ENVIRONMENTALLY FRIENDLY COOLING IN HOT CLIMATES

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1 ENVIRONMENTALLY FRIENDLY COOLING IN HOT CLIMATES Hanne Kauko SINTEF Energy Research

2 This is SINTEF Energy Research We shape energy solutions for the future SINTEF Energy Research is an institute for applied research dedicated to create innovative energy solutions. 2 Strategic focus: Energy efficiency CCS Hydropower Offshore windfarms Bioenergy System integration of renewable energy Smartgrids Power exchange between Norway and Europe Gas technology, LNG and hydrogen Subsea power supply and processing

3 SINTEF Energy Research Long-term experience and research on cooling concepts based on natural refrigerants

4 A wise man said 20 years ago We have heard a great deal lately of the harmful effects to the environment when halocarbon refrigerants are lost to the atmosphere. This should not really have come as a surprise since similar problems have happened over and over again. Numerous cases are on record where new chemicals, believed to be a benefit to man, have turned out to be environmentally unacceptable, sometimes even in quite small quantities (DDT, PCB, Pb etc.). In the present situation, when the CFCs and in a little longer perspective the HCFCs are being banned by international agreement, it does not seem very logical to try to replace them by another family of related halocarbons, the HFCs, equally foreign to nature. Prof. Gustav Lorentzen ( ) International Journal of Refrigeration 9. Vol. 18, No. 3, pp , 1995

5 Cooling with natural refrigerants in high ambient temperatures Carbon dioxide (CO 2, R744) Ammonium (NH 3, R717) Hydrocarbons: e.g. isobutane (R600a), propane (R290) Advantages High energy efficiency Environmentally friendly, nonflammable, non-toxic High energy efficiency Climate friendly High energy efficiency Environmentally friendly Disadvantages Low critical temperature: heat rejection at high ambient temperatures can be problematic Highest energy efficiency when combined with heating demand E.g. hot water preparation Toxicity and light flammability requires careful design Flammability requires careful design 5

6 SINTEF activities on heating and cooling with natural refrigerants Commercial refrigeration (supermarkets) using CO 2 as the only refrigerant A newly started project on eco-friendly refrigeration and AC for supermarkets in India Onshore and marine freezing applications with ammonium (NH 3 ) and NH 3 /CO 2 (cascade) as refrigerants 6 High-temperature heat pumps (producing heat to up to C) based on natural refrigerants

7 One of Norway's most energy efficient supermarkets Based on transcritical CO 2 refrigeration Uses approximately 1/3 less energy than a comparable, standard supermarket Won the Energy saving price of the City of Trondheim in 2014

8 CO 2 heat pumps in Japan Two million Japanese families and companies have chosen heat pumps using CO 2 as refrigerant designed at SINTEF/NTNU This technology saved Japan for climate gas emissions corresponding to 1.1 mtonnes CO 2 in 2015

9 SINTEF activities related to district heating and cooling INTERACT - Efficient interaction between energy demand, surplus heat/cool flows and thermal storage in building complexes Modelling tool for designing low-temperature DH grids 9 Intermediate temperature networks with distributed heat pumps

10 District cooling Low temperature (LT) distribution Central heat pump/chiller that produces the entire cooling load Distribution at low temperature level (~4 C) High demand for insulation The supply temperature level determined by the cooling demand of the most demanding customer, i.e. the lowest temperature level High initial investment cost 10

11 NH 3 heat pump in a district heating and cooling system at Gardermoen airport (1998) 11 Norway s largest ammonium chiller/heat pump system, with three units Total heating capacity 12.5 MW, cooling capacity 10 MW The system utilizes a vast groundwater aquifer in the area as a thermal energy storage (ATES) Snow storage used as an additional thermal storage

12 NH 3 Heat Pump at Statoil Research Centre (1994) 2400 kw heating, 1350 kw cooling 12

13 District cooling Intermediate temperature (IMT) distribution 13 Central heat pump/chiller that produces cool water at an intermediate temperature level, 5-25 C Local heat pumps installed at each building use the IMT network as their heat sink and source, to produce cooling (and hot tap water/heating when needed) Less demand for insulation owing to the higher temperature level Lower investment cost Higher energy efficiency

14 Intermediate temperature network at the University of Bergen 14

15 How we could contribute Designing energy efficient cooling(/heating) solutions for building complexes with cooling (and heating/hot water) demand Finding the best heat pump/chiller technology, based on natural refrigerants, for a given task 15

16 Teknologi for et bedre samfunn