation tests were carried out in complete condensation mode where all the steam entering the condenser bundle is completely condensed. Condensation heat transfer coefficients (HTC) were obtained for various steam flow rate. The condensation pressure depended on the inlet steam flow rate which happens to be the maximum condensation rate for the given test pressure. Data on condensation heat transfer were obtained for primary pressure raging from 110–270 kPa. The tube bundle condensation heat transfer rates were compared with single tube heat transfer rates from previous work. The results showed that the condensation heat transfer coefficient for the tube in bundle was comparable with single tube, however the secondary side heat transfer coefficients for the tubes in bundle was higher than for the single tube. Condensation heat transfer for tube in bundle ranged from 7500 W/ m2K to 20,000 W/ m2K for the range of pressure studied. A heat and mass analogy model was developed and the condensation heat transfer prediction from the model was compared with experimental data.

Experimental Research on Steam Condensation on Cold Surface: Facility Design

2014 ◽  
Author(s):  
Li-Yong Han ◽  
Lin Yang ◽  
Shan Zhou ◽  
Shen Wang ◽  
Chun-Lai Tian ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Test Section ◽  
Cooling System ◽  
Theoretical Research ◽  
Test Facility ◽  
Measurement Technology ◽  
Ambient Conditions ◽  
Steam Condensation ◽  
Cold Surface ◽  
Process Gas

The passive containment cooling system (PCCS) of the 3rd generation APWR utilizes natural phenomena to transfer the heat released from the reactor to the environment during postulated designed basic accidents. Steam condensation on the inner surface of the containment shell is one of the most dominate mechanism to keep the ambient conditions within the design limits. Extensive experiment and theoretical research shows condensation is a complex process, gas pressure, film temperature and velocity of the gas have impact on the heat transfer coefficient. To span the expected range of conditions and provide proper model for evaluating the condensation heat transfer process, SCOPE test facility was designed by State Nuclear Power Technology Research & Development Centre (SNPTRD) in various conditions anticipated the operating range of CAP1400 in accident conditions. Pressurized test section with a rectangular flowing channel was used, with one of the walls cooled to maintain low temperature for condensing, supplying systems was designed for different pressures, gas temperatures, velocities and coolant water temperatures. Facility components, test section structure, supplying systems and measurement technology were described in this paper, also results of some pre-tests was introduce to show property of the facility.

Experimental Apparatus for Measuring in Tube Condensation Heat Transfer Coefficient and Pressure Drop Using Smooth and Micro-Fin Tubes for HFC Refrigerants

2008 ◽  
Author(s):  
Pradeep A. Patil ◽  
S. N. Sapali
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Condensation Heat Transfer ◽  
Test Facility ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Fin Tube ◽  
Condensation Heat Transfer Coefficient

An experimental test facility is designed and built to calculate condensation heat transfer coefficients and pressure drops for HFC-134a, R-404A, R-407C, R-507A in a smooth and micro-fin tube. The main objective of the experimentation is to investigate the enhancement in condensation heat transfer coefficient and increase in pressure drop using micro-fin tube for different condensing temperatures and further to develop an empirical correlation for heat transfer coefficient and pressure drop, which takes into account the micro-fin tube geometry, variation of condensing temperature and temperature difference (difference between condensing temperature and average temperature of cooling medium). The experimental setup has a facility to vary the different operating parameters such as condensing temperature, cooling water temperature, flow rate of refrigerant and cooling water etc and study their effect on heat transfer coefficients and pressure drops. The hermetically sealed reciprocating compressor is used in the system, thus the effect of lubricating oil on the heat transfer coefficient is taken in to account. This paper reports the detailed description of design and development of the test apparatus, control devices, instrumentation, and the experimental procedure. It also covers the comparative study of experimental apparatus with the existing one from the available literature survey. The condensation and pressure drop of HFC-134a in a smooth tube are measured and obtained the values of condensation heat transfer coefficients for different mass flux and condensing temperatures using modified Wilson plot technique with correlation coefficient above 0.9. The condensation heat transfer coefficient and pressure drop increases with increasing mass flux and decreases with increasing condensing temperature. The results are compared with existing available correlations for validation of test facility. The experimental data points have good association with available correlations except Cavallini-Zecchin Correlation.

Evaluation of the Scaling Analysis Model of the EU-APR1400 Core Catcher Cooling System Test Facility

2014 ◽  
Author(s):  
Bo W. Rhee ◽  
K. S. Ha ◽  
R. J. Park ◽  
J. H. Song
Keyword(s):  
Performance Test ◽  
Cooling System ◽  
Reactor Core ◽  
Test Facility ◽  
Scaling Analysis ◽  
Analysis Model ◽  
System Pressure ◽  
Test Loop ◽  
Core Catcher ◽  
The Eu

This paper describes the basic design features of the EU-APR1400 reactor core catcher cooling system and its test facility, and the associated scaling analysis model. An assessment of the validity of the scaling analysis using the preliminary performance test result of the test facility is described. This includes comparison of the predicted mass flow rate of the test loop as a function of the heat load to the facility, inlet flow subcooling and system pressure to the experimental results.

Prediction of Bundle Shell Side Condensation Heat Transfer Coefficient

2008 ◽  
Author(s):  
Tailian Chen
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Reasonable Agreement ◽  
Condensation Heat Transfer ◽  
Condenser Tube ◽  
Shell Side ◽  
3 Dimensional ◽  
Design Engineers ◽  
Condensation Heat Transfer Coefficient

Prediction of condenser bundle performance is of great interest to chiller design engineers and tube developers as well. Depending on their locations in a condenser bundle, tubes are subjected to inundation or flooding of condensate coming from those above them. The tubes located in the top portion of the bundle are not or slightly inundated whereas the tubes located deep in the bundle experience larger degree of inundation; those in the bundle bottom are the most severely inundated. For a condenser bundle to have good performance, it is necessary for the tubes to perform well in both non-inundated and inundated conditions. In this paper, the outside condensation heat transfer coefficient and its sensitivity to inundation for a condenser tube of enhanced 3-dimensional (3D) outside fins were measured. Based on the single tube measurements, shell side condensation performance of a condenser bundle was predicted. The predicted bundle outside heat transfer coefficient has a reasonable agreement with that of a condenser tested in a 500-ton chiller.

Experimental Study on Condensation Heat Transfer and Flow Modes of R245fa on Enhanced Surface Tubes

2015 ◽  
Vol 23 (02) ◽  
pp. 1550014 ◽  
Author(s):  
Daisuke Jige ◽  
Tomonobu Matsuno ◽  
Norihiro Inoue
Keyword(s):  
Heat Transfer ◽  
Saturation Temperature ◽  
Condensation Heat Transfer ◽  
Flow Mode ◽  
Heat Transfer Characteristics ◽  
Enhanced Heat Transfer ◽  
Finned Tubes ◽  
Transfer Characteristics ◽  
Grooved Tube ◽  
Enhanced Surface

The present study experimentally investigated the condensation heat transfer characteristics and condensate flow mode of R245fa on horizontal low-finned and microscopic-grooved tubes. Five low-finned tubes and a microscopic-grooved tube with tube diameters at the fin tip of approximately 19 mm were used. Experiments were conducted at a saturation temperature of 40°C. The fundamental heat transfer characteristics of the low-finned and microscopic-grooved tubes were experimentally investigated to clarify the flow modes of the condensate and the efficacy of the enhanced heat transfer.

Sign in / Sign up

Export Citation Format

Share Document