Dynamic modelling of solar storage system: a case study of leisure centre

2016 ◽  
Vol 5 (2) ◽  
pp. 165-175
Author(s):  
Seyed Masoud Sajjadian

Purpose – The purpose of this paper is to present the advantages of a solar store system with transpired solar air collector (TSC) in North Wales, UK. The collectors are designed as a proposal to meet the target of the solar air storage and heating project to improve the efficiency of solar collectors in the UK. Design/methodology/approach – IES software simulation is used to examine the potential of a solar store system in Deeside Leisure Centre compared to the traditional constant air volume (CAV) system and CAV system with heat pump. The design parameters and configurations are determined on the basis of the monitoring results gained from recent experiments. Findings – The result demonstrates good agreement between simulations and monitoring results and the solar store system demonstrates considerably lower energy consumption compared to the traditional CAV system with and without heat pump. Originality/value – The usage of TSC is proven to be useful in improving COP of the heat pumps and reducing overall energy consumption in a leisure center. The framework proposed in this study could also be applied to different building types in order to highlight their advantages.

2012 ◽  
Vol 9 (2) ◽  
pp. 65
Author(s):  
Alhassan Salami Tijani ◽  
Nazri Mohammed ◽  
Werner Witt

Industrial heat pumps are heat-recovery systems that allow the temperature ofwaste-heat stream to be increased to a higher, more efficient temperature. Consequently, heat pumps can improve energy efficiency in industrial processes as well as energy savings when conventional passive-heat recovery is not possible. In this paper, possible ways of saving energy in the chemical industry are considered, the objective is to reduce the primary energy (such as coal) consumption of power plant. Particularly the thermodynamic analyses ofintegrating backpressure turbine ofa power plant with distillation units have been considered. Some practical examples such as conventional distillation unit and heat pump are used as a means of reducing primary energy consumption with tangible indications of energy savings. The heat pump distillation is operated via electrical power from the power plant. The exergy efficiency ofthe primary fuel is calculated for different operating range ofthe heat pump distillation. This is then compared with a conventional distillation unit that depends on saturated steam from a power plant as the source of energy. The results obtained show that heat pump distillation is an economic way to save energy if the temperaturedifference between the overhead and the bottom is small. Based on the result, the energy saved by the application of a heat pump distillation is improved compared to conventional distillation unit.


HortScience ◽  
1994 ◽  
Vol 29 (4) ◽  
pp. 249a-249
Author(s):  
Eric A. Lavoie ◽  
Damien de Halleux ◽  
André Gosselin ◽  
Jean-Claude Dufour

The main objective of this research was to produce a simulated model that permitted the evaluation of operating costs of commercial greenhouse tomato growers with respect to heating methods (hot air, hot water, radiant and heat pumps) and the use of artificial lighting for 1991 and 1992. This research showed that the main factors that negatively influence profitability were energy consumption during cold periods and the price of tomatoes during the summer season. The conventional hot water system consumed less energy than the heat pump system and produced marketable fruit yields similar to those from the heat pump system. The hot water system was generally more profitable in regards to energy consumption and productivity. Moreover, investment costs were less; therefore, this system gives best overall financial savings. As for radiant and hot air systems, their overall financial status falls between that of the hot water system and the heat pump. The radiant system proved to be more energy efficient that the hot air system, but the latter produced a higher marketable fruit yield over the 2-year study.


Author(s):  
Oluwole K. Bowoto ◽  
Omonigho P. Emenuvwe ◽  
Meysam N. Azadani

AbstractThis study proposes a design model for conserving and utilizing energy affordably and intermittently considering the wind rush experienced in the patronage of renewable energy sources for cheaper generation of electricity and the solar energy potential especially in continents of Africa and Asia. Essentially, the global quest for sustainable development across every sector is on the rise; hence, the need for a sustainable method of extracting energy cheaply with less wastage and pollution is on the priority list. This research, integrates and formulates different ideologies, factors and variables that have been adopted in previous research studies to create an efficient system. Some of the aforementioned researches includes pumped hydro gravity storage system, Compressed air gravity storage system, suspended weight in abandoned mine shaft, dynamic modelling of gravity energy storage coupled with a PV energy plant and deep ocean gravity energy storage. As an alternative and a modification to these systems, this research is proposing a Combined solar and gravity energy storage system. The design synthesis and computational modelling of the proposed system model were investigated using a constant height and but varying mass. Efficiencies reaching up to 62% was achieved using the chosen design experimental parameters adopted in this work. However, this efficiency can be tremendously improved upon if the design parameters are modified putting certain key factors which are highlighted in the limitation aspect of this research into consideration. Also, it was observed that for a test load of 50 × 103 mA running for 10 h (3600 s), the proposed system will only need to provide a torque of 3.27Nm and a height range of 66.1 × 104 m when a mass of 10 kg is lifted to give out power of 48 kwh. Since gravity storage requires intermittent actions and structured motions, mathematical models were used to analyse the system performance characteristics amongst other important parameters using tools like MATLAB Simscape modelling toolbox, Microsoft excel and Sysml Model software.


2011 ◽  
Vol 347-353 ◽  
pp. 587-590
Author(s):  
Qing Hai Luo ◽  
Zheng Zuo

This paper analyzes the energy consumption of hot water supply in buildings and the insurmountable shortcoming of low energy efficiency of conventional water heaters, and investigates the progress and problems of developing heat pump water heaters. It is pointed out that developing of heat pump water heaters is one of the efficient approaches to improve the energy efficiency of hot water supply.


Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1885
Author(s):  
Sónia Ferreira ◽  
Sabine Sochard ◽  
Sylvain Serra ◽  
Frederic Marias ◽  
Jean-Michel Reneaume

An open system based on physical adsorption phenomena with humid air and zeolite 13X is herein discussed for residential heat storage purposes. A model has been developed to describe the conservation of mass and heat in the system. A simplified approach of a complete model describing both mass conservation in the macroporous and microporous domains is used based on the linear driving force (LDF) model. Local mass and heat transfer properties have been used. To describe the equilibrium, the Aranovich–Donohue isotherm model is selected. As an example, the developed model is compared and fitted to experimental data from a pilot scale system. A parametric study on operating and design parameters is given to understand their effect on the amount and/or duration of heat supply, concentration, and temperature profiles. The studied parameters are the inlet adsorbate concentration, fluid temperature, and velocity, as well as particle and zeolite crystal sizes. This analysis shows that an identification of values for the set of parameters tested can possibly suit the energy needs for a case study of domestic heat supply. Future work will focus on the optimization of these parameters.


2012 ◽  
Vol 9 (2) ◽  
pp. 65
Author(s):  
Alhassan Salami Tijani ◽  
Nazri Mohammed ◽  
Werner Witt

Industrial heat pumps are heat-recovery systems that allow the temperature of waste-heat stream to be increased to a higher, more efficient temperature. Consequently, heat pumps can improve energy efficiency in industrial processes as well as energy savings when conventional passive-heat recovery is not possible. In this paper, possible ways of saving energy in the chemical industry are considered, the objective is to reduce the primary energy (such as coal) consumption of power plant. Particularly the thermodynamic analyses of integrating backpressure turbine of a power plant with distillation units have been considered. Some practical examples such as conventional distillation unit and heat pump are used as a means of reducing primary energy consumption with tangible indications of energy savings. The heat pump distillation is operated via electrical power from the power plant. The exergy efficiency of the primary fuel is calculated for different operating range of the heat pump distillation. This is then compared with a conventional distillation unit that depends on saturated steam from a power plant as the source of energy. The results obtained show that heat pump distillation is an economic way to save energy if the temperature difference between the overhead and the bottom is small. Based on the result, the energy saved by the application of a heat pump distillation is improved compared to conventional distillation unit. 


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chengjun Rong ◽  
Huaqi Lian ◽  
Yulong Li

Purpose Oil-free heat pumps that use the system refrigerant gases as lubricants are preferred for thermal management in future space applications. This study aims to numerically and experimentally investigate the static performance of externally pressurized thrust bearings lubricated with refrigerant gases. Design/methodology/approach The refrigerant gases R22, R410A and CO2 were chosen as the research objects, while N2 was used for comparison. Computational fluid dynamics was used to solve the full 3 D Navier–Stokes equations to determine the load capacity, static stiffness and static pressure distribution in the bearing film. The numerical results were experimentally verified. Findings The results showed that the refrigerant-gas-lubricated thrust bearings had a lower load capacity than the N2-lubricated bearings, but they presented a higher static stiffness when the bearing clearance was less than 9 µm. Compared with the N2-lubricated bearings, the optimal static stiffness of the R22- and CO2-lubricated bearings increased by more than 46% and more than 21%, respectively. The numerical and experimental results indicate that a small bearing clearance would be preferable when designing externally pressurized gas thrust bearings lubricated with the working medium of heat pump systems for space applications. Originality/value The findings of this study can serve as a basis for the further investigation of refrigerant gases as lubricants in heat pump systems, as well as for the future design of such gas bearings in heat pump systems for space applications.


Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3391
Author(s):  
Roberto Bruno ◽  
Francesco Nicoletti ◽  
Giorgio Cuconati ◽  
Stefania Perrella ◽  
Daniela Cirone

The spread of near-Zero Energy Buildings (nZEB) involves the employment of high performant air-conditioning plants where renewable sources can be integrated easily. In this context, heat pumps appear as a promising solution given their ability to exploit aerothermal, hydrothermal and geothermal sources and to supply both heating and cooling loads with the same device. In order to evaluate the energy performances in transient conditions, the actual winter (COP) and summer (EER) performance indexes, in the function of the sources’ temperatures and the capacity ratio (CR), have to be available. Nevertheless, heat pump manufactures often provide the trend of the performance indexes in the function of the temperatures of the sources specifically for nominal conditions, whereas the dependence of the performance indexes in the function of CR, that takes into account the part-load operation, is almost always not provided. Alternatively, specific technical standards suggest the use of a correction factor to modify nominal COP and EER for the attainment of the real performance indexes. In this paper, by using data from an experimental set-up equipped with air-water heat pumps, these correlations were tested and tuned. Winter results showed that correction factors suggested by standards have to be modified in the presence of a storage system. In summer, instead, a new correlation was developed to find a function between nominal and actual EERs in the function of CR by exploiting a similar approach employed for the COP calculation.


1996 ◽  
Vol 118 (2) ◽  
pp. 89-96 ◽  
Author(s):  
M. Conti ◽  
C. Bellecci ◽  
Ch. Charach

This paper analyzes the irreversibilities due to the heat transfer processes in a latent heat thermal storage system. The Thermal Storage Module (TSM) consists of a cylindrical shell that surrounds an internal coaxial tube. The shell side is filled by a Phase Change Material (PCM); a fluid flows through the inner tube and exchanges heat along the way. The most fundamental assumption underlying this study is that the exergy of the hot fluid stream in the active phase is discharged into the environment and completely destroyed, unless it is partially intercepted by the storage system. A numerical study is conducted to identify and to minimize the thermodynamic losses of the storage and removal processes. The dependence of the second-law efficiency of the system on various design parameters is investigated and discussed.


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