Indiacool - UK-India Solar Cooling Innovation (Energy Catalyst Mid-stage Programme)

Lead Research Organisation: Imperial College London
Department Name: Department of Chemical Engineering

Abstract

The India-UK Innovative Solar Cooling (Indiacool) project is an industrial R&D collaboration between UK and India corporate and academic partners, Imperial College, Solar Polar Limited, Mamata Energy and Anna University, Chennai. It aims to investigate and advance the development of an innovative UK solar-cooling technology for its use and further commercialisation for two applications: 1) provision of low-cost solar cooling of crops and food in rural communities in developing countries as part of the food 'cold-chain'; and 2) low-cost solar air-conditioning of dwellings and small retail and industrial buildings.

The first application has potential for commercialisation in India and throughout the developing world, where wastage of crops and food due to the lack of an adequate cold-chain can be as high as 50%. The second application has significant commercialisation potential in India and worldwide as it can potentially provide a viable alternative to compressor based air-conditioning which is responsible for substantial consumption of electricity and very significant carbon emissions.

Imperial College's main contribution is to: 1) lead the computational modelling of Solar Polar's cooling technology for thermodynamic and thermal performance analysis that takes into account the varying climatic conditions in India; 2) investigate the optimisation of the technology for operating in the Indian climate and for the two different cooling applications, with particular focus on working fluid selection, working pressures, system design and key component modifications; 3) support the design and development of prototype systems incorporating the results of the optimisation work; and 4) support the testing and monitoring of the performance of the prototypes within field trials (within both applications) in India.

Within the computational modelling task, thermodynamic and thermal performance analysis will be assisted by harnessing existing modelling tools for this technology which have been developed at Imperial College, based on a laboratory absorption-cooling system. Imperial College will provide expertise on thermodynamics, thermofluids, thermal modelling and absorption-cooling systems. Using this expertise, Imperial College will also assist in extending the complexity of these modelling tools to include (and allow) component and fluid design for the Solar Polar system and to extend the predictive capabilities of these tools to include dynamic modelling of the system within India's varying climatic conditions. This activity will allow optimised Solar Polar cooling units to be designed for the two specific applications and for the climatic conditions in India.

Optimised Solar Polar's systems, suggested by the models, will be confirmed by laboratory testing on a Solar Polar cooling system. Specifically, the effect on system performance of different working pressures and working fluids will be investigated and results from these experiments will be used to feed into the modelling work. Imperial College will also investigate the impact on performance optimisation that may be achieved by modifications to system components.

Based on the results from the research undertaken in relation to 1) and 2) above, Imperial College will support Solar Polar in the development of optimised design specifications and drawings for prototypes (that will be constructed for use in field trials).

Imperial College will also provide expertise in the design, testing and monitoring specification for use within the field trial phase of the project. This will include definition of test protocols, assessment and selections of monitoring equipment and formulation of specifications for data collection, transmission and analysis. Imperial College will support Solar Polar in its procurement of the required monitoring equipment and in the installation and commissioning of the equipment within field trial prototype systems.

Planned Impact

The initial direct beneficiaries of the Imperial College contribution will be Imperial College and Solar Polar, as the project will advance the development and commercial prospects of Solar Polar's solar absorption-cooling system, while also advancing the computational modelling and design-tool capabilities of this technology at Imperial College.

The Indian corporate partner, Mamata Energy, will also benefit from the project as it will provide a platform for commercialisation of solar cold-chain storage facilities and air-conditioning technologies in India, throughout Asia and globally, responding to a 'growth sector of tomorrow', providing very substantial job creation potential.

The project responds to real and significant market needs in India. The research and critical investigation within the project's work programme will advance the development of two applications of a highly innovative UK solar cooling technology (currently at TRL 3 to 4), with the potential to deliver cost effective solar cooling of produce (without any requirement for mains electricity) and low cost, zero carbon solar air-conditioning.

This project will forge a new partnership between UK and Indian industrial and academic partners which will foster increasing collaborative research and development and incorporates knowledge transfer that will contribute to the development of India's knowledge based economy.

Once the solar cooling cold storage application reaches the commercialisation stage, rural communities in India and other developing countries will benefit from a cost effective means of keeping their food and produce cool, this reducing wastage, improving incomes within the communities and lowering food prices.

Commercialisation of the solar air-conditioning application will provide a benefit to occupants of dwellings requiring air-conditioning by reducing electricity bills. For housing developers within countries in which there is a demand for air-conditioning, Solar Polar's solar cooling system will help meet low or zero energy building standards.

Uptake of Solar Polar's solar cooling system at scale will be of benefit to municipal and national government by lowering carbon emissions and by alleviation of the electrical loads on electricity grids (conventional compressor-based air-conditioning technology can in some countries place significant strains on their electrical infrastructure and result in 'brown outs').

The research findings will be integrated into the teaching materials for undergraduate and master's level students to inspire the next generation of research engineers, and will lead to follow-on research projects, PhD and otherwise. The Imperial College team has a range of parallel, connected research activities that will benefit from this work; vice versa, some of these resources (personnel and hardware) will be harnessed for the delivery of the present project. This project proposal will also act as a direct output of the on-going early-stage research activities at Imperial College and our collaborators on the development of these advanced modelling methodologies for the assessment of the performance and operation, as well as the optimisation, of next-generation affordable solar cooling systems.
 
Description Through the laboratory testing, field testing and computer modelling undertaken in this project, the performance of the solar diffusion absorption refrigeration (DAR) system has been assessed under a wide range of operating conditions and system configurations. It has been shown that there is a need to further optimise the system to improve its performance within the temperature range achievable with low-cost, non-concentrating solar collectors. An understanding has also been gained of the restrictions imposed by the environmental conditions in the parts of India that the system was trialled. The adjustable parameter for ammonia/water mixture were investigated (different pressure different compositions). The investigation of alternative working fluid mixtures is now an area of primary importance for the optimisation of the system for the present application. A number of assumptions used in the system model have been re-evaluated as a result of this work. As result of the knowledge gained through the experimental study, the system model has been adapted to include features that more accurately describe performance compared to other existing models in the literature. A diurnal performance study is going to conduct by using a solar simulator to simulate the start-up and shut-down of the laboratory DAR. In addition, concerning the investigation of different working, the DAR system performance has been simulated using different working fluids and under different climatic conditions.
Exploitation Route The research findings will be integrated into the teaching materials for undergraduate and master's level students to inspire the next generation of research engineers, and will lead to follow-on research projects, PhD and otherwise. The Imperial College team has a range of parallel, connected research activities that will benefit from this work; vice versa, some of these resources (personnel and hardware) will be harnessed for the delivery of the present project. This project proposal will also act as a direct output of the on-going early-stage research activities at Imperial College and our collaborators on the development of these advanced modelling methodologies for the assessment of the performance and operation, as well as the optimisation, of next-generation affordable solar cooling systems. On the experimental side, three experimental apparatus were developed (DAR apparatus, mixing and charging apparatus, and solar heat-pipe tester apparatus), along with operating and safety procedures, that will be used by future students and researchers.
Sectors Aerospace, Defence and Marine,Agriculture, Food and Drink,Chemicals,Construction,Electronics,Energy,Environment,Healthcare,Manufacturing, including Industrial Biotechology,Pharmaceuticals and Medical Biotechnology,Retail,Transport

 
Description The findings of the project have been used to assist in the development of a grid-independent solar-cooling system for use in cold chain applications. In rural areas and developing economies, a major challenge is to provide a continuous cold chain for vaccines and crops to prevent spoilage. At present, approximately 20% of harvest food is wasted due to gaps in the cold chain. In areas not served by an electricity grid, solar-refrigerators based on PV panels are expensive, particularly when using electrical batteries. The solar diffusion absorption refrigeration technology being investigated in this project has the potential to provide a low-cost, environmentally friendly solution with a long operational lifetime. By improving the cold chain provision in some of the world's poorest areas, this could have a major societal impact on rural communities and a positive economic impact through increasing agricultural output and minimising wastage. The findings of the project so far have been communicated to the primary collaborators, Solar-Polar Ltd, and have informed the direction for the next phase of work. The findings relate to the design and configuration of the diffusion-absorption refrigeration (DAR) cycle, the selection of an appropriate solar collector, and the integration of these two components. The results from the experimental work have been used to inform decisions on the design and configuration of the system being commercialised by Solar-Polar. The experimental results have also been used for the validation of computation models being developed by the team at IC. The models allow for a more detailed analysis of the system performance, and for optimisation of the cycle under different operating conditions, and with different working fluid mixtures. We are also working closely with other groups in the Department of Chemical Engineering, specialising in computer-aided molecular design (CAMD), to apply existing tools for working fluid design and optimisation to the present system as a case study. In the context of designing working fluids for running solar-powered DAR units, an integrated computer-aided molecular and process design is adopted where using mathematical programming allows us to design the working fluid structure, as well as some of the process variables to seek optimum performance under different climatic conditions.
First Year Of Impact 2018
Sector Agriculture, Food and Drink,Construction,Creative Economy,Education,Energy,Healthcare,Manufacturing, including Industrial Biotechology
Impact Types Societal,Economic

 
Description The Energy Entrepreneurs Fund
Amount £226,459 (GBP)
Organisation Department for Business, Energy & Industrial Strategy 
Sector Public
Country United Kingdom
Start 04/2018 
End 10/2018
 
Title Experimental facility for the mixing of working fluid solution and charging of DAR system 
Description An apparatus and methodology has been developed to allow the mixing of a working fluid pair for use in the diffusion absorption refrigeration (DAR) system. This allows for fast adjustments to be made to the system's fluid concentration and pressure in a safe and repeatable manner. Training materials have been put in place for the teaching of researchers and students. 
Type Of Material Improvements to research infrastructure 
Year Produced 2017 
Provided To Others? Yes  
Impact The facility was used during an experimental campaign to map the performance of the DAR system over a range of pressures and working-fluid concentrations. The results of this work were presented at the ISES Solar World Congress, and are being written into a journal paper. The results of this work has also formed the basis of further discussion with the collaborator Solar-Polar Ltd. 
 
Title Laboratory diffusion absorption apparatus 
Description An experimental diffusion absorption refrigeration system, with instrumentation to provide detailed measurements of system temperatures, pressure, and heat flows. Control of the heat input to the system is provided through a computer interface allowing the study of the system in steady-state or dynamic conditions. A further development allow for the control of ambient air temperature to assess the impact on heat rejection capability. 
Type Of Material Improvements to research infrastructure 
Year Produced 2017 
Provided To Others? Yes  
Impact This apparatus was used to experimentally map the performance of the DAR system under various operating conditions, system pressure and thermal inputs; and to validate computational models of the system developed in parallel. The results of this work were presented at the ISES Solar World Congress in November 2017, and are currently in preparation for submission to a major academic journal. 
 
Title Solar heat pipe tester apparatus 
Description An experimental apparatus for the testing of solar heat pipe collectors over a wide range of operating temperatures. Heat pipe collectors have been identified for their suitability with the solar diffusion absorption (DAR) application due to their passive operation principle. An apparatus was designed to allow the collectors to be tested at high temperatures using a flow of thermal oil circulated in open-loop at a controlled flow-rate and inlet temperature. 
Type Of Material Improvements to research infrastructure 
Year Produced 2017 
Provided To Others? Yes  
Impact The results of this work were used to map the performance of a low-cost solar heat pipe collector for which there was no published performance data available, and to assess its suitability in the field-tests of the solar-DAR system. 
 
Title Mathematical lumped thermodynamic model for diffusion absorption refrigeration system performance prediction 
Description A mathematical model describing the solar-powered diffusion absorption refrigeration system allowing the prediction of system performance under different operating conditions. 
Type Of Material Computer model/algorithm 
Year Produced 2018 
Provided To Others? No  
Impact This is an on-going work. It will help us understand the system characteristics and improve the design of the diffusion absorption refrigeration system. 
 
Title Solar-DAR system model 
Description A thermal model of a diffusion absorption refrigeration (DAR) system with thermal energy input from a solar thermal collector array. The model incorporates a detailed sub-models of the DAR system components (generator, rectifier, condenser, evaporator and absorber), integrated with a thermal model of a solar thermal collector array. The model uses time-varying environmental data (solar irradiance, ambient temperature) as inputs. The thermal energy storage capacity of the DAR system generator is also taken into account in the model. 
Type Of Material Computer model/algorithm 
Year Produced 2017 
Provided To Others? Yes  
Impact The model has been used to assist the design and development of the solar-DAR system by Solar-Polar Ltd, currently being field-tested in India, and to recommend the optimal system configuration with regard to the system pressure and solar-collector array size. The model has also been used to simulate the performance of the system in two regions of India (Chennai, and Ahemdabad), and with two types of heat-pipe solar collector. 
 
Description Energy Transitions 
Organisation Energy Transitions Ltd
PI Contribution Working with Energy Transitions and Solar-Polar to implement, modifiy and test new controller hardware for the control of the DAR system apparatus.
Collaborator Contribution Energy Transitions Ltd supplied the original controller system and provided training on its use.
Impact The controller has been successfully used to test the system under dynamic operating conditions representative of the solar application. A conference paper was co-authored, and presented at the ISES Solar World Congress in November 2017.
Start Year 2017
 
Description Solar-Polar 
Organisation Solar-Polar Ltd
PI Contribution Experimental work to map the performance of a diffusion absorption refrigeration (DAR) system. The experimental results are used for the validation of computational models of the system developed in parallel with the experimental work. We have also provided assistance to Solar-Polar in the following areas: (i) selection of suitable solar collectors for the solar-DAR system; (ii) setting up field tests in India (selecting monitoring equipment, on-site installation, remote monitoring); (iii) diagnostics and interpretation of the filed-test data.
Collaborator Contribution Solar-Polar have provided the experimental apparatus on which the laboratory testing has been based. They have also provided access to their field-trial data and on-site environmental data, which has been useful for the validation of the "whole system" Solar-DAR model. Application data such as cooling loads, cooling delivery temperatures etc. were also provided by Solar-Polar, which have been useful as modelling case studies.
Impact An academic paper, co-authored by Imperial College and Solar-Polar was presented at the ISES Solar World Congress in Abu Dhabi in November 2017.
Start Year 2017
 
Description "Imperial Lates" event (October 2018) 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Study participants or study members
Results and Impact Imperial Lates is our after-hours programme of events which celebrate science and engineering. It gives the public a chance to bring out their inner child and have fun with our research, as well as debate the major issues of the day with our scientists and engineers.
Year(s) Of Engagement Activity 2018
URL http://www3.imperial.ac.uk/newsandeventspggrp/imperialcollege/eventssummary/event_16-8-2018-18-22-1
 
Description Imperial Festival (April 2018) 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Study participants or study members
Results and Impact Imperial Festival is an open day activity to present interesting research to the public.
Year(s) Of Engagement Activity 2018
 
Description Industrial partership - SOLAR POLAR 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact Support in prototype development.
Year(s) Of Engagement Activity 2017,2018,2019
 
Description Invited to attend UK-China Cold Chain Workshop 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Invited to attend UK-China Cold Chain Workshop, held in Gansu, China, 6-8 March
Year(s) Of Engagement Activity 2019
 
Description The China-UK Workshop on Renewable Energy Systems in Zero Carbon Villages 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Dr. James Freeman was invited to present our work on solar-driven diffusion absorption refrigeration at the China-UK Workshop on Renewable Energy Systems in Zero Carbon Villages, which was held in Lhasa, Tibet, China, 6-8 August 2018.
Year(s) Of Engagement Activity 2018
URL https://www.cardiff.ac.uk/conferences/china-uk-workshop-on-renewable-energy-systems-in-zero-carbon-v...