scholarly journals Using CFD to improve the performance of a heat exchanger from a gasifier

2021 ◽  
Vol 286 ◽  
pp. 01010
Author(s):  
Liliana Dumitrescu ◽  
Edmond Maican ◽  
Ioan Pavel ◽  
Cătălin Dumitrescu ◽  
Iuliana Găgeanu ◽  
...  

In this paper, a Computational Fluid Dynamics (CFD) analysis is performed on a gas-liquid heat exchanger fitted on a gasification equipment. The flow and temperature patterns are preliminary investigated using SolidWorks Flow Simulation software, in order to gain insight into the involved physical processes, and to find the exchanger weak points before being manufactured and tested. The analysed equipment tranfers heat from the flue gasses generated by a gasification system, towards a liquid heat transfer medium. This is subsequently sent to a second liquidliquid heat exchanger used to heat water from a boiler. As a result of the analysis, solutions aiming at performance improvement of the equipment are discussed and proposed.

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 602 ◽  
Author(s):  
Christopher Vella ◽  
Simon Paul Borg ◽  
Daniel Micallef

One parameter that may affect the performance of a ground source heat pump is the shank-space, the center-to-center distance between the two branches of a vertical U-tube used in a ground heat exchanger. A 3D steady-state computational fluid dynamics (CFD) model of a U-tube ground heat exchanger was used to investigate the influence of varying shank-space on the thermal performance of two isolated vertical shallow U-tubes, one 20 m deep and the other 40 m deep, given that most existing research focuses on systems making use of deeper boreholes. The models adopt an innovative approach, whereby the U-junction at the bottom of the U-tube is eliminated, thus facilitating the computational process. The results obtained show that, although the temperature drop across the U-tube varies for different shank-spaces and is lowest and highest for the closest and the widest shank-spaces, respectively, this temperature drop is not linear with increases in shank-space, and the thermal performance improvement drastically diminishes with increasing shank-space. This indicates that, for shallow U-tubes, the temperature drop is more dependent on the length of the pipework.


Author(s):  
Jay A. Cossentine ◽  
Jere J. Matty ◽  
Robert J. Shaw

The Arnold Engineering Development Center (AEDC) and the NASA Lewis Research Center (LeRC) have formed a government alliance aimed at establishing and supporting a national, application-oriented computational fluid dynamics (CFD) capability, centered around the NPARC flow simulation software. The Alliance is supported by and responsive to an association made up of more that 100 active users at over 60 government, industry, and academic institutions. This paper discusses the history, structure, and philosophy of the NPARC Alliance.


TAPPI Journal ◽  
2015 ◽  
Vol 14 (1) ◽  
pp. 51-60
Author(s):  
HONGHI TRAN ◽  
DANNY TANDRA

Sootblowing technology used in recovery boilers originated from that used in coal-fired boilers. It started with manual cleaning with hand lancing and hand blowing, and evolved slowly into online sootblowing using retractable sootblowers. Since 1991, intensive research and development has focused on sootblowing jet fundamentals and deposit removal in recovery boilers. The results have provided much insight into sootblower jet hydrodynamics, how a sootblower jet interacts with tubes and deposits, and factors influencing its deposit removal efficiency, and have led to two important innovations: fully-expanded sootblower nozzles that are used in virtually all recovery boilers today, and the low pressure sootblowing technology that has been implemented in several new recovery boilers. The availability of powerful computing systems, superfast microprocessors and data acquisition systems, and versatile computational fluid dynamics (CFD) modeling capability in the past two decades has also contributed greatly to the advancement of sootblowing technology. High quality infrared inspection cameras have enabled mills to inspect the deposit buildup conditions in the boiler during operation, and helped identify problems with sootblower lance swinging and superheater platens and boiler bank tube vibrations. As the recovery boiler firing capacity and steam parameters have increased markedly in recent years, sootblowers have become larger and longer, and this can present a challenge in terms of both sootblower design and operation.


Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 589
Author(s):  
Qilu Chen ◽  
Yutao Shi ◽  
Zhi Zhuang ◽  
Li Weng ◽  
Chengjun Xu ◽  
...  

Heat pipe heat exchangers (HPHEXs) are widely used in various industries. In this paper, a novel model of a liquid–liquid heat pipe heat exchanger in a countercurrent manner is established by considering the evaporation and condensation thermal resistances inside the heat pipes (HPs). The discrete method is added to the HPHEX model to determine the thermal resistances of the HPs and the temperature change trend of the heat transfer fluid in the HPHEX. The established model is verified by the HPHEX structure and experimental data in the existing literature and demonstrates numerical results that agree with the experimental data to within a 5% error. With the current model, the investigation compares the effectiveness and minimum vapor temperature of the HPHEX with three types of HP diameters, different mass flow rates, and different H* values. For HPs with a diameter of 36 mm, the effectiveness of each is improved by about 0.018 to 0.029 compared to HPs with a diameter of 28 mm. The results show that the current model can predict the temperature change trend of the HPHEX well; in addition, the effects of different structures on the effectiveness and minimum vapor temperature are obtained, which improve the performance of the HPHEX.


1992 ◽  
Vol 114 (1) ◽  
pp. 79-90 ◽  
Author(s):  
O. P. Sharma ◽  
G. F. Pickett ◽  
R. H. Ni

The impacts of unsteady flow research activities on flow simulation methods used in the turbine design process are assessed. Results from experimental investigations that identify the impact of periodic unsteadiness on the time-averaged flows in turbines and results from numerical simulations obtained by using three-dimensional unsteady Computational Fluid Dynamics (CFD) codes indicate that some of the unsteady flow features can be fairly accurately predicted. Flow parameters that can be modeled with existing steady CFD codes are distinguished from those that require unsteady codes.


2013 ◽  
Vol 850-851 ◽  
pp. 355-358
Author(s):  
Dong Du

This paper describes the use of Fluid Flow Simulation Software to model a passenger aircraft engine environmental control system. The analysis simulates the cooling pack and the engine distribution system in a single model.The engine environmental system is very important for engine working efficiently. Using AMEsim software to simulate the cooling system can make it easily and clearly. The influence of the heat component and the fan operating is studied also. Through the analysis of the cooling system, we know that with the help of fan, the system can get additional air in the radiator and make the temperature decrease consequently.


2021 ◽  
Author(s):  
Teymour Javaherchi ◽  
Susheel Brahmeshwarkar ◽  
Raja Faruq ◽  
Chinmay Deshpande

Abstract This work will demonstrate how the Energy Recovery Inc. (ERI) engineering team improved the efficiency of a multistage pump by about 10% at the first stage, which translated into a 3% increase in the overall multistage pump efficiency; according to a set of engineering calculations and review of the archived in-house test data for the legacy multistage pumps, it was hypothesized that the performance pain-point of the pump was inefficient performance of the first stage, due to the formation of a strong pre-swirl right before its inlet. The validity of this hypothesis then was confirmed via RANS CFD simulations of the flow field inside the inlet suction housing and pump impeller. Same CFD methodology was used to evaluate multiple engineering solutions to reduce the strength of the inflow pre-swirl by modifying the inlet suction housing geometry. The obtained RANS CFD solutions guided the engineering team towards the most promising hardware modification proposal. The proposed geometrical modification of the inlet suction housing was implemented and tested on different multistage pumps. All of the test results validated the obtained RANS CFD numerical solution. The state of the art in this successful performance improvement process was first the on-point hypothesis development based on fundamentals of engineering and archived test data. Second, the proper RANS CFD methodology development to model/confirm the initial hypothesis and vet all possible engineering solutions to maximize the multistage pump efficiently and accurately. This can be a great example for various relevant turbomachinery industrial applications.


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