Welkom. Optimalisatie CO2 systemen m.b.v. ejecteur

Transcription

1 Welkom Optimalisatie CO2 systemen m.b.v. ejecteur 1 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

2 Today s speaker Kenneth Bank Madsen. Global Application Expert at Danfoss since years at Danish Technological Institute, responsible for commercial cooling. Bachelor in Mechanical Engineering in year 2000 from Engineering College of Aarhus, Denmark. 2 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

3 Agenda 1. What is an ejector and how does it work? 2. Transcritical CO2 systems moving forward Booster system Parallel compression Parallel compression with ejector Flooded systems with liquid ejector Low pressure lift ejector 3. Energy consumption and pay back 4. Questions 3 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

4 What is an ejector and how does it work? 4 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

5 What is an ejector and how does it work? Motive flow 100% 37 C/95 bar Discharge flow 112% 38 bar Suction flow 24% 26 bar 12 bar lift 5 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

6 Danfoss Ejector offering overview Type Pressure lift / entrainment ratio Media on suction side High pressure lift 5 18 C C Low pressure lift 3 bar/60%@24 C 7 bar/50%@36 C Liquid ejector 5 5 C 5 20 C CO2 Gas (up to 10% liquid) CO2 Gas (up to 10% liquid) Liguid CO2 (Gas will reduce entrainment) 5 18 C: 5 bar lift, 12% entrainment at 18 C inlet temp pressure using Danfoss algorithem. 6 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

7 How does the Multi Ejector work? Off Off Off On On On High pressure inlet Lowest pressure due to high velocity MT pressure inlet Receiver pressure inlet 7 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

8 Mass flow 90 bar 35C] Capacity control Multi ejector VS proportional control ejector Ejector capacity control HP ejector Multi ejector controls the capacity by changing the combination of the ejectors in a binary pattern That way the capacity is controlled in steps of 5-6 kw. The capacity between steps is controlled with a neutral zone controller, like on compressors. Ejector 5 Ejector 4 Ejector 3 Ejector 2 Ejector Step 8 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

9 Transcritical CO 2 systems moving forward

10 Technology status Technology allows for world wide adoption of CO 2 only systems 27 C/82 F 38 C/101 F All ambient All ambient All ambient Booster system (reference) Parallel Compression system Ejector system Flooded system Cost reduction simplicity systems 1000 systems 100 systems 50 systems 3 systems 2007 Commercially Available 2011 Commercially Available 2015 Testing 2017 Commercially Available 2015 Testing 2018 Commercially Available 2015 Early Testing 2018 Extended field trials 10 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

11 1 st generation: Booster system The transcritical booster system is the most commonly used CO 2 system today. 40C/104F 102 bar/1480 PSI Mass flow Pressure levels GC Pressure HP bar 100% The installed base is systems with Danfoss components (as of August 2017). Liquid line bar 45% Pressure suction MT bar The market has chosen this as the standard system. 55% MT 55% LT Pressure suction LT bar 11 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

12 1 st generation: Booster system Pros: Long track record with large install base mainly in colder climates. Relatively simple compared to most of the other systems on the market. Approx. 12% lower energy consumption than R404a in Amsterdam. Cons: Energy consumption in warm ambient temperature is the main problem. Swept volume increases dramatically in warm ambient temperatures. Application: The system covers from small and all the way up to very large systems (CDU, Discounters up to Hypermarkets). Geographically, the system has a very good foothold in the northern European climate. 12 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

13 2 nd generation: Parallel compression Parallel compression is the first step into the development towards bringing CO 2 into a warmer climate. Parallel compression is giving a significant improvement of COP in warm climates. In addition to that, it is also giving a reduction of swept volume of the compressors (lower first cost). 40C/104F 102 bar/ 1480 PSI Liquid line bar Mass flow Pressure levels GC 45% MT Pressure HP bar 100% Pressure suction MT bar 55% 55% This reduction of cost can not be realized on systems smaller than approx kw, but on larger systems a reduction in cost present. LT 13 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept Pressure suction L ba

14 2 nd generation: Parallel compression Pros The system has been on the market for some years and the installations are counted in several hundreds. Approx. 18% saving on energy consumption in Amsterdam VS R404A Compressor sizes are smaller and not as growing as fast in warm ambient Integration with AC makes sense Cons The system is more complex than the booster system. Small systems are difficult because the compressors are divided in to 2 suction groups Application: The system fits system sizes from approx kw and up. System can be combined with AC with good results. Geographically, the system has the largest install base in southern Europe and warmer ambient. 14 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

15 3 rd generation: Parallel compression with gas ejector First system in opperation with Danfoss Multi Ejector started in January The ejectors are moving gas from MT suction to parallel compressor. In some cases, all gas can be moved from MT to parallel compressor (high ambient temperature or 100% heat recovery). 40C/104F 102 bar/ 1480 PSI Liquid line bar 55% Mass flow Pressure levels GC 25% MT Pressure HP bar 100% 70% 30% 55% Pressure suction MT bar LT Pressure suction LT bar 15 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

16 3 rd generation: Parallel compression with gas ejector Pros: System is penetrating the market this years Solutions shows better energy consumption in any climate and removes the CO 2 equator Compressor sizes are smaller and not as grooving as fast Combination with AC makes very good sense Approx. 20% savings VS R404A in Amsterdam Cons: The system is more complex than the booster systems and also parallel compression Small systems are difficult because of the compressors divided in to 2 suction groups Application: The system fits system sizes from approx kw and up. System can be combined with AC with very good results. Geographically the system can be installed in any climate with lower energy consumption than R404a. 16 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

17 Next generation: Liquid ejector Add on to transcritical systems Liquid ejector systems allow the MT evaporator to be flooded. The saving is coming from the higher suction pressure of the compressors. Ejector is in this case substituting a pump or other means of removing the liquid from the suction side Trials has been running since 2013 with good results. Evaporation temperature is in average raised by 5K. Saving is load dependent and dependent on most leaded evaporator GC MT LT 17 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

18 Next generation: Liquid ejector Pros: Very promising results from the tests running Relatively simple system where the complexity is in the controllers and not in the lay out. Commercially available Q Approx. 10% saving in energy and can be added to the previous savings Cons: Increases complexity slightly of the systems and controls Reducing superheat will give some of the same effects Application: The system covers from small and all the way up to very large systems (CDU, Discounters up to Hypermarkets). Geographically the system will provide the saving in any climate. 18 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

19 Direct expansion Temperatur Air temp Evaporation temp Superheat dt Temperatur Air temp Evaporation temp Pinch point Superheat dt Distance Distance Temperatur Air temp Evaporation temp Evaporation temperature can not be lifted because the SH creates a pinch point dt Superheat Temperatur Air temp Evaporation temp Superheat dt Distance Distance 19 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

20 Flooded evaporator without Po optimization Temperatur Pinch point Air temp Evaporation temp dt Temperatur Pinch point Air temp dt Evaporation temp Distance Distance Temperatur Pinch point When the pinch point is moved and larger the evaporation temperature can be lifted Air temp Evaporation temp dt Temperatur Pinch point Air temp Evaporation temp dt Distance Distance 20 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

21 Flooded evaporator and Po optimization Temperatur Pinch point Air temp Evaporation temp dt Temperatur Pinch point Air temp Evaporation temp dt Distance Distance Temperatur Pinch point Evaporation temp When the pinch point is moved and larger the evaporation temperature can be lifted Air temp dt Temperatur Pinch point Air temp Evaporation temp dt Distance Distance 21 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

22 Evaporation temperature [C] Evaporation temperature as a function of superheat Data for a full multievaporator system using modulating thermostat and Po optimization. Data are from a periode of 4-7 days and Po is an average Superheat [K] 22 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

23 Temperature penalty [K] Energy penalty 5 4,5 4 3,5 3 Evaporation temperature penalty VS superheat Penalty is calculated as the difference in Po at the different superheats versus the evaporation temperature at 1K superheat. For energy is used 2,5%/K. 12% 10% 8% 2,5 6% 2 1,5 4% 1 0,5 2% Superheat 0% 23 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

24 Next generation: Low pressure lift ejectors for small systems The Low pressure lift ejector system can be used for smaller applications Simple setup very much like a booster systems Can also be combined with liquid ejector and in warm periods there is no need for suction accumulator (receiver will work as suction accumulator) GC MT LT 24 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

25 Next generation: Low pressure lift ejectors for small systems Pros: Very promising results from the tests running Cost savings and energy savings go hand in hand. Suited for systems small systems Simple system Flooded evap. Is easy to implement 16 28% saving in Amsterdam Vs R404A Cons: Only limited results from the field (only 3 systems in operation) Patents can be a problem in some regions (not in Holland) Application: Condensing units, smaller supermarket systems. 25 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

26 Energy savings and Pay back

27 Energy saving CO 2 VS R404A 20% 15% 10% 5% 0% -5% -10% -15% CO2 Booster system Parallel compression Parallel + ejector 27 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

28 30% Energy saving CO 2 VS R404A Amsterdam Athens Berlin Copenhagen London Madrid Moscow Oslo Paris Rome Sofia Stockholm 25% 20% 15% 10% 5% 0% CO2 Booster Parallel compression Multi Ejector Solution -5% 28 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

29 Pay back 75 kw system VS Booster Pay back parallel 75 kw Pay back Multi Ejector Solution 75 kw Amsterdam Athens Berlin Copenhagen London Madrid Moscow Oslo Paris Rome Sofia Stockholm 29 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

30 Pay back 150 kw system VS booster Pay back parallel 150 kw Pay back Multi Ejector Solution 150 kw Amsterdam Athens Berlin Copenhagen London Madrid Moscow Oslo Paris Rome Sofia Stockholm 30 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

31 Pay back 300 kw system VS booster Pay back parallel 300 kw Pay back Multi Ejector Solution 300 kw Amsterdam Athens Berlin Copenhagen London Madrid Moscow Oslo Paris Rome Sofia Stockholm 31 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

32 Pay back time liquid ejector solutions in Amsterdam 4,00 3,50 3,00 2,50 2,00 1,50 1,00 0,50 - Pay back Booster + Liq 40 kw Pay back Booster + Liq 75 kw Pay back Booster + Liq 150 kw Pay back Booster + Liq 300 kw 32 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

33 Pay back for Low pressure lift ejector system Not enough data to say something precise at this moment When technology is matured there is a potential for lower cost than a booster system even on smaller systems. This combined with energy savings makes it very interesting. 33 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

34 Questions? Questions and feedback 34 Danfoss Cooling Danfoss Refrigerant Week Cool Tools Sept. 2017

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