IIAR Technical Program Highlights Industry Issues

The idea formed in Ron Worley’s mind six years ago when he began auditing ammonia refrigeration systems at Nestlé, where he was a manager of refrigeration engineering before his retirement.

As he collected data, he discovered there was not a standardized tool to determine if there was adequate ventilation in the machinery room or if the systems met required codes and standards. With 60 facilities to audit, that presented a problem. So he invented the machinery room ventilation calculation tool, or MRVCT.

The MRVCT, introduced at this year’s annual Conference and Heavy Duty Equipment Show in Nashville, is one of eight workshops or technical papers that cover a range of technical issues and innovations.

The MRVCT works by automatically providing calculations for data applicable to a specific code or standard. It will also determine if the ventilation system was in compliance with the codes or standards in effect at the time of installation – all the way back to the early 1990s – for all refrigerants.

“It will tell facilities what size ventilation systems they need, what parts of the system are meeting code and what parts are not,” Worley said.

The tool isn’t intended to replace a registered professional engineer in determining the design of a ventilation system, but it is being used across the industry to supplement existing design protocols.

Meanwhile, another conference workshop will look at optimizing the applications of industrial heat pumps by examining how they provide savings, energy reduction, CO2 emissions reduction and sustainability benefits to the end user.

“There is a lack of knowledge on how to even go about applying heat pumps,” said Sam Gladis of Emerson Climate Technologies, who will run the workshop. “This is an educational opportunity based on our experience discovering what works under certain operating conditions.”

Three options will be presented for optimizing the applications of industrial heat pumps, which involve: the base load strategy, the dedicated host compressor and the condenser unit.

The industrial heat pump reduces energy consumption and cost because the majority of what can be conserved is fossil fuel energy. At the same time, the amount of water being used by outside condensers and chemicals is reduced because waste heat is no longer expelled into the atmosphere. It is instead converted by high pressure compressors into gas that is used to heat cold water normally serviced by boilers.

This year, IIAR technical program participants will also compare evaporative and air-cooled condensing for ammonia systems with a technical paper presented by Doug Scott, president of VaCom Technologies.

Scott’s paper details a study that analyzed a medium-sized refrigeration facility on an hourly basis for one year, using a variety of climate conditions, electric rates and operating loads to assess the costs of evaporative versus air-cooling condensing.

“Historically, most ammonia systems have used evaporative condensing,” he said. “The advantage of aircooling condensing is that it doesn’t consume water or require water treatment. Water is becoming more expensive and sometimes isn’t available.

The intent [of the study] was to provide an accurate assessment of the energy use, including the costs and differences between the two methods of condensing. If you want to use aircooled condensing, it’s important to know the pros and cons.” The study reveals additional options for ammonia refrigeration systems. “While not comparing HFC and ammonia efficiencies, the result tells us that if you must use air-cooled systems, ammonia is still the best refrigerant,” Scott said. “The conclusion was that from an operating cost standpoint, air-cooled is reasonably competitive in much of the country.”

In addition to the papers and workshops that focus on system optimization, safety will also be a hot topic covered by IIAR’s program.

Kim Snowden, of Snowden Engineering, will discuss options for ammonia refrigeration machinery exhaust treatment that can substantially reduce off-site consequences and aid emergency responders in the case of a liquid release.

Most ammonia refrigeration rooms vent directly into the atmosphere. That’s in line with code regulations, but established protocol can leave emergency responders in a bind if there is a large liquid release. Snowden will present two options to reduce ammonia concentration before it discharges into the atmosphere.

One option involves a scrubber pipe, which is a dedicated piece of equipment that enables air from the engine room to discharge through the scrubber and disperse through water, removing much of the ammonia. However, large quantities of fresh water make-up are needed, and ammonia-tainted water from scrubbing must be addressed, making this technique expensive.

Snowden’s less costly alternative is to use a condenser to dilute the ammonia. In this case, discharged air from the engine room mixes with fresh air so that the ammonia that is discharged is greatly diluted.

“The decision on which option to use depends on the proximity of the surrounding population,” said Snowden. “If you have some flexibility, you’d go with the dilution method. It’s a much cheaper approach and you won’t have waste water to deal with afterward.”

Conducting a Layers of Protection Analysis is a topic that will also be examined by Peter Jordan, president of MBD Risk Management Services. His technical paper discusses the layers of protection, or LOPA, in an ammonia refrigeration system. Jordan looks at high-risk scenarios for which large facilities can do a protection analysis.

“This technique takes certain scenarios and determines if a facility has proper protection,” he said. “Probability and frequency estimates determine how likely a scenario is to occur, how severe are the consequences, and does a facility have enough layers of protection to prevent it from occurring.”

The paper will apply LOPA to five high-risk scenarios: A high discharge on the output of a compressor; high levels in a vessel that provide suction to a compressor; low levels of a vessel that provide suction to a pump; leaks in the engine room during transfer operations and leaks in a liquid pipe in a production area.

“I wouldn’t encourage everyone to go out and do a LOPA,” Jordan said. “This is only good for these high-risk scenarios.”

In total, IIAR’s 2014 technical program consists of eight technical papers, eight workshops, a research panel, an international panel and a closing forum which will highlight the characteristics and applications of small charge ammonia systems.