This page has only limited features, please log in for full access.

Dr. Yuehong Su
Department of Architecture and Built Environment, University of Nottingham, Nottingham NG7 2RD, UK

Basic Info


Research Keywords & Expertise

0 Air Conditioning
0 Desalination
0 heat storage
0 Solar concentrators for PV & daylighting
0 PHOTOPIA optical simulation

Fingerprints

Desalination
heat storage
Solar concentrators for PV & daylighting
Air Conditioning
EnergyPlus simulation

Honors and Awards

The user has no records in this section


Career Timeline

The user has no records in this section.


Short Biography

The user biography is not available.
Following
Followers
Co Authors
The list of users this user is following is empty.
Following: 0 users

Feed

Journal article
Published: 03 August 2021 in Sustainable Cities and Society
Reads 0
Downloads 0

Recent breakthroughs in preparing near-perfect emitters have made it possible to realize daytime radiative cooling under intensive solar radiation. However, a typical radiative cooler cannot deliver heat and may even cause an undesired cooling effect on cold days. Instead of rejecting the solar radiation back to the sky, this work proposes a new concept of capturing this “free” renewable energy while dumping waste heat through radiative cooling. The new structure features an upper solar-transparent radiative emitter and a lower solar absorber. Simulation results suggest that, to realize daytime solar heating and radiative cooling simultaneously, the emitter solar-absorptivity should be extremely low, and the absorbed solar heat should be instantly and effectively taken away by thermal carriers. With an ambient temperature of 25 °C and a maximum solar irradiance of 1000 W/m2, the emitter can always reach a sub-ambient temperature if the absorber temperature is lower than 33.9 °C in the non-vacuum case, and can exceed 70 °C if the air cavity between the emitter and absorber is vacuumized. A performance simulation in three consecutive days in Shanghai reveals that the emitter can realize daytime radiative cooling with a temperature reduction of over 9.3°C from the ambient temperature around noon.

ACS Style

Mingke Hu; Bin Zhao; Suhendri; Jingyu Cao; Qiliang Wang; Saffa Riffat; Yuehong Su; Gang Pei. Feasibility of realizing daytime solar heating and radiative cooling simultaneously with a novel structure. Sustainable Cities and Society 2021, 74, 103224 .

AMA Style

Mingke Hu, Bin Zhao, Suhendri, Jingyu Cao, Qiliang Wang, Saffa Riffat, Yuehong Su, Gang Pei. Feasibility of realizing daytime solar heating and radiative cooling simultaneously with a novel structure. Sustainable Cities and Society. 2021; 74 ():103224.

Chicago/Turabian Style

Mingke Hu; Bin Zhao; Suhendri; Jingyu Cao; Qiliang Wang; Saffa Riffat; Yuehong Su; Gang Pei. 2021. "Feasibility of realizing daytime solar heating and radiative cooling simultaneously with a novel structure." Sustainable Cities and Society 74, no. : 103224.

Editorial
Published: 30 June 2021 in Renewable Energy
Reads 0
Downloads 0
ACS Style

Aleksandar Georgiev; Gang Pei; Yuehong Su; Petia Bobadova. Editorial/ Preface of VSI:AESMT′20. Renewable Energy 2021, 179, 204 -205.

AMA Style

Aleksandar Georgiev, Gang Pei, Yuehong Su, Petia Bobadova. Editorial/ Preface of VSI:AESMT′20. Renewable Energy. 2021; 179 ():204-205.

Chicago/Turabian Style

Aleksandar Georgiev; Gang Pei; Yuehong Su; Petia Bobadova. 2021. "Editorial/ Preface of VSI:AESMT′20." Renewable Energy 179, no. : 204-205.

Journal article
Published: 09 June 2021 in Future Cities and Environment
Reads 0
Downloads 0
ACS Style

James Riffat; Cagri Kutlu; Emmanuel Tapia Brito; Yuehong Su; Saffa Riffat. Performance Analysis of a PV Powered Variable Speed DC Fridge Integrated with PCM for Weak/Off-Grid Setting Areas. Future Cities and Environment 2021, 7, 1 .

AMA Style

James Riffat, Cagri Kutlu, Emmanuel Tapia Brito, Yuehong Su, Saffa Riffat. Performance Analysis of a PV Powered Variable Speed DC Fridge Integrated with PCM for Weak/Off-Grid Setting Areas. Future Cities and Environment. 2021; 7 (1):1.

Chicago/Turabian Style

James Riffat; Cagri Kutlu; Emmanuel Tapia Brito; Yuehong Su; Saffa Riffat. 2021. "Performance Analysis of a PV Powered Variable Speed DC Fridge Integrated with PCM for Weak/Off-Grid Setting Areas." Future Cities and Environment 7, no. 1: 1.

Journal article
Published: 24 May 2021 in Electronics
Reads 0
Downloads 0

It is widely believed that the incorporation of renewable energy to the current power grid is the way forward in achieving sustainable power generation. Currently, with the reduction of PV prices, many countries have started connecting PV systems into their grid network, hence leading to a sharp increase of the penetration levels of renewable electricity production. This will bring significant change in the load pattern and the ramping requirements of the grid’s conventional generation system due to the varying nature of the renewable energy generation. This significant change affects the stability of the grid frequency because it becomes more challenging for the system operators to maintain the equilibrium between the generation and load. Additionally, this significant change affects the PV system potential hosting capacity of the traditional grid because of the PV system’s curtailment in order to comply with the constraints of the grid’s conventional generation system. In this paper, the net load, grid frequency stability, and grid potential hosting capacity are evaluated in the situation of increasing the penetration level of large-scale PV systems generation into the grid. The results show that the grid operators will face increasingly variable net load patterns and steeper ramping events as the PV system penetration level increases. Additionally, the results show the requirement of having flexibility measures that target each grid constraint as the PV system penetration level increases.

ACS Style

Abdullah Alshahrani; Siddig Omer; Yuehong Su. An Investigation into the Potential of Hosting Capacity and the Frequency Stability of a Regional Grid with Increasing Penetration Level of Large-Scale PV Systems. Electronics 2021, 10, 1254 .

AMA Style

Abdullah Alshahrani, Siddig Omer, Yuehong Su. An Investigation into the Potential of Hosting Capacity and the Frequency Stability of a Regional Grid with Increasing Penetration Level of Large-Scale PV Systems. Electronics. 2021; 10 (11):1254.

Chicago/Turabian Style

Abdullah Alshahrani; Siddig Omer; Yuehong Su. 2021. "An Investigation into the Potential of Hosting Capacity and the Frequency Stability of a Regional Grid with Increasing Penetration Level of Large-Scale PV Systems." Electronics 10, no. 11: 1254.

Journal article
Published: 02 April 2021 in Journal of Building Engineering
Reads 0
Downloads 0

Daylighting harvest systems have been improved in recent decades. They have been dramatically used in green buildings to achieve a more sustainable living environment. However, their cost, sizes, shapes, materials, accuracy and control methods are considered as critical aspects towards their feasibility and practicality. The optimal integration between these aspects can achieve more reliable and practical daylight harvest systems. Grasshopper, as a parametric control method, can be exploited in such systems to optimise the use of each aspect. Parametric approach is considered as the most convenient way to control and manipulate different parameters simultaneously, with respond to the sun movement. This study investigates a parametrically controlled daylighting louver system, which can respond to the sun movement to collect as much daylight as possible inside the deep room, via using parametrically-angled reflective slats. To consider our main purpose of feasibility and performance, the study will evaluate the performance of the proposed system by changing its slats’ size and shape to achieve optimum balance between practicality and performance. The study found that reducing the louver size and modifying the slat’s curvature, can significantly increase the daylight coverage percentage inside the deep room from 93% to 98% within the illuminance standard range 300 ∼ 500 lx, in addition to reducing the glare probability to an imperceptible level, besides achieving lighter weight and better strength-limber shape.

ACS Style

Ahmad Eltaweel; Yuehong Su; M. Alaa Mandour; Omar O. Elrawy. A novel automated louver with parametrically-angled reflective slats; design evaluation for better practicality and daylighting uniformity. Journal of Building Engineering 2021, 42, 102438 .

AMA Style

Ahmad Eltaweel, Yuehong Su, M. Alaa Mandour, Omar O. Elrawy. A novel automated louver with parametrically-angled reflective slats; design evaluation for better practicality and daylighting uniformity. Journal of Building Engineering. 2021; 42 ():102438.

Chicago/Turabian Style

Ahmad Eltaweel; Yuehong Su; M. Alaa Mandour; Omar O. Elrawy. 2021. "A novel automated louver with parametrically-angled reflective slats; design evaluation for better practicality and daylighting uniformity." Journal of Building Engineering 42, no. : 102438.

Journal article
Published: 25 March 2021 in Energy Conversion and Management
Reads 0
Downloads 0

Solar energy and universe coldness are two renewable and clean energy constantly sent from outer space to the earth. Solar thermal collectors and radiative coolers respectively harvest heat and cooling energy in this context. However, their static and monofunctional spectral properties mismatch energy demands in regions with large air temperature fluctuations throughout the whole year. In this work, a rotatable bifacial solar photothermic and radiative cooling (PT-RC) module capable of flexibly switch between solar heating and radiative cooling modes is proposed to realize smart thermal management. In the solar heating mode with solar irradiance of 1000 W/m2, the PT-RC module shows 83.3% solar thermal efficiency, which is even slightly higher than that of a typical solar thermal module. In the radiative cooling mode, the PT-RC module reaches up to 69.9 W/m2 net radiative cooling power and 11.7 °C temperature reduction. The heat and cooling energy of the PT-RC module throughout a typical day in Hefei city totals 17.7 MJ. This bifacial PT-RC module provides an alternative solution for integrating solar energy and universe coldness and shows potential in flexibly providing heat and cooling energy in different seasons.

ACS Style

Mingke Hu; Bin Zhao; Xianze Ao; Suhendri; Jingyu Cao; Qiliang Wang; Saffa Riffat; Yuehong Su; Gang Pei. Performance analysis of a novel bifacial solar photothermic and radiative cooling module. Energy Conversion and Management 2021, 236, 114057 .

AMA Style

Mingke Hu, Bin Zhao, Xianze Ao, Suhendri, Jingyu Cao, Qiliang Wang, Saffa Riffat, Yuehong Su, Gang Pei. Performance analysis of a novel bifacial solar photothermic and radiative cooling module. Energy Conversion and Management. 2021; 236 ():114057.

Chicago/Turabian Style

Mingke Hu; Bin Zhao; Xianze Ao; Suhendri; Jingyu Cao; Qiliang Wang; Saffa Riffat; Yuehong Su; Gang Pei. 2021. "Performance analysis of a novel bifacial solar photothermic and radiative cooling module." Energy Conversion and Management 236, no. : 114057.

Journal article
Published: 04 December 2020 in Renewable Energy
Reads 0
Downloads 0

An evacuated flat-plate photovoltaic/thermal (E-PV/T) collector was proposed. The inner space of the E-PV/T collector is vacuumed to suppress non-radiative heat losses, thus increasing thermal efficiency of the collector. Therefore, the E-PV/T collector has the potential to simultaneously deliver electricity and heat at high temperatures. A mathematic model was developed to evaluate the performance of the E-PV/T collector. The effect of some key parameters (e.g., initial water temperature in the water tank, vacuum degree, long-wave panel emissivity, and temperature coefficient of solar cells) on the performance of the E-PV/T system was investigated and the results were compared with a normal flat-plate PV/T (N-PV/T) system. Results suggest that the vacuum helps to enhance the total efficiency by nearly 10 percentage points in high-temperature conditions (>80 °C). The vacuum degree of the upper space exerts a greater effect on system efficiencies compared to that of the lower space. Lower long-wave panel emissivity and greater temperature coefficient of the solar cell promote the performance of the collector. By lowering the long-wave panel emissivity from 0.95 to 0.05, the total efficiency soars from 26.82% to 61.20%. This study may help to guide parametric optimization and operation strategy of flat-plate PV/T collectors for high-temperature applications.

ACS Style

Mingke Hu; Chao Guo; Bin Zhao; Xianze Ao; Suhendri; Jingyu Cao; Qiliang Wang; Saffa Riffat; Yuehong Su; Gang Pei. A parametric study on the performance characteristics of an evacuated flat-plate photovoltaic/thermal (PV/T) collector. Renewable Energy 2020, 167, 884 -898.

AMA Style

Mingke Hu, Chao Guo, Bin Zhao, Xianze Ao, Suhendri, Jingyu Cao, Qiliang Wang, Saffa Riffat, Yuehong Su, Gang Pei. A parametric study on the performance characteristics of an evacuated flat-plate photovoltaic/thermal (PV/T) collector. Renewable Energy. 2020; 167 ():884-898.

Chicago/Turabian Style

Mingke Hu; Chao Guo; Bin Zhao; Xianze Ao; Suhendri; Jingyu Cao; Qiliang Wang; Saffa Riffat; Yuehong Su; Gang Pei. 2020. "A parametric study on the performance characteristics of an evacuated flat-plate photovoltaic/thermal (PV/T) collector." Renewable Energy 167, no. : 884-898.

Review
Published: 26 November 2020 in Buildings
Reads 0
Downloads 0

Radiative cooling (RC) is attracting more interest from building engineers and architects. Using the sky as the heat sink, a radiative cooling material can be passively cooled by emitting heat to the sky. As a result of the development of material technology, RC research has been revived, with the aim of increasing the materials’ cooling power as well as finding reliable ways to utilize it in cooling for buildings. This review identifies some issues in the current implementation of RC technologies in buildings from an architectural point of view. Besides the technical performance of the RC technologies, some architectural aspects, such as integration with architectural features, aesthetic requirements, as well as fully passive implementations of RC, also need to be considered for building application. In addition, performance evaluation of a building-integrated RC system should begin to account for its benefit to the occupant’s health and comfort alongside the technical performance. In conclusion, this review on RC implementation in buildings provides a meaningful discussion in regard to the direction of the research.

ACS Style

Suhendri; Mingke Hu; Yuehong Su; Jo Darkwa; Saffa Riffat. Implementation of Passive Radiative Cooling Technology in Buildings: A Review. Buildings 2020, 10, 215 .

AMA Style

Suhendri, Mingke Hu, Yuehong Su, Jo Darkwa, Saffa Riffat. Implementation of Passive Radiative Cooling Technology in Buildings: A Review. Buildings. 2020; 10 (12):215.

Chicago/Turabian Style

Suhendri; Mingke Hu; Yuehong Su; Jo Darkwa; Saffa Riffat. 2020. "Implementation of Passive Radiative Cooling Technology in Buildings: A Review." Buildings 10, no. 12: 215.

Journal article
Published: 11 November 2020 in Energy and Buildings
Reads 0
Downloads 0

Energy-saving potential in lighting is significant in office buildings due to their primary occupancy during the daytime. This potential can be realised with an advanced daylighting system being particularly able to deliver more uniform and steadier illumination. This paper presents prototyping and experimental validation of an automated louver with parametrically-angled reflective slats, in order to reflect sunlight to evenly distributed target positions on a ceiling. The illuminated ceiling acts as a source of diffuse light to the room. The physical rotation of the automated louver is controlled parametrically using Grasshopper software together with Arduino board, motors for the motion and illuminance sensors. Validation is an essential stage to ensure the performance of such systems. Two prototypes of the proposed system with different scales are presented, 1:20 and 1:1 scaled mock-ups. The monitoring results verify the principle and aim of the proposed design, i.e., more uniform and distributed daylight illumination, automation control method besides its practicality.

ACS Style

Ahmad Eltaweel; Yuehong Su; Mohamed Hafez; Waleed Eltaweel. An automated louver with innovative parametrically-angled reflective slats: Prototyping and validation via using parametric control in Grasshopper along with Arduino board. Energy and Buildings 2020, 231, 110614 .

AMA Style

Ahmad Eltaweel, Yuehong Su, Mohamed Hafez, Waleed Eltaweel. An automated louver with innovative parametrically-angled reflective slats: Prototyping and validation via using parametric control in Grasshopper along with Arduino board. Energy and Buildings. 2020; 231 ():110614.

Chicago/Turabian Style

Ahmad Eltaweel; Yuehong Su; Mohamed Hafez; Waleed Eltaweel. 2020. "An automated louver with innovative parametrically-angled reflective slats: Prototyping and validation via using parametric control in Grasshopper along with Arduino board." Energy and Buildings 231, no. : 110614.

Journal article
Published: 23 August 2020 in Journal of Cleaner Production
Reads 0
Downloads 0

The energy mix of developing countries is dominated by fossilized energy resources. As such technological improvements for cleaner power generation and better environmental performance are crucial. Power generation by coal also causes many environmental externalities, which requires more scientific analysis to develop appropriate cleaner production measures for ecological and energy conservations. A cleaner coal-fired power plant at Sahiwal, Pakistan has been recently installed and started electricity generation under a bilateral economic initiative known as the China-Pakistan Economic Corridor (CPEC) project. This study is aimed to analyse the life cycle impacts of process stages (material and coal transportation, and plant operations) of this coal-fired power plant. Functional unit of 1 MWh of electricity generated has been selected to depict the results, which reveal highest impact score in the climate change potential category (7.41E+02 kg CO2 eq.) whereas, least impact was noted in stratospheric ozone depletion category of (8.27E-08kg CFC11 eq.) The operational stage of the plant has been a major impact contributor in all the selected midpoint categories except for human toxicity potential. Overall, this power plant is effectively reducing its eco-footprints because of cleaner supercritical power generation technology, high thermal efficiency, lesser CO2 emissions and modern pollution monitoring and management system. Real-time scientific cleaner energy-management as presented in this study can help in the development of optimal policy framework to steer cleaner coal power generation in developing countries for a greater energy sustainability.

ACS Style

Rizwan Rasheed; Hajra Javed; Asfra Rizwan; Faiza Sharif; Abdullah Yasar; Amtul Bari Tabinda; Sajid Rashid Ahmad; Yubo Wang; Yuehong Su. Life cycle assessment of a cleaner supercritical coal-fired power plant. Journal of Cleaner Production 2020, 279, 123869 .

AMA Style

Rizwan Rasheed, Hajra Javed, Asfra Rizwan, Faiza Sharif, Abdullah Yasar, Amtul Bari Tabinda, Sajid Rashid Ahmad, Yubo Wang, Yuehong Su. Life cycle assessment of a cleaner supercritical coal-fired power plant. Journal of Cleaner Production. 2020; 279 ():123869.

Chicago/Turabian Style

Rizwan Rasheed; Hajra Javed; Asfra Rizwan; Faiza Sharif; Abdullah Yasar; Amtul Bari Tabinda; Sajid Rashid Ahmad; Yubo Wang; Yuehong Su. 2020. "Life cycle assessment of a cleaner supercritical coal-fired power plant." Journal of Cleaner Production 279, no. : 123869.

Journal article
Published: 18 August 2020 in International Journal of Thermal Sciences
Reads 0
Downloads 0

The present study on vertical two-phase closed thermosyphon (TPCT) is aimed to determine the suitable volume-filling ratio, as a function of geometries, heat flux and vapor temperature, in order to avoid the potential local dryout in the evaporator section and hence to maximize the performance. In the study, the droplet entrainment, which is caused by the internal counter flow during the nucleate boiling within the falling liquid film in the evaporator section, is introduced to improve the existing TPCT model, so a comprehensive model with considering all three heat transfer regimes in the evaporator is further established. The suggested lower and upper limits of volume-filling ratio (CFR and EFR) are then determined by utilizing the criterias for local dryout, flooding limit and boiling limit. Furthermore, the effects of geometries, heat flux and vapor temperature on the range of volume-filling ratio are analyzed in details, a simplified correlation of CFR is then proposed based on the numerical modeling results. Particularly, the predictions of the distribution of falling film thickness and onset of flooding are validated with the published experimental data and other numerical simulation results. It is also found that the droplet entrainment significantly influences the thickness and distribution of the falling film. Increasing vapor temperature and inner diameter and decreasing the evaporator length significantly enlarge the volume-filling ratio range (between CFR and EFR), operation envelope (corresponding to boiling limit and flooding limit) of TPCT. Increasing the condenser length increases the volume-filling ratio range and operation envelope to a small extent. The influence mechanisms of the optimum filling ratio by the heat flux and geometries are complicated; however, a correlation of CFR can be obtained in a good agreement with the numerical modeling results within ±30% deviation for the whole limited scope.

ACS Style

T. Zhang; Z.W. Yan; L.Y. Wang; W.J. Zheng; Y.H. Su; R.C. Zheng. Droplet entrainment within the evaporator to the suitable volume-filling ratio of a vertical two-phase closed thermosyphon. International Journal of Thermal Sciences 2020, 159, 106576 .

AMA Style

T. Zhang, Z.W. Yan, L.Y. Wang, W.J. Zheng, Y.H. Su, R.C. Zheng. Droplet entrainment within the evaporator to the suitable volume-filling ratio of a vertical two-phase closed thermosyphon. International Journal of Thermal Sciences. 2020; 159 ():106576.

Chicago/Turabian Style

T. Zhang; Z.W. Yan; L.Y. Wang; W.J. Zheng; Y.H. Su; R.C. Zheng. 2020. "Droplet entrainment within the evaporator to the suitable volume-filling ratio of a vertical two-phase closed thermosyphon." International Journal of Thermal Sciences 159, no. : 106576.

Journal article
Published: 03 August 2020 in Applied Energy
Reads 0
Downloads 0

Radiative cooling (RC) sees great developments in recent years due to its unique feature of sending waste heat to the cold universe without any additional energy consumption, which is extensively proved in many application scenarios, including its integration into solar installations. The comprehensive solar photovoltaic/thermal (PV/T) technology is becoming popular due to its multi-function and high overall efficiency. The integration of RC into a PV/T collector can further contribute to such merits by adding a night sky cooling function, so a PV/T-RC collector can produce electricity and heat during the daytime and provide cooling energy during the nighttime. Without any structural modification, a flat-plate PV/T collector with a typical glass cover is confirmed to be able to realize a good radiative cooling in the present study. A mathematic model for the nighttime performance evaluation of a typical PV/T module was developed to characterize the nocturnal cooling capacity of the module. Results suggest that the absorber plate can be cooled to nearly 9.5 °C below the ambient air over a consecutive five hours nighttime period. Further parametric studies were carried out to investigate the effect of some key structural and environmental parameters on the radiative cooling performance of the PV/T module. Under some favorable radiative cooling conditions, the absorber plate can realize a stagnation temperature of nearly 11 °C lower than the ambient temperature and reach a maximum cooling power of over 50 W/m2.

ACS Style

Mingke Hu; Bin Zhao; Xianze Ao; Suhendri; Jingyu Cao; Qiliang Wang; Saffa Riffat; Yuehong Su; Gang Pei. An analytical study of the nocturnal radiative cooling potential of typical photovoltaic/thermal module. Applied Energy 2020, 277, 115625 .

AMA Style

Mingke Hu, Bin Zhao, Xianze Ao, Suhendri, Jingyu Cao, Qiliang Wang, Saffa Riffat, Yuehong Su, Gang Pei. An analytical study of the nocturnal radiative cooling potential of typical photovoltaic/thermal module. Applied Energy. 2020; 277 ():115625.

Chicago/Turabian Style

Mingke Hu; Bin Zhao; Xianze Ao; Suhendri; Jingyu Cao; Qiliang Wang; Saffa Riffat; Yuehong Su; Gang Pei. 2020. "An analytical study of the nocturnal radiative cooling potential of typical photovoltaic/thermal module." Applied Energy 277, no. : 115625.

Journal article
Published: 06 July 2020 in Energy and Built Environment
Reads 0
Downloads 0

Radiative cooling (RC) shows good potential for building energy saving by throwing waste heat to the cosmos in a passive and sustainable manner. However, most available radiative coolers suffer from low cooling flux. The situation becomes even deteriorated in the daytime when radiative coolers are exposed to direct sunlight. To tackle this challenge, an idea of employing both a spectrally selective cover and a spectrally selective emitter is proposed in this study as an alternative approach. A comparative study is conducted among four RC modules with different spectral characteristics for the demonstration of how the spectral profiles of the cover and the emitter affects the RC performance. The results under given conditions show that the RC module with a spectrally selective cover and a spectrally selective emitter (SC/SE) reaches a net RC power of 62.4 W/m2 when the solar radiation is 800 W/m2, which is about 1.8 times that of the typical RC module with a spectrally non-selective cover and a spectrally selective emitter (n-SC/SE). When the ambient temperature is 30 °C, the SC/SE based RC module realizes a daytime sub-ambient temperature reduction of 20.0 °C, standing for a further temperature decrement of 9.2 °C compared to the n-SC/SE based RC module.

ACS Style

Mingke Hu; Suhendri; Bin Zhao; Xianze Ao; Jingyu Cao; Qiliang Wang; Saffa Riffat; Yuehong Su; Gang Pei. Effect of the spectrally selective features of the cover and emitter combination on radiative cooling performance. Energy and Built Environment 2020, 2, 251 -259.

AMA Style

Mingke Hu, Suhendri, Bin Zhao, Xianze Ao, Jingyu Cao, Qiliang Wang, Saffa Riffat, Yuehong Su, Gang Pei. Effect of the spectrally selective features of the cover and emitter combination on radiative cooling performance. Energy and Built Environment. 2020; 2 (3):251-259.

Chicago/Turabian Style

Mingke Hu; Suhendri; Bin Zhao; Xianze Ao; Jingyu Cao; Qiliang Wang; Saffa Riffat; Yuehong Su; Gang Pei. 2020. "Effect of the spectrally selective features of the cover and emitter combination on radiative cooling performance." Energy and Built Environment 2, no. 3: 251-259.

Journal article
Published: 22 June 2020 in Solar Energy
Reads 0
Downloads 0

Advanced daylighting systems have become commonly used in modern architecture for a more sustainable environment. The mainstream of recent daylighting studies focuses not only on the quantity but also the quality of daylight delivered to an interior space. The more uniform daylight is distributed in the required illuminance range, the more light stability is achieved, and the longer time is illuminated by daylight, the more electrical lighting energy can be potentially saved. This study proposes an advanced daylighting design based on a parametrically controlled louver with reflective slats to redirect sunlight onto a ceiling, which can then serve as a source of diffuse light to illuminate a room. The design aims to achieve steadier and more uniform daylight distribution during the working hours in a deep-plan office room. The angle of each slat of the louver is parametrically controlled to target a corresponding area on the ceiling. In order to achieve a steadier daylighting, a bi-axis design and a two-layer design with a shifted target are evaluated and compared with a one-axis design. A daylighting analysis of the proposed design is exemplified for a south-oriented 8 m deep office room in a hot arid territory. The daylight analysis was performed using Grasshopper software as a parametric tool to link with Radiance and DAYSIM daylighting analysis. The proposed design shows promising merit that it can provide a relatively steady and distributed daylight coverage for more than 90% of the floor area within the recommended acceptable range 300–500 lx during the working hours.

ACS Style

Ahmad Eltaweel; Yuehong Su; Qinghua Lv; Hui Lv. Advanced parametric louver systems with bi-axis and two-layer designs for an extensive daylighting coverage in a deep-plan office room. Solar Energy 2020, 206, 596 -613.

AMA Style

Ahmad Eltaweel, Yuehong Su, Qinghua Lv, Hui Lv. Advanced parametric louver systems with bi-axis and two-layer designs for an extensive daylighting coverage in a deep-plan office room. Solar Energy. 2020; 206 ():596-613.

Chicago/Turabian Style

Ahmad Eltaweel; Yuehong Su; Qinghua Lv; Hui Lv. 2020. "Advanced parametric louver systems with bi-axis and two-layer designs for an extensive daylighting coverage in a deep-plan office room." Solar Energy 206, no. : 596-613.

Journal article
Published: 20 June 2020 in Applied Sciences
Reads 0
Downloads 0

The efficiency improvement of household refrigerators is of significance to electricity consumption reduction of residential buildings. The cold loss recovery in household refrigerators is a promising development direction. In this study, a refrigerator improved by heat pipes is designed to reduce the cold loss at freezer walls to enhance the overall efficiency of the refrigerator. A complete steady-state mathematical model is built for characterizing its overall energy saving behaviors by introducing the real structural parameters of a Midea BCD-111 refrigerator and measured temperature boundary conditions. The performances of the improved refrigerator are investigated with typical operating states, variable ambient temperature, and heat pipe design. The simulative results indicate that the cold loss of the freezer of the improved refrigerator can be reduced by 8.3–16.5%, and the energy saving capability is relatively reliable. Results verify that the cold loss recovery of the improved refrigerator is feasible in various operating conditions.

ACS Style

Jingyu Cao; Qiliang Wang; Mingke Hu; Xiao Ren; Weixin Liu; Yuehong Su; Gang Pei. Investigation on an Improved Household Refrigerator for Energy Saving of Residential Buildings. Applied Sciences 2020, 10, 4246 .

AMA Style

Jingyu Cao, Qiliang Wang, Mingke Hu, Xiao Ren, Weixin Liu, Yuehong Su, Gang Pei. Investigation on an Improved Household Refrigerator for Energy Saving of Residential Buildings. Applied Sciences. 2020; 10 (12):4246.

Chicago/Turabian Style

Jingyu Cao; Qiliang Wang; Mingke Hu; Xiao Ren; Weixin Liu; Yuehong Su; Gang Pei. 2020. "Investigation on an Improved Household Refrigerator for Energy Saving of Residential Buildings." Applied Sciences 10, no. 12: 4246.

Journal article
Published: 14 May 2020 in Energy
Reads 0
Downloads 0

Solar-driven organic Rankine cycle (s-ORC) power generation is a promising technology with thermal storage for flexible operation to meet domestic variable electricity demand. A satisfactory efficiency of this technology can be obtained only at medium-to-high temperature, for which conventional flat plate and evacuated tube solar collectors are not suitable while solar concentrators cannot efficiently utilize diffuse solar radiation. Evacuated flat plate (EFP) collectors have recently been developed for efficient solar heat collection in the temperature range from 100 to 200°C, suitable for the ORC system. At present, the cost of EFP collectors is relatively high and will lead to a long payback period of the s-ORC system. To increase the annual power yield and reduce the payback time, inexpensive amorphous silicon (a-Si) solar cells are proposed to be integrated into the EFP collectors. It is the first time to put forward such photovoltaics/thermal (PV/T) design combining a-Si cells and EFP collectors. Compared with polycrystalline silicon cells (poly-Si), a-Si cells may have a higher electrical efficiency at a higher operating temperature due to the thermal annealing effect and are expected to have a long lifetime without encapsulation in the vacuum environment provided by the EFP collectors. In this study, the a-Si PV/T-ORC system using EFP collectors is investigated. Transient performance analysis of a-Si PV/T-ORC is given for the weather data of two selected days. A comparison is also made with a stand-alone poly-Si PV system, poly-Si PV/T-ORC system and s-ORC system with EFP collectors alone, respectively. The results indicate that for a typical day in July, the a-Si PV/T-ORC system has the highest daily power output of 0.822 kWh/m2, 102.3% more than the s-ORC system, 23.8% more than the stand-alone poly-Si PV system and 12% more than the poly-Si PV/T-ORC system, respectively.

ACS Style

Cagri Kutlu; Jing Li; Yuehong Su; Yubo Wang; Gang Pei; Saffa Riffat. Investigation of an innovative PV/T-ORC system using amorphous silicon cells and evacuated flat plate solar collectors. Energy 2020, 203, 117873 .

AMA Style

Cagri Kutlu, Jing Li, Yuehong Su, Yubo Wang, Gang Pei, Saffa Riffat. Investigation of an innovative PV/T-ORC system using amorphous silicon cells and evacuated flat plate solar collectors. Energy. 2020; 203 ():117873.

Chicago/Turabian Style

Cagri Kutlu; Jing Li; Yuehong Su; Yubo Wang; Gang Pei; Saffa Riffat. 2020. "Investigation of an innovative PV/T-ORC system using amorphous silicon cells and evacuated flat plate solar collectors." Energy 203, no. : 117873.

Journal article
Published: 29 April 2020 in Energy
Reads 0
Downloads 0

This study presents a scroll expander modelling methodology for small scale power generation systems by combining scroll geometry and semi-empirical model. Although the semi-empirical model is quite popular, its dependence on several experimentally-determined scroll geometrical and operational parameters makes this approach inflexible for different capacities and operating conditions. Some studies have sought to improve its flexibility in terms of using different working fluids and more accurate empirical parameters, however, those improved models still depend on a considerable number of experimentally-obtained scroll parameters. Therefore, in this study, a practical methodology for a simpler semi-empirical model combined with the operational flexibility of the scroll geometry is presented. Firstly, the flow rates of mainstream and leakage flows are analysed, where a correlation between scroll clearance and pressure ratio is determined. Secondly, a simpler approach to the semi-empirical model of scroll expander is proposed, whereby dependent parameters have been reduced to two parameters by using scroll geometrical calculations. The model is further improved to predict the rotational speed and electricity output by considering the overall friction coefficient of the coupled expander-generator unit. The findings are then compared with the results of an experimental study. The results show that the effective clearance values between scrolls vary according to pressure ratios, increasing from 20μm to 34μm. Mass flow rate can be predicted within 10% deviation from the experimental results for the same inlet conditions and rotational speed at a transient state. Additionally, considering steady state conditions, modelling results show that the rotational speed and electricity output can also be predicted within 8% and 7.5% of deviation, respectively.

ACS Style

Cagri Kutlu; Mehmet Tahir Erdinc; Jing Li; Yuehong Su; Gang Pei; Guangtao Gao; Saffa Riffat. Evaluate the validity of the empirical correlations of clearance and friction coefficients to improve a scroll expander semi-empirical model. Energy 2020, 202, 117723 .

AMA Style

Cagri Kutlu, Mehmet Tahir Erdinc, Jing Li, Yuehong Su, Gang Pei, Guangtao Gao, Saffa Riffat. Evaluate the validity of the empirical correlations of clearance and friction coefficients to improve a scroll expander semi-empirical model. Energy. 2020; 202 ():117723.

Chicago/Turabian Style

Cagri Kutlu; Mehmet Tahir Erdinc; Jing Li; Yuehong Su; Gang Pei; Guangtao Gao; Saffa Riffat. 2020. "Evaluate the validity of the empirical correlations of clearance and friction coefficients to improve a scroll expander semi-empirical model." Energy 202, no. : 117723.

Journal article
Published: 03 April 2020 in Journal of Daylighting
Reads 0
Downloads 0

Louvre is a common type of shading devices and has been increasingly used in office buildings. Meanwhile, some reflective types of louvre have been used to provide shade and to redirect daylight deep into buildings interior simultaneously. Furthermore, daylighting systems have been recently engaged with automation control to improve their performance and increase their accuracy. Accordingly, automation of a louvre can optimise daylighting performance, maximising visual comfort, and lighting energy saving. In order to maximise the benefits of daylight, these shading devices should be controlled efficiently using advanced control methods. On the other hand, one of the significant application in daylighting systems is the prismatic panel, which was used in several buildings to improve daylighting due to its easy installation, which also based on redirecting the light into the interior of the buildings, besides its reflective and refractive characteristic. This article presents a feasibility study on the combination of two advanced daylighting designs, i.e., prismatic panel and automated louvre, aiming to achieve simultaneous shading and redirecting daylight for better daylight distribution. In the proposed design, the louvre is comprised of prismatic slats, i.e., prismatic panel as slat. The prismatic louvre is implemented virtually based on an algorithmic system using parametric software Grasshopper, in order to control the automation process parametrically as a first step, and then the daylighting performance is simulated using Radiance as a plug-in to Grasshopper. The optical characteristics of the prismatic slats in an automated louvre is investigated. A comparison has been made in simulation between a prismatic panel and the automated louvres with reflective slats and prismatic slats, respectively, to evaluate their daylighting performance in a south-orientated virtual room in New Cairo. The simulation results are given for the conditions of clear sky on the 21st of June, 21st of September, and 21st of December. Header of solarlits.com

ACS Style

Ahmad Eltaweel; Mohamed Alaa Mandour; Qinghua Lv; Yuehong Su. Daylight Distribution Improvement Using Automated Prismatic Louvre. Journal of Daylighting 2020, 7, 84 -92.

AMA Style

Ahmad Eltaweel, Mohamed Alaa Mandour, Qinghua Lv, Yuehong Su. Daylight Distribution Improvement Using Automated Prismatic Louvre. Journal of Daylighting. 2020; 7 (1):84-92.

Chicago/Turabian Style

Ahmad Eltaweel; Mohamed Alaa Mandour; Qinghua Lv; Yuehong Su. 2020. "Daylight Distribution Improvement Using Automated Prismatic Louvre." Journal of Daylighting 7, no. 1: 84-92.

Journal article
Published: 21 January 2020 in Renewable Energy
Reads 0
Downloads 0

Domestic hot water (DHW) has a significant share in building’s energy consumption. In order to reduce this consumption, various solutions have been proposed such as controlling the system in an efficient way, using renewable sources and using phase change materials (PCM) in the system to increase heat capacity. However, this study is not only offering heat capacity improvement of the DHW storage unit but also proposing that energy efficiency can be improved by controlling the heat releasing time of the PCM. In this study, supercooled PCM tubes are placed in a water tank and charged with a solar assisted heat pump unit, these supercooled PCM tubes can then be discharged anytime when the hot water is required. In this paper, a transient thermodynamic model is built for the whole system including solar collector, heat pump, water tank with PCM and DHW demand profile. System components are modelled and a 24 h of demand profile is used in simulation for a UK home for summer and spring weather conditions. The results show that the PCM tubes effectively compensate the morning peak hot water demand and reduce daily energy consumption around 12.1% and 13.5% by shifting heating provision from immersion heater to solar heat pump.

ACS Style

Cagri Kutlu; Yanan Zhang; Theo Elmer; Yuehong Su; Saffa Riffat. A simulation study on performance improvement of solar assisted heat pump hot water system by novel controllable crystallization of supercooled PCMs. Renewable Energy 2020, 152, 601 -612.

AMA Style

Cagri Kutlu, Yanan Zhang, Theo Elmer, Yuehong Su, Saffa Riffat. A simulation study on performance improvement of solar assisted heat pump hot water system by novel controllable crystallization of supercooled PCMs. Renewable Energy. 2020; 152 ():601-612.

Chicago/Turabian Style

Cagri Kutlu; Yanan Zhang; Theo Elmer; Yuehong Su; Saffa Riffat. 2020. "A simulation study on performance improvement of solar assisted heat pump hot water system by novel controllable crystallization of supercooled PCMs." Renewable Energy 152, no. : 601-612.

Journal article
Published: 18 January 2020 in Solar Energy
Reads 0
Downloads 0

Loop thermosyphon (LT) is usually introduced to overcome the freezing and corrosion problems associated with the conventional solar water heating (SWH) system. Compared with the conventional SWH system, the LT-SWH system possesses a lower nighttime heat loss because of the thermal diode property of loop thermpsyphon but bigger daytime heat loss because of the secondary heat exchange. However, the effect of above interaction to the system performance is rarely reported based on long-term running. In this study, based on the typical meteorological year data of Fuzhou city, annual performances of above two systems, including the effective number of supplying days, effective heat gain and nighttime heat loss, are comparatively analyzed under two different operational modes. Variations of above mentioned variables with the increment in the set temperature are discussed. The results indicate that, under the discontinuous heating mode, the effective numbers of supplying days of SWH system and LT-SWH system are 139 and 153, respectively. While the numbers of days are respectively 168 and 173 under the continuous heating mode. The SWH system possesses an expected bigger nighttime heat loss ratio with an average annual value of 15.07% corresponding to 6.15% for the LT-SWH system. Particularly, for the LT-SWH system, the different relative magnitudes of heat loss coefficients functioning at different times leads to a smaller temperature drop at night and also a smaller temperature rise at the subsequent day. It generates an unanticipated results that corresponds to the same month from November to April, the two systems have the approximate effective heat gain. The set temperature significantly influences the relative magnitudes of annual effective number of supplying days and annual effective heat gain, the superiority of LT-SWH system gradually diminishes and even reverses with the increment in the set temperature. The bigger daytime heat loss dominating the dominance is responsible for that transition. Combining with a longer static payback period, it is conditional to substitute the conventional SWH system with the LT-SWH system, especially when the water temperature on demand is high.

ACS Style

T. Zhang; Z.W. Yan; L.Y. Wang; W.J. Zheng; Y.H. Su. Comparative study on the annual performance between loop thermosyphon solar water heating system and conventional solar water heating system. Solar Energy 2020, 197, 433 -442.

AMA Style

T. Zhang, Z.W. Yan, L.Y. Wang, W.J. Zheng, Y.H. Su. Comparative study on the annual performance between loop thermosyphon solar water heating system and conventional solar water heating system. Solar Energy. 2020; 197 ():433-442.

Chicago/Turabian Style

T. Zhang; Z.W. Yan; L.Y. Wang; W.J. Zheng; Y.H. Su. 2020. "Comparative study on the annual performance between loop thermosyphon solar water heating system and conventional solar water heating system." Solar Energy 197, no. : 433-442.