As ATMOsphere America draws near, we are proud to announce the latest case study selections, featuring innovative technologies using ammonia, CO2 and even water from industry trailblazers Bitzer, Carnot Refrigeration, Isotherm, Alfa Laval, Accent Refrigeration Systems, Broad USA, Gas Technologies Institute, Rebound Technologies and Heat Transfer Technologies.
Bitzer - “Industrommercial” Part II: NH3 Systems in SupermarketsWhile CO2 Booster systems are becoming the defacto future choice of northern climates, the obvious solution for southern regions is more difficult to find. One possibility gaining traction is the use of CO2/NH3 cascade systems. The study will look at the different technology used in NH3 systems that have been installed in supermarkets; however, each of the pilot stores have taken very different avenues. Citing four current installations, Joe Sanchez will compare the technologies, including energy efficiency analysis and energy / operational costs, so that the future designers and end users are more informed about what style of system to pursue.
Carnot – Eco efficient cooling system for large cold storage
Carnot Refrigeration has experience with more than 30 projects of CO2 transcritical cooling system retrofits for supermarkets and ice rinks. It is sometimes difficult to make a theoretical calculation of energy comparison because several operational factors influence the energy consumption of each site. Among the many sites that were renovated, two supermarkets and three arenas are good examples of "before - after" since the area and use has remained substantially the same. This case study will demonstrate how the use of Carnot Refrigeration cooling systems was able to generate a considerable saving to the level of consumption of energy at these sites.
Isotherm - “Thin film Low Charge Evaporator at Winery Plant”
As the industry evolves, low-charge systems are becoming crucial in ammonia-based industrial refrigeration. This case study examines a new and patented thin film low charge evaporator, designed and fabricated by Isotherm, Inc., at a winery plant in California. The operational data was analyzed based on the temperature pull down. Comparing the field data to the design parameters, the evaporator showed close agreement. A quick comparison of this new chiller and a conventional flooded chiller is also presented. With the chiller operating successfully in the winery plant, the goal is to have this new chiller introduced in the broader industrial refrigeration market.
Alfa Laval - Innovative Ultra Low Charge Shell& Plate Ammonia Evaporator with integrated separator
The market requirement for low-charge ammonia systems is increasing in most parts of the world. It is also of interest to make systems more compact and provide solutions with integrated functionality. This study will describe a unique design of a plate optimized for flooded ammonia evaporation where all the needed functionality is integrated into the plate and the shell. It comprises area for separating liquid and gas as well as space for separating oil and liquid. The liquid drop leg is also integrated into the plate. The plate design also comprises features to improve the separation of gas and liquid as well as distribution of brine over the heat transfer area in order to enhance heat transfer. The plate can also be used as a condenser. The compact design enables high efficiency operation at ammonia charges less than 40 g/kW.
Accent Refrigeration Systems - Community Energy Sharing System
The Westhills Recreation Centre in Langford, British Columbia, is the centerpiece for one of the fastest growing communities in Canada. The 75,000-sq. ft. facility consists of an NHL-size indoor ice rink, an outdoor ice rink and a skating trail joining the two rinks together. The facility also houses a 20-lane bowling alley, restaurant/lounge, party rooms and 10,000 sq. ft. of leased office space with multiple sport- related tenants. The outdoor ice rink was designed with embedded refrigeration piping for winter ice and water fixtures to convert it into a children’s splash park in summer, making use of the same footprint for both summer and winter. The facility eliminated its natural gas consumption by using waste heat from the refrigeration system to satisfy all heating loads, and any remaining waste energy is pumped to a growing housing development for household heat pumps. In order to supply the balance of heat in the housing development two 180 ton VFD- driven ammonia heat pumps that use a geothermal field below a soccer field were designed as the energy source. The ammonia heat pumps are only required in the winter and operate at COPs ranging from 8 to 15. The heat pumps maintain the housing energy loop at a constant 60F, which results in very favorable COPs for the household heat pumps.
BROAD USA - Using Absorption with Natural Refrigerant R718 for HVAC as well as process systems
This presentation will simplify the key points relating to how one can utilize natural refrigerants to do the same thing that manmade chemical refrigerant based systems are required to do. It will also show how these systems can be applied in a few different types of building for a lower total cost of ownership and substantially lower carbon footprints. The case study will also demonstrate how these modern systems can be installed and monitored for the life of the project. Surprisingly for the projects highlighted there is little or no need for operating staff on behalf of the end user. All three systems will run automatically without the need for human intervention or decision-making. Lastly. the systems are extremely environmentally friendly as they all have greatly reduced carbon footprints when compared to systems using electric grid delivered systems using chemical refrigerants.
Gas Technologies Institute - Field Trial of Residential Ammonia-Water Absorption Heat Pump Water Heaters
In this case study, the Gas Technology Institute (GTI) reports on their experience during field trials of six pre-commercial prototypes of a residential gas-fired heat pump water heater (GHPWH), with an estimated measured energy efficiency over twice that of baseline equipment. The GHPWH is based on the single-effect vapor absorption cycle, using the ammonia-water working fluid pair. Similar to commercially available heat pump water heaters using a conventional vapor compression cycle, the GHPWH is an air-source heat pump and has an integrated design, mating the absorption heat pump and storage tank in a single package. The nominal 3kW output heat pump, driven by a 1.9kW natural gas burner, heats stored water in a nominal 80 gallon tank.
Rebound Technologies - Freeze Point Suppression Heat Pumps - A New Technology for Efficient Refrigeration & Energy Storage
This case study examines an innovative alternative to vapor compression for low temperature refrigeration. In development since 2012, the technology is now being implemented in pilot projects with the support of Southern California Edison, Whole Foods, and a large US cold storage company. The system integrates freeze point suppression cycles, ice based thermal energy storage and waste heat utilization. A solution refrigerant undergoes solid-liquid phase changes to move heat between low and high temperature reservoirs. The hot and cold side heat pump temperatures are established by the solution, rather than the pressure, as is the case in vapor compression cycles.
Heat Transfer Technologies, LLC - Advanced copper heat exchanger coils for natural refrigerants
Smaller-diameter copper tubes are attractive for use in air-conditioning and refrigeration systems that use natural refrigerants. They allow for a reduction in refrigerant charge and maintain high burst pressures with thinner walls. In an R290 air-conditioner condenser application, copper usage was reduced up to 26 percent while increasing capacity up to 6.5 percent as tube diameters were decreased from 9.52 mm (3/8 in.) and 7.94 mm (5/16 in.) to 5 mm; and tube walls were thinned from 0.41 mm (16 mils) and 0.33 mm (13 mils) to 0.25 mm (10 mils), respectively. Advantages realized using smaller diameter MicroGroove tubes in an R744 gas cooler will also be presented. Noninvasive pressure expansion techniques are emerging as a workable alternative to traditional bullet expansion methods in the manufacture of heat exchanger coils built from smaller-diameter copper tubes and are available for tubes up to 10 feet in length.
Carnot Refrigeration has experience with more than 30 projects of CO2 transcritical cooling system retrofits for supermarkets and ice rinks. It is sometimes difficult to make a theoretical calculation of energy comparison because several operational factors influence the energy consumption of each site. Among the many sites that were renovated, two supermarkets and three arenas are good examples of "before - after" since the area and use has remained substantially the same. This case study will demonstrate how the use of Carnot Refrigeration cooling systems was able to generate a considerable saving to the level of consumption of energy at these sites.
Isotherm - “Thin film Low Charge Evaporator at Winery Plant”
As the industry evolves, low-charge systems are becoming crucial in ammonia-based industrial refrigeration. This case study examines a new and patented thin film low charge evaporator, designed and fabricated by Isotherm, Inc., at a winery plant in California. The operational data was analyzed based on the temperature pull down. Comparing the field data to the design parameters, the evaporator showed close agreement. A quick comparison of this new chiller and a conventional flooded chiller is also presented. With the chiller operating successfully in the winery plant, the goal is to have this new chiller introduced in the broader industrial refrigeration market.
Alfa Laval - Innovative Ultra Low Charge Shell& Plate Ammonia Evaporator with integrated separator
The market requirement for low-charge ammonia systems is increasing in most parts of the world. It is also of interest to make systems more compact and provide solutions with integrated functionality. This study will describe a unique design of a plate optimized for flooded ammonia evaporation where all the needed functionality is integrated into the plate and the shell. It comprises area for separating liquid and gas as well as space for separating oil and liquid. The liquid drop leg is also integrated into the plate. The plate design also comprises features to improve the separation of gas and liquid as well as distribution of brine over the heat transfer area in order to enhance heat transfer. The plate can also be used as a condenser. The compact design enables high efficiency operation at ammonia charges less than 40 g/kW.
Accent Refrigeration Systems - Community Energy Sharing System
The Westhills Recreation Centre in Langford, British Columbia, is the centerpiece for one of the fastest growing communities in Canada. The 75,000-sq. ft. facility consists of an NHL-size indoor ice rink, an outdoor ice rink and a skating trail joining the two rinks together. The facility also houses a 20-lane bowling alley, restaurant/lounge, party rooms and 10,000 sq. ft. of leased office space with multiple sport- related tenants. The outdoor ice rink was designed with embedded refrigeration piping for winter ice and water fixtures to convert it into a children’s splash park in summer, making use of the same footprint for both summer and winter. The facility eliminated its natural gas consumption by using waste heat from the refrigeration system to satisfy all heating loads, and any remaining waste energy is pumped to a growing housing development for household heat pumps. In order to supply the balance of heat in the housing development two 180 ton VFD- driven ammonia heat pumps that use a geothermal field below a soccer field were designed as the energy source. The ammonia heat pumps are only required in the winter and operate at COPs ranging from 8 to 15. The heat pumps maintain the housing energy loop at a constant 60F, which results in very favorable COPs for the household heat pumps.
BROAD USA - Using Absorption with Natural Refrigerant R718 for HVAC as well as process systems
This presentation will simplify the key points relating to how one can utilize natural refrigerants to do the same thing that manmade chemical refrigerant based systems are required to do. It will also show how these systems can be applied in a few different types of building for a lower total cost of ownership and substantially lower carbon footprints. The case study will also demonstrate how these modern systems can be installed and monitored for the life of the project. Surprisingly for the projects highlighted there is little or no need for operating staff on behalf of the end user. All three systems will run automatically without the need for human intervention or decision-making. Lastly. the systems are extremely environmentally friendly as they all have greatly reduced carbon footprints when compared to systems using electric grid delivered systems using chemical refrigerants.
Gas Technologies Institute - Field Trial of Residential Ammonia-Water Absorption Heat Pump Water Heaters
In this case study, the Gas Technology Institute (GTI) reports on their experience during field trials of six pre-commercial prototypes of a residential gas-fired heat pump water heater (GHPWH), with an estimated measured energy efficiency over twice that of baseline equipment. The GHPWH is based on the single-effect vapor absorption cycle, using the ammonia-water working fluid pair. Similar to commercially available heat pump water heaters using a conventional vapor compression cycle, the GHPWH is an air-source heat pump and has an integrated design, mating the absorption heat pump and storage tank in a single package. The nominal 3kW output heat pump, driven by a 1.9kW natural gas burner, heats stored water in a nominal 80 gallon tank.
Rebound Technologies - Freeze Point Suppression Heat Pumps - A New Technology for Efficient Refrigeration & Energy Storage
This case study examines an innovative alternative to vapor compression for low temperature refrigeration. In development since 2012, the technology is now being implemented in pilot projects with the support of Southern California Edison, Whole Foods, and a large US cold storage company. The system integrates freeze point suppression cycles, ice based thermal energy storage and waste heat utilization. A solution refrigerant undergoes solid-liquid phase changes to move heat between low and high temperature reservoirs. The hot and cold side heat pump temperatures are established by the solution, rather than the pressure, as is the case in vapor compression cycles.
Heat Transfer Technologies, LLC - Advanced copper heat exchanger coils for natural refrigerants
Smaller-diameter copper tubes are attractive for use in air-conditioning and refrigeration systems that use natural refrigerants. They allow for a reduction in refrigerant charge and maintain high burst pressures with thinner walls. In an R290 air-conditioner condenser application, copper usage was reduced up to 26 percent while increasing capacity up to 6.5 percent as tube diameters were decreased from 9.52 mm (3/8 in.) and 7.94 mm (5/16 in.) to 5 mm; and tube walls were thinned from 0.41 mm (16 mils) and 0.33 mm (13 mils) to 0.25 mm (10 mils), respectively. Advantages realized using smaller diameter MicroGroove tubes in an R744 gas cooler will also be presented. Noninvasive pressure expansion techniques are emerging as a workable alternative to traditional bullet expansion methods in the manufacture of heat exchanger coils built from smaller-diameter copper tubes and are available for tubes up to 10 feet in length.
