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Experimental Investigation Of A Domestic Refrigeration Appliance Based On Exergy Destruction, Mehrdad Taghavi, Maria Goossens, Seppo Syrjala, Tero Joronen May 2021

Experimental Investigation Of A Domestic Refrigeration Appliance Based On Exergy Destruction, Mehrdad Taghavi, Maria Goossens, Seppo Syrjala, Tero Joronen

International Refrigeration and Air Conditioning Conference

Since refrigeration appliances consume more than 15% of electrical energy over the globe, many solutions have been proposed to enhance the efficiency of these appliances. However, the solutions mostly rise the expenditure and complexity of the appliances, making these methods less feasible for manufacturing. Therefore, some inexpensive and less complicated modifications should be proposed to enhance the efficiency and performance of the appliances affordably. This paper presents a new solution using unutilized cooling capacity of evaporator for cooling compressor. The experimental exergy analysis of a domestic refrigerator in which the suction pipe absorbs heat from the compressor shell illustrates a …

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A Lattice Boltzmann Model For Phase Change Material (Pcm) Melting With Porous Media In Heat Exchanger, Dongyu Chen, Amir Riaz, Vikrant C. Aute, Reinhard Radermacher May 2021

A Lattice Boltzmann Model For Phase Change Material (Pcm) Melting With Porous Media In Heat Exchanger, Dongyu Chen, Amir Riaz, Vikrant C. Aute, Reinhard Radermacher

International Refrigeration and Air Conditioning Conference

Phase change material (PCM) is widely used in thermal energy storage systems as it can absorb and release a large amount of heat by the phase change process. Both experimental and numerical studies of PCM have increased substantially in the past two decades. Among them, the phase change in porous media is one of the significant topics. The simulation of PCM melting in porous media is required to characterize the fluid flow and heat transfer behavior, and to provide guidance for the further design and optimization of PCM heat exchangers and thermal energy storage systems. In this paper, a model …

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An Inverse Method To Estimate Bulk Density And Specific Heat Of Cereal Grains During Heat Pump Drying, Amir Ebrahimifakhar, David Yuill May 2021

An Inverse Method To Estimate Bulk Density And Specific Heat Of Cereal Grains During Heat Pump Drying, Amir Ebrahimifakhar, David Yuill

International Refrigeration and Air Conditioning Conference

Cereal grains are one of the most important sources of nutrients in both developed and developing countries. Quality preservation of cereal grains is a major issue between harvest and utilization. Heat pump grain dryers can be used to preserve grain quality during storage, since grain spoilage can be averted by drying or chilling the grain. In this paper, the use of inverse methods to estimate grain properties during heat pump drying is investigated. An inverse method was developed to estimate the bulk density and specific heat of cereal grains during heat pump drying during the heat and mass transfer processes …

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Numerical Analysis Of Active Flow Boiling Regime Management Using A Vapor-Compression Cycle Applied To Electronic Processor Cooling, Riley B. Barta, Davide Ziviani, Eckhard A. Groll May 2021

Numerical Analysis Of Active Flow Boiling Regime Management Using A Vapor-Compression Cycle Applied To Electronic Processor Cooling, Riley B. Barta, Davide Ziviani, Eckhard A. Groll

International Refrigeration and Air Conditioning Conference

As computing power continues to grow at a rapid rate, the thermal load generated from electronic devices follows. Furthermore, reduced size requirements for electronic devices have driven engineers to produce this increased computing power in smaller packaging than ever before. The combination of these two trends results in high heat flux processors that require innovative cooling techniques. Industry and academia alike have anticipated this trend and have developed several general families of solutions to cooling high-heat flux processors. This work proposes the use of flow boiling in a vapor compression cycle and a spreader to distribute the heat from a …

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Cfd-Based Analysis & Correlation Development For A Novel Multi-Furcating Heat Exchanger For High Temperature, High Pressure Applications, James Tancabel, William Gerstler, Daniel Erno, Jiazhen Ling, Vikrant Aute, H Peter J. De Bock, Reinhard Radermacher May 2021

Cfd-Based Analysis & Correlation Development For A Novel Multi-Furcating Heat Exchanger For High Temperature, High Pressure Applications, James Tancabel, William Gerstler, Daniel Erno, Jiazhen Ling, Vikrant Aute, H Peter J. De Bock, Reinhard Radermacher

International Refrigeration and Air Conditioning Conference

The thermal efficiency of indirectly heated power cycles such as supercritical carbon dioxide (sCO2) closed Brayton cycles are typically limited by their heat exchangers (HXs), which require high heat transfer effectiveness while operating for tens of thousands of hours under high temperature (>800°C) and pressure (>80 bar) conditions. Previous literature has shown that the use of nature-inspired furcating flow channels represents an exciting opportunity to improve HX thermal-hydraulic performance. In this paper, we analyze the novel multi-furcating HX manifold concept, that was previously shown experimentally to reduce HX volume and mass compared to a baseline oil cooler by …

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Properties Of Polyol Esters For Low Gwp Refrigerants, Tatsuki Nakajima, Yuya Mizutani, Yasushi Onumata May 2021

Properties Of Polyol Esters For Low Gwp Refrigerants, Tatsuki Nakajima, Yuya Mizutani, Yasushi Onumata

International Refrigeration and Air Conditioning Conference

HFC (Hydrofluorocarbon) refrigerants, whose ODP (Ozone Depletion Potential) is 0, are used in refrigeration and air conditioning equipments recently. It is known that HFCs are high GWP (Global Warming Potential) refrigerants. In October 2016, Kigali Amendment to the Montreal Protocol was stated to achieve the phase-down of HFC refrigerants to prevent global warming. Transition of current HFCs to low GWP refrigerants would be accelerated around the world. HFO (Hydrofluoroolefin) refrigerants such as R1234yf, R1234ze etc. are low GWP refrigerants. Refrigerant manufacturers are introducing not only HFO itself, but also mixture of HFC and HFO. HFO is known to be less …

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Stratified Flow Model To Predict Oil Retention In Horizontal Refrigerant Gas Lines Of Unitary Split Systems Running R410a And Poe32, Vatsal M. Shah, Eckhard A. Groll, James E. Braun May 2021

Stratified Flow Model To Predict Oil Retention In Horizontal Refrigerant Gas Lines Of Unitary Split Systems Running R410a And Poe32, Vatsal M. Shah, Eckhard A. Groll, James E. Braun

International Refrigeration and Air Conditioning Conference

Most air conditioning and refrigeration systems that employ the vapor compression cycle rely on oil circulating with refrigerant to lubricate the bearings and other contact surfaces in the compressor. The lubricant acts as a sealant to reduce leakage losses during the compression process and it also helps to absorb some of the excess heat that is generated in the compression chamber. However, this oil circulation results in oil retention in various other components outside the compressor depending on the physical interaction between lubricant and refrigerant and their transport properties. Other factors, such as geometry and orientation of connecting lines and …

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Review Of Heat Pump Tumble Clothes Dryer Energy Efficiency And Related Technologies, Allison Graban, Eckhard Groll, James Braun, Davide Ziviani May 2021

Review Of Heat Pump Tumble Clothes Dryer Energy Efficiency And Related Technologies, Allison Graban, Eckhard Groll, James Braun, Davide Ziviani

International Refrigeration and Air Conditioning Conference

As energy constraints and consumption in the world increase, it is important to investigate all areas of technology for improvement. In the residential building sector, clothes drying is a significant consumer of energy accounting for 6% of residential electricity in the U.S. (EPA, 2011). Heat pump technology has become increasingly popular for residential tumble clothes dryers. This paper presents a detailed review of heat pump tumble dryer research covering technologies for air conditioning waste heat recovery, recuperative heat exchangers, system modeling, and control optimization. Additional technologies related more broadly to vapor compression cycle enhancement are also reviewed, including alternative working …

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Optimization Of Combined Casing Treatment Structure Applied In A Transonic Axial Compressor Based On Surrogate Model, Jiaxuan Liu, Min Dai, Fusheng Yang, Jianqiang Deng, Zaoxiao Zhang May 2021

Optimization Of Combined Casing Treatment Structure Applied In A Transonic Axial Compressor Based On Surrogate Model, Jiaxuan Liu, Min Dai, Fusheng Yang, Jianqiang Deng, Zaoxiao Zhang

International Compressor Engineering Conference

For modern high load compressors, an excellent stability-enhancing capability by casing treatment (CT) is desirable. However, it is very time consuming to accomplish effective CT design. In this study, a new combined CT structure composed of axial skewed slots and end-wall injection, was proposed to be installed in transonic axial compressors to improve the overall performance. Considering the high computation cost for CFD simulation of the flow field in transonic compressor, a Gaussian Process Regression (GPR) surrogate model combined with Latin hypercube sampling, was utilized to predict compressor performance. For optimization process, a multi-objective evolutionary algorithm (NSGA-Ⅱ) was adopted to …

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1d Design And Optimization Of A Micro-Centrifugal Compressor For An Air Conditioner Using R600a, Zhenyuan Mei, Tao Cao, Yunho Hwang May 2021

1d Design And Optimization Of A Micro-Centrifugal Compressor For An Air Conditioner Using R600a, Zhenyuan Mei, Tao Cao, Yunho Hwang

International Compressor Engineering Conference

Miniature compressors play an important role in compact air conditioning systems. Its small size means smaller weight and less material cost. Centrifugal compressors do not have displacement volume and has only one major moving part, which makes it a good candidate for miniature compressor. Typical residential air conditioning systems use R410A as refrigerant due to its good thermodynamic properties and no ozone depletion potential. However, its global warming potential is even higher than that of R22. In addition, it requires high operating speed for a centrifugal compressor. One alternative for R410A is R600a. It has good thermodynamic performance and low …

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Novel Refrigeration Cycle With Continuous Cooling Turbo Compressor And Condensing Ejector Using Water As Refrigerant, Tadayoshi Shoyama, Bunki Kawano, Iori Maruhashi, Hongzhi Sun, Michiyoshi Kusaka, Junki Yoshimoto, Masaru Matsui May 2021

Novel Refrigeration Cycle With Continuous Cooling Turbo Compressor And Condensing Ejector Using Water As Refrigerant, Tadayoshi Shoyama, Bunki Kawano, Iori Maruhashi, Hongzhi Sun, Michiyoshi Kusaka, Junki Yoshimoto, Masaru Matsui

International Compressor Engineering Conference

Turbo chiller using water as a refrigerant was developed. A refrigeration cycle using water (R718) as a refrigerant has a high theoretical efficiency, but the cycle pressure ratio is high, and the compressor discharge temperature is elevated. Although the conversion of the compressor to a multistage compressor and the addition of an intercooler between each stage are known to lower the discharge temperature and improve performance, the resulting increased size is problematic. To resolve this issue, this study develops a refrigeration cycle that lowers discharge temperature during the compression process without enlarging the device. Using a continuous cooling compressor that …

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Computational Fluid Dynamics Study On Transonic Axial Compressors Using Cartesian Cut-Cell Based Method With Adaptive Mesh Refinement And Boundary Layer Mesh, Yanheng Li, David Henry Rowinski, Karthik Rudra Reddy, Karan Bansal May 2021

Computational Fluid Dynamics Study On Transonic Axial Compressors Using Cartesian Cut-Cell Based Method With Adaptive Mesh Refinement And Boundary Layer Mesh, Yanheng Li, David Henry Rowinski, Karthik Rudra Reddy, Karan Bansal

International Compressor Engineering Conference

Axial compressors are used extensively in the energy, power, and transportation industries. Computational Fluid Dynamics (CFD) has been widely used in research and development of dynamic compressors. CFD modeling for such designs often presents great challenges in terms of meshing and computational cost due to moving parts with complex shapes, tiny gaps, and a large range of length scales and time scales to resolve. In this work, a Cartesian cut-cell based method with adaptive mesh refinement (AMR) is used to study Rotor 67, a transonic axial compressor design from NASA. The adopted method is demonstrated to be easily implemented and …

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Regenerative Gas Turbine Power Plant: Performance & Evaluation, Momin Elhadi Abdalla, Siddharth Pannir, Amina Husseinahmed, Aya Mahjob, Salah Ahmed Abdalla May 2021

Regenerative Gas Turbine Power Plant: Performance & Evaluation, Momin Elhadi Abdalla, Siddharth Pannir, Amina Husseinahmed, Aya Mahjob, Salah Ahmed Abdalla

International Compressor Engineering Conference

In this work, comprehensive operational and conceptual design basics of the Regenerative Gas Turbine were studied and applied to the Khartoum North Thermal Power Station, Sudan, which has a total power of 187MW. The analysis and results of this work were executed using the Engineering Equation Solver.The results show that, the increasing the effectiveness of the regenerative cycle increased the thermal efficiency. However, there is a turning point of compressor inlet temperature, after which the further increase of temperature and regenerator effectiveness will lead to decline in the thermal efficiency of the cycle. At lower regeneration and moderate regenerator effectiveness, …

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Thermal Charging Rate Of Composite Wax-Expanded Graphite Phase Change Materials, Jason Robert Hirschey, Navin Kumar, Tim Laclair, Kyle R. Gluesenkamp, Samuel Graham May 2021

Thermal Charging Rate Of Composite Wax-Expanded Graphite Phase Change Materials, Jason Robert Hirschey, Navin Kumar, Tim Laclair, Kyle R. Gluesenkamp, Samuel Graham

International High Performance Buildings Conference

Phase change materials (PCMs) are valuable for their ability to store heat nearly isothermally around their phase transition temperature. PCMs are at the core of latent heat thermal energy storage (LHTES) systems, which provide the ability to buffer high thermal loads or decouple the time when heating or cooling is needed from when it is produced. Thermal charging and discharging of LHTES systems often employ a constant temperature source, and the rate at which heat can be exchanged is dependent on the thermophysical properties of the PCM. For graphite composite PCMs, the high thermal conductivity of the graphite enables an …

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Clearing The Cloudiness On Lubricant-Refrigerant Miscibility, Andrew D. Sumner, Anthony J. Barthel May 2021

Clearing The Cloudiness On Lubricant-Refrigerant Miscibility, Andrew D. Sumner, Anthony J. Barthel

International Refrigeration and Air Conditioning Conference

The phase interaction of liquid refrigerant with liquid lubricant is commonly described as miscibility. Lubricant and refrigerant combinations can be described as single liquid phase (miscible) or multiple liquid phases (immiscible). In specific system designs, good miscibility between the compressor lubricant and refrigerant play important roles in system functionality. Inadequate miscibility can lead to lubricant accumulation in the evaporator, which can cause degraded heat transfer properties as well as lubricant starvation in the compressor. Governments are implementing stricter environmental standards in the HVAC&R industry including higher efficiency targets and lower GWP (global warming potential) refrigerants. Equipment design changes are increasingly …

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A Proposal Of Lean Design Integration Method For Hierarchical Architecture Type Product Systems (A Practical Lean Development Example In Domestic Refrigerator Energy Saving Design With A Combination Of Cae, Real Experiment And Humanistic Collaboration), Takashi Kobayashi, Takuya Kodama, Hitoshi Maruyama May 2021

A Proposal Of Lean Design Integration Method For Hierarchical Architecture Type Product Systems (A Practical Lean Development Example In Domestic Refrigerator Energy Saving Design With A Combination Of Cae, Real Experiment And Humanistic Collaboration), Takashi Kobayashi, Takuya Kodama, Hitoshi Maruyama

International Refrigeration and Air Conditioning Conference

In developing process for competitive commercial refrigerator/ air-conditioning system products, practical whole system integration method is very important to realize a compact product with high cost performance. These products are characterized by hierarchical architecture type module product systems. This paper proposes a practical lean development method which combines 1D and 3D-CAE analysis with human decision making process. A Model-based development method using product base platform is also proposed for realizing a practical product family series development. Finally, the effectiveness of this method is demonstrated quantitatively by applying to an energy saving type household refrigerator.

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Development And Experimental Evaluation Of An Automated Charge Testing Methodology For Domestic Refrigerators, Changkuan Liang, Orkan Kurtulus, Davide Ziviani, Eckhard A. Groll, James E. Braun May 2021

Development And Experimental Evaluation Of An Automated Charge Testing Methodology For Domestic Refrigerators, Changkuan Liang, Orkan Kurtulus, Davide Ziviani, Eckhard A. Groll, James E. Braun

International Refrigeration and Air Conditioning Conference

Optimizing the refrigerant charge in a vapor compression cycle can lead to improvements in system performance and energy savings. Manufacturers often perform extensive experimental charge testing under different operating conditions to determine the optimal system charge of a certain product. However, the current de-facto industry standard procedure for performing such evaluation involves repeated charging and evacuating of equipment which is a time-consuming effort. In this work, an automated charge testing device and method were developed to perform a charge optimization for domestic refrigerators with the unit operating. This device consists of a combination of three solenoids to isolate a small …

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Investigation On Phase Change Material (Pcm)-To-Refrigerant Heat Exchanger In Air-Conditioning Systems, Yiyuan Qiao, Tao Cao, Yunho Hwang, Reinhard Radermacher May 2021

Investigation On Phase Change Material (Pcm)-To-Refrigerant Heat Exchanger In Air-Conditioning Systems, Yiyuan Qiao, Tao Cao, Yunho Hwang, Reinhard Radermacher

International Refrigeration and Air Conditioning Conference

Recently, the application of phase change material (PCM) for thermal energy storage shows great potential because of PCM’s capability to absorb heat within a narrow range of temperatures. However, most previous studies used single phase liquid as the heat transfer fluid. The use of two-phase fluid is very limited, which can be applied in many fields, such as waste heat recovery and personal cooling systems. To fill this research gap, a shell-and-tube configured PCMto-refrigerant heat exchanger (PCMRHX) coupled in a refrigeration system was investigated experimentally and numerically in this study. The enthalpy method was applied to the phase change process …

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Chebyshev Expansions Empower Faster And More Precise Pure Fluid Calculations, Ian Bell May 2021

Chebyshev Expansions Empower Faster And More Precise Pure Fluid Calculations, Ian Bell

International Refrigeration and Air Conditioning Conference

Computationally efficient simulation of thermal systems is usually limited by evaluation of thermophysical properties. It is common (for instance in heat exchanger simulation) that more than 90% of the total runtime may be spent evaluating thermophysical properties. A key (and computationally expensive, especially for mixtures) part of that calculation is the determination of phase equilibrium. This work demonstrates that the use of Chebyshev expansions combined with extended precision calculations allows for a non-iterative numerical formulation that is more accurate than the iterative calculations with the full equation of state and is also much faster to evaluate. In essence, this approach …

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A Method Of Mapping Heat Exchanger As Simple Polynomials, Deokgeun Park, Fangzhou Guo, Bryan P. Rasmussen May 2021

A Method Of Mapping Heat Exchanger As Simple Polynomials, Deokgeun Park, Fangzhou Guo, Bryan P. Rasmussen

International Refrigeration and Air Conditioning Conference

Conducting economic comparison studies of vapor-compression systems early in the product development process allows the designer to balance competing objectives of raw material costs, life-cycle cost, and system performance. However, detailed performance simulation models typically require iterative solutions at both the component and system levels. These nested iterative models make economic comparison studies computationally prohibitive. To address the challenge of nested iterations, non-iterative polynomial representations of components can be implemented. In this paper, a method to represent the heat exchangers’ effectiveness, pressure loss, refrigerant charge, and mass with non-iterative models is presented. A method of mapping the heat exchanger using …

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Simulation Of Pendant Droplet Behavior On Plain And Patterned Surfaces Using Surface Evolver, Hieu Phan, Andrew Sommers, Giancarlo Corti May 2021

Simulation Of Pendant Droplet Behavior On Plain And Patterned Surfaces Using Surface Evolver, Hieu Phan, Andrew Sommers, Giancarlo Corti

International Refrigeration and Air Conditioning Conference

In this work, pendant droplets of different liquids (i.e. water, ethylene glycol, methanol, and acetone) on a plain aluminum surface and a three-stripe patterned surface were simulated using the Surface Evolver (SE) software. The critical droplet volume before detachment from a surface and droplet properties such as diameter, height, and surface energy were measured. Surface Evolver is a program that models liquid surfaces shaped by different forces and constraints. The program works by modifying a surface toward minimal thermodynamic energy by a gradient descent method. The initial input to Surface Evolver is a script file containing all the pertinent information …

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A Three-Dimensional Transient Model For Evaluating The Performance Of Cement-Based Thermoelectric Module, Xiaoli Liu, Ming Qu, Kazuaki Yazawa May 2021

A Three-Dimensional Transient Model For Evaluating The Performance Of Cement-Based Thermoelectric Module, Xiaoli Liu, Ming Qu, Kazuaki Yazawa

International High Performance Buildings Conference

The thermoelectric module (TEM) is a device that integrates multiple thermoelectric (TE) elements to realize the mutual conversion of heat and power. Due to the advantages of no moving parts and flexible expansion, the application of conventional Bi2Te3-based TEM in buildings has attracted the attention of researchers. On the other hand, the TE behavior of hardened cement composites was found by combining conductive additives with cement. Therefore, a new study on cement-based TEM for building energy harvesting and temperature control is proposed. To simulate the performance of cement-based TEM, a three-dimensional heat transfer model considering temperature-dependent TEM characteristics was established. …

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Enabling Solar Power With Residential Water Heater Load-Shifting, Celeste Fieberg May 2021

Enabling Solar Power With Residential Water Heater Load-Shifting, Celeste Fieberg

International High Performance Buildings Conference

As governments and international organizations aim to increase renewable energy production in response to climate change, there is a growing demand for energy storage. A temporal mismatch in the daily profiles of solar energy production and residential energy use causes an imbalance between generation and demand. Load shifting presents a key grid control strategy that minimizes this mismatch and the resulting rapid ramp rates in fossil fuel-based electricity generation. Water heaters are a principal contributor to residential electricity consumption from the grid, and they offer a good potential for thermal energy storage due to low ambient energy loss and water’s …

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Novel Dishwasher With Thermal Storage And Thermoelectric Heat Recovery, Navin Kumar, Kyle R. Gluesenkamp, Joseph Rendall, Viral Patel, Tony Gehl, Ahmad Abu-Heiba, Tugba Turnaoglu, Guolian Wu, Raveendran Vaidhyanathan May 2021

Novel Dishwasher With Thermal Storage And Thermoelectric Heat Recovery, Navin Kumar, Kyle R. Gluesenkamp, Joseph Rendall, Viral Patel, Tony Gehl, Ahmad Abu-Heiba, Tugba Turnaoglu, Guolian Wu, Raveendran Vaidhyanathan

International High Performance Buildings Conference

Residential dishwashers typically consume domestic hot water, heat it further with electric resistance heating elements, and drain the soiled heated water before each subsequent water fill. During the final rinse, the water is heated to a temperature of approximately 54.5–57.2°C (130–135°F) to heat the load and promote passive drying after the final drain event. In this work, the energy consumption, water consumption, and drying performance of a conventional dishwasher were measured under test conditions similar to U.S. energy efficiency test standards but with an unsoiled load. These measurements were considered baseline performance metrics. The dishwasher was then experimentally modified to …

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Integration Of Phase Change Material-Based Storage In Air Distribution Systems To Increase Building Power Flexibility, Philani Hlanze, Aly Elhefny, Zhimin Jiang, Jie Cai, Hamidreza Shabgard May 2021

Integration Of Phase Change Material-Based Storage In Air Distribution Systems To Increase Building Power Flexibility, Philani Hlanze, Aly Elhefny, Zhimin Jiang, Jie Cai, Hamidreza Shabgard

International High Performance Buildings Conference

This paper presents a novel energy storage solution by incorporating phase change material (PCM) in the building supply-air duct to increase a building’s thermal storage capacity. This solution has various advantages compared to PCM-integrated walls including more effective heat transfer (forced convection and greater temperature differentials). During off-peak hours, the system runs at a supply-air temperature below the material’s solidification point to charge the PCM with cooling energy. During on-peak hours, a higher supply-air temperature is utilized so that the stored energy can be discharged into the supply-air. This shifts a portion of the building’s cooling load from the on-peak …

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Assessment Of Metal-Hydride Energy Storage Coupled With Heat Pumps And Solar Pv For Residential Cooling And Heating, Patrick Krane, Davide Ziviani, James E. Braun, Neera Jain, Amy Marconnet May 2021

Assessment Of Metal-Hydride Energy Storage Coupled With Heat Pumps And Solar Pv For Residential Cooling And Heating, Patrick Krane, Davide Ziviani, James E. Braun, Neera Jain, Amy Marconnet

International High Performance Buildings Conference

The extension of time-of-use (TOU) rates to residential buildings has incentivized the use of thermal energy storage (TES) to shift heating and cooling loads away from on-peak hours. At the same time, the growing use of solar photovoltaics (PV) for on-site energy generation with variable buy back rates also encourages the use of TES to store energy generated at hours of peak solar radiation. Metal hydrides are reversible chemical compounds that form when certain metals react with hydrogen. Since these reactions depend on both temperature and pressure, metal hydrides can be used for thermochemical energy storage across a range of …

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Review Of Low-Cost Organic And Inorganic Phase Change Materials With Phase Change Temperature Between 0°C And 65°C, Jason Robert Hirschey, Navin Kumar, Tugba Turnaoglu, Kyle R. Gluesenkamp, Samuel Graham May 2021

Review Of Low-Cost Organic And Inorganic Phase Change Materials With Phase Change Temperature Between 0°C And 65°C, Jason Robert Hirschey, Navin Kumar, Tugba Turnaoglu, Kyle R. Gluesenkamp, Samuel Graham

International High Performance Buildings Conference

Phase change materials (PCMs) that undergo a phase transition may be used to provide a nearly isothermal latent heat storage at the phase change temperature. This work reports the energy storage material cost ($/kWh) of various PCMs with phase change between 0 – 65°C. Four PCM classes are analyzed for their potential use in building systems: 1) inorganic salt hydrates, 2) organic fatty acids, 3) organic fatty alcohols, and 4) organic paraffin waxes. Many salt hydrates have low material costs (0.09 – 2.53 $/kg), high latent heat of fusion (100 – 290 J/g), and high densities (1.3 – 2.6 g/cm3), …

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Analysis Of Residential Time-Of-Use Utility Rate Structures And Economic Implications For Thermal Energy Storage, Sara Sultan, Jason Hirschey, Kyle R. Gluesenkamp, Samuel Graham May 2021

Analysis Of Residential Time-Of-Use Utility Rate Structures And Economic Implications For Thermal Energy Storage, Sara Sultan, Jason Hirschey, Kyle R. Gluesenkamp, Samuel Graham

International High Performance Buildings Conference

Thermal energy storage (TES) is an increasingly popular tool to level out the daily electrical demand and add stability to the electrical grid as more intermittent renewable energy sources are installed. TES systems can locally decouple high thermal loads from the operation of a heat pump or reduce the electrical energy demand of the heat pump by providing a more favorable temperature gradient. In addition, many policy makers and utility providers have introduced time-of-use (TOU) rate schedules for residential customers to better reflect the price of electricity generation and demand for specific times. TOU rate schedules price grid-provided electricity differently …

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A Natural Wind Defrosting, Nano-Coated Antibacterial Self-Cleaning Energy-Saving Health Air-Cooled Refrigerator, Zhongbao Liu, Jiayang Gao, Xu Chen, Yating Zhang May 2021

A Natural Wind Defrosting, Nano-Coated Antibacterial Self-Cleaning Energy-Saving Health Air-Cooled Refrigerator, Zhongbao Liu, Jiayang Gao, Xu Chen, Yating Zhang

International Refrigeration and Air Conditioning Conference

The air-cooled frost-free household refrigerator is popular in the market because of its large size and frost-free size. However, the evaporator defrost process consumes a large amount of electrical energy to limit the wide spread of this refrigerator, at the same time because of its structural problems, resulting in its evaporator, air duct can not be artificially cleaned, leading to the growth of bacteria, pollution of food storage. This research has developed a self-cleaning energy-saving health refrigerator that uses indoor natural wind defrosting, ultra-hydrophilic nano-titanium dioxide coating photocatalytic sterilization and sterilization. After experimental comparison, under the same operating time of …

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20/20 Vision – Interaction Of Lubricants And Next Generation Refrigerants, Joseph Karnaz May 2021

20/20 Vision – Interaction Of Lubricants And Next Generation Refrigerants, Joseph Karnaz

International Refrigeration and Air Conditioning Conference

The refrigeration and air conditioning industry still struggle on a global level to identify a unified direction on next generation lower global warming potential (GWP) refrigerants. This includes what to do for original equipment changeover and retrofit change outs. Refrigerant suppliers are scrambling today to introduce their options to the market, some refrigerants have gained a foothold while others are still being evaluated or developed. Issues like refrigerant flammability levels, charge size restrictions and overall stability have limited a timely and smooth transition to lower GWP options. Despite the unknown situation, lubricant suppliers need to be ready with whatever direction …

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