Design and simulation of a prototype of a small-scale solar CHP system based on evacuated flat-plate solar collectors and Organic Rankine Cycle

Calise, Francesco; d’Accadia, Massimo Dentice; Vicidomini, Maria; Scarpellino, Marco

doi:10.1016/j.enconman.2014.11.014

Cited by 145 publications

(50 citation statements)

References 32 publications

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“…The detailed description of such components models is reported in the reference of TRNSYS software [25]. The model of the evacuated flat-plate collectors is reported in reference [27]. The parameters used for the simulation of the solar collectors are reported in Table 3.…”

Section: Methodsmentioning

confidence: 99%

Energy and Economic Analysis of Energy Savings Measures in a Swimming Pool Centre by Means of Dynamic Simulations

2018

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Sport centres thermal demand is extremely high due to the large amount of sanitary hot water production. Therefore, energy savings actions must be performed in order to optimize system efficiency. In this framework, the present paper investigates the possibility to perform an energy rehabilitation of an indoor swimming pool centre by means of solar thermal collectors and heat pump technologies integrated with the existing plant. The case study consists of a university indoor swimming pool centre located in Naples, South of Italy. A dynamic simulation model is developed by TRNSYS software (Thermal Energy System Specialists, LLC, Madison, WI, USA). An experimental investigation is also performed in order to calibrate the swimming pool thermal model and the space conditioning equipment operation. Real data concerning the thermal demand of the centre are implemented and the dynamic behaviour of the swimming pool occupants is also considered. The proposed technical solutions are analysed from an energy and economic point of view. A parametric analysis aiming at determining the effect of the size of the solar field on the system performance is performed. The comparison outlines that the best energy and economic performance is achieved by evacuated solar thermal collectors. In particular, the Simple Pay Back (SPB) period results about 14 years without incentives and it decreases to 5 years considering the Italian incentive policy. For an evacuated collector field of 150 m 2 , the SPB without incentive results below 9 years.

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Section: Methodsmentioning

confidence: 99%

Energy and Economic Analysis of Energy Savings Measures in a Swimming Pool Centre by Means of Dynamic Simulations

2018

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“…Then, the code evaluated the mechanical work of the expander according to its operating case (under or over expansion) by using Eq. (11)(12). Post expander, the amount of the rejected heat and the consumed pump work was determined by using Eq.…”

Section: Simulation Proceduresmentioning

confidence: 99%

“…They reported that the solar collector generated heat with temperature of 165 ºC and the cycle efficiency was 25%. In order to address the variability nature of solar energy sensible heat storage (SHS) system has been used in solar ORCs [12]. For instance, a dynamic simulation study of flat-plate collectors based solar ORC system using an oil storage tank was conducted by [12].…”

Section: Introductionmentioning

confidence: 99%

A Theoretical and Experimental Study of HFE-7000 in a Small Scale Solar Organic Rankine Cycle As a Thermofluid

Helvaci

Khan

2017

Volume 2: I&C, Digital Controls, and Influence of Human Factors; Plant Construction Issues and Supply Chain Management; Pla

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Renewable energy technologies and sources have been playing a key role in reducing reliance on fossil fuels and significantly reducing CO 2 emissions and its footprint. EU initiative of generating 50% of the energy needs through sustainable sources by 2050 needs a direct response in terms of providing applied solutions to realize this target on time. Solar energy is one of the major and abundantly renewable energy sources which are free and clean. Solar energy can be utilized by means of solar Photovoltaic (PV) or solar collectors. Concentrating solar collectors supply thermal energy from medium to high grade where as non-concentrating collectors (flat plate) delivers low-grade thermal energy. The use of thermofluids with boiling temperatures lower than the water, allows the operation of low grade solar thermal systems on an Organic Rankine Cycle (ORC) to generate both mechanical and heat energy. At the same time, the selection of appropriate thermofluid is an important process and has a significant effect both on the system performance and the environment. Conventional thermofluids such as Chlorofluorocarbons (CFCs) and Hydrochlorofluorocarbons (HCFCs) have high ozone depletion (ODP) and high global warming (GWP) potential. It is therefore important to investigate novel and environmentally friendly thermofluids to address environmental impacts as global warming and ozone layer depletion. Hydrofluoroethers (HFEs) are non-ozone depleting substances and they have relatively low GWP. Therefore, HFEs can be used as a replacement for CFCs and HCFCs. In this study, a solar ORC is designed and commissioned to use HFE 7000 as a thermofluid. The proposed system consists of a flat-plate solar collector, a vane expander, a condenser and a pump where the collector and the expander are used as the heat source and prime mover of the cycle respectively. The performance of the system is determined through energy analysis. Then, a mathematical model of the cycle is developed to perform the simulations using HFE-7000 at various expander pressure. Experimental data indicated that the efficiency and the net mechanical work output of the cycle was found to be 3.81% and 135.96 W respectively. The simulation results showed that increasing the pressure ratio of the cycle decreased the amount of the heat that is transferred to HFE 7000 in the collector due to the increased heat loss from the collector to the environment. Furthermore, net output of the system followed a linear augmentation as the pressure ratio of the system increased. In conclusion, both the experimental and theoretical research indicates that HFE 7000 offers a viable alternative to be used efficiently in small scale solar ORCs to generate mechanical and heat energy.

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“…0 前言* 有机朗肯循环(Organic Rankine cycle，ORC)系统一直以来都被用于中低温热能的回收与利用中，在太阳能、地热能、生物质能、海洋能和工业余热方面有广泛利用 [1] 。CALISE 等 [2] 讨论了小型太阳能驱动的 ORC 热发电系统的应用。YU 等 [3] 仿真研究了采用内燃机余热驱动的 ORC 系统的性能。WEI * 天津市科技支撑计划资助项目(15ZCZDGX01030)。 20160902 收到初稿， 20170509 收到修改稿等 [4] 研究了用于余热回收的 ORC 系统在入口热源温度波动情况下的性能表现。在 ORC 系统的应用过程中，热源不稳定、系统启停以及动态控制等瞬态系统特性 [5] ，使 ORC 系统的动态性能研究受到研究学者的广泛关注，以期对系统控制策略的制定提供参考，并指导系统设计与试验研究。热力系统稳态模型主要适用于研究 ORC 系统的系统配置、性能评估或循环优化 [5] 。为研究系统在动态运行条件下的循环特性，需要建立 ORC 循环的动态模型。文献调研结果显示，ORC 系统模型由换热器、泵和汽轮机的各子模型耦合形成；并且，由于泵与汽轮机在动态变化过程中时间常数小，可将其考虑成稳态模型，从而整个系统的动态特性研究主要针对换热器的动态特性进行。在 20 世纪 90 年代末，HE 等 [6] 和 WILLATZEN 等 [7] 各自分别讨论如何用移动边界法构建存在两相区的换热器模型，丹麦科技大学的 JENSEN [8] …”

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Dynamic Simulation of an Organic Rankine Cycle System

Ni¹

2017

JME

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Abstract：The existing dynamic model of the organic Rankine cycle(ORC) system is based on the distributed parameter model or the moving boundary model of heat exchanger, which results in a low calculation speed. A new method has been proposed to analyse the dynamic model of heat exchanger. The model is described by four parameters, reducing the number of the equations to improve the calculation speed. Then on this basis, the model is used to study the dynamic performances of various heat exchangers with different heat transfer capacity as well as different volumes within the exchanger. It indicates that the dynamic of the one with the better heat transfer capacity and the less volume is faster. What's more, a dynamic model of ORC has been established with the new model of heat exchanger on the platform software Matlab/Simulink, and validated by the experiment data. The two results coincide well with each other. At last, enthalpy fluctuation at the evaporator outlet caused by the inlet temperature of heat source has been discussed. It reveals that it's effective to stabilize the enthalpy with an earlier control, while it's less meaningful to take a control after a certain amount of time. The results can provide reference for the control strategy. Key words：organic

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Design and simulation of a prototype of a small-scale solar CHP system based on evacuated flat-plate solar collectors and Organic Rankine Cycle

Cited by 145 publications

References 32 publications

Energy and Economic Analysis of Energy Savings Measures in a Swimming Pool Centre by Means of Dynamic Simulations

Energy and Economic Analysis of Energy Savings Measures in a Swimming Pool Centre by Means of Dynamic Simulations

A Theoretical and Experimental Study of HFE-7000 in a Small Scale Solar Organic Rankine Cycle As a Thermofluid

Dynamic Simulation of an Organic Rankine Cycle System

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