The ATMOsphere Review Panel has announced its first round of case studies selected for ATMOsphere Europe 2015, which will take place on 16 & 17 March in Brussels, Belgium. The case studies cover a range of applications including commercial, industrial and transport refrigeration, heat pumps and HORECA.
Advansor, CAREL, Thermo King, Frigo-Consulting, Johnson Controls, Green Cooling, AF Consulting and the Universitat Politècnica de València / Università degli Studi di Napoli Federico II will be presenting their innovative natural refrigerant technology case studies at the 6th ATMOsphere Europe conference.Commercial refrigeration
Transcritical CO2 retail technologies taking Southern tracks by Torben Hansen, Advansor
The new F-gas regulation has put the pressure on end users to find low GWP alternatives. While transcritical CO2 has been proven in Northern Europe, where lower energy consumption and attractive ROI are no longer debated, the challenge remains in proving the solution suitable for the Southern European Region. The standard process used in Northern Europe is both inexpensive and uncomplicated; yet, it does not show good energy savings when applied in Southern European climatic conditions.
However, from a technical perspective, a wide range of CO2 technologies are already on the radar for Southern European applications: parallel compression, mechanical sub cooling and various techniques incorporating ejectors. While most are well described in available literature, only few field tests have been published so far. Some Southern European end users have doubts about what their future design and refrigerant strategy will look like. During 2014, Advansor built 10 systems with different designs for operation in Romania, Piemonte and in Spain. This case study presentation will evaluate these different designs on both complexity and energy performance.
BLDC waterloop systems in commercial refrigeration: the new frontier for natural refrigerants by Diego Malimpensa, CAREL
In 2014, a new type of refrigeration system was successfully introduced on the refrigeration market and is now receiving growing attention from the industry. Water-cooled self-contained refrigeration units have been used in the HVAC&R industry for years, for example in air conditioning and, in the past, in the refrigeration industry. What is new is the possibility to use BLDC rotary/scroll compressors that drastically improve the energy efficiency levels compared to standard applications with compressor racks and remote cabinets.
A BLDC waterloop system for commercial applications is a simple system in which each cabinet has its own small refrigeration system (self-contained) with a dedicated modulating compressor. The compressor is mounted in a box on top or below the cabinet. The heat generated by the compressors is not directly released (as in standard plug-ins) but is driven outside by a waterloop cooled down by a simple dryer. Because every compressor is working at its own best possible working condition, the wide range of modulation and the higher efficiency at partial load permit up to 25% increases in energy saving compared to similar on/off systems. These systems are also suitable for warm climates.
While such systems are already available with HFCs, CAREL is now adding the benefits of natural refrigerants to the system, pioneering the research and testing of the BLDC waterloop system with propane and CO2. The case study will present data from sites running with R410A and will compare them with lab tests done with propane and CO2.
CO2 refrigeration system for tropical region by Erik Wiedenmann, Frigo-Consulting
Since the beginning of November 2014, groceries at the Migros branch in Ibach, Switzerland have been cooled at evaporation temperatures of -2°C resp. -25°C, compared with conventional refrigerating units with average values of -8°C and -33°C. These extremely high temperature levels in commercial refrigeration are setting new benchmarks worldwide. During the remodeling of the supermarket, an advanced CO2 refrigeration system was installed, which supplies 170 metres of medium and low temperature cabinets and 280m2 of cold rooms and freezers with cooling capacity. Two identical CO2 booster units provide an unprecedented total of 250 kW of refrigerating capacity.
The significant increase in efficiency compared with conventional CO2 refrigeration systems is attributable to three effects. First off, both of the CO2 refrigeration units are designed so that all medium and low temperature evaporators can be operated “partially flooded” which increases the heat exchange efficiency of the evaporators and guarantees the product temperature despite the higher evaporation temperatures. A major contribution to the boost in efficiency is reached by using five ejectors per CO2 refrigeration unit. These five ejectors allow the system to react to all operating conditions and load situations and ensure the highest possible operational reliability. The combination of ejectors and parallel compressors allows for the recovery of energy released during expansion and for the reduction of internal throttling losses. Last but not least, the CO2 refrigeration systems are cooled in the summer months by groundwater, which allows for a reduction in the high pressure of the units and enables more efficient operation. After one year of operation, these three effects have resulted in an annual increase in efficiency of at least 25%.
Industrial refrigeration
Cranswick Country Foods (UK) by Ilse Derijck, Johnson Controls
The case study will discuss Johnson Controls’ collaboration with a leading UK food supplier, Cranswick Country Foods, to optimize the new industrial refrigeration system of their pig abattoir in Watton, Norfolk. By installing Sabroe industrial refrigeration heat pump reciprocating compressors, Johnson Controls was able to reduce the food supplier’s energy costs by £500K per year, increase the productivity by 30% and decrease the weight loss of the carcasses from 2,3% to 1,4%. This solution set a new standard for the industry, as it not only monitors and trends the performance of the plant, but it actively hunts for optimal set points to reduce energy usage. In addition, monitoring energy relating ancillaries were installed to prove the functional advantages.
The project involved the replacement of nearly 30 year old, light industrial refrigeration HFC equipment. The new equipment installed included Sabroe industrial refrigeration heat pump reciprocating compressors, an industrial refrigeration system consisting of a 4 stage ammonia/glycol system for low temperature pallet blast and pre chill, medium temperature equalisation rooms, factory air conditioning, heat pumps for 65c water and ISAC hardware and software for the SCADA control system of the site. Overall, the financial return on investment is £4M for the complete project in less than 3 years of operation. In addition, the heat pumps reduced the Cranswick site’s dependency on natural gas. The solution provides cooling and heating capacities of 3 mega-watts and 650 kW respectively and provides standby facility throughout the factory.
CO2 transcritical in a freezing factory by Paul Rivet, AF Consulting
AF Consulting will present a case study about a freezing factory, which, since mid 2014, has produced frozen cooked small fish portions called “bouchons.” The plant includes two continuous freezers with a capacity of 350 kW at -40°C, frozen storage rooms (100 kW capacity at -25°C) and working areas for 150 kW at +8/+10°C. Such plants usually use ammonia as the refrigerant; however, this particular case employs transcritical CO2.
The decision to use CO2 came about during the preliminary planning, due to the geographical situation, constraints of the French ammonia regulations and concerns for safety of workers and stored products. Several solutions were investigated including direct pumped NH3, direct pumped HFC, hybrid CO2/NH3 and full CO2. Taking into account investment, running costs, safety, service and the possibility for heat recovery, transcritical CO2 was selected and installed. The transcritical CO2 system provides advantages when the evaporation temperature is low, especially the need for heat for cooking is important, which must take place at the same time as freezing. The case study highlights the benefits of the CO2 system compared to other systems including ammonia systems.
Heat pumps
A propane water-to-water heat pump booster for sanitary hot water production by J.M. Corberan, J. Gonzalvez, C. Montagud & E.Navarro-Peris, Instituto de Ingeniería Energética, Universitat Politècnica de València and R. Mastrullo, A.W. Mauro & M. Tammaro, Dipartimento di Ingegneria Industriale - Sezione ETEC, Università degli Studi di Napoli Federico II.
This study is related to one of the heat pump prototypes developed under the framework of an FP7 European Project, Next Heat Pump Generation Working with Natural Fluids (NxtHPG), which aims at the definition of five high efficiency heat pump prototypes working with natural fluids. The prototype presented in this case study is a 50 kW heat pump booster for heat recovery of waste heat from a neutral water loop with temperatures in the range of 10-30°C for domestic hot water production at 60°C. Recovery of waste heat is for example from a water condensation loop of a refrigeration system (25-30°C) or from sewage water (10-15°C). The heat pump, which has been manufactured by CIATESA, works with propane. It is currently being measured at the Institute for Energy Engineering (IIE) laboratory of the Universitat Politècnica de València (UPVLC).
This case study will discuss the main characteristics of the design, construction and performance of the heat pump prototype and will present experimental measurements obtained during the first experimental campaign of the prototype. At the moment, different possibilities for producing a variable subcooling and controlling it to approach the optimum value are being investigated and this presentation will highlight the first results. It will also present an integrated model of the system developed in TRNSYS including the heat pump, the neutral loop, the controls and the thermal load. This model has been used to optimise the operation of the unit, to assist in the design of the system and to assess the yearly performance of the system.
Other applications (transport & HORECA refrigeration)
Thermo King CryoTech equipped trailers that use 25% of the total energy and generate 75% less emissions than an equal-sized domestic refrigerator by Duygu Seker, Thermo King
Thermo King will present its CryoTech technology for transport refrigeration, which uses liquid R744 in an open-loop system, delivering efficient refrigeration and significant reductions in emissions while improving performance compared to conventional diesel-powered units. The recovered R744 used for cooling is obtained as a by-product of industrial processes that would otherwise have been released into the atmosphere. As such, there are no new CO2 emissions during operation of the CryoTech system. The technology reduces the transport refrigeration equipment carbon footprint by up to 90% compared to conventional refrigeration units.
The CryoTech units feature faster temperature recovery compared to diesel driven refrigeration and allow for up to four times faster temperature pull-downs, which is crucial in situations where the cooling unit is often interrupted as drivers deliver goods to multiple locations. With better temperature management, less of the perishable goods being transported go to waste. CryoTech units are PIEK certified with noise levels below 60dB(A) without compromising performance. Nearly 1000 CryoTech units are currently on European roads. This case study will highlight an example with Delhaize Belgium, the first retailer in Belgium to use CryoTech technology. Estimations have shown that the CryoTech equipped Delhaize trailers use only 25% of the total energy and generate 75% fewer emissions than an equal-sized domestic refrigerator. The scope of the project includes the installation of Thermo King CT15 units on 10 normal trailers with a length of 13.6 meters and on five city trailers with a length of 10.5 meters.
CO2 food service refrigeration system installed at Canary Wharf London by Garry Broadbent, Green Cooling
This case study focuses on the creation of a new 1,500 cover restaurant to cater to a new refurbished office complex located in a high rise tower at the Canary Wharf business area in London’s docklands. The main contractor, Overbury, provided project management and overall coordination for the client, KPMG, whilst food service contractor Berkeley Projects provided all of the contract elements related to the catering facility design and installation. One of the main project requirements was to achieve BREEAM accreditation (UK sustainable building design standard using an accumulated points system based on sustainability and efficiency of the installed design) to satisfy the planning/design demands for the project as a whole. Due to this requirement, the food service consultant Humble Arnold turned to CO2 specialist Dave Blinkhorn of Green Cooling to provide a refrigeration system design.
To ensure the highest levels of operational performance and efficiency, Green Cooling specified CO2 as the refrigerant operating within the refrigeration system. A twin refrigeration Enex CO2 pack design utilising a total of 6 Dorin compressors was chosen. In addition, a 4,500 litre hot water production system was incorporated within the CO2 system design to ‘upcycle’ and reuse the waste heat from the refrigeration system to provide an increased level of overall system efficiency.
The CO2 system provides the facility with a high efficiency and sustainable cooling system that matches the flexible and variable load conditions found within a busy restaurant environment. Cold rooms and kitchen refrigeration systems are satisfied by the BREEAM compliant CO2 system, which enables the complete catering facility to benefit from an efficient and sustainable design. This system is seen as a major step forward in the UK HORECA market, as this type of sustainable approach to refrigeration is normally only the preserve of the large capacity retail sector. Especially the integration of hot water production with cooling was an important aspect of the project, as in practice, this can be challenging due to the fact that the two disciplines of food service design and mechanical services design do not normally communicate. The case study will show how Green Cooling was able to design and specify their integrated cooling and heating system.
About ATMOsphere Europe 2015
16 & 17 March 2015 at the Crowne Plaza Le Palace Hotel in Brussels, Belgium
The meeting place for HVAC&R industry experts to discuss the latest natural refrigerant technology developments, market trends and regulatory issues returns for its 6th edition. To find out more about programme highlights, please visit www.ATMO.org/europe2015/programme.
To register for the event, please visit www.ATMO.org/europe2015/registration
