Small cooling capicity hybrid refrigeration system using R723
Lead Research Organisation:
University of Warwick
Department Name: Sch of Engineering
Abstract
In the past two decades, concern about the impact of CFCs, HCFCs or CO2 emissions on the environment and in particular on the ozone layer and global warming phenomena has reactivated interest in Sorption Technology applied to heat pumps and refrigerating systems. This is for two main reasons: the refrigerants used (ammonia, water or alcohols) are less harmful to the environment (zero Global Warming Potential - GWP and zero Ozone Depletion Potential - ODP) and the systems are heat driven therefore could use 'free' or low cost heat sources such as solar energy, biomass or waste heat (domestic or industrial). With EU regulations aimed at enforcing the Kyoto Protocol and the rising cost of the primary sources of energy (Oil and Gas) worldwide, the need for environmentally friendly and highly efficient heat pumps and refrigerating systems is required. The current project proposes a Hybrid Refrigeration System using the environmentally friendly refrigerant R723 (azeotropic mixture: 40% DME and 60% Ammonia) that is compatible with conventional refrigeration copper alloy (CuNi10) It is a Combined Sorption-Vapour Compression Refrigeration System driven by a dual source (heat and/or electricity). Both the use of this refrigerant in an adsorption cycle and the hybrid energy source are key novelties.
Numerous Hybrid Refrigeration System layouts are to be modeled in association with the development of system control strategy. A proof of concept prototype of 10 kW cooling capacity will be designed, built and its performance (COP and cooling power) evaluated.
Numerous Hybrid Refrigeration System layouts are to be modeled in association with the development of system control strategy. A proof of concept prototype of 10 kW cooling capacity will be designed, built and its performance (COP and cooling power) evaluated.
Planned Impact
For two decades, there have been national and international efforts through various Protocols (Kyoto, 1997), Acts (UK Climate Change Act 2008) and Memorandums of Understanding (Copenhagen 2009 Accord) to reduce the emission of greenhouse gases (Methane, Nitrous Oxide N2O, CFCs, HCFCs and CO2) that are responsible for global warming. The proposed project fits this context not only by using refrigerant of very low GWP and ODP (R723) but also by blending the driving energy source (conventional and renewable) of the refrigeration system for improved flexibility and cost-effectiveness. In addition to this, industry (component and system manufacturers), end users and the scientific and engineering communities will gain benefits.
New market could open up to the manufacturers of activated carbon, heat exchangers and refrigeration systems without substantial additional capital investment. For instant, a manufacturer of activated carbon
could gain a potentially additional annual sell of £16.5M with only 2% of annual market penetration of the new technology. It is also estimated that if such hybrid systems are introduced in UK, there will a potential reduction of CO2 emission of 11% over ten years period through fuel saving.
The direct social benefits attached to this proposed system could be a better quality of air in addition to economic benefits and reduction of other cost linked to the consequences of CO2 emissions.
The dissemination of the results of this work through publications or communications in international journals (example: International Journal of Refrigeration), conferences (example: IIR-International Congress of Refrigeration) and various networks (example: SIRAC or IoR) will contribute and make an impact to future research and system design of heating and cooling equipment.
New market could open up to the manufacturers of activated carbon, heat exchangers and refrigeration systems without substantial additional capital investment. For instant, a manufacturer of activated carbon
could gain a potentially additional annual sell of £16.5M with only 2% of annual market penetration of the new technology. It is also estimated that if such hybrid systems are introduced in UK, there will a potential reduction of CO2 emission of 11% over ten years period through fuel saving.
The direct social benefits attached to this proposed system could be a better quality of air in addition to economic benefits and reduction of other cost linked to the consequences of CO2 emissions.
The dissemination of the results of this work through publications or communications in international journals (example: International Journal of Refrigeration), conferences (example: IIR-International Congress of Refrigeration) and various networks (example: SIRAC or IoR) will contribute and make an impact to future research and system design of heating and cooling equipment.
Publications
Lychnos G
(2014)
Performance of hybrid refrigeration system using ammonia
in Applied Thermal Engineering
Tamainot-Telto Z
(2016)
Thermal conductivity measurement of activated carbon with granular graphite
Tamainot-Telto Z.
(2016)
Towards optimum specifications of adsorbent for heat pump and refrigeration applications
Tamainot-Telto Z
(2016)
Novel method using Dubinin-Astakhov theory in sorption reactor design for refrigeration and heat pump applications
in Applied Thermal Engineering
Tamainot-Telto Z
(2017)
Advanced heat driven hybrid refrigeration and heat pump systems
Tamainot-Telto Z
(2018)
Efficient Solar Driven Air Conditioning System for Hot Climates: Case Study of Doha
Lychnos G
(2018)
Prototype of hybrid refrigeration system using refrigerant R723
in Applied Thermal Engineering
Description | A proof of concept 10 kW nominal cooling capacity hybrid refrigeration machine was designed and built at University of Warwick. The hybrid system uses ammonia mixture R723 (40% Dimethyl ether, 60% Ammonia) which is compatible with conventional refrigeration copper alloy (CuNi10) and environmentally friendly. It combines sorption (thermal) and conventional vapour compression (electrical) technology in two separate refrigerant loops. Tubular adsorption generators utilising the activated carbon - R723 pair were used as thermal compressor while a semi hermetic reciprocating compressor was used in the conventional vapour compression loop. The hybrid machine was designed as water chiller with an evaporation temperature of 5 oC and condensing temperature of 40 oC. The experimental results show a total cooling production of 6 kW (4 kW from electricity and 2 kW from heat). |
Exploitation Route | 1. The cooling performance will be evaluated and checked against the model predictions: MSc student contribution during 2016/2017 for his project but further is still needed. 2. The current project has incubated a concept of Advanced hybrid cooling machine fully driven by primary heat source: Preliminary modelling work was carried in course of 2017 including communication before IEA-Heat Pump Conference 2017 in Rotterdam (The Netherlands). Possible grant application in the near future is useful to take this work further. 3) Development of novel technique for characterisation of adsorption reactor for refrigeration and heat pump applications: Preliminary work was completed and published in 2016 and further work is in progress and could be possibly published in 2018. The development of specific adsorbents for Refrigeration and Heat Pump applications is needed and this work is progressively ongoing through MSc Student Projects |
Sectors | Agriculture, Food and Drink,Energy,Environment,Retail,Transport,Other |
URL | http://wrap.warwick.ac.uk/view/author_id/7558.html |
Description | Activated carbon for Refrigeration and Heat Pump Applications |
Organisation | Chemviron Carbon |
Country | United Kingdom |
Sector | Private |
PI Contribution | Adsorption characterization of activated carbon-R723 pair including other thermo-physical properties such thermal conductivity and permeability of packed granular activated carbon. |
Collaborator Contribution | Providing test samples, useful technical information and advice including those leading to the selection of appropriate activated carbon for our application. |
Impact | N/A |
Description | Development high density storage of Ammonia gas for DeNOx in automotive application |
Organisation | Aaqius & Aaqius SA |
Country | Switzerland |
Sector | Private |
PI Contribution | - High density and high conductivity adsorbent for storage of Ammonia gas at low pressure. - Modelling, designing, manufacturing and testing module prototypes. - Definition of manufacturing process and an Ammonia loading protocol. - Definition of technical specifications of potential commercial module. |
Collaborator Contribution | - Project Funding - Development of light weight pressure vessel |
Impact | Confidential |
Start Year | 2011 |
Title | A SORPTION DEVICE |
Description | A sorption device comprising a heat exchanger, wherein the heat exchanger comprises: a sorbate chamber containing a porous sorbent material, a thermal fluid conduit that is fluidly isolated from the sorbate chamber, and solid heat transfer means for providing thermal communication between a thermal fluid in the thermal fluid conduit and the porous sorbent material, characterised in that the porous sorbent material has a thermal conductivity of >0.3Wm-1K-1, preferably >0.4Wm-1, and the porous sorbent material is selected such that the ratio H1/H2 is 0.7 or less, wherein H2 is the heat energy used to heat the porous sorbent material and sorbate from a first temperature at which the porous sorbent material contains a maximum cyclic concentration of adsorbed sorbate to a second temperature at which the porous sorbent material has a minimum cyclic concentration of adsorbed sorbate, and H1 is the heat energy that is used to heat the heat transfer means and thermal fluid during the course of heating the porous sorbent material and sorbate from the first temperature to the second temperature. |
IP Reference | WO2013083992 |
Protection | Patent granted |
Year Protection Granted | 2013 |
Licensed | Yes |
Impact | - Acceleration of the development of gas fired adsorption heat pumps - Contribution to numerous publications |
Title | SORPTION MODULE |
Description | Combined reactor-condenser-evaporator as single module device. |
IP Reference | EP1535002 |
Protection | Patent application published |
Year Protection Granted | 2005 |
Licensed | Yes |
Impact | - Grants awarded for proof of concept - Numerous publications |
Title | THERMAL COMPRESSIVE DEVICE |
Description | A thermal compressive device provides energy-efficient heating or cooling by exploiting heat regeneration in a sorption system. The device comprises an array of generator modules (7) arranged in two banks (10, 11) to either side of a heating zone (13). Heat carrier fluid is driven past the modules in a reversible direction. During one phase, generators in the first bank (10) are cooled and therefore in various stages of sorbate re-adsorption. Sorbate in associated evaporator region(s) (26) will boil, enabling cooling of surrounding fluid (33). Generators (7) in the other bank (11) will be in various stages of desorption. Sorbate in associated condenser region(s) (21) will condense, enabling heating of its environment. During the other phase, each generator (7) switches function, but cooling remains at evaporator regions (26) and heating at condenser regions (21). Each module may be a self-contained unit comprising generator (7), condenser (21) and evaporator (26) sections. In operation, the evaporator section (26) is arranged to be filled with condensed sorbate (28). |
IP Reference | WO2004011859 |
Protection | Patent application published |
Year Protection Granted | 2004 |
Licensed | Yes |
Impact | Development of Experimental prototype of sorption modular device concept (EU SOCOOL Project) leading to numerous pubications |
Company Name | Sorption Energy Ltd. |
Description | Sorption Energy Ltd. develops adsorption heat pumps, boilers, vehicle air-conditioning, and domestic heating and hot water |
Year Established | 2009 |
Impact | - Development of domestic gas fired adsorption heat pump. - Industrial links and networking. - Stimulation of innovative and sustainable technologies |
Website | https://www.nexok.co.uk/company/06791484/sorption-energy-limited/financials-accounts |
Description | 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics (HEFAT2014), Orlando (USA) |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Type Of Presentation | poster presentation |
Geographic Reach | International |
Primary Audience | Schools |
Results and Impact | Presenting a paper through a poster and chairing conference sessions. The poster sums up the effect of packing density on thermal properties of granular activated carbon packed bed by using of inverse heat conduction method Networking and potential research collaboration. |
Year(s) Of Engagement Activity | 2014 |
URL | http://edas.info/web/hefat2014/home.html |
Description | 2nd IEA-HPP Annex 43 Expert Meeting - Paris, 4-5 June, 2014 |
Form Of Engagement Activity | A formal working group, expert panel or dialogue |
Part Of Official Scheme? | Yes |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | Discussions are mainly on Fuel Driven Sorption Heat Pumps for residential and small scale commercial heating applications: the of the art of current Research and Development and shaping foundation of future development including influencing policy makers in respect of regulations and R&D funding. / |
Year(s) Of Engagement Activity | 2013,2014 |
URL | https://www.annex43.org/ |
Description | Friends of Sorption Conference - Milazzo, Sicily (ITALY), 12-14 September 2015 |
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 | Attending "Friends of Sorption Conference" and discussing about the current trend of development of Sorption Technology including applications as Heat Storage, Refrigeration, Heat pumping and Gas storage. Networking activities |
Year(s) Of Engagement Activity | 2015 |
Description | International Sorption Heat Pump Conference, Washington - Mariland (USA) |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Type Of Presentation | paper presentation |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | 1) By Z. Tamainot-Telto: The talk was about a novel cost effective technique of characterising adsorbent-refrigerant pair within the context of designing a physical adsorption reactors. The discussions were interesting as most the questions were about the possibility of extending this technique to chemical adsorption characterization: this could constitute a further research work. 2) By G. Lychnos: Presentation of progress Hybrid cooling system using R723 project through the experimental investigation of activated carbon - R723 pair. The work was aimed to confirm that activated carbon does not act as catalyser in contact with R723 (blend 60% Ammonia and 40% DME) within the operating conditions of refrigeration applications (driving temperature up to 170 oC and pressure up to 15 bar). Most of questions were out of the range of the current study which require further. Possible research collaboration by two companies interested in Hybrid cooling systems. |
Year(s) Of Engagement Activity | 2014 |
URL | http://toc.proceedings.com/22410webtoc.pdf |
Description | IoR /SIRAC Networking Event: Student and Young Engineers Networking Meeting - 14th November 2012 |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Professional Practitioners |
Results and Impact | Discussions between students, young engineers, manufacturers of refrigeration systems and academics were highly beneficial for all parties involved. The Tour of our facilities including Adsorption Gas Fired Heat Pump prototype under test sparks more curiosity and questions from students and young engineers who are more familiar with vapour mechanical compression than thermal compression. |
Year(s) Of Engagement Activity | 2012,2013,2014 |
URL | http://www.ior.org.uk/ior_news.php?#PPFWXY817411 |
Description | Member of Advisory Committee for Heat Powered Cycles Conference HPC2016, 26 - 29 June 2016, Nottingham (UK) |
Form Of Engagement Activity | A formal working group, expert panel or dialogue |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | - Technical and Scientific review of Conference papers. - Conference sessions chairing. - other related activities. |
Year(s) Of Engagement Activity | 2016 |
URL | http://www.heatpoweredcycles.org/com2016.html |
Description | Participant of 12th IEA Heat Pump Conference 2017 (HPC 2017), Rotterdam (The Netherlands), 15-18 May 2017 |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | Presenting of preliminary simulation results of research work on Advanced Hybrid Refrigeration and Heat pump. |
Year(s) Of Engagement Activity | 2017 |
URL | https://www.eiseverywhere.com/ehome/165152/441319/ |
Description | Qatar Foundation Annual Research Conference (ARC'16), Qatar , 22-23 March 2016 |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Schools |
Results and Impact | - Poster Presentation; - Discussions about sustainable domestic and industrial cooling in the Middle-East Region; - Networking; - Visit of Research Institution facilities for Solar Thermal and PV. |
Year(s) Of Engagement Activity | 2016 |
URL | http://wrap.warwick.ac.uk/79784/ |