scholarly journals Concurrent optimization of thermal and electric storage in commercial buildings to reduce operating cost and demand peaks under time-of-use tariffs

2019 ◽  
Vol 254 ◽  
pp. 113630 ◽  
Author(s):  
Christoph J. Meinrenken ◽  
Ali Mehmani
2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Philip L. Andrew ◽  
Harika S. Kahveci

Avoiding aerodynamic separation and excessive shock losses in gas turbine turbomachinery components can reduce fuel usage and thus reduce operating cost. In order to achieve this, blading designs should be made robust to a wide range of operating conditions. Consequently, a design tool is needed—one that can be executed quickly for each of many operating conditions and on each of several design sections, which will accurately capture loss, turning, and loading. This paper presents the validation of a boundary layer code, MISES, versus experimental data from a 2D linear cascade approximating the performance of a moderately loaded mid-pitch section from a modern aircraft high-pressure turbine. The validation versus measured loading, turning, and total pressure loss is presented for a range of exit Mach numbers from ≈0.5 to 1.2 and across a range of incidence from −10 deg to +14.5 deg relative to design incidence.


Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2642 ◽  
Author(s):  
Yi Zhang ◽  
Guanmin Zhang ◽  
Aiqun Zhang ◽  
Yinhan Jin ◽  
Ruirui Ru ◽  
...  

Frost layer on the outdoor air heat exchanger surface in an air-source heat pump (ASHP) can decrease the system coefficient of performance (COP). Although the common defrosting and anti-frosting methods can improve the COP, the periodic defrosting not only reduces the system energy efficiency but also deteriorates the indoor environment. To solve these problems, it is necessary to clearly understand the frosting phenomenon and to achieve the system frost-free operation. This paper focused firstly on the analyses of frosting pathways and frosting maps. Followed by summarizing the characteristics of frost-free technologies. And then the performances of two types of frost-free ASHP (FFASHP) systems were reviewed, and the exergy and economic analysis of a FFASHP heating system were carried out. Finally, the existing problems related to the FFASHP technologies were proposed. Results show that the existing frosting maps need to be further improved. The FFASHP systems can not only achieve continuous frost-free operation but reduce operating cost. And the total COP of the FFASHP heating system is approximately 30–64% higher than that of the conventional ASHP system under the same frosting conditions. However, the investment cost of the FFASHP system increases, and its reliability also needs further field test in a wider frosting environment. In the future, combined with a new frosting map, the control strategy for the FFASHP system should be optimized.


2014 ◽  
Vol 629 ◽  
pp. 152-157
Author(s):  
Navanitha Marimuthu ◽  
Ermira Junita Abdullah ◽  
Dayang L.A. Majid ◽  
Fairuz I. Romli

Micro Air Vehicle (MAV) has the capability to fly autonomously in complex environments which enables human to conduct surveillance in areas which are deemed too dangerous or in confined spaces that does not allow human entry. Research and development of MAVs aim to reduce their size further, thus novel techniques need to be explored in order to achieve this objective while still maintaining the MAVs’ current performance. In this paper, a conceptual design of an MAV with a main drive system using shape memory alloy (SMA) actuator to provide the flapping motion is proposed. SMA is considered superior to other smart materials due to its efficiency and large energy storage capacity. By incorporating SMA in the flapping wing MAV, it will provide users the flexibility to add more payloads by reducing bulky cables or reduce operating cost by using less fuel. However, there are some drawbacks in using SMAs such as nonlinear response of the strain to input current and hysteresis characteristic as a result of which their control is inaccurate and complicated.


2021 ◽  
Author(s):  
Eliav J. Eini

A simulation study is presented to investigate the use of the Anammox process for removing nitrogen compounds from wastewater to reduce operating cost. The literature review of technologies for removal of Total Nitrogen includes an overview of the biological nitrogen cycle, the discovery of Anammox, bioreactor design, operational strategies, and start-up of full-scale processes. A facility of 656 MLD with influent loading of 35 mg/L as NH3-N and 250 mg/L as BOD is used as a basis of the simulation study. Preliminary bioreactor sizing calculations are developed for six configurations. Subsequently, eight whole-plant simulation cases are compared to demonstrate operational savings for removal of Total Nitrogen. For the sample facility, this is shown to be on the order of $460 to $680K/year while attaining 66-70% Total Nitrogen removal and reduced greenhouse gas emissions by 2 kt CO2/year. The project concludes with ideas about future development of the Anammox process.


2021 ◽  
Author(s):  
Okon Edet Ita ◽  
Dulu Appah

Abstract The ability to identify underperforming wells and recover the remaining oil in place is a cornerstone for effective reservoir management and field development strategies. As advancement in computing programming capabilities continuous to grow, Python has become an attractive method to build complicated statistical models that predicts, diagnose or analyze well performance, efficiently and accurately. The aim of this study is to develop a computational model that will allows us to diagnose and analyze well performance using nodal analysis with the help of python. In this study, python was used to compute Nodal analysis method using Darcy and Vogel Equations. A case study was carried out using the data obtained from a field operating in the Niger Delta. Again, sensitivity of tubing size was conducted using python. The results obtained showed that a computational model with python has the ability to visualize, model and analyze wells performances. This technique will petroleum engineers to better monitor evaluate and enhance their production operation without the need for expensive softwares. This will reduce operating cost increases revenue.


Author(s):  
Jennifer L. Y. Chalmers ◽  
Jeff W. Bird ◽  
Donald Gauthier

The aerospace industry is aggressively pursuing many avenues of engine health monitoring to improve aircraft safety and reduce operating cost. A PT6/T400 turboshaft engine has been instrumented specifically to determine if measurable compressor aerodynamic behavior can provide a warning of impending stall or surge, especially in a small (< 5kg/s), service-exposed, axi-centrifugal compressor. In accordance with a survey of experience and methods for stall testing and detection methods, the engine was instrumented with nine fast-response pressure transducers (monitored at 25 kHz) divided between the axial compressor first stage leading edge, the axial compressor exit, and the outlet of the centrifugal compressor diffuser. An automatic bleed valve was gradually disabled to induce compressor stall. The engine response to this gradual change corresponded to the predictions of a simple engine surge model. A technique for monitoring blade air-flow regularity was developed and used to prove that aerodynamic changes could be successfully detected before the onset of stall/surge. The new technique compared favorably to conventional time series analysis, fast Fourier transform and wavelet processing techniques. Recommendations are made for further improvements and study of test and analysis methods.


Author(s):  
Philip L. Andrew ◽  
Harika S. Kahveci

Avoiding aerodynamic separation and excessive shock losses in gas turbine turbomachinery components can reduce fuel usage, and thus reduce operating cost. In order to achieve this, blading designs should be made robust to a wide range of operating conditions. Consequently, a design tool is needed which can be executed quickly for each of many operating conditions, and on each of several design sections which will accurately capture loss, turning and loading. This paper presents the validation of a boundary layer code, MISES, versus experimental data from a 2-D linear cascade approximating the performance of a moderately-loaded, mid-pitch section from a modern aircraft high-pressure turbine [1–2]. The validation versus measured loading, turning, and total pressure loss is presented for a range of exit Mach numbers from ≈ 0.5 to 1.2, and across a range of incidence from −10° to +14.5° relative to design incidence.


2010 ◽  
Vol 156-157 ◽  
pp. 1545-1554 ◽  
Author(s):  
Napassavong Rojanarowan ◽  
Angsumalin Senjuntichai

The objective of this study is to develop an efficient washing system to remove cutting oil from machining part surface. The proposed washing system consists of two processes: the dipping process and the modified automatic ultrasonic washing process. The automatic ultrasonic washing process is redesigned and developed to reduce operating cost and increase productivity from the previously developed machine. For this proposed system, experiments have been performed to determine the washing conditions that yield satisfactory proportion of defectives due to oil contamination. Under the suggested operating conditions, the proportion of defectives due to oil contamination is reduced from 12.8% to 1.78%, which leads to $16,800 defective cost reduction. The proposed washing system yields 42.9% increase in washing productivity. Furthermore, it as has more standard procedure than the current washing process.


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