The Experts below are selected from a list of 6447 Experts worldwide ranked by ideXlab platform
Da-wen Sun - One of the best experts on this subject based on the ideXlab platform.
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Precooling techniques and applications for horticultural products — a review
International Journal of Refrigeration-revue Internationale Du Froid, 2001Co-Authors: Tadhg Brosnan, Da-wen SunAbstract:Abstract One of the most important factors affecting the postharvest life and quality of horticultural crops is temperature. Quality loss after harvest occurs as a result of physiological and biological processes, the rates of which are influenced primarily by product temperature. As the maintenance of market quality is of vital importance to the success of the horticultural industry, it is necessary not only to cool the product but to cool it as quickly as possible after harvest. The process of Precooling is the removal of field heat which arrest the deteriorative and senescence processes so as to maintain a high level of quality that ensures customer satisfaction. This paper provides a critical review to portray Precooling as an intricate part of temperature management and to highlight the importance of its utilisation for extending the shelf life and maintaining the quality of horticultural products with emphasis on cut flowers. Various different Precooling methods are depicted with the benefits and ambiguities of each shown. The applicability and cooling efficiency of each are also illustrated. Through this review, it is aimed to promote interest in Precooling and encourage its use on a more widespread basis.
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Precooling techniques and applications for horticultural products a review
International Journal of Refrigeration-revue Internationale Du Froid, 2001Co-Authors: Tadhg Brosnan, Da-wen SunAbstract:Abstract One of the most important factors affecting the postharvest life and quality of horticultural crops is temperature. Quality loss after harvest occurs as a result of physiological and biological processes, the rates of which are influenced primarily by product temperature. As the maintenance of market quality is of vital importance to the success of the horticultural industry, it is necessary not only to cool the product but to cool it as quickly as possible after harvest. The process of Precooling is the removal of field heat which arrest the deteriorative and senescence processes so as to maintain a high level of quality that ensures customer satisfaction. This paper provides a critical review to portray Precooling as an intricate part of temperature management and to highlight the importance of its utilisation for extending the shelf life and maintaining the quality of horticultural products with emphasis on cut flowers. Various different Precooling methods are depicted with the benefits and ambiguities of each shown. The applicability and cooling efficiency of each are also illustrated. Through this review, it is aimed to promote interest in Precooling and encourage its use on a more widespread basis.
Qian Chen - One of the best experts on this subject based on the ideXlab platform.
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An RC-Network Approach for HVAC Precooling Optimization in Buildings
IEEE Transactions on Sustainable Computing, 2019Co-Authors: Hongsen Shi, Jia Liu, Qian ChenAbstract:To lower buildings' significant energy consumption and high impacts on environmental sustainability, recent years have witnessed rapidly growing interests in efficient HVAC Precooling control and optimization. However, due to the complex analytical modeling of building thermal transfer, rigorous mathematical optimization for HVAC Precooling is highly challenging. As a result, progress on HVAC Precooling optimization remains limited in the literature. Our main contribution is that we overcome the aforementioned challenge and propose an accurate and tractable HVAC Precooling optimization framework. The main results of this paper are three-fold: i) We develop an RC-network-based analytical model for multi-zone HVAC Precooling to minimize both total energy costs and peak load demand; ii) We show that the HVAC procooling optimization problem based on the proposed RC network model admits a convex approximation, which enables an efficient optimization algorithm design; and iii) Based on the convex approximation insight and by exploiting special problem structures, we develop an efficient distributed algorithm to solve the HVAC Precooling optimization problem. Further, we conduct extensive simulation studies to verify the performance of our proposed mathematical model and algorithms. Our numerical results indicate that compared with the five existing HVAC control strategies, the proposed algorithm consistently outperforms existing state-of-the-art approaches.
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e-Energy - HVAC Precooling Optimization for Green Buildings: An RC-Network Approach
Proceedings of the Ninth International Conference on Future Energy Systems, 2018Co-Authors: Hongsen Shi, Jia Liu, Qian ChenAbstract:To lower buildings' significant energy consumption and high impacts on environmental sustainability, recent years have witnessed rapidly growing interests in efficient HVAC Precooling control and optimization. However, due to the complex analytical modeling of building thermal transfer, rigorous mathematical optimization for HVAC Precooling is highly challenging. As a result, progress on HVAC Precooling optimization remains rather limited in the literature. Our main contribution in this paper is that we overcome the aforementioned challenge and propose an accurate and tractable mathematical HVAC Precooling optimization framework. The main results of this paper are three-fold: i) We develop an RC-network-based analytical model for multi-zone HVAC Precooling to minimize both total energy costs and peak load demand; ii) We show that the HVAC procooling optimization problem based on the proposed RC network model admits a convex approximation, which enables efficient optimization algorithm design; and iii) Based on the convex approximation insight and by exploiting special problem structures, we develop an efficient distributed algorithm to solve the HVAC Precooling optimization problem. Further, we conduct extensive simulation studies to verify the performance of our proposed mathematical model and algorithms. Our numerical results indicate that the proposed optimization algorithm consistently achieves energy cost reduction ranging from 30% to 60%.
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hvac Precooling optimization for green buildings an rc network approach
International Conference on Future Energy Systems, 2018Co-Authors: Hongsen Shi, Jia Liu, Qian ChenAbstract:To lower buildings' significant energy consumption and high impacts on environmental sustainability, recent years have witnessed rapidly growing interests in efficient HVAC Precooling control and optimization. However, due to the complex analytical modeling of building thermal transfer, rigorous mathematical optimization for HVAC Precooling is highly challenging. As a result, progress on HVAC Precooling optimization remains rather limited in the literature. Our main contribution in this paper is that we overcome the aforementioned challenge and propose an accurate and tractable mathematical HVAC Precooling optimization framework. The main results of this paper are three-fold: i) We develop an RC-network-based analytical model for multi-zone HVAC Precooling to minimize both total energy costs and peak load demand; ii) We show that the HVAC procooling optimization problem based on the proposed RC network model admits a convex approximation, which enables efficient optimization algorithm design; and iii) Based on the convex approximation insight and by exploiting special problem structures, we develop an efficient distributed algorithm to solve the HVAC Precooling optimization problem. Further, we conduct extensive simulation studies to verify the performance of our proposed mathematical model and algorithms. Our numerical results indicate that the proposed optimization algorithm consistently achieves energy cost reduction ranging from 30% to 60%.
Luo Ercang - One of the best experts on this subject based on the ideXlab platform.
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numerical study of a 10 k two stage pulse tube cryocooler with Precooling inside the pulse tube
IOP Conference Series: Materials Science and Engineering, 2017Co-Authors: Pang Xiaomin, Wang Xiaotao, Dai Wei, Hu Jianyin, Luo ErcangAbstract:High efficiency cryocoolers working below 10 K have many applications such as cryo-pump, superconductor cooling and cryogenic electronics. This paper presents a thermally coupled two-stage pulse tube cryocooler system and its numeric analysis. The simulation results indicate that temperature distribution in the pulse tube has a significant impact on the system performance. So a Precooling heat exchanger is put inside the second stage pulse tube for a deep investigation on its influence on the system performance. The influences of operating parameters such as Precooling temperature, location of the Precooling heat exchanger are discussed. Comparison of energy losses apparently show the advantages of the configuration which leads to an improvement on the efficiency. Finally, the cryocooler is predicted to be able to reach a relative Carnot efficiency of 10.7% at 10 K temperature.
B.f. Song - One of the best experts on this subject based on the ideXlab platform.
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Numerical analysis on natural circulation Precooling of cryogenic liquid rocket engine
2012 7th IEEE Conference on Industrial Electronics and Applications (ICIEA), 2012Co-Authors: J.z. Wang, E.f. Chen, B.f. SongAbstract:Natural circulation Precooling of cryogenic liquid rocket engine is a spontaneous high velocity reflooding heat transfer process. In the present study, the flow regimes and heat transfer characteristics of this Precooling process have been analyzed, and one set of heat transfer models, which couples the heat release equation of the pipeline wall and the flow and heat transfer equations of cryogenic liquid, has been established and validated to investigate the heat transfer characteristics of the unsteady Precooling process. The results indicate that the circulation flow rate of the Precooling process fluctuates due to the unstable heat released to the cryogenic liquid. Moreover, it is found that the optimal reflux location is at 4 ~ 6 meters above the bottom header, and the Precooling effects can be enhanced by decreasing the gas pillow pressure.
Tadhg Brosnan - One of the best experts on this subject based on the ideXlab platform.
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Precooling techniques and applications for horticultural products — a review
International Journal of Refrigeration-revue Internationale Du Froid, 2001Co-Authors: Tadhg Brosnan, Da-wen SunAbstract:Abstract One of the most important factors affecting the postharvest life and quality of horticultural crops is temperature. Quality loss after harvest occurs as a result of physiological and biological processes, the rates of which are influenced primarily by product temperature. As the maintenance of market quality is of vital importance to the success of the horticultural industry, it is necessary not only to cool the product but to cool it as quickly as possible after harvest. The process of Precooling is the removal of field heat which arrest the deteriorative and senescence processes so as to maintain a high level of quality that ensures customer satisfaction. This paper provides a critical review to portray Precooling as an intricate part of temperature management and to highlight the importance of its utilisation for extending the shelf life and maintaining the quality of horticultural products with emphasis on cut flowers. Various different Precooling methods are depicted with the benefits and ambiguities of each shown. The applicability and cooling efficiency of each are also illustrated. Through this review, it is aimed to promote interest in Precooling and encourage its use on a more widespread basis.
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Precooling techniques and applications for horticultural products a review
International Journal of Refrigeration-revue Internationale Du Froid, 2001Co-Authors: Tadhg Brosnan, Da-wen SunAbstract:Abstract One of the most important factors affecting the postharvest life and quality of horticultural crops is temperature. Quality loss after harvest occurs as a result of physiological and biological processes, the rates of which are influenced primarily by product temperature. As the maintenance of market quality is of vital importance to the success of the horticultural industry, it is necessary not only to cool the product but to cool it as quickly as possible after harvest. The process of Precooling is the removal of field heat which arrest the deteriorative and senescence processes so as to maintain a high level of quality that ensures customer satisfaction. This paper provides a critical review to portray Precooling as an intricate part of temperature management and to highlight the importance of its utilisation for extending the shelf life and maintaining the quality of horticultural products with emphasis on cut flowers. Various different Precooling methods are depicted with the benefits and ambiguities of each shown. The applicability and cooling efficiency of each are also illustrated. Through this review, it is aimed to promote interest in Precooling and encourage its use on a more widespread basis.
