scholarly journals Sound reduction in heat exchanger modules by integrating plate absorbers with sub-millimeter openings

Acta Acustica ◽  
2021 ◽  
Vol 5 ◽  
pp. 35
Author(s):  
Felix Czwielong ◽  
Sebastian Floss ◽  
Manfred Kaltenbacher ◽  
Stefan Becker

In air conditioning systems heat exchangers are frequently installed upstream of ventilators. These modules are part of the daily life of humans and should therefore create an environment that is as quiet as possible. The heat exchanger generates increased turbulence, which leads to increased sound emissions of the ventilator. Due to installation space limitations, it is not possible to connect silencers to the heat exchanger module. A novel concept is presented, which allows to reduce the sound emissions of heat exchanger due to plate absorbers without the need of additional installation room. The plates contain sub-millimeter openings. They are integrated into the heat exchanger housing together with back volumes. This arrangement guarantees compactness and generates no additional flow resistance. The emitted sound could be reduced by up to 2.9 dB in the partial load range. The main advantages of the concept presented are individual adjustment, cost-effective design and simple installation.

2021 ◽  
Vol 5 (2) ◽  
pp. 17
Author(s):  
Valli Trisha ◽  
Kai Seng Koh ◽  
Lik Yin Ng ◽  
Vui Soon Chok

Limited research of heat integration has been conducted in the oleochemical field. This paper attempts to evaluate the performance of an existing heat exchanger network (HEN) of an oleochemical plant at 600 tonnes per day (TPD) in Malaysia, in which the emphases are placed on the annual saving and reduction in energy consumption. Using commercial HEN numerical software, ASPEN Energy Analyzer v10.0, it was found that the performance of the current HEN in place is excellent, saving over 80% in annual costs and reducing energy consumption by 1,882,711 gigajoule per year (GJ/year). Further analysis of the performance of the HEN was performed to identify the potential optimisation of untapped heating/cooling process streams. Two cases, which are the most cost-effective and energy efficient, were proposed with positive results. However, the second case performed better than the first case, at a lower payback time (0.83 year) and higher annual savings (0.20 million USD/year) with the addition of one heat exchanger at a capital cost of USD 134,620. The first case had a higher payback time (4.64 years), a lower annual saving (0.05 million USD/year) and three additional heaters at a capital cost of USD 193,480. This research has provided a new insight into the oleochemical industry in which retrofitting the HEN can further reduce energy consumption, which in return will reduce the overall production cost of oleochemical commodities. This is particularly crucial in making the product more competitive in its pricing in the global market.


2017 ◽  
Vol 107 (05) ◽  
pp. 352-358
Author(s):  
S. Prof. Simon ◽  
S. Wichmann ◽  
A. Brill

Von der Brandenburgischen Technischen Universität (BTU) sind in Zusammenarbeit mit der TU Liberec Untersuchungen zur Verbesserung der Energieeffizienz an spanenden Werkzeugmaschinen durchgeführt worden. Im Gegensatz zu bereits durchgeführten Untersuchungen wurde der Fokus hier auf das Belastungsverhalten im Teillastbereich gerichtet. Die durchgeführten Untersuchungen beschränkten sich auf das Längsdrehen mit geringen Schnitttiefen. Als Werkstoffe kamen ein Baustahl und ein Vergütungsstahl zum Einsatz. Durch die Bestimmung der Leerlaufleistung der verwendeten Drehmaschine waren tatsächliche Aussagen über die Schnittleistung möglich. Für das Ermitteln des Wirkungsgrades wurden auch die Schnittleistungen bei verschiedenen Drehzahlen aufgenommen. Alle weiteren Spanungsbedingungen blieben für die Untersuchungen konstant. Im Ergebnis der Untersuchung bestätigte sich das Potenzial der Minimalmengenschmierung. Der Wirkungsgrad verbesserte sich durchschnittlich um 5 %. Beachtenswert ist der Einfluss des Einstellwinkels. Hier liegt das Optimierungspotenzial der Energieeffizienz in Summe bei 14 %. Die Untersuchungen ergaben weiterhin eine hohe Korrelation von Spanungsbedingungen, Werkstückwerkstoff und verwendetem Schmiermittel.   The Brandenburg University of Technology has carried out investigations in cooperation with the technical University of Liberec to improve the energy efficiency of cutting machine tools. In contrast to investigations already carried out, the focus here was on the loading behavior in the partial load range. The investigations carried out were limited to longitudinal turning with low cutting depths. A structural steel and a tempering steel were used as materials. By determining the no-load power of the used lathe, actual statements about the cutting performance were possible. For the determination of the efficiency, the cutting performance was recorded at different speeds. All further stress conditions remained constant for the investigations. As a result of the investigation, the potential of minimum quantity lubrication was confirmed. The efficiency improved by an average of 5 %. The influence of the angle of setting was remarkable. The optimization potential of energy efficiency was at 14 %. The investigations also revealed a high correlation between stress conditions, workpiece material and lubricant used.


Author(s):  
Anton Moisseytsev ◽  
Qiuping Lv ◽  
James J. Sienicki

The capability to utilize dry air cooling by which heat is directly rejected to the air atmosphere heat sink is one of the benefits of the supercritical carbon dioxide (sCO2) energy conversion cycle. For the selection and analysis of the heat exchanger options for dry air cooling applications for the sCO2 cycle, two leading forced air flow design approaches have been identified and analyzed for this application; an air cooler consisting of modular finned tube air coolers; and an air cooler consisting of modular compact diffusion-bonded heat exchangers. The commercially available modular finned tube air cooler is found to be more cost effective and is selected as the reference for dry air cooling.


2012 ◽  
Author(s):  
Sharifah Rafidah Wan Alwi ◽  
Muhammad Azan Tamar Jaya ◽  
Zainuddin Abdul Manan

Kilang penapisan minyak sawit lazimnya melibatkan proses penggunaan tenaga yang tinggi. Peningkatan kecekapan tenaga adalah amat penting bagi memastikan keuntungan tercapai. Kertas kerja ini menggunakan teknik analisis jepit bagi memaksimumkan penggunaan semula haba dan meningkatkan kecekapan sistem rangkaian haba sedia ada di kilang penghasilan minyak sawit, tertakluk kepada kekangan–kekangan proses. Langkah–langkah yang terlibat ialah penetapan sasaran guna semula haba maksimum diikuti dengan reka bentuk rangkaian haba yang ekonomik. Aplikasi teknik berkenaan kepada kilang penghasilan minyak sawit telah menghasilkan pengurangan penggunaan haba panas dan sejuk sebanyak 700 kW (21%), atau penjimatan kos utiliti sebanyak RM370,787, dengan pelaburan kapital sebanyak RM656,293 dan jangka pulangan balik selama 1.77 tahun. Kata kunci: Analisis jepit; minyak kelapa sawit; sedia ada; rangkaian pemindahan haba; kitar semula haba maksimum A palm oil refinery involves energy–intensive processes. Maximizing thermal efficiency of palm oil refinery is crucial for the plant profitability. This work implements a pinch analysis retrofit technique to maximize heat recovery and thermal efficiency of a palm oil refinery, subject to the existing process constraints. The procedures involve setting the maximum heat recovery targets and cost–effective retrofit of the heat exchanger network (HEN). Application of the technique on a palm oil refinery results in reduction of 700 kW (21%) heating and cooling loads or a saving of RM370,787, incurring a capital investment of about RM656,293 and a payback period of 1.77 years. Key words: Pinch analysis; palm oil; retrofit; heat exchanger network; maximum heat recovery


Batteries ◽  
2018 ◽  
Vol 4 (4) ◽  
pp. 53 ◽  
Author(s):  
Nicholas Gurieff ◽  
Victoria Timchenko ◽  
Chris Menictas

Vanadium redox flow batteries (VRFBs) offer great promise as a safe, cost effective means of storing electrical energy on a large scale and will certainly have a part to play in the global transition to renewable energy. To unlock the full potential of VRFB systems, however, it is necessary to improve their power density. Unconventional stack design shows encouraging possibilities as a means to that end. Presented here is the novel concept of variable porous electrode compression, which simulations have shown to deliver a one third increase in minimum limiting current density together with a lower pressure drop when compared to standard uniform compression cell designs.


Author(s):  
Osamu Kurata ◽  
Norihiko Iki ◽  
Takayuki Matsunuma ◽  
Tetsuhiko Maeda ◽  
Satoshi Hirano ◽  
...  

Combined heat and power (CHP) systems are widely used to prevent global warming and reduce energy costs. Both high efficiency of the elements and good coordination of the systems are considered as the points to solve. A microturbine CHP with a latent heat storage system was demonstrated at Sapporo City University. The heat exchanger of the CHP and an economizer were located in parallel downstream a bypass-dumper of the exhaust gas. The latent heat storage tank was located downstream the economizer. The bypass-dumper released exhaust gas when the boiler water in the heat exchanger exceeded 90°C. It is very important to use the heat supply of hot water as much as possible. At Sapporo City University, the winter term heat demand from 6pm to 7pm was somewhat smaller than that from 8am to 6pm. We tested a partial load from 6pm to 7pm to observe how it would respond to the heat demand. The heat supply from the microturbine CHP from 6pm to 7pm was shown to be controllable with heat storage. The heat supply from the microturbine CHP at the lowest power was larger than the heat demand so without the heat storage it was uncontrollable.


Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1482 ◽  
Author(s):  
Wenting Chen ◽  
Hang Liu ◽  
Yonggang Lin ◽  
Wei Li ◽  
Yong Sun ◽  
...  

Based on wind lidar, a novel yaw control scheme was designed that utilizes forecast wind information. The new scheme can reduce the power loss caused by the lag of accurate measurement data in the traditional yaw control strategy. A theoretical analysis of the power loss caused by the traditional wind measurement inherent error and the wind direction based traditional yaw control strategy was conducted. The yaw angle error and yaw stop/start frequency in an actual wind field were statistically analyzed, and a novel Long Short Term-Neural Network (LSTM-NN) yaw control strategy based on wind lidar information was proposed. An accurate forecast of the wind direction could reduce the power loss caused by the inherent yaw misalignment, while an accurate forecast of wind speed could increase the stop/start frequency in the medium speed section within the partial load range and reduce the frequency in the low speed section within the partial load range. Thus, the power captured could be increased by 3.5% under certain wind conditions without increasing the yaw duty. Based on a simple wind evolution model and a novel yaw control strategy, the validity of the yaw control strategy was verified in a FAST/Simulink simulation model.


Sign in / Sign up

Export Citation Format

Share Document