Low Energy Air Conditioning

Transcription

1 INTRO 2004 Low Energy Air Conditioning Inventors: Chua Kian Jon Ernest; Ng Kim Choon Chou Siaw Kiang Ho Ghim Wei Richard Kwok (STK) October 24, 2012

2 Trends in kw/rton of chillers at ARI conditions (exclude cooling towers and pumps) Most likely combined system efficiency in kw/rton 2

3 Existing Problems Technology Overview Conventional air-conditioning in hot-humid climates has to cool and dehumidify air. If cooling and dehumidification are decoupled, cooling energy is markedly reduced. Commercial desiccant (Silica-gel) wheels used in existing HVAC require high temperature heat to regenerate and causes large pressure drop High operating cost. Proposed Solution Dehumidification Novel nano-woven membrane + low temperature regenerative composite desiccants Greener Cooling Technology for Buildings or Large Scale District Cooling Cooling Higher temperature chilled water system with lower heat losses. Breakthrough air-conditioning technology with low kw of energy input per ton of cooling (towards 0.65 to 0.5 kw/ton**) ** Energy efficiency of cooling technology defined by amount of electrical power (kw) required to deliver one refrigeration ton (RT) of cooling. The lower the value, the more energy savings. 3 3

4 Technology Overview Cooling Coil Decoupling moisture removal and cooling improves chiller performance by at least 40%. NO reheating required. Chilled water temperature can be raised from 5/10 o C to 12/18 o C. Conventional HVAC Chilled water dehumidification and reheat Dehumidification and chilled water decoupled Hybrid membrane/composite desiccant dehumidification would easily add another 5 to 10% improvement in efficiency. 4

5 Technology Overview Composite desiccant system Silica Gel Clay/Calcium Chloride Composite Adsorption Capacity (kg/kg) Silica Gel Composite Desiccant Relative humidity (%) Adsorption capacity of the composite desiccant material is approximately 3 to 4 X times higher than that of silica gel at high relative humidity. Membrane Control desired pore structure and tune pore size Structured pores increased mass transport. Synthesis technique: Film uniformity, low-temperature fabrication, and high reproducibility. 5

6 To employ new knowledge on nano-science/nano-technology to weave the state-ofthe-art membranes Membrane for air Technology dehumidification Development 1 To employ nano-science/nano-technology to produce membranes for air dehumidification Thin membranes sieving water from air a combination transport mechanisms: enhanced hydrophilicity, molecular sieving and capillary condensation. Control key properties tune pore sizes, control pore distributions and improve mechanical strength/durability. Compared to Prior Art Energy efficient dehumidification, Pollutant Monitoring and Disinfection. Impregnated with photocatalytic particles with UV light to administer air disinfection. A non-invasive air dehumidifiers rejunevates new or existing HVAC systems. Easy integration to the proposed co-generation/district cooling systems. 6

7 To employ new knowledge on nano-science/nano-technology to weave the state-ofthe-art Membrane membranes Technology for air dehumidification Sensing and Disinfection Sensing capability of Pollutants such as VOC Natural sunlight feasible light source for photocatalytic disinfectant of organic pollutants Schematic of testing rector (extension of existing set-up). 7

8 To employ new knowledge on nano-science/nano-technology to weave the state-ofthe-art membranes Membrane for air Technology dehumidification Development 2 Membrane Advanced Research Projects Agency - Energy ARPA E Project Selections (July 12, 2010) Ceramic Membrane* 8

9 To employ new knowledge on nano-science/nano-technology to weave the state-of- From Lab to Commercial Application the-art membranes for air dehumidification Lab test facility + Excellent Results ~ 10% RH reduction for single membrane Sam 1: Sol H (TiO2) gel submerge twice Sam 2: Sol H (TiO2) gel submerge once Sam 3: Sol H (TiO2) gel submerge thrice Feed side Permeate side Insert: Membrane samples Sam 1: Sol H (TiO2) gel submerge twice Effect of inlet air humidity on the outlet air humidity (Sam1; Sam2; Sam3; PTFE membrane; temperature: K; inlet air flow rate: 1.3m/s; at 1 atmospheric condition; uncertainty:2%). Development of Membrane Dehumidification for Large Commercial Application Core Innovation: Hybrid mesoporous inorganic TiO 2 framework with polymeric support membrane. Mesoporous framework loaded with nanoparticles for enhanced UV-Vis light disinfectant, anti-biofouling (self-cleaning) and sensing. Scalable process: sol-gel dip coating Scalable process: cast films Mesophase ordering and structuring to attain tunable pore size. Scale-up commercial membrane fabrication Table shows wide range of respective physical filtration capabilities. Scalability: Commercial large scale dip coater 4 9

10 New Paradigm Change in Cooling System integration optimization Sensible cooling 12/18 deg C Nation-wide CWS network Waste heat utilization + Latent cooling Integration of electric, AB and AD chillers at centralized power plants Steam fired AHP -excess steam Development of HYBRID-based dehumidifier Existing Power plants Electricity production Engineering/Science research:- AD chillers for waste heat utilization and HYBRID dehumidifier for moisture removal

11 To employ new knowledge on nano-science/nano-technology to weave the state-of- Latest News on Efficient Cooling Technology in Singapore the-art membranes for air dehumidification NUS-designed system helps Hyatt slash energy use, emission 01 August 2012 The desiccant dehumidifier, jointly patented by Grand Hyatt Singapore and NUS, dehumidifies outdoor air for the hotel lobby and dining room. The only engine in the world that operates on town gas and is capable of switching to natural gas when it becomes available The Grand Hyatt Singapore has won the 2012 National Energy Global Award for Singapore as well as Achievement of Excellence in the Green Technology Awards winners at the Singapore Sustainability Awards 2012, thanks to a new ecofriendly trigeneration plant it jointly developed with NUS. The first hotel in the world with such a retrofitted implementation, the system is set to cut the hotel's energy consumption by 22 per cent, helping it save S$800,000 in electricity bill. More importantly, its daily carbon dioxide emission of 5.72 tons will be slashed by 3.52 tons, which would amount to that discharged from 300 cars for a year. Residual heat generated by the new system is harnessed to produce steam and hot water for the hotel's laundry plant. The remaining heat is captured for dehumidifying the outdoor air introduced to the lobby and dining room. A silica gel-based dehumidifier unit was built for this purpose. Hyatt and NUS have jointly filed for a patent in the waste heat-driven dehumidifier developed.

12 To employ new knowledge on nano-science/nano-technology to weave the state-of- Motivation: System Versatility the-art membranes for air dehumidification Can be employed for Co-generation based cooling plants. Can be employed for District Cooling Systems. More realizable energy savings for district cooling due to ECONOMIC of SCALE. Electricity production for national grid Industrial complex/ factories Moisture removal by HYBRID technology Commercial complexes/ Offices Moisture removal by HYBRID technology 12 Primary fuel Cogenerationbased cooling plants Chilled-water distribution grid at 12/18 o C Commercial centers Moisture removal by HYBRID technology Townships/ housing estates Moisture removal by 12 HYBRID technology hospitals/ schools/colleges moisture removal by HYBRID technology

13 AD Technology Beyond Proven Concept ( PCT/SG2009/ , filing No. 61/226,783, No.: 61/297,347, PCT/SG2012/000076) Saudi Arabia KAUST, 10Rtons Solar Powered Singapore 45Rtons Each, Solar Powered Singapore NUS 10Rtons, Waste Heat Prototype 3 prototypes in Saudi Arabia and Singapore. 4 commercial prototypes in Singapore and Poland (Wroclaw University of Technology). Test data shows that cooling capacity from 24 to 40 Rton and 8 to 28 tonne of water per tonne of adsorbent. H Reaction bed tower 5 Condenser 2 Purified water storage tank Evaporator 1 3 Reaction bed tower 4 3 large ADCs (>3000 Rtons, 250 m3/d) planned for SA. d d 13

14 An example of Common Services Tunnel (CST) at Marina Bay, Singapore August 12 th, 2012, Straight Times

15 Team members Professor Chou Siaw Kiang, works on air-conditioning and thermal engineering for many years. He is a consultant on renewable energy applications to the Tianjin Eco-City project. He has rich experience in energy performance studies of large buildings, clean and renewable energy systems and thermal power generation. Professor Ng Kim Choon, works on chillers and heat pumps, adsorption cooling and desalination, co-generation systems analysis and testing. He has worked on several hybrid cogeneration-based district cooling (HCDC) for island-wide implementation. He has won numerous local and international awards for his works on heat-driven cooling systems for large-scale applications. Co-PI, Dr. Ho Ghim Wei, has been a specialist in nano-technology research. She has extensive knowledge of top-down and bottom-up fabrication of nanostructures. She is an expert in synthesizing and characterization of nano-structures with simultaneous control of the dimensions, properties, and morphology for the development of any nano-structure based device. Industrial Co-I Dr. Richard Kwok the Chief Technical Officer (CTO) of STK is a highly regarded technical officer with invaluable experience in conducting high-end research. He is an engineer, a technologist, an academia, and a researcher. Dr. Richard is very active in many Ministry of Defence projects and is a champion of renewable clean energy technologies. He is in many governmental review panels on innovative energy technologies and future energy landscape. 15

16 Closure Hybrid systems marked improved performance compared with commercial silica desiccant (1) lower regenerative temp (2) greater moisture absorption; and (3) lower P. Quantum leap towards the realization of present 0.9 kw/ton of cooling towards ultimate target of 0.65 to 0.5 kw/ton. Intangible benefits: footprint/space savings to building owners, lower operating cost; District Cooling - no system maintenance.

17 Thank You For further enquiries, please NUS Principle Investigator : Chua Kian Jon Ernest ( mpeckje@nus.edu.sg; Tel: ) 17