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2003 IIAR Technical Papers
25th Annual Meeting
Comparing R-134a Chillers versus Packaged Ammonia Chillers for Air-conditioning Applications
Author: Holger Tychsen
Packaged ammonia chillers (PACs) are similar to R-134a chillers. Both are factory-assembled refrigeration systems that use conventional refrigeration drivelines. PACs are becoming increasingly popular for non-air-conditioning applications. In this paper, the author analyzes ammonia's competitiveness in the water-cooled screw chiller air-conditioning market and discusses lifecycle costs, first costs, current technology, and provides some insight into future technologies.
Lessons Learned: OSHA PSM Inspection of a Food Processing Plant with an Ammonia Refrigeration System
Author: Myron L. Casada, P.E. and Daniel L. Machiela
OSHA inspected a food processing plant with an ammonia refrigeration system that was covered by process safety management (PSM) regulations. This paper describes some of the lessons learned from the inspection and discusses how these lessons could be pertinent to other ammonia refrigeration facilities. The paper also addresses how to manage PSM inspections to best answer OSHA’s questions while still meeting facility objectives.
Central Plant Chiller Systems: Ammonia vs. R-134a
Author: Robert P. Port, Jr.
The relative merits of using ammonia vs. R-134a will receive increasingly greater attention as the phase-out date for R-22 approaches. Through case studies of two plants, this paper examines the relevant issues regarding the use of ammonia vs. R-134a, including how the fundamental thermodynamic properties of the two refrigerants affect the design of real world refrigeration systems. It also compares first costs and operating costs for chillers or central plant refrigeration systems, and the advantages and disadvantages of ammonia systems vs. R-134a systems. Finally, the paper examines the costs of addressing regulations for ammonia vs. R-134a, and compares the code requirements for design and installation using each refrigerant.
What Is TRUE Compliance With PSM and RMP?
Author: Mike Chapman
In the course of doing business, PSM/RMP teams occasionally find things that seem to “slip through the cracks.” This paper describes how to make sure that nothing is overlooked, including how to stay in compliance, how to avoid penalties in an audit, what to look for prior to an audit, what to expect during an audit, and how to maintain your Operating Procedures, P&lDs and maintenance programs. The paper also outlines how to keep your team in ship shape with a topnotch emergency response program and true coordination with local emergency responders.
Low-Charge Ammonia Plants: Why Bother?
Author: Andy Pearson, CEng
Technical, commercial, and legal developments have motivated a re-examination of ammonia refrigeration system design in some European countries and the United States. This fresh start has produced new concepts, such as the use of plate heat exchangers, spray chillers, and low-pressure receiver systems, and more recently, the development of ammonia/carbon dioxide cascade systems. This paper reviews the various ways in which reduced-charge systems can be engineered for different applications, and suggests some further ways in which the ammonia market may develop over the next few years.
Case Study: Effectively Remediating an Ammonia Release in an Operating Freezer
Author: Charles M. Chambers and Ken Williams
On a summer night in 2002, a 5-inch valve split open and ammonia was released into two connected cold store rooms. The remediation team effectively coped with several challenges, including working against tight time constraints, the close proximity of the facility to the fence line, and preserving as much of the product as possible. This paper describes how portable monitors were used to provide feedback on the effectiveness of actions taken to remove the ammonia. The remediation team applied innovative procedures for ventilation and removal specifically adapted to the prevailing conditions. They met each challenge and removed the ammonia quickly and safely leaving no hazardous residue.
Preventing and Controlling Condensation in Meat Packing Plants
Author: Klaas Visser
Condensation has a negative impact on food safety in meat packing plants, and is difficult to prevent, control, and remove. This paper analyzes the factors that promote condensation, and provides guidance on refrigeration and air handling design procedures that can prevent moisture infiltration and quickly remove moisture after wash down. The paper also details refrigeration cycle control methods for hot boxes. Finally, the paper discusses control of condensation in different types of buildings and provides recommendations on minimizing the influence of high thermal inertia in heavy buildings.
IIAR’s Ammonia Refrigeration Management Program: Helping Small Plants Cope with Regulatory Issues
Author: Peter Jordan
Plants containing refrigeration systems with ammonia charges of less than 10,000 pounds are typically not subject to OSHA’s Process Safety Management (PSM) or EPA’s Risk Management Program (RMP) regulations. Still, these facilities must operate safely and responsibly, complying with other government regulations, including the General Duty Clause. Often, these plants do not have the time, resources, or knowledge to cope fully with these requirements. This paper describes how refrigeration contractors and facility personnel can use IIAR’s newly developed Ammonia Refrigeration Management (ARM) program to ensure that refrigeration systems in relatively small plants operate safely and comply with relevant regulations.
Thermosiphon System Design
Author: Jeff Welch, P.E.
For operations and maintenance reasons, thermosiphon systems have become a very popular oil cooling method among designers. While many systems are installed every year, problems still occur because of incomplete understanding of how these systems should be designed and installed. This paper presents a theoretical method for modeling a flooded or thermosiphon system that designers can use to obtain more precise and economical designs, and also to analyze systems that do not perform as required. The paper also presents a listing of design guidelines and precautions.
Ammonia/C02 Cascade System in a Large Freeze-Drying Plant: Lessons Learned During Installation and Commissioning
Author: Paul Homsy
For most installations, project managers are faced with difficult choices: “Good, Fast, Inexpensive: Choose Two.” In response to this challenge, one company employs a rigorous quality control assessment, known as a “Technical Installation Risk Analysis” (TIRA). In a TlRA exercise, the project manager assesses the risks involved with ensuring the quality of an installation while addressing practical installation issues. TlRA is highly focused on the plant’s reliability and longevity This paper describes the TIRA exercise as it was performed on a large cascade project, highlighting the difficulties encountered during installation and commissioning as well as the lessons learned. This installation has now been running successfully for more than two years.
Introducing a New Ammonia/C02 Cascade Concept for Large Fishing Vessels
Author: Per Skaerbaek Nielsen and Thomas Lund
Until recently, fishing vessels could use R-22 to preserve the catch, but this refrigerant is no longer an option in many areas. Ammonia has always been an efficient alternative, but has been perceived as difficult and expensive to handle on the production deck of fishing vessels. Combining the strengths of two environmentally friendly and efficient refrigerants, ammonia and CO2, and using standard industrial refrigeration components, a cascade refrigeration solution was developed for this application. This paper discusses the technical challenges, solutions, and benefits of these types of systems.
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