Production Of Refrigeration Research Articles

Exergy analysis of gas turbine trigeneration system for combined production of power heat and refrigeration

A conceptual trigeneration system is proposed based on the conventional gas turbine cycle for the high temperature heat addition while adopting the heat recovery steam generator for process heat and vapor absorption refrigeration for the cold production. Combined first and second law approach is applied and computational analysis is performed to investigate the effects of overall pressure ratio, turbine inlet temperature, pressure drop in combustor and heat recovery steam generator, and evaporator temperature on the exergy destruction in each component, first law efficiency, electrical to thermal energy ratio, and second law efficiency of the system. Thermodynamic analysis indicates that exergy destruction in combustion chamber and HRSG is significantly affected by the pressure ratio and turbine inlet temperature, and not at all affected by pressure drop and evaporator temperature. The process heat pressure and evaporator temperature causes significant exergy destruction in various components of vapor absorption refrigeration cycle and HRSG. It also indicates that maximum exergy is destroyed during the combustion and steam generation process; which represents over 80% of the total exergy destruction in the overall system. The first law efficiency, electrical to thermal energy ratio and second law efficiency of the trigeneration, cogeneration, and gas turbine cycle significantly varies with the change in overall pressure ratio and turbine inlet temperature, but the change in pressure drop, process heat pressure, and evaporator temperature shows small variations in these parameters. Decision makers should find the methodology contained in this paper useful in the comparison and selection of advanced heat recovery systems.

Sales: Tests of theories on causality and timing

Modern theories of sales make conflicting predictions about the temporal pattern of sales, which we test using grocery scanner data. We examine both frozen orange juice, which consumers can store, and refrigerated orange juice, which is more perishable, to determine what role—if any—durability plays in the pattern of sales. We examine (1) whether sales are more frequent for national brands than for private label brands; (2) whether manufacturers, retailers, or others determine sales; (3) the distribution of prices; (4) whether sales and their effects differ for durable (frozen) or nondurable (refrigerated) products; and (5) the temporal ordering of sales. We use correlations, runs tests, probit regressions, and vector-autoregressive analyses to test our hypotheses. Some of our more striking findings are that retailers rather than manufacturers determine sales, private labels have sales as often as national brands, and that a sale of a national brand is more likely to “cause” sales of other products than is a sale of a private label product.

Systemic Analysis for Inter-Relation of Identified Critical Success Factors in Enterprise Systems Projects

While Enterprise Systems (ES) have the potential to offer benefits beyond traditional legacy systems, many organizations report that these have been less successful than originally anticipated. The difficulties of ES implementation have been widely cited in the literature but research on critical success factors (CSFs) for initial and ongoing ES implementation success is found to be fragmented. The paper presents an exploratory research study, where, particular ranked list of CSFs was first established and then used to analyze project performance in a case study of ES implementation in an airconditioning and refrigeration products industry. The CSFs identified were found to be helpful in investigating the causes for initial failure and subsequent success of the project. It was also observed that a change in attitude of top management, project management and users caused the success of the project. The study employed appropriate quantitative measures viz. statistical mean, reliability and content validity test for identification of CSFs. The case was studied using qualitative SAP-LAP (Situation-Actor-Process – Learning-Action-Performance) framework, and Causal Loop Diagramming to extend the explanatory power of CSFs in a richer framework.

Scheduling with High Variety of Customized Compound Products

Domestic appliance is an instance of manufacturing various products on clients demand with frequent changes of production. Although the technological process for each individual product is relatively simply, the variety of products, mixed orders, frequent machines changeovers, machines with unusual service policy, lack or limited storage, etc., generates quite nontrivial planning, batching and scheduling problems and furthermore of a huge size. In this paper, we present speci c real process of production of refrigerators, mathematical and graph models of the problem and an outline of solution algorithm, based the on local search approach.

Product lifecycle information acquisition and management for consumer products

PurposeThis paper aims to capture and manage the product lifecycle data for consumer products, especially data that occur in distribution, usage, maintenance and end‐of‐life stages, and to use them to provide information and knowledge.Design/methodology/approachA lifecycle information acquisition and management model is proposed, and an information management system framework is formulated. The information management system developed is then used in actual field trials to manage lifecycle data for refrigeration products and game consoles.FindingsIt has been demonstrated that valuable services can be delivered through a lifecycle information management system.Practical implicationsLifecycle information management systems can open new horizons for product design which are sustainable and environmentally sensitive. They also contribute to the wider exploration of eco‐design and development of next generation consumer products (e.g. smart home appliances).Originality/valueExisting lifecycle information systems cannot support all phases of the product lifecycle. They mainly manage the lifecycle data only during the design and manufacture stages. Lifecycle data during distribution, usage, maintenance and end‐of‐life stages are usually hard to acquire and in most cases lost. The lifecycle information management system developed can capture them, and manage them in an integrated and systematic manner to provide information and knowledge.

Solar cooling with concentrating photovoltaic/thermal (CPVT) systems

Simultaneous production of electrical and high grade thermal energy is proposed with a concentrating photovoltaic/thermal (CPVT) system operating at elevated temperature. CPVT collectors may operate at temperatures above 100 °C, and the thermal energy can drive processes such as refrigeration, desalination and steam production. The performance and cost of a CPVT system with single effect absorption cooling are investigated in detail. The results show that under a wide range of economic conditions, the combined solar cooling and power generation plant can be comparable to, and sometimes even significantly better than, the conventional alternative.

The cooling effect by an adsorption-desorption refrigeration cycle

An experiment has been carried out utilizing the activated carbon granules as an adsorbent indige-nously developed from coconut shell and carbon dioxide gas as an adsorbate in a small experimental chamber, specially designed for this purpose. Adsorption followed by removal of heat of adsorp-tion and subsequent desorption produces refrigera-tion. After a few cycles in the chamber, tempera-tures drop from 304 K to 282.5 K. Therefore, con-tinuous production of refrigeration could be achieved by a suitable mechanism. The paper describes the details of the design and fabrication of the experimental chamber, the experimental proce-dure and discusses the results obtained to assess its feasibility towards development of an alternative eco friendly refrigeration cycle for replacement of chlorofluorocarbons.

Simulation of an air conditioning absorption refrigeration system in a co-generation process combining a proton exchange membrane fuel cell

In this work, a computer simulation program was developed to determine the optimum operating conditions of an air conditioning system during the co-generation process. A 1 kW PEMFC was considered in this study with a chemical/electrical theoretical efficiency of 40% and a thermal efficiency of 30% applying an electrical load of 100%. A refrigeration-absorption cycle (RAC) operating with monomethylamine–water solutions (MMA–WS), with low vapor generation temperatures (up to 80 °C) is proposed in this work. The computer simulation was based on the refrigeration production capacity at the maximum power capacity of the PEMFC. Heat losses between the fuel cell and the absorption air conditioning system at standard operating conditions were considered to be negligible. The results showed the feasibility of using PEMFC for cooling, increasing the total efficiency of the fuel cell system.

Lactic acid bacteria associated with vacuum-packed cooked meat product spoilage: population analysis by rDNA-based methods

To determine the lactic acid bacteria (LAB) implicated in bloating spoilage of vacuum-packed and refrigerated meat products. A total of 18 samples corresponding to four types of meat products, with and without spoilage symptoms, were studied. In all, 387 colonies growing on de Man, Rogosa and Sharpe, yeast glucose lactose peptone and trypticase soy yeast extract plates were identified by internal spacer region (ISR), ISR-restriction fragment length polymorphism and rapid amplified ribosomal DNA restriction analysis profiles as Lactobacillus (37%), Leuconostoc (43%), Carnobacterium (11%), Enterococcus (4%) and Lactococcus (2%). Leuconostoc mesenteroides dominated the microbial population of spoiled products and was always present at the moment bloating occurred. Lactobacillus sakei, Lactobacillus plantarum and Lactobacillus curvatus were found in decreasing order of abundance. The analysis of two meat products, 'morcilla' and 'fiambre de magro adobado' obtained from production lines revealed a common succession pattern in LAB populations in both products and showed that Leuc. mesenteroides became the main species during storage, despite being below the detection level of culture methods after packing. Our results pointed to Leuc. mesenteroides as the main species responsible for bloating spoilage in vacuum-packed meat products. Prevention of bloating spoilage in vacuum-packed cooked meat products requires the sensitive detection of Leuc. mesenteroides (i.e. by PCR).

Wear of aluminium bronze in sliding contact with lubricated stainless steel sheet material

Aluminium bronze, well known for its good sliding properties, is frequently applied as tool material in sheet metal forming (SMF) of stainless steel, e.g. for the production of washing, refrigeration and cooking equipment. The limited hardness of the material makes it, however, sensitive to tool wear that is: volumetric wear of the tool due to sliding contact with the sheet material. Conventional wear tests like the rubber wheel abrasion test or the Taber abrader test cannot be used to simulate the interaction of the tooling with lubricated sheet material. Dedicated tribo tests are therefore conducted with the slider-on-sheet test. The aim of the research is to measure the specific wear rate of aluminium bronze at SMF-like conditions. Experimental results showed a pronounced influence of lubricant selection and sheet material selection. The measured specific wear rate varied from 10 −8 mm 3 /N m for a smooth stainless steel sheet quality to 10 −6 mm 3 /N m for a rough surface quality.

Experimental study on adsorbent of activated carbon with refrigerant of methanol and ethanol for solar ice maker

Two different working pairs, one of them activated carbon–methanol and the other activated carbon–ethanol, are used in a solar ice maker to determine ice production and refrigerant criteria in desorption and adsorption processes under similar radiation energy and environmental conditions. Experimental results show that ice can be produced with activated carbon–methanol, however, ice could not be obtained with the use of activated carbon–ethanol using the same solar ice maker with similar environments and radiation intensities. Further experiments have shown that the adsorbing and desorbing refrigerant amounts of the two working pairs gave quite different results, the activated carbon–methanol has proven to be the superior one of the two working pairs in ice production of solar adsorption refrigeration.

Computer-aided design and manufacturing of scroll compressors

Scroll type compressors have been becoming increasingly popular in refrigeration and air conditioning products due to their high efficiency, low noise, fewer components, low vibration, light weight and small size compared with other types of compressors. To design and manufacture scroll compressors, however, is not easy as their key parts have complex shapes with involute curves. A high degree of accuracy during assembly is required which brings difficulty into the manufacturing cycle. This paper presents the integrated approach of computer-aided design (CAD) and computer-aided manufacturing (CAM) for the design and manufacture of refrigeration scroll compressors. The approach is based on concurrent engineering and is implemented in Pro/ENGINEER software and Visual C++ programming. The work presented is focused on the integration of constructive solid geometry (CSG) solid modelling and CAM to effect the design of scroll compressors in particular. The involute scroll curve is created from equations. Designers can transfer the model to a manufacturing engineer for process planning, etc. The manufacturing engineer can also advise the designer if some revisions are needed and the model can even be evaluated through the Internet. Many experts can check the models and processes of design and manufacturing. Thus, solid modelling and machine tool path simulation can bridge the gap between design and manufacturing which is essential for concurrent engineering. With this approach a correct and precise solid model can be achieved, which leads to an optimal design in terms of quality, delivery time and cost. This work is essential for the manufacturing of the scroll components and their inspection on co-ordinate measuring machines (CMMs) during manufacture. This CAD/CAM system has a potential application to other complex mechanical components, as the approach is a generic one.

The Climate Change Implications of Manufacturing Refrigerants: A Calculation of ‘Production’ Energy Contents of Some Common Refrigerants

Total Equivalent Warming Impact (TEWI) analysis has been shown to be a useful aid to quantifying the climate change effect of potential emissions from the operation of systems that involve the use of greenhouse gases and consume energy, so generating CO 2 emissions. It enables these systems to be optimized for minimum global warming impact. In previous studies 1,2,3 , the energies required to manufacture the greenhouse gases themselves were not included; by analogy with other chemical manufacturing processes they were assumed to be small in the context of climate change. In the work described here, climate change impacts from the energy used to produce a number of common refrigerant fluids are evaluated. These impacts are compared with the potential impact on global warming from the other components of TEWI: use and disposal of the refrigerants, including direct release into the environment. It is shown that the implications for climate change of the production of traditional refrigerants like ammonia, hydrocarbons or CFC–12 and new refrigerating fluids, such as HFC–134a, are truly insignificant in comparison with other stages of the life cycle of a refrigerator and have no role in TEWI.

97/03195 Industry status of CFC chiller retrofits and replacements

The US ban on production of CFC refrigerants arrived on January 1, 1996 without much public attention thanks to many years of preparation by refrigerant producers and equipment manufacturers. Virtually all CFC equipment production lines have been retooled to produce equipment using non-CFC refrigerants. Producers of alternative refrigerants and equipment manufacturers worked closely for many years to develop non-CFC refrigerants for use in many types of air conditioning and refrigeration equipment. On-going research, such as the Materials Compatibility and Lubricants Research Program conduced by Air-Conditioning and Refrigeration Technology Institute, is examining the compatibility of equipment components with alternative refrigerants and lubricants. In 1993, US manufacturers of large tonnage liquid chillers stopped making CFC chillers and produced newly designed chillers using alternative refrigerants that are up to 40 percent more energy efficient than the chillers produced 20 years ago.

Characteristics of Voorhees refrigerating machine with hermetic piston compressor producing refrigeration at one or two temperature levels

Research on the operation of the refrigerating machine working on the Voorhees cycle which permits two-stage compression in a single-cylinder compressor has been carried out. The purpose of this research was to study the possibilities of using the Voorhees machine in a domestic refrigerator for production of refrigeration at one or two temperature levels. The experiments were carried out on the basis of a small hermetic lubricated compressor with a low refrigerating capacity operating on a commonly used R12 and natural refrigerant isobutane R600a. The improved refrigerating capacity in the Voorhees cycle with isobutane makes the latter an alternative substitute for conventional refrigerants. Some peculiarities in the operation of a hermetic piston compressor as part of the Voorhees refrigerating machine have been revealed. They require the use of a compressor developed specially for the Voorhees cycle. The method of optimizing the cycle parameters for a one temperature refrigerating system is suggested in this paper. The research carried out proved that the optimum intermediate pressures of the Voorhees refrigerating machine producing refrigeration either at one or two temperature levels are different.

データおよび手法の相違によるインベントリーへの影響 素材の製造データの相違による影響

For the production of refrigerators, CO2 emissions was estimated as affected by variations in estimation of CO2 emissions from electricity production, and differences in the process data and system boundaries used in the bottom-up approach. The results indicate that the amount of CO2 emitted in raw materials production was influenced by variations in CO2 per kWh electricity consumed, but the ratio of CO2 emis-sions from direct processrelated sources was not influenced. The amount of CO2 emis-sions in material production and the ratio of CO2 emissions in material production were influenced by the process data and system boundaries used in the calculations. In particular, as the process of aluminum ingots lead to large CO2 emissions, it is necessary to carefully consider the system boundary definition use when comparing estimates obtained from different data sources.The estimated CO2 emissions obtained via the bottom-up approach was then compared to that obtained using the Input-Output table analysis. The total CO2 emissions and the relative contribution of different sources in material production were influenced. It is also important to note that the calculated value using the Input-Output table is smaller than that from the bottom-up approach. It is reason that the data in the Input-Output table do not go into sufficient detail.

Antimicrobial Effects of Lactates: A Review

Sodium lactate is used as humectant and flavor enhancer in meat and poultry products, and there is growing evidence of antimicrobial properties of the salt. Potassium and calcium lactate are equally effective in controlling growth of aerobes and anaerobes in meats, and antibotulinal and antilisterial activities of the lactate anion have been established. The specific action of lactate on the microbial cell is not well understood. No intracellular pH lowering effect could be demonstrated, and the reported small decreases in water activity appear insufficient to explain the effect. Other explanations have been proposed but not yet confirmed. Although lactates appear to be bacteriostatic, their ability to control spoilage and pathogenic bacteria in fresh and processed meat favors their use, particularly in refrigerated meat products in combination with other microbial inhibitors.

Impact of CFC regulations on the air conditioning and refrigeration industry

I welcome the opportunity to speak about a subject of great importance to our industry. The biennial conferences at Purdue have acquired a justified reputation for substance and excellence, and I'm glad to see the large attendance. Given the recent significant developments pointing toward possible further CFC restrictions and the continuing need for high efficiency compressors, the conferences take on a greater significance than ever. Everyone in our industry, and indeed all people in the world who depend upon the products we provide, face some difficult choices and possibly some disruptions during the next decade or two as we shift away from refrigerants that have been used for more than 50 years. With modern technology, and with ingenuity and determination, we should be able to find alternative ways of refrigerating. But it will take time. It will not be easy. We have an enormous investment in current technology and a vast worldwide inventory of equipment which will continue to need service for years. Will we be given the time needed to accomplish the transition? How do we do it? How long will it take? What are the implications if our governments, responding to public concerns, insist on rapidly terminating production of CFC refrigerants? I don't anticipate that I can answer those questions completely in this presentation, but I will attempt to identify the main concerns as I see them and suggest some actions which we should all be considering in responding to this developing issue.

The Effects of Water as a Partial Blowing Agent for Rigid PUR and PUR/PIR Foams

A preliminary evaluation of HCFC 123 and HCFC 141 b demonstrated that they appeared to be technically viable CFC-11 replacements only after substantial reformulation. Partial water blowing was proposed as a possible short/medium term solution to the decreasing availability of CFC-11 as a consequence of the Montreal Protocol. In both polyurethane refrigeration and lamination products partial water blowing was shown to be a practical possibility up to a CFC-11 reduction of 50%. Slight deterioration in thermal efficiency was compensated for through formulation optimisation. Preliminary work on the type of formulations used to produce PUR/PIR foams in the USA boardstock industry showed that a 25% reduction of CFC-11 was so far achievable without loss of mechanical and fire properties.

An adaptive demand defrost and two-zone control and monitor system for refrigeration products

A defrost system that adapts to usage patterns and ambient conditions is described. The following parameters determine the interval between defrost operations: the amount and duration of door openings, the length of previous defrost operations, and the current freezer temperature. A two-temperature control system which allows the user to independently select freezer and fresh-food compartment temperatures is also discussed. The compressor run time and the air flow to the fresh-food compartment are controlled to achieve the desired results. These controls have been incorporated in a total control and monitor system which was recently introduced. The other features of this control are also briefly described.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>