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Efficiency Enhancement By Subcooling The Carbon Dioxide Process With Water As Refrigerant, Florian Hanslik, Juergen Suess, Juergen Koehler Jan 2018

Efficiency Enhancement By Subcooling The Carbon Dioxide Process With Water As Refrigerant, Florian Hanslik, Juergen Suess, Juergen Koehler

International Refrigeration and Air Conditioning Conference

As a consequence of the F-Gas regulation R404A is no longer an option for commercial refrigeration applications. Therefore, this paper focuses on natural refrigerants. There are a few options like carbon dioxide, which has an efficiency loss with increasing ambient temperatures. A promising option is subcooling of the carbon dioxide process with a chiller using water as the refrigerant. This will result in a new optimized high pressure of the carbon dioxide process depending on the ambient temperature. Finally the annual COP values of the standard transcritical and subcooled system will be discussed.

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Experimental Analysis To Mitigate Flow Induced Noise In Expansion Devices, Yingyue Zhang, Stefan Elbel Jan 2018

Experimental Analysis To Mitigate Flow Induced Noise In Expansion Devices, Yingyue Zhang, Stefan Elbel

International Refrigeration and Air Conditioning Conference

Flow-induced noise produced by expansion devices can be very disturbing to the user, especially when the device is in the close vicinity of the occupants. This paper characterizes the relationship between flow-induced noise and the flow regime, which may aid the design process of future geometry improvements of thermostatic expansion valves (TXV). A refrigerant loop using pumped R134a with appropriate pre-conditioning sections to vary inlet and outlet conditions is connected to a TXV and an automotive microchannel evaporator. The experiment is set up in a semi-anechoic chamber using microphones, accelerometer, and high-speed pressure transducers. Noise spectrum analysis is performed using …

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A Control Platform Based On Internet Of Things For Commercial Refrigeration, Günter Johann Maass, Daniel Hense Jan 2018

A Control Platform Based On Internet Of Things For Commercial Refrigeration, Günter Johann Maass, Daniel Hense

International Refrigeration and Air Conditioning Conference

In commercial refrigeration market, lots of equipment are installed and exposed to a variety of environment and use conditions. The owners of these refrigeration equipment, usually the brands of the refrigerated goods (such as ice creams and beverages), don’t have the immediate information about the health of the equipment, quality of their products or sales. Usually, they have to work reactively, therefore the information comes too late to prevent cumulative losses. A technology based on Internet of Things was developed by Embraco to address such real life problems for the commercial refrigeration market, the information being translated to intelligent actions …

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Defrosting Performance Of Patterned Heat Transfer Surfaces With A Superhydrophobic Silica Nanosprings Coating, Nickolas C. Schmiesing, Griffin Barrington, Giancarlo Corti, Andrew Sommers Jan 2018

Defrosting Performance Of Patterned Heat Transfer Surfaces With A Superhydrophobic Silica Nanosprings Coating, Nickolas C. Schmiesing, Griffin Barrington, Giancarlo Corti, Andrew Sommers

International Refrigeration and Air Conditioning Conference

The overall aim of this work was to study the defrosting performance of functionalized heat transfer surfaces containing a novel, silica nanosprings coating combined with preferential microstructural roughness. In doing this, differences in drainage rates and defrosting effectiveness were explored both on patterned and non-patterned surfaces. To date, ten different surfaces have been examined— an uncoated, untreated aluminum plate (S1), plates containing a silica nanospring (SN) coating of varying thickness (S2-S6), a plate containing evenly-spaced microchannels both with and without the SN surface coating (S7, S8), and then finally a plate containing a microstructural roughness gradient both with and without …

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Thermal-Hydraulic Optimization Of Fan-Supplied Tube-Fin Evaporators For Frosting Conditions Aiming At Minimum Energy Consumption, Rafael Ribeiro, Christian Hermes, Diogo Lôndero Da Silva Jan 2018

Thermal-Hydraulic Optimization Of Fan-Supplied Tube-Fin Evaporators For Frosting Conditions Aiming At Minimum Energy Consumption, Rafael Ribeiro, Christian Hermes, Diogo Lôndero Da Silva

International Refrigeration and Air Conditioning Conference

This work is aimed at the optimal design (i.e. number of transversal and longitudinal tube rows, number of fins) of fan-supplied tube-fin evaporators for light commercial refrigeration applications operating under frosting conditions. Quasi-steady-state algebraic models were put forward for the refrigeration cycle and its components for computing not only the cooling capacity depletion due to the evaporator frosting over time, but also the changes experienced by the evaporating temperature and its effect on the compressor power. Transient, unsteady-state algebraic models were also advanced to account for the temperature and humidity variations inside the refrigerated compartment, and so the compressor runtime. …

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Defrost Cycle Optimization For Fan-Supplied Tube-Fin Evaporators Subjected To Frosting Conditions, Diogo Lôndero Da Silva, Christian Hermes Jan 2018

Defrost Cycle Optimization For Fan-Supplied Tube-Fin Evaporators Subjected To Frosting Conditions, Diogo Lôndero Da Silva, Christian Hermes

International Refrigeration and Air Conditioning Conference

Frost accretion on a tube-fin evaporator surface raises its thermal and hydraulic resistances, which in turn deteriorates the cooling capacity of the refrigeration system. For this reason, periodic defrost operations are required to recover the initial performance of the system. Most defrost techniques rely on supplying heat to the frost layer. Due to technological and thermodynamic limitations, only part of the heat supply is effectively used to melt the frost built-up on the evaporator, while the rest increases the refrigerator thermal load. Therefore, the amount of heat dissipated, the duration of a defrost operation, and the time between two consecutives …

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An Experimentally Validated Model Of Single-Phase Flow Distribution In Brazed Plate Heat Exchangers, Wenzhe Li, Predrag S. Hrnjak Jan 2018

An Experimentally Validated Model Of Single-Phase Flow Distribution In Brazed Plate Heat Exchangers, Wenzhe Li, Predrag S. Hrnjak

International Refrigeration and Air Conditioning Conference

This paper presents a mathematical model to predict single-phase flow distribution in brazed plate heat exchangers (BPHEs). In this model, the flow distribution among parallel channels is predicted by imposing the condition that each flow path in the heat exchanger has an identical total pressure drop. The model has been validated by the experiments, in which the pressure drop of gas flow in the headers, as well as across the channels is measured. This model is then used to explore the effect of maldistribution on the thermal performance of the heat exchangers. The experimental and modeling results show that, for …

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Economic Model Predictive Control For Variable Refrigerant Systems, Brett Lenhardt, Matthew J Ellis, Robert D. Turney Jan 2018

Economic Model Predictive Control For Variable Refrigerant Systems, Brett Lenhardt, Matthew J Ellis, Robert D. Turney

International Refrigeration and Air Conditioning Conference

Variable refrigerant (VRF) systems are in a unique position to be combined with economic model predictive control (MPC) in order to reap significant benefits. In buildings with a variable utility price, it is feasible to use the building mass to shift a portion of the building heating, ventilation, and air conditioning (HVAC) load from the high priced (peak) period to the low priced (off-peak) period. It is also feasible for further savings to be visualized through a reduction of the monthly demand charge. By employing the building mass as an element to store thermal energy, one can see a significant …

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Empirical Study On The Heat Exchange Effectiveness Of A Cross-Flow Thermoelectric Air To Air Heat Pump Unit, Seongyong Cheon, Jae-Weon Jeong Jan 2018

Empirical Study On The Heat Exchange Effectiveness Of A Cross-Flow Thermoelectric Air To Air Heat Pump Unit, Seongyong Cheon, Jae-Weon Jeong

International Refrigeration and Air Conditioning Conference

A thermoelectric module (TEM), non-vapor compression heat pump, has attracted research interesting as a substitution of the conventional vapor compression heat pump. However, there are few studies for analysing a heat exchange effectiveness and performance of TEM for application to the HVAC system. The purpose of this research is to propose an empirical model for predicting the heat exchange effectiveness in air heat-pump system using TEM. The proposed system consists of aflat plate fin array that is heat exchanger integrated TEM for cooling and heating. In this study, the enthalpy efficiency is adopted as the TEM heat exchange performance index. …

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Effect Of The Use Pattern On Performance Of Heat Pump Water Heater, Ce Shi, Predrag S. Hrnjak Jan 2018

Effect Of The Use Pattern On Performance Of Heat Pump Water Heater, Ce Shi, Predrag S. Hrnjak

International Refrigeration and Air Conditioning Conference

This paper presents the performance of the Heat Pump Water Heater (HPWH) in warm-up and recovery at different draw rates and draw amount. Performance is evaluated based on COPsys and Recovery Efficiency as measure. Results show that the recovery efficiency is proportional to draw amount. With increase of draw rate, stratification worsens causing lower recovery efficiency. This paper also presents numerical investigations to validate the influence of draw rate and analyze the influence of baffle, nozzle and inlet position on tank stratification by Three-Dimensional Computational Fluid Dynamics (CFD) methods. CFD results are confirmed with the experimental data indicating that higher …

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Optimization Of Foam Characteristics For Falling Film Evaporators, Jayakumar Arjun, Mani Annamalai Jan 2018

Optimization Of Foam Characteristics For Falling Film Evaporators, Jayakumar Arjun, Mani Annamalai

International Refrigeration and Air Conditioning Conference

There is an acute scarcity in availability of water across the world. As per United Nations Development Programme (UNDP) report on Human Development almost one-fifth of the world’s population, live in areas of physical water scarcity. To combat this situation establishment of desalination plants is considered as one of the most feasible option. Multi-Effect Desalination systems are thermal based system with horizontal falling film evaporators (HTFFE). HTFFE are featured by evaporation from the liquid film over the surface of the tube and simultaneous condensation inside the tube. Condensation heat transfer coefficient is higher than evaporative heat transfer and can be …

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Investigation Of Desirable Arrangement Of Thermoelectric Modules For The Radiant Cooling Panel, Hansol Lim, Jae-Weon Jeong Jan 2018

Investigation Of Desirable Arrangement Of Thermoelectric Modules For The Radiant Cooling Panel, Hansol Lim, Jae-Weon Jeong

International Refrigeration and Air Conditioning Conference

The thermoelectric module radiant cooling panel (TEM-RCP) is an alternative of the conventional hydraulic radiant cooling panels which has advantages of no refrigerant, no chemical reactions, and no moving parts. In addition, it has merits of easy control, fast response through direct heat absorption from TEM without water. However, there are few guidelines for designing the TEM-RCP and no study suggested how to arrange the thermoelectric modules for the radiant cooling panel. Therefore, this study aims to propose the desirable arrangement of thermoelectric modules for radiant cooling panel. To achieve this purpose, the design methods for TEM-RCP was developed based …

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High Temperature Heat Pumps: Market Overview, State Of The Art, Research Status, Refrigerants, And Application Potentials, Cordin Arpagaus, Frédéric Bless, Michael Uhlmann, Jürg Schiffmann, Stefan Bertsch Jan 2018

High Temperature Heat Pumps: Market Overview, State Of The Art, Research Status, Refrigerants, And Application Potentials, Cordin Arpagaus, Frédéric Bless, Michael Uhlmann, Jürg Schiffmann, Stefan Bertsch

International Refrigeration and Air Conditioning Conference

This study reviews the current state of the art of high temperature heat pumps (HTHPs) with heat sink temperatures of 90 to 160°C. The focus is on the analysis of heat pump cycles, suitable refrigerants, and the operating ranges of commercially available HTHPs and heat pumps at the research status. More than 20 HTHP models from 13 manufacturers have been identified on the market that are able to provide heat sink temperatures of at least 90°C. Only a few heat pump suppliers have already managed to exceed 120°C. Large application potentials have been recognized particularly in the food, paper, metal, …

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An Experimental Study Of Hc-600a Flow Through Variable Expansion Devices For Household Refrigerators, Fernando Testoni Knabben, Joel Boeng Jan 2018

An Experimental Study Of Hc-600a Flow Through Variable Expansion Devices For Household Refrigerators, Fernando Testoni Knabben, Joel Boeng

International Refrigeration and Air Conditioning Conference

This work focuses on the HC-600a flow through small capacity fixed and variable expansion devices. To this end three electronic expansion valves of the same innovative design but with distinct orifices, were firstly tested in a dry nitrogen flow testing apparatus by varying the opening ratio an the operating conditions. Secondly, equivalent capillary tubes were defined based on the measured nitrogen mass flow rates through an updated version of the well know Kipp Schmidt’s equation. Thirdly, simulations were carried out with an in-house validated capillary tube model to estimate the HC-600a mass flow rate, using the length and inner diameter …

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Estimation Of Refrigerant Charge Inventory For An Automotive Air Conditioning System, Vikas Pulinkuzhi, Vatsal Thakor, Santanu Prasad Datta, Prasanta Kumar Das Jan 2018

Estimation Of Refrigerant Charge Inventory For An Automotive Air Conditioning System, Vikas Pulinkuzhi, Vatsal Thakor, Santanu Prasad Datta, Prasanta Kumar Das

International Refrigeration and Air Conditioning Conference

The knowledge about the refrigerant charge distribution in each component of an automotive air-conditioning system (AACS) is essential to predict any leakage into the system, health monitoring and estimation of overall system performances. However, estimating charge distribution in each component is not as easy as finding the total refrigerant mass into the system. There are some additional factors which also govern the distribution of refrigerant such as ambient temperature, compressor speed, blower speed, etc. Due to this, the refrigerant distribution in each component of an AACS is not uniform in a particular driving condition. Further, the condenser and the evaporator …

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Fast And Accurate Co2 Properties Calculation Algorithm For Massive Numerical Simulations Of Supersonic Two-Phase Ejectors, Yu Fang, Marco De Lorenzo, Philippe Lafon, Sébastien Poncet, Yann Bartosiewicz, Hakim Nesreddine Jan 2018

Fast And Accurate Co2 Properties Calculation Algorithm For Massive Numerical Simulations Of Supersonic Two-Phase Ejectors, Yu Fang, Marco De Lorenzo, Philippe Lafon, Sébastien Poncet, Yann Bartosiewicz, Hakim Nesreddine

International Refrigeration and Air Conditioning Conference

This work presents a look-up table method to compute the thermodynamic properties of CO2. It is motivated by the massive employment of this fluid in the industrial domain, especially in the ejector-expansion cycle. Computational Fluid Dynamics (CFD) simulations have been used in the past to investigate two-phase ejector flows. CO2 exhibits then large property variations due to phase transition. As a result, it cannot be accurately modelled by a general analytical Equation of State (EoS), such as Peng-Robinson EoS and Perfect gas EoS, etc. Hence, a tabulated EoS is developed here based on the Span-Wagner (EoS), covering the temperature range …

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Dynamic Investigation Of Thermal Behavior In A Hot Water Storage Tank, Ruiqi Yang, Bo Zheng, Xiangfei Liang, Rong Zhuang, Youlin Zhang Jan 2018

Dynamic Investigation Of Thermal Behavior In A Hot Water Storage Tank, Ruiqi Yang, Bo Zheng, Xiangfei Liang, Rong Zhuang, Youlin Zhang

International Refrigeration and Air Conditioning Conference

Air Source Heat Pump Water Heater is an environmental –friendly technology with high efficiency. The thermal behavior of water in the storage tank has great importance for designing a more energy-saving control strategy. In this study, the time-dependent temperature distributions during typical transient processes including heating up and tapping processes are studied with a 3D CFD model of the water storage tank in a cyclic heat pump water heater. The simulated temperature profiles in the heating up period were in good agreement with the experimental results. Different initial conditions were tested in the heating up periods, and they had little …

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Vapor Compression Refrigeration System For Cold Storage On Spacecrafts, Cai Stephen Rohleder, Kunal Bansal, Bryce Shaffer, Eckhard A. Groll Jan 2018

Vapor Compression Refrigeration System For Cold Storage On Spacecrafts, Cai Stephen Rohleder, Kunal Bansal, Bryce Shaffer, Eckhard A. Groll

International Refrigeration and Air Conditioning Conference

NASA’s future missions involve sending astronauts back to the moon, and further. Challenges associated with this goal are not limited to the science involved with propelling these astronauts to their destination. Life support systems must also advance to improve astronaut health during their long flights in space. Currently, food consumed in space is processed to be shelf stable, and recent experiments have shown that nutrients of these shelf stable foods decay over time. Refrigeration storage for more nutritional food has remained undeveloped due to fluid flow and heat transfer management difficulties in microgravity. As part of a NASA SBIR Phase …

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Intermediate Vapor Bypass: A Novel Design For Mobile Heat Pump At Low Ambient Temperature, Lili Feng, Predrag S. Hrnjak Jan 2018

Intermediate Vapor Bypass: A Novel Design For Mobile Heat Pump At Low Ambient Temperature, Lili Feng, Predrag S. Hrnjak

International Refrigeration and Air Conditioning Conference

With market share of electric vehicles continue to grow, there is an increasing demand of mobile heat pump for cabin climate control, as it has much higher energy efficiency than electric resistive heating and hence much less impact on electric drive range. However, current mobile heat pump systems using low pressure refrigerant like R134a and R1234yf suffer from significant heating capacity loss at low ambient temperature. As a result, a large electric heater needs to be installed to supplement the capacity shortage at low ambient temperature, and electric drive range can be greatly reduced due to large power consumption for …

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Feasibility Of Controlling Heat And Enthalpy Wheel Effectiveness To Achieve Optimal Closed Doas Operation, Omer Sarfraz, Peter Armstrong, Christian K. Bach Jan 2018

Feasibility Of Controlling Heat And Enthalpy Wheel Effectiveness To Achieve Optimal Closed Doas Operation, Omer Sarfraz, Peter Armstrong, Christian K. Bach

International Refrigeration and Air Conditioning Conference

Dedicated outdoor air systems (DOAS) make use of the sensible and latent capacity of the return (exhaust) air to cool and dehumidify the supply (outside) air. “Closed DAOS” is an advanced form of typical DOAS with desuperheater and evaporatively cooled condenser in the return air stream. The air entering the condenser in Closed DOAS is in the fully saturated state. In order to fully saturate the return air, it needs to be sprayed by water. Sufficient amounts of water is required for fully saturating the air and keeping the coils of the condenser wet during the process. This water is …

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R134a And Its Low Gwp Substitutes R1234yf And R1234ze(E) Flow Boiling Inside A 4mm Horizontal Smooth Tube, Giovanni A. Longo, Simone Mancin, Giulia Righetti, Claudio Zilio Jan 2018

R134a And Its Low Gwp Substitutes R1234yf And R1234ze(E) Flow Boiling Inside A 4mm Horizontal Smooth Tube, Giovanni A. Longo, Simone Mancin, Giulia Righetti, Claudio Zilio

International Refrigeration and Air Conditioning Conference

The substitution of HFC134a with low GWP refrigerants is one of the most important challenge for refrigeration and air conditioning. The possible substitutes include natural refrigerants, such as HC600 (Butane) and HC600a (Isobutane), and also synthetic refrigerants, such as HFO1234yf and HFO1234ze(E). The HC refrigerants exhibit very low GWP, 3 and 4 HC600a and HC600 respectively, good thermodynamic and transport properties, and pressure and volumetric performance very similar to HFC134a. The major drawback of HC refrigerants is their high flammability, being classified in class A3 according to ASHRAE classification. Also the HFO refrigerants present a mild flammability, being classified in …

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Experimental Analysis And Design Improvements On Combined Viper Expansion Work Recovery Turbine And Flow Phase Separation Device Applied In R410a Heat Pump, Riley Barta, Florian Simon, Eckhard A. Groll Jan 2018

Experimental Analysis And Design Improvements On Combined Viper Expansion Work Recovery Turbine And Flow Phase Separation Device Applied In R410a Heat Pump, Riley Barta, Florian Simon, Eckhard A. Groll

International Refrigeration and Air Conditioning Conference

In light of recent trends towards energy efficiency and environmental consciousness, the heating, ventilation, air conditioning and refrigeration (HVAC&R) industry has been pushing for technological developments to meet both of these needs. As such, several solutions for harnessing the energy released from refrigerants during the expansion process of a conventional vapor-compression cycle have been developed to increase overall cycle efficiency. The study presented in this paper focuses on investigating the potential impact of installing an energy recovery expansion device known as the Viper Expander into an R410A heat pump. The Viper Expander operates by using a nozzle to accelerate the …

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Heat Transfer Enhancement By Using Fin For Mh Hydrogen Storage Tank - Discuss On The Geometrical Optimization Of Fin -, Yuki Igarashi, Masafumi Katsuta, Sangchul Bae, Kuan-Ting Lin Jan 2018

Heat Transfer Enhancement By Using Fin For Mh Hydrogen Storage Tank - Discuss On The Geometrical Optimization Of Fin -, Yuki Igarashi, Masafumi Katsuta, Sangchul Bae, Kuan-Ting Lin

International Refrigeration and Air Conditioning Conference

The expectation for renewable energy is rising from the viewpoints of recent environmental problems and energy problems. The reason why renewable energy is not widespread is that there are temporal and spatial restrictions on real application. There is an increasing interest in hydrogen energy as energy that compensates for such weaknesses of renewable energy.　Hydrogen can easily converted to be thermal energy, mechanical energy, electric energy and used. It is important to establish effective saving techniques for effective development of hydrogen energy systems. Three methods of liquification, pressurization and metal hydride (on briefly, referred to as MH) are the major …

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Evaluation Of Stainless Steel Press Fittings For Use In Transcritical R744 Refrigeration Systems, Neal Lawrence, Stefan Elbel, Sharat Raj, Tony Lagrotta, Michael Duggan Jan 2018

Evaluation Of Stainless Steel Press Fittings For Use In Transcritical R744 Refrigeration Systems, Neal Lawrence, Stefan Elbel, Sharat Raj, Tony Lagrotta, Michael Duggan

International Refrigeration and Air Conditioning Conference

Successful implementation of R744 (CO2) as a refrigerant on a large scale and its introduction to new applications has motivated the development of new system components tailored specifically for use in high-pressure R744 systems, including reliable, low-cost refrigeration fittings. One option for fittings to be used in R744 systems are quick and reliable press fittings. Previous research has shown that this type of fitting can undergo extended vibration and thermal (pressure and temperature) cycling without compromising the fitting. This paper investigates the durability of stainless steel press fittings designed specifically for R744 systems, with particular focus on the effects of …

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Non-Flammable R-410a Alternative For Commercial Refrigeration And Air Conditioning, Joshua Hughes, Barbara Haviland Minor Jan 2018

Non-Flammable R-410a Alternative For Commercial Refrigeration And Air Conditioning, Joshua Hughes, Barbara Haviland Minor

International Refrigeration and Air Conditioning Conference

It is well known that R-410A is the predominant refrigerant used globally in air conditioning systems. However, there has recently been growing interest in 410A use in commercial refrigeration applications in Japan. Along with the Kigali amendment to the Montreal Protocol to phase down use of HFCs, Japan has enacted HFC regulations with specific GWP limits. For commercial condensing units and larger refrigeration systems, a GWP limit of < 1500 GWP will be implemented starting in 2025. To address the need for a lower GWP R-410A alternative, a nonflammable hydrofluoroolefin (HFO) refrigerant mixture with named XP41 (R-463A pending) has been developed. XP41 is a five-component mixture of HFO-1234yf using HFC-32, 125, and 134a and a small amount of CO2. HFO-1234yf is included in the formulation to reduce the GWP. HFC-32 and CO2 have been added to increase the cooling capacity and provide comparable performance to R-410A. For large building air conditioning where variable refrigerant flow (VRF) use is growing, there is also a significant challenge to safely use flammable refrigerants due to large charge sizes. XP41 could potentially address this need as well This paper will provide detailed information on the properties and other key characteristics of XP41, including drop-in testing in an air conditioning system.

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Theoretical And Experimental Investigations On The Recirculation Of The Solution (Mix-Flow) In An Absorption Resorption Refrigeration System, Oliver Ziegler, Ullrich Hesse Jan 2018

Theoretical And Experimental Investigations On The Recirculation Of The Solution (Mix-Flow) In An Absorption Resorption Refrigeration System, Oliver Ziegler, Ullrich Hesse

International Refrigeration and Air Conditioning Conference

Ammonia water absorption resorption refrigeration systems do not need a rectification column like conventional absorption refrigeration systems do. In this case such systems need a recirculation of the solution. This so called “mix flow” is necessary to prevent the dilution of the solution in the “cold cycle” of the system which is caused by the relative high concentration of water in the hot vapor. The influence of this recirculation of the solution on the performance of the system could be shown in previous studies and is now modelled and investigated more in detail. As a result of the theoretical investigation, …

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Dynamic Performance Of A Mechanical Vapor Compression (Mvc) Desalination System, Sergio Morales Ruiz, Jesús Castro, Joaquim Rigola, Carles Oliet, Assensi Oliva Jan 2018

Dynamic Performance Of A Mechanical Vapor Compression (Mvc) Desalination System, Sergio Morales Ruiz, Jesús Castro, Joaquim Rigola, Carles Oliet, Assensi Oliva

International Refrigeration and Air Conditioning Conference

This paper presents a numerical model to analyze the thermal and fluid dynamic behavior of a mechanical vapour compression MVC desalination system. The MVC desalination method is an evaporation and condensation process that occurs at low pressure, which requires a compression work to increase the saturation temperature of the vapor. The compressed vapor is condensed and its latent heat is transferred to the feed seawater. The MVC desalination is used at low and medium scale in comparison with other techniques such as: multistage flash desalination (MSF) or reverse osmosis (RO). The MVC desalination unit studied in this paper uses renewable …

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Evaluation And Optimization Of System Performance Using Hfo-Mix Refrigerants For Vrf And Mini-Split Air-Conditioner, Tomoatsu Minamida, Ikuhiro Iwata, Eiji Kumakura, Kazuhiro Furusho, Tomoyuki Haikawa, Shigeharu Taira Jan 2018

Evaluation And Optimization Of System Performance Using Hfo-Mix Refrigerants For Vrf And Mini-Split Air-Conditioner, Tomoatsu Minamida, Ikuhiro Iwata, Eiji Kumakura, Kazuhiro Furusho, Tomoyuki Haikawa, Shigeharu Taira

International Refrigeration and Air Conditioning Conference

Global demand for air conditioning is expected to increase continuously. In order to minimize the impact on the climate as a total amount of CO2 equivalent, it is essential to continue to search for better refrigerants. On the other hand, product size and cost are important factors in providing value to users. This time, while using the experiment result of the mini-split type air-conditioner reported in the past, in addition, we conducted a new experiment on multi-type VRF air-conditioner. Then, the difference in COP performance between R-410A and alternative candidate refrigerants was evaluated. In addition, we studied the product design …

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A Literature Review Of Numerical Modeling Techniques For Vapor Compression Systems With Focus On Heat Exchanger Modeling, Omer Sarfraz, Christian K. Bach, Craig Bradshaw Jan 2018

A Literature Review Of Numerical Modeling Techniques For Vapor Compression Systems With Focus On Heat Exchanger Modeling, Omer Sarfraz, Christian K. Bach, Craig Bradshaw

International Refrigeration and Air Conditioning Conference

Vapor compression systems are the most widely used system type in heating, ventilation, air-conditioning, and refrigeration (HVAC&R) applications. Experimental and numerical modeling techniques are used to analyze the performance of the vapor compression systems. With the introduction of high-performance computers, numerical modeling techniques are used extensively to develop cost-effective and efficient HVAC&R equipment. Experimental iterations on the design of vapor compression systems are costly; however, numerical techniques can reduce the number of experimental iterations, substantially decreasing the development cost and time. Because of the benefits associated with the numerical simulation, many researchers working in the HVAC&R field have attempted to …

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Model-Based Performance Comparison Of Ammonia Chemisorption Heat Pumps For Cold Climate With Different Working Pairs And Cycle Configurations, Zhiyao Yang, Ming Qu, Kyle Gluesenkamp Jan 2018

Model-Based Performance Comparison Of Ammonia Chemisorption Heat Pumps For Cold Climate With Different Working Pairs And Cycle Configurations, Zhiyao Yang, Ming Qu, Kyle Gluesenkamp

International Refrigeration and Air Conditioning Conference

Sorption heat pumps utilize the thermal effect of the sorbent bonding with the refrigerant (sorbate) through a variety of physio-chemical processes, and when such bonding is due to chemical reaction between solid sorbent and gas refrigerant, the system is known as chemisorption heat pump. The most commonly used refrigerant in chemisorption systems is ammonia, and it can work with a variety of sorbent materials across a wide temperature range. The abundance in working pair selection and the viability of resorption configuration leads to multiple available cycle configurations and working pairs for heat pump system design. Therefore, preliminary evaluation of these …

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