Numerical study of flow and direct contact condensation of entrained vapor in water jet eductor

2021 ◽  
Author(s):  
Ravi Koirala ◽  
Kiao Inthavong ◽  
Abhijit Date
Keyword(s):  
Direct Contact ◽  
Numerical Study ◽  
Water Jet ◽  
Contact Condensation

Numerical study on direct-contact condensation of vapor in cold water

2002 ◽  
Vol 63-64 ◽  
pp. 421-428 ◽  
Author(s):  
Kazuyuki Takase ◽  
Yasuo Ose ◽  
Tomoaki Kunugi
Keyword(s):  
Direct Contact ◽  
Cold Water ◽  
Numerical Study ◽  
Contact Condensation

Development of Technologies on Innovative-Simplified Nuclear Power Plant Using High-Efficiency Steam Injectors: Part 12—Evaluations of Spatial Distributions of Flow and Heat Transfer in Steam Injector

2006 ◽  
Author(s):  
Yutaka Abe ◽  
Yujiro Kawamoto ◽  
Chikako Iwaki ◽  
Tadashi Narabayashi ◽  
Michitsugu Mori ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Flow Rate ◽  
Direct Contact ◽  
Nuclear Reactor ◽  
High Efficiency ◽  
Flow Behavior ◽  
Water Jet ◽  
Next Generation ◽  
Contact Condensation

Next-generation nuclear reactor systems have been under development aiming at simplified system and improvement of safety and credibility. One of the innovative technologies is the supersonic steam injector, which has been investigated as one of the most important component of the next-generation nuclear reactor. The steam injector has functions of a passive pump without large motor or turbo-machinery and a high efficiency heat exchanger. The performances of the supersonic steam injector as a pump and a heat exchanger are dependent on direct contact condensation phenomena between a supersonic steam and a sub-cooled water jet. In previous studies of the steam injector, there are studies about the operating characteristics of steam injector and about the direct contact condensation between static water pool and steam in atmosphere. However, there is a little study about the turbulent heat transfer and flow behavior under the great shear stress. In order to examine the heat transfer and flow behavior in supersonic steam injector, it is necessary to measure the spatial temperature distribution and velocity in detail. The present study, visible transparent supersonic steam injector is used to obtain the axial pressure distributions in the supersonic steam injector, as well as high speed visual observation of water jet and steam interface. The experiments are conducted with and without non-condensable gas. The experimental results of the interfacial flow behavior between steam and water jet are obtained. It is experimentally clarified that an entrainment exists on the water jet surface. It is also clarified that discharge pressure is depended on the steam supply pressure, the inlet water flow rate, the throat diameter and non-condensable flow rate. Finally a heat flux is estimated about 19MW/m2 without non-condensable gas condition in steam.

Study on Turbulent Behavior of Water Jet in Supersonic Steam Injector

2008 ◽  
Author(s):  
Akira Fukuichi ◽  
Yutaka Abe ◽  
Akiko Fujiwara ◽  
Yujiro Kawamoto ◽  
Chikako Iwaki ◽  
...  
Keyword(s):  
Shear Stress ◽  
Turbulent Flow ◽  
Momentum Transfer ◽  
Total Pressure ◽  
Direct Contact ◽  
High Speed ◽  
Flow Behavior ◽  
Water Jet ◽  
High Efficient ◽  
Contact Condensation

One of the most interesting devices for Next-generation nuclear reactor systems aimed at simplified system, improvement of safety and credibility is a supersonic steam injector. Supersonic steam injector is a passive jet pump without rotating machine and high efficient heat exchanger because of the direct contact condensation between the supersonic steam and the subcooled water jet. It is considered that flow behavior in the supersonic steam injector is governed by the complicated turbulent flow with large shear stress induced by velocity difference between the steam and water and direct contact condensation. There are various studies about formulation of operating characteristic of the steam injector and jet structure in it [1][5]. According to these investigations, heat and momentum transfer of the steam injector are supposed to be related to the turbulent eddy diffusion. However, the studies about the turbulent flow under the large shear stress with direct contact condensation are not enough. Especially mechanisms of the momentum and the heat transfer are not clarified in detail. Objective of the present study is to investigate the turbulent behaviors of the water jet and the interface between the water and the supersonic steam that play an important role in the heat and the momentum transfer. Radial velocity distribution was measured by a special pitot tube. Fluctuation of the total pressure which doesn’t depnd on the density of the fluid is measured by the pitot measurement. It was found that the streamwise velocity increased as it approaches downstream of the injector. Fluctuation of the total pressure is large at the mixing region of the water and the steam. Visual measurement of the turbulent water jet was conducted by high speed camera in order to identify the position of unstable interface and its behavior. It was confirmed that wave propagated on the interface. And its velocity is obtained.

DIRECT CONTACT CONDENSATION OF FLOWING STEAM ONTO INJECTED WATER

1978 ◽  
Author(s):  
Shigebumi Aoki ◽  
Akira Inoue ◽  
Yoshiyuki Kozawa ◽  
H. Akimoto
Keyword(s):  
Direct Contact ◽  
Contact Condensation

Reduce odor and NH3 emission: condensation of the carbonatation vapors

2017 ◽  
pp. 534-537
Author(s):  
Nico Antens ◽  
Jan L.M. Struijs
Keyword(s):  
Direct Contact ◽  
Waste Heat ◽  
Pilot Scale ◽  
Sugar Production ◽  
Two Stage ◽  
Indirect Contact ◽  
Nh3 Emission ◽  
Emission Limits ◽  
Plant Trials ◽  
Contact Condensation

At beet sugar production, vapors from first and second carbonatation contain a significant amount of odor components, NH3 and waste heat, which are normally directly released into the environment. Due to sustainability motivations, obligations regarding odor nuisance and expected stricter regulations regarding NH3 emission limits, Suiker Unie decided to take measures to reduce emission via the carbonatation vapors. During the 2015 beet campaign, pilot scale plant trials have been performed to investigate the effectiveness of indirect contact and direct contact condensation of these vapors. Based on this experimental work a two-stage gas scrubbing concept was designed: in the first stage main goal is condensing the vapors and reuse the heat of condensation to heat up limed juice, while the actual scrubbing takes place in the second scrubber. This two-stage gas scrubbing installation has been built at the Vierverlaten factory and was started up in the 2016 beet campaign. The background, pilot scale trials, concept of design and achieved reductions in odor and NH3 emission at industrial scale are discussed.

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