1990 IIAR Technical Papers
  Memphis, TN
 12th Annual Meeting

CFC Issue - Update
Author: Sydney M. Miner, P.E.

In my report to you last year on this subject, I covered several aspects of IIAR activities and Ammonia as an alternative refrigerant. This year I will leave it to others to report on the work of IIAR in the areas of NH3 research, OSHA, TLV's, etc. I will limit my remarks to the basic CFC issue update. Reference to our own Government Relations and CFC committees can provide more detailed information and on an ongoing basis - particularly on any aspects relating to NH3. Also, those of our members who are affiliated with ARI or The Alliance will find they keep a very detailed file on all activity - as well as creating much of their own - relating to all aspects of the CFC issue.
Refrigeration Lubricants Update: Synthetic and Semi-Synthetic Oils are Solving Problems with Ammonia and Alternative Refrigerants 
Author: Glenn D. Short

The use of synthetic lubricants in positive displacement refrigeration compressor systems is a fast-growing trend. Synthetic lubricants are being developed to improve reliability and increase efficiency in refrigeration compressors and maximize system performance. The status of the evaluation of specific lubricants through bench tests and field performance is discussed with specific reference to ammonia and "alternative" refrigerants. This paper reviews the field performance of ammonia refrigeration oils from superyrefined, hydrotreated high-viscosity index (HVI) base stocks. The development of these lubricants was described in "Hydrotreated Oils for Ammonia Refrigeration." [Short (1985)]. Case studies are provided by original equipment manufacturers and refrigeration plant operators. These reports confirm that these synthetic fluids provide longer life, reduced wear, cleaner operation, and a thirty to ninety percent reduction in oil consumption. Synthetic oils are being designed to provide miscibility with HFC-134a and other fluorinated refrigerants for use with flooded evaporators. The status of lubricant development and performance is discussed. The development of a more efficient lubrication system using synthetic lubricants with HFC-134a is described.
Packaged Ammonia Rooftop or Outdoor Refrigeration Systems
Author: David A. Lueders

This paper will focus on three concerns to the marketplace (Designers, Owners, & Contractors) when applying ammonia to three typical refrigeration applications. These three applications are: Rooftop mounted air cooling units - direct ammonia. Rooftop or outdoor mounted HVAC Units for use in office buildings using water or glycol chillers to assure no refrigerant leak into air stream. Outdoor installation of larger glycol chillers and/or icebuilders for larger office buildings or industrial applications where ammonia inside the building may be politically undesirable. The three concerns that are at issue when designing, installing and operating a refrigeration system are: Design issues relative to application of ammonia refrigeration systems in an outdoor environment. Equipment package costs and installation costs. Operating and maintenance cost issues. These are the issues that will be discussed in detail in the rest of this paper.
Regulation and Reporting of Hazardous Materials 
Author: Arthur F. Christensen, P. E.

We must clean up our act and stop poisoning the environment. There has been a profusion of Federal Legislation in the last 20 years toward that end. CERCLA and its amendment SARA Title III are of particular concern to us as members of IIAR. Though the other pieces of legislation may be of equal importance to some members, they do not apply to ammonia. Therefore, only CERCLA and SARA Title III will be discussed by this paper. Time does not permit discussion of all 16 pieces of legislation in this session.
Ammonia Flares: Costs, Codes, Installation and Design Considerations
Author: James J. Shepherd

The main objective of this paper is to stimulate interest in a safe and environmentally acceptable method for disposing of ammonia in an industrial refrigeration system. A flare is a burner that is designed to oxodize waste gas originating from an ammonia refrigeration system during normal operation or during emergencies. The flare burner, or tip, is a waste gas disposal unit utilizing a high temperature oxidation process. Flares are an effective method of economically eliminating many types of gaseous waste streams. In most industrial refrigeration cases, the ammonia vapors are vented to the atmosphere. This approach presents two major problems: 1. Safety and 2. Environmental pollution.
Concentrations of Ammonia in the Vicinity of Vapor Releases 
Author: W. F. Stoecker

Ammonia is well established as a refrigerant in the industrial refrigeration sector, having many favorable thermodynamic and physical properties which leads to its frequent choice for economic and operating advantages. But ammonia has one major drawback-the low concentration levels considered toxic. Releases of ammonia must, therefore, always be managed with care, not only for the protection of those within the plant but to protect the neighbors as well. The paper addresses one of the several situations in which ammonia might be released, namely, as a vapor from a pressure relief valve. The operator should be able to predict serious release situations and as a responsible corporate neighbor guard against them. A further benefit intended for data such as provided in this paper is to work with local officials in planning community responses to releases of ammonia. This paper presents magnitudes of ammonia concentrations at various distances under several different wind speeds for several different rates of release of ammonia vapor. The graphs were derived from runs made on a computer program that is widely used in environmental studies. The program has some important limitations, and the results cannot be considered authoritative for all situations. But the predicted magnitudes of ammonia concentration suggest that the vapor release problem may not be insurmountable. An important realization uncovered by the study is that concentrations can be reduced significantly by proper stack design. A high stack that directs the release vertically upward with a high velocity is particularly effective in reducing concentrations in the neighborhood.
Gas Powered Liquid Recirculation Compared to Mechanical Pumps 
Author: James D. Wright, P.E.

The intent of this paper is to present a simplified mathematical model used to analyze the energy required to operate a Constant Pressure Liquid recirculation system. The basis for the analysis presented here grew out of an actual system design, in which there was both a 120 ton two-stage, -40F load, and a 75 ton, single stage, 0.F load. The design criteria for each type of recirculation system will be explained separately, and the calculation procedures clearly defined. The analysis has been expanded to include two other common suction temperatures, -20F two stage and +20F single stage. All the energy calculations have been normalized to a "per-100-ton" basis for convenient reference. Besides comparing operating energy with that of a pump, the analysis reveals some critical observations that result in a list of recommendations for design and operation of an efficient Constant Pressure Liquid recirculation system.
Large Central Water Chilling System Design, Cost and Energy Comparison: R-22 vs. Ammonia 
Author: Ronald A. Cole, P.E.

Since R-22 is being looked upon as the foremost candidate to replace the banned CFC's in the short term and ammonia has been identified as a potential candidate as an alternate, a comparison between the two should be useful. The vehicle for this comparison is a large water chilling system typical of that which would be used for air conditioning in a district cooling application. The system design is based on a gross cooling capacity of 8000 ton using standard commercial equipment to provide 16,000 gpm of 44 F chilled water.
R-22 vs. R717 (Ammonia) Capital and Operating Cost Comparison Studies for Refrigerated Facilities 
Author: Thomas Leighty

The question of using R-22 versus R-717 (Ammonia) as a refrigerant in the industrial refrigeration market place is much older than the consideration of the replacement of R-22 due to its environmental implications. This issue has been so important to those involved that equipment manufacturers, installing contractors and large end-users formed the International Institute of Ammonia Refrigeration several years ago to promote ammonia’s use. This paper will review a few aspects of the evaluation process frequently done by an owner/end-user, his engineering consultant, or contractor to make the decision of refrigerant choice on a project.
Refrigeration Pumps Sealed and Sealess 
Author: John Claydon, Lee Courtemanche,  Alec Iseppon, and Kenneth Wasch

There are several types of pumps utilized as the prime mover for commonly used refrigerants like freon, ammonia, and TEC. These include positive displacement types, commonly gear or sliding vane, and various centrifugal styles. Our discussion relates to the use of mechanically sealed, and hermetically sealed centrifugal pumps for refrigeration service. We will discuss the axial and radial forces which are present in a centrifugal pump, how the pump designer controls these forces and how a refrigeration system affects the outcome of the pump designer's solutions.
Gas Powered Liquid Recirculation Compared to Mechanical Pumps (Another View)
Author: Rex Brown, P.E., Ron Cole, P.E. and Vern Karman, P.E.

The increased awareness of energy costs in the last fifteen years has prompted a greater interest in the relative cost of ownership of the two types of pumping systems. There have been many debates and discussions concerning relative operating costs. This paper will continue to do that in hopes that more engineers and end users can become more knowledgeable on the subject. This knowledge can then be applied to make better decisions about design features of new systems, whether to retrofit old systems, and how to operate existing systems most efficiently. The paper attempts to recap some of the pertinent thermodynamic principles, papers that have been written on the subject, as well as some actual experiences, and several theoretical case studies. The reader is then encouraged to use this information to analyze his or her particular situation to make the necessary decisions.