用于集中太阳能的热能存储技术外文文献

Review Thermal energy storage technologies for concentrated solar power e A review from a materials perspective A Palacios a C Barrenechea b M E Navarroa Y Dinga aBirmingham Centre for Energy Storage School of Chemical Engineering University of Birmingham Birmingham B15 2TT United Kingdom bDepartment of Materials Science LF Linear Fresnel DP Dish Parabolic PTO Power Tower Corresponding author Birmingham Centre for Energy Storage School of Chemical Engineering University of Birmingham Birmingham B15 2TT United Kingdom Corresponding author E mail addresses c barreneche ub edu C Barreneche h navarro bham ac uk M E Navarro Contents lists available at ScienceDirect Renewable Energy journal homepage https doi org 10 1016 j renene 2019 10 127 0960 1481 Crown Copyright 2019 Published by Elsevier Ltd All rights reserved Renewable Energy xxx xxxx xxx Please cite this article as A Palacios et al Thermal energy storage technologies for concentrated solar power e A review from a materials perspective Renewable Energy https doi org 10 1016 j renene 2019 10 127 3 4 3 Nanofluids 00 3 5 Thermochemical 00 3 5 1 Storage technology 00 3 5 2 Advantages and disadvantages 00 3 5 3 Scientific contribution see Figs 8 9 and 10 00 3 5 4 Actual state and future trends 00 4 CSP configuration 00 4 1 Parabolic trough 00 4 2 Dish engine parabolic systems 00 4 3 Power tower central receiver 00 4 4 Linear Fresnel collectors LFC 00 5 CSP perspective 00 5 1 CSP configuration 00 5 2 Storage technology 00 5 2 1 Commercial technologies 00 5 2 2 Non commercial technologies 00 5 3 CSP location 00 5 4 CSP overview 00 Declaration of competing interest 00 Acknowledgements 00 References 00 1 Introduction Global warming is one of the greatest challenges that mankind is currently facing Given the scale of the problem major coordi nated efforts from academia industrialists politicians and policy makers have been oriented to tackle this problematic One of the cutting off measures triggered by this set of actions that has had global implications is the 2016 Paris Agreement 1 The Article 2 of the Agreement states the following a Holding the increase in the global average temperature to 700 C to increase the effi ciency of the plant and enable Brayton cycle High charging and discharging rates Low cost Good chemical compatibility with the system High energy and exergetic effi ciency 95 Large energy density MJ m3 Low cost Safety and environmental impact Fig 3 Publications patents and projects registered between 2002 and 2018 in the CSP sector The keywords use as search tools are the following concentrated solar power and thermal energy storage Fig 4 TES capacity vs Technology readiness level TRL outline A Palacios et al Renewable Energy xxx xxxx xxx5 Please cite this article as A Palacios et al Thermal energy storage technologies for concentrated solar power e A review from a materials perspective Renewable Energy https doi org 10 1016 j renene 2019 10 127 Thermal and chemical stability over thousands of cycles Given the number of requirements needed for a proper inte gration of the storage tank within the CSP plant there is a need for fi nding a compromise between practical working conditions and desired requirements stated in an ideal case In the last years sensible heat has stood as the best alternative becoming the preferred option as the highest storage installed capacity in CSP good examples of this are steam molten salts and packed bedrocks Even though the energy density is lower than the one for the other TES technologies it still accomplishes the compromise between cost and energy density at the current technological deployment level Under practical conditions researchers have not been able to deploy latent heat and thermochemical systems to make them economically profi table 9 Therefore the low cost of sensible systems and low complexity is crucial to understand their high CSP deployment in a short period of time So far commercial TES sys tems are mostly based on molten salts two tank type due to its low cost and acceptable energy density and operational temperature suitable for Rankine cycle However the energy density and the working temperature is desired to be higher to increase the effi ciency of the plant and its corrosive nature lead tosevere damage in the heat exchangers and pipes which after several cycles turns onto higher maintenance cost In this section an overview of the storage systems and media deployed demonstrated and or research for use in CSP plants is provided The eventual aim is to assess each technology s advan tages and disadvantages while linking the fundamental concept to its scientifi c contribution or commercial deployment The storage media are grouped according to the TES system following the traditional TES classifi cation as shown in Fig 5 In the following lines each technology will be assessed by describing the principles of the storage technology analysing the advantages and disadvantages and correlating them to the scien tifi c contribution and commercial deployment A brief description of the actual state and the future trends are also included in this section An EOA for each technology was assessed by using the Scopus database All relevant information such as publications year of publication country and type of publication was evaluated Table 1 The patents were also reviewed through Scopus and compared to the United States Patent and Trademark Offi ce for concision purposes A summary of the period of publication and the current TRL level is shown in Fig 6 where the TRL is related to the publication rate over the years from 2008 to 2018 The total number of pub lications for TES CSP issued in that period of time is also illustrated by a blue dotted line Sensible heat technologies are in light blue while thermochemical and latent heat are represented by dark blue and pink respectively Given the low deployment of latent heat and thermochemical heat technologies these are just represented as one group while sensible heat technologies are broken down to concrete molten salts steam packed bed nanofl uids liquid metals and particulate solids A signifi cant gap between commercial and non commercial technology can be seen While sensible storage technologies such as molten salts concrete steam and packed bed are fully commercial TRL 8e9 latent heat thermochemical and new generation HTFs nanofl uids particulate solids and liquid metals are still at a low TRL 3000500 to 10001e50020e35 3126 5Operational and under construction development Steam and molten salts1 5 to 17 5 A Palacios et al Renewable Energy xxx xxxx xxx17 Please cite this article as A Palacios et al Thermal energy storage technologies for concentrated solar power e A review from a materials perspective Renewable Energy https doi org 10 1016 j renene 2019 10 127 respectively and none of them had storage facility Regarding the operational plants they were built between 2009 and 2014 in Spain India and Italy see Fig 12 Only the two operational plants in Spain Puerto Errado thermosolar power plant have a storage unit based on the Ruth s tank 105 a steam storage accumulator with 0 5 h single thermocline storage tank 27 The currently largest operational Linear Fresnel array is in Dhusar India under operation since 2014 125 MW with no storage 27 LFR is the technology that is using different TES media despite steam is the most used one In that plants under development contract or construction the storage media will be steam molten salts or concrete see Fig 9 China is the only country supporting new generation storage media such as concrete the plants Zhangbei and Zhangjiakou CSG Fresnel with 50 MW capacity and 14h storage will be commissioned in 2020 27 Nevertheless other two plants with molten salt as storage media two tank indirect are under development in China both of them with a capacity of 50 MW Urat 50 MW Fresnel CSP project and Dacheng Dunhuang 50 MW Molten Salt Fresnel project 27 Morocco and France have commissioned three small size LFR plants with 1e9MW capacity two Morocco and one France using from 20 min to 4h storage steam s capacity The other project under construction in 2017 is in north of India 14 MW installed with no storage Dadri ISCC Plant 5 CSP perspective A thorough analysis of the actual situation on the CSP technol ogy portrait from several points of view is shown in this conclusive section The authors aim to interconnect and link all the informa tion gathered along this review to provide a future s perspective instead of a regular conclusion section to draw the pathways of CSP in the following years 5 1 CSP confi guration Parabolic trough Parabolic trough is a promising technology and one of the traditionally preferred confi gurations of CSP in the market This technology is the one that has more operational plants in the world 70 and under development or construction 19 than any other one The total capacity installed is 6178 MW more than half of it using a storage system based on molten salts and the rest with no storage system integrated in the facility The use of storage in this confi guration is widespread although it should be increased to allow this technology to participate in the power market base load to displace conventional fossil fuel power sources The storage capacity is currently limited to 8 h however in few years is ex pectedtoreachupto12 h decreasing its levelized costof electricity from 14 2 kWh in 2015 to 9 KWh in 2020 89 This tech nology is not just expected to decrease its storage cost but also to compete with the electricity produced from conventional natural gas fi red plants 106 Linear Fresnel collector This is the technology that has less operational plants in the world 4 out of 14 the rest are under development 3 and construction 6 The CSP capacity installed is around 373MW much lower than the other technologies The storage system used is steam accumulator 4 molten salt 2 and concrete 2 Even though Linear Fresnel cannot compete with Parabolic trough or Power tower in terms of operational tempera ture and capacity these plants are especially suited for small land installations and small units to supplement thermal power stations Collectors based on linear Fresnel could fi ll the gap between roof solar collectors and large scale installation for bulk electricity generation This technology offers a modular installation capacity that varies from KW to MW and the lowest land occupancy within the CSP confi gurations To fi nd its place in the industrial sector the storage needs to offer dispatchability at any time of the day Power tower Power tower has been tagged by media and re searchers as the future of solar thermal energy This technology has the potential to offer higher effi ciency and better energy storage capability than trough systems In 2020 there will be 35 plants using Power Tower technology in the world the second most deployed technology after Parabolic Trough The capacity installed is half the one for parabolic trough systems 3126 MW However this is the technology that will increase the most its capacity from 2018 to 2020 Molten salt is the most used system as the storage medium 24 plants out of 35 have storage facilities thus allowing to store up to 17 5 h Even though Power Tower appears to hold the best long term promise in terms of large power capacity and low costelectricitysupply therearestill many innovations to face in the future To keep up the role that it has been given Power Tower should increase the practical upper temperature limit and fi nd new storage alternatives that would allow the plant to operate at ideal conditions higher temperatures up to 500 C Dish engine parabolic The current dish engine systems are not under operation and they do not use any storage unit This confi guration experienced its upturn in the 90s before the deployment of other confi gurations costlier effective and with a lower collection temperature None of the projects commissioned bet on Parabolic Dish as a technology for the future Major im provements in its confi guration must be undertaken to increase its implementation 5 2 Storage technology An outlook of the commercial and non commercial technologies is presented in this section publications patents projects and CSP confi guration are interrelated to outline the future deployment of each TES technology 5 2 1 Commercial technologies Steam this technology has had a rapid deployment in the last 10 years just used in linear Fresnel 3 and power tower systems 2 It accounts for 5 projects in total most of them under con struction and development Steam accumulators might be a tem poral technology that deployed quite fast to fulfi l the needs at that time However it has not a high deployment potential in the future since it is just adequate for small scale and a further cost reduction is not foreseen Technology confi guration Steam accumulator horizontal Capacity installed 100 MWh Storage capacity time 5 h Installed in India United States Australia Italy Molten salts this technology has been deployed for over 14 years and the most popular storage material in CSP plants Mostly implemented in parabolic trough 44 then power tower system 22 but some TES systems can be found in commercial linear Fresnel 2 plants The installed capacity is quite similar between Parabolic trough 3796 MW and Power tower 2514 MW 72 projects in total most of them under construction 14 and devel opment 24 34 operational projects Molten salts could be replaced by nanofl uids soon after nanofl uids technology TRL scales up they show an increase on the specifi c heat and the thermal conductivity than the base fl uid molten salt Many challenges must be address before this happens agglomeration stability etc Technology confi guration Two tank direct indirect A Palacios et al Renewable Energy xxx xxxx xxx18 Please cite this article as A Palacios et al Thermal energy storage technologies for concentrated solar power e A review from a materials perspective Renewable Energy https doi org 10 1016 j renene 2019 10 127 Capacity installed 6411MW total Storage capacity between 5 and 20 h Installed in Spain and United States Concrete It stands as an alternative to molten salts when the operational temperature is lower than 500 C Up to that temper ature stability problems appears and concrete does not stand as a suitable option Concrete had a rapid deployment in less than 10 years and accounts for a TRL of 8 However not many plants are operating using concrete It has been just implemented in Linear Fresnel refl ector systems the outlet temperature matches the operational conditions of this storage media The lifetime is currently an issue due to spalling at high temperature and the cracks in its structure after repeated cycles of thermal expansion and contraction New concrete compositions are required to push this technology forward in the market Technology confi guration Concrete fi eld accumulator Capacity installed is in total 200 MW Storage capacity more than 10 h Installed in China 5 2 2 Non commercial technologies Phase change materials could allow lower tank volume but many challenges must be faced to increase the TRL level in the next years thermal and chemical stability charging discharging rate and corrosion PCMs have been mainly studied at lab scale and some low capacity pilot plants The fact that they can just be implemented into specifi c confi gurations and the inlet outlet temperature works in a narrow temperature range makes them diffi cult for implementation LHTES system could be applied in commercialized CSP plant in the future after conducting thorough parametric studies solid systematic optimization and pilot scale system tests The fi rst publication on the topic was in 2012 since then 61 papers have been published reaching the peak in 2016 After that it seems the interest on PCM is shifting to other tech nologies such as thermochemical systems and nanofl uids Particulate solids Particulate solids are an early stage tech nology just a few papers can be found on the topic 10 papers The fi rst one was published in 2013 It seems that this technology is attracting more funding and attention from the researchers mainly focused in USA and pushed by the SunShot project Particulate solids can store high amounts of energy at higher temperatures higher than any other available and studied storage material including the fully commercial technologies ones such as molten salts above 600 C Even if a lower amount of papers were found for this technology particulate solids have more patents registered than any other technologywith higher TRL This fact denotes that in the next years it might scale up and reach levels similar to other sensible heat technologies Prior to commercialisation solid par ticulates must be studied at demonstration level and critical chal lenges such as agglomeration and sintering must be solved The main innovation needs in this technology are related to the inte gration of the storage to the system e g conveyance fl uidised bed design increase effi ciency Thermochemical Despite thermochemical is the technology that accounts for the oldest papers on the topic the TRL level is still quite low and no demonstration plant can be found using ther mochemical materials as TES storage media The complexity of the system and the mismatch between theoretical and practical energy density make this technology diffi cult to reach commercial levels The progression is slowly moving forward but the fact that calcium looping has been studied for CO2capture has triggered the deployment in the last years More papers can be found on the topic in the past three years especially in 2017 when the papers where 20 times more than in 2012 and double than the previous year Liquid metals This technology has drawn important attention in the past 4 years because of the search for alternatives to molten salts with higher operating temperatures thus higher effi ciencies A total of