Ice Bank Research Articles

Cooling liquid substances Peltier device from the use of exo-thermic pathways application

This work presents the development of an innovative device capable of instantly freezing water. The main objective was to design and build an efficient and practical system to provide chilled water in situations requiring rapid consumption, such as in domestic, commercial, or industrial environments. To achieve this goal, research was conducted on the fundamental principles of refrigeration and ice formation. Based on this information, a device was conceived, consisting of a thermally insulated container and a cooling mechanism. To relate thermodynamics and the Peltier effect, it is necessary to differentiate the relationship between heat, energy, and work in thermodynamics and the thermoelectric phenomenon that involves heat transfer through electric current in a device with semiconductor junctions when referring to the Peltier effect. A practical example of the combination of these two terms is the heat transfer generated by a temperature gradient in a material. In this project, the physical effects of Peltier plates were modeled as the main factor for heat transfer, as well as a brief study on ice banks where it was possible to improve and meet all the expectations of the prototype.

Requirements and Economic Implications of Integrating a PV-Plant-Based Energy System in the Dairy Production Process

To expand the potential of renewable energies, energy storage is required to level peaks in energy demand and supply. The aim of the present study was to examine and characterize the energy consumption of a milk production system to find possibilities and boundaries for a self-sufficient energy system. A detailed quantification of energy production of the test farm and the consumption of the milk production system showed, that the total energy production could cover the energy consumption of the production process. However, the temporal distribution of energy production and consumption requires energy storage in the production process. Though ice bank milk cooling and water heating have the potential to cover parts of this storage capacity, battery storage is mandatory to enable full autarky. The consideration of different seasons leads to different optimal dimensions of the energy system. The energy price is decisive for profitability, both in the purchase and in the sale. Smaller energy systems are generally at an advantage due to the higher self-consumption quota.

Performance of an Ice Bank with Falling Film Flow around a Melting Surface

Performance of an Ice Bank with Falling Film Flow around a Melting Surface

Investigation of the discharging performance of an ice bank with a falling film flow around a melting surface

For the first time, the technical characteristics of an ice bank with a falling film flow around melting ice on the surface of coaxial tube coils in the temperature range of 20÷60 °C and mass flow rates of 0,25÷1,0 kg/s of water at the apparatus inlet are studied. The discharging rate is determined depending on the mass flow to wetted perimeter ratio, the temperature of the water at the apparatus inlet and the discharging duration. The film flow allows obtaining water at the apparatus outlet with a temperature of only 0,5÷1 °C higher than the melting point of ice. Keywords: ice bank, ice, film flow, melting, peak load, refrigeration galinagoncharova@mail.ru, korolev.vnihi@mail.ru

Erratum in: Goncharova G.Y. et al. “Prospects for Creating a New Generation of Ice banks for Systems with Uneven Heat Loads”

We made corrections in the article "Prospects for Creating a New Generation of Ice banks for Systems with Uneven Heat Loads" by G.Y. Goncharova et al. published in 'Refrigeration Technology' 2022;111(2) doi: 10.17816/RF108496. The wrong affiliation info was published on the page 106: "V.M. Gorbatov Federal Research Center for Food Systems of Russian Academy of Science" is the proper title of the organization. The proper title is ""V.M. Gorbatov Federal Research Center for Food Systems" of RAS".
 Also we correct the title of the article "Prospects for Creating a New Generation of Ice banks for Systems with Uneven Heat Loads". Current title is "Prospects of a new generation of ice banks development for systems with uneven heat load".
 Editorial team and authors belives that these errors did not affect published data interpretation by readers, so the article should not be retracted. The article has been corrected and replaced online.

Prospects for Creating a New Generation of Ice banks for Systems with Uneven Heat Loads

BACKGROUND: The rational application of thermal energy storages with phase transition for objects of the food industry with significantly uneven heat loads is discussed in this article. The drawbacks of existing ice banks, suppressing their spread, are analyzed. Possible methods of addressing these problems during the designing process are considered.
 AIM: Development of a new generation of ice banks with a high intensity of ice melting processes and the ability to adjust the heat load.
 MATERIALS AND METHODS: The brand-new discharge method based on the film flow around ice surfaces is proposed. The proposed approach allows us to optimize the heat load and provide the maintenance of the required ice water temperature. The laboratory sample of the coaxial film heat exchanger (FHE) was designed by the authors.
 RESULTS: Experimental results in the operating range of the levels of supplied water temperatures 20 ℃, 40 ℃, and 60 ℃ and mass flow rates 15, 30, 45, and 60 kg/min are carried out. The experimental results confirmed that the development construction of the FHE with the film mechanism of the heat transfer provides increasing efficiency in orders of magnitude in comparison with ice banks with bulk melting. The reduced heat load with a mass flow rate of 60 kg/min and medium temperature on 60 ℃ was 220240 kW/m2, and the maximal reduced heat load of the upper layer of coil reached 1300 kW/m2. The generalization of the results showed the application prospects of film ice banks in the refrigeration systems of various industrial and agricultural objects.

Design and performance optimization of a tri‐generation energy hub considering demand response programs

AbstractThe design and development of renewable energy resources‐based poly‐generation microgrids have recently increased to supply multiple demands such as cool, heat, and power as well as mitigate pollutants improving efficiency. This paper aims to develop a combined cooling, heating, and power production network integrating photovoltaic panels (PVs), wind and gas turbines, a battery, an ice bank tank, a heater, an electrical chiller, a thermal energy storage medium. In this tri‐generation facility, natural gas is utilized for district heating and fueling the gas turbine power generation cycle. The local power distribution system in combination with the output powers of PVs, wind and gas turbines is used to directly supply the electrical appliances, ice maker process, and chiller as well as charge the battery storage unit. Moreover, the air/water‐cooled chiller procures the cooling flux for a benchmark microgrid. Its heating energy requirement is also provided by the gas‐fired heater, the flue gases of the gas turbine, and the thermal storage medium. A mixed integer linear programming problem is coded using a generalized algebraic modeling system (GAMS) to minimize daily operating costs and emissions. Simulations are examined and analyzed over a 24‐h study horizon on a sample summer day. Time‐of‐use energy rates and RTPs are considered two strategic demand response schemes to investigate the cost‐effectiveness capability of the gas‐power nexus model. The proposed approach is coded using a GAMS to confirm its effectiveness and cost‐environ benefits in four cases with and without heat/cool/electrical storage units considering time‐of‐use energy rates and real‐time prices.

Impact of the pipe row spacing on the capacity of ice bank formed in a volume-limited water bath

In this study, a design of an ice bank heat exchanger with pipes arranged in a column inside a volume-limited water bath, was investigated by a numerical simulation. The aim of the research is to determine the design of heat exchanger which would result in the highest quantity of ice formed in a given time period. Prior to the consideration, the accuracy of the numerical model was validated by comparison with experimental measurements. The boundary conditions are chosen to simulate the real process during the regeneration of the ice bank in the draft beverage cooler. The study is carried out for the condition of natural convection in a water bath and constant temperatures of a secondary coolant flowing through the pipes. The base design of the water bath and the heat exchanger used in the experimental measurements was further considered by CFD simulations through the variation of number of pipes in a column i.e. pipe row spacing. The optimal distance between the axes of the adjacent pipes and consequently the optimal distance gap between the pipes (x) are found as a function of the pipe diameter (d) as x/d ∼ 1.5. This finding is further confirmed by CFD simulations which are performed for cases of different pipe diameters, with different water bath height as well as by heat flow analysis for individual pipes in the bundle.

SUPERVISED TUNING OF A CHILLER WITH A COLD PHASE-CHANGE MATERIAL USING AN RSM-SMITH PREDICTOR

The proposed work is focused on the tuning of the latent-heat storage of a PCM with MWCNT encapsulation for a chiller system in the milk-pasteurization process using an RSM-based predictive Smith controller. The PCM was synthesized using sodium polyacrylate and MWCNT particles, encapsulated in spherical balls stored in the IBT (ice bank tank of the chiller unit). Experimental work is conducted on the heat-transfer characteristics of the chiller unit with servo-operated flow-control valves based on the central composite design of experiments. The system is cascaded using a PID controller with a Smith predictor to stabilize the latent temperature of milk cooling in the chiller system. The system is considered to be a first-order transformation with the rise and settling time. The plant model is obtained, using the response-surface method based on the transfer function to minimize the error derivatives of the chiller system. Results of the proposed method show a robust performance in keeping the PCM temperatures and bacterial-growth value stabilized, allowing a less drastic control compared to the cascade-model predictive control.

A novel solar-powered milk cooling refrigeration unit with cold thermal energy storage for rural application.

This experimental study analyzed the use of solar photovoltaic energy for operating a novel twin-circuit DC milk chiller without batteries using water-based cold thermal energy storage for different seasons in Chennai, India. HFC-134a and HC-600a were used as refrigerants in the two individual circuits. For each season, the test was conducted continuously for 18days to analyze the quantity of generated ice that could be utilized to chill 10 L of milk in the morning and in the evening. The average quantity of ice formed per day in the ice bank during monsoon, winter, and summer seasons was found to be 3.61, 19.75, and 27.97kg, respectively. Thus, it is evident that the use of solar energy with thermal energy storage is effective for operating the milk chilling unit for two seasons, namely winter and summer. However, the system requires an additional power source for continuous operation during the monsoon season. It is noteworthy to mention that the use of a solar milk chiller instead of a conventional milk chiller resulted in 91.15% lesser CO2 emission with 27.6% less LCC. In this study, solar photovoltaic power was observed to be a good choice for chilling milk in the context of global warming and energy consumption. The use of thermal energy storage also allows the initial cost to be reduced.

Experimental and numerical study on water ice forming on pipe columns in a limited-volume storage

Draft beverage is mostly cooled with a direct expansion refrigeration system equipped with ice bank thermal storage in the form of a bath and coiled heat exchangers for beverage cooling. This study conducts a numerical simulation and experimental validation of the ice bank forming inside the experimental model of a draft beverage cooler with a natural convection flow. Key design parameters of the test rig were water bath dimensions, number of pipes, pipe diameter and its position inside the water bath, as well as the initial water temperature in the pull-down time process. These were chosen to be as close as possible to the properties of a real draft beverage cooler. Furthermore, glycol solution was used instead of a refrigerant to provide approximately constant inner pipe temperatures during the experiments corresponding to refrigerant temperatures in the real draft cooler operation. Experimental validation is carried out by comparison of temperatures inside the water bath, profile of formed ice mass, and heat flow on pipes. Comparison of the mass of formed ice under different temperatures of glycol solution was performed to validate the simulation model in the conditions of variable evaporation temperature of the refrigerant as prevailing in real refrigeration units. The results obtained by the simulation are in a good agreement with results obtained by the experiment. This study is part of a comprehensive research on energy efficiency of draft beverage coolers. The simulation model validated in this study is developed with intention to be a part of a broader simulation system for analysis of the complete refrigeration system of the draft beverage cooler.

Charge optimisation of a solar milk chiller with direct current compressors

In view of promoting the utilization of solar photo-voltaic energy for milk chilling application a custom designed milk chiller with DC compressors was fabricated. Two different DC compressors were used operating with HFC-134a and HC-600a refrigerants to ascertain the performance of HFC and HC refrigerants when used in solar powered application. In view of optimizing the performance of both refrigerants, charge optimization was experimentally carried out for both refrigerant circuits. The optimum charge was obtained based on the maximum coefficient of performance and exergy efficiency. When comparing ice formation and coefficient of performance, the HC-600a refrigerant circuit was lower than that of HFC-134a circuit. It was also observed that the total exergy destruction experienced was maximum in the HFC-134a circuit than that of the HC-600a circuit. The magnitude of exergy destruction was found to be maximum in the compressor and then followed by the condenser, evaporator and finally the capillary for both refrigeration circuits. This study showed an efficient way for using the solar power for operating a milk chiller with DC compressors and with ice bank tank to avoid the dependency on batteries.

A standalone PV operated DC milk chiller for Indian climate zones

This work illustrates the design of a standalone solar power system used to power a milk chiller with 200 W DC compressors using the PVsyst software for different climatic zones in India. The design includes determination of minimum number of PV panels and batteries and also the means of obtaining annual solar fraction values for five different climatic zones of India using the software. Simulations were performed considering two different operational modalities. The first modality considered a milk chiller with an inbuilt ice bank tank for cool thermal energy storage. The ice formed during sunshine hours take care of the cooling of the milk throughout. The second modality considered a milk chiller coupled with a battery backup to get charged during sunshine hours and to run the compressor throughout. The first modality was found to be advantageous in terms of PV panel requirement, battery backup as well as better solar fraction. Hence the same was experimentally studied for Chennai’s climate condition to confirm the maintenance of milk temperature. The power supply from the PV panel was simulated using a regulated power supply. While doing so, considering the maximum power point, the power supply was varied every hour as predicted by the PVsyst software. From the experiment, it was found that the required number of PV panels got reduced from 4 to 2 panels when considering the maximum power point for a typical summer day. The custom built milk chiller was able to chill down the milk from 37°C to 4°C within 2 hours on all days using cold energy from the ice bank tank.

A comprehensive multiphase CO2 release model for carbon sequestration QRA purposes. Modeling and conditions for simplifying assumptions and solid CO2 occurrence

In the framework of emerging Global Warming strategies, CO2 sequestration pipelines require attentive hazard studies to ensure a safe operability, but current risk assessment procedures applied to CO2 pipeline failures lack reliable and comprehensive source models. This work suggests a resolutive and robust multiphase discharge model suited for matching all expected CO2 discharge mechanisms.The application to real scale CO2 pipelines shows an essential incidence of the pipeline geometry (length and internal diameter) as well as of the orifice size on the release features. Wider thermal dynamics and enlarged solid contents are expected in short pipelines subjected to large ruptures. The resulting expansion transformations are characterized by increasing degrees of reversibility. Results show that expected solid content may amount up to 45% on a mass basis under usual carbon sequestration operative conditions. The latter, being linked to the initial CO2 aggregation state, play a key role in determining the whole discharge dynamics especially because of the effects of phase change mechanisms. A peculiar mass flow rate discharge profile is observed depending on the occurrence of liquid-vapor and solid-vapor mixtures.Specific set of geometric and operative conditions allow for the applicability of the isothermal bulk hypothesis and negligible wall effect in heat transfer mechanisms. Main governing parameters are the ratio between the pipeline length and internal diameter L/D and that between the orifice and the internal pipeline diameter d/D.Essential in driving the QRA procedure is the occurrence of the solid phase in rapid depressurizations that is expected only for pipeline shorter than 1500 m subjected to d/D > 0.30. Independently on the operative temperature, only pipelines carried at pressures above 55 barg lead to CO2 solid-vapor mixtures. Under these conditions, the solid CO2 cannot be neglected thus requiring a QRA modelling procedure considering additional scenarios involving sublimative dynamics of a dry ice bank.

Experimental and numerical analyses of a cooling energy storage system using spherical capsules

Cold energy storage during the off-peak hours to supply the cooling demand during the peak hours leads to reduction of the chiller size and energy expenses. In this paper, the performance of an ice bank system based on spherical capsules is experimentally analyzed and the effects of different parameters are investigated using a numerical model. The numerical simulation is performed for optimum design of the energy storage system and the results of numerical simulation are validated against the experimental data. Moreover, temperature distribution inside the ice bank is evaluated, experimentally and numerically, and heat transfer rate from the spherical capsules wall and the liquid fraction inside these spherical capsules are determined using numerical simulations during the charge and discharge processes. The results indicate that utilization of two inlets for heat transfer fluid (HTF) leads to decrease of charging time by 11 min and increase of the efficiency by 37%. Moreover, the best efficiency during the charge and discharge modes are 77% and 51% using 0.04 kg/s mass flow rate, respectively. Furthermore, the results showed that when the capacity of the system increases by increase of spherical capsules from 60 to 120, the system efficiency during the charge and discharge processes increase by 26% and 23%, respectively.

An experimental research on energy efficiency of a beverage cooler with the latent heat storage

The experimental study has been performed on a beverage cooler with latent heat storage, on the unit which can be considered as representative for the whole market of similar equipment. Studies of the energy efficiency of such a refrigeration equipment were not previously performed due to a lack of interest in present relations between customers and suppliers, which makes the presented study original and a good starting point for further research. Experimental study focused on energy consumption and energy efficiency measures concerning a control system of beverage coolers with latent heat storage (ice bank). Results show that replacement of a thermostat with an ice bank relay as a control device can provide two main benefits: up to 15% reduction of energy consumption and significant decrease of refrigeration system start-ups what can extend service life of compressor. An analysis of intermittent mode of operation of the agitator (mixer) integrated into the latent heat storage was investigated resulting in up to 55% reduction of energy consumption in stand-by mode and 17% reduction during the refrigeration system operation. Optimization of ice bank mass could give additional reduction in energy consumption, but it requires additional research on dynamic behaviour of the cold storage.

Practical Applications of Performance of Private Credit Funds: A First Look

Practical Applications Summary In Performance of Private Credit Funds: A First Look, from the Fall 2018 issue of The Journal of Alternative Investments, Shawn Munday of the University of North Carolina, Wendy Hu of Burgiss, Tobias True of Adams Street Partners, and Jian Zhang of Adams Street Partners analyze the performance of private credit funds and conclude that they deliver superior performance relative to the S&P/LSTA US Leveraged Loan 100 index. They further conclude that direct lending funds, which compose a subset of private credit funds, offer the attractive combination of low beta and high alpha relative to both the S&P/LSTA US Leveraged Loan 100 index and the ICE Bank of America Merrill Lynch Global High Yield Index. Additionally, direct lending funds offer notable diversification benefits because of their generally low correlation with all relevant benchmark indexes.

MODELING AND TESTING OF AN ICE BANK FOR MILK COOLING AFTER MILKING

ABSTRACT Based on mass and energy balance equations and data collected in specialized bibliographies, it was proposed a methodology for modeling of an ice bank for thermal storage of energy at low temperature to be used in milk cooling. The data obtained by the equations arrangement were used in the design and installation of a real system, which was tested to collect data and to compare it with the estimated. The data obtained in terms of prediction of ice formation, temperature of the ice bank, water and capacity of the selected refrigeration system prove the adequacy of the equations arrangement, showing that it can be used as a tool for sizing solid ice bank in smooth pipe coils, with good approximation.

Formation, collapse and composition of ice banks in a macrotidal channel of the Bay of Fundy

Large ice blocks containing enough sediment to be denser than sea water form in the Minas Basin of the Bay of Fundy, Canada. Ice block composition and the timing of ice block formation were monitored to improve understanding of the potential threat to tidal power generators posed by collision with ice blocks. Field studies were carried out in 2012 and 2013 in the Kennetcook River, which is a tributary of the Minas Basin of the Bay of Fundy. In 2012, the cross-sectional area of the channel at the study site decreased by 21% due to the formation of ice walls. In 2013, it decreased by 24%. Large ice blocks separated from the ice walls during spring tides following a time lag of the minimum air temperature. The time lag was 20 days in 2012 and 21 days in 2013. Eleven percent of samples from ice blocks were denser than sea water.

Electricity & direct water consumption on Irish pasture based dairy farms: A statistical analysis

With the abolishment of the European Union milk quota system in April 2015, the Irish government has targeted a 50% increase in milk production by 2020 over 2007–09 levels. Resulting milk price volatility and environmental constraints are forcing farmers to produce milk at lower costs with a lower overall environmental footprint. This entails using less energy and water resources to maintain commercial competitiveness and to reduce the environmental consequences of the production. This paper presents a detailed analysis of electricity and direct water consumption of 58 pasture-based, Irish commercial dairy farms. Data was acquired through a remote monitoring system installed on each farm in 2014 alongside corresponding milk production, stock, infrastructural and managerial data. The results derived from the analysis of this data allow key drivers of both electricity and water consumption to be understood with the ultimate aim of generating data to develop footprint models, to achieve a reduction in electricity and water use and to improve the cost efficiency of Irish pasture based dairy farms. The analysis showed electricity use of 39.84WhLm−1 and water use of 7.43LwLm−1 for the period Jan - Dec 2015. Dairy farm processes directly associated with milk production (milk harvesting and milk cooling) were responsible for 47% of overall electricity consumption. Milk cooling systems which utilised ice chiller units or ice bank milk tanks consumed 32% greater WhLm−1 for milk cooling compared with direct expansion milk tanks. This increase in consumption was met with a 25% decrease in day-time hours consumption due to their load shifting capabilities resulting in no difference in milk cooling related cost per Lm when under a day and night electricity tariff structure. Mean milk cooling electricity savings of 21% were achieved across farms with the incorporation of ground water through a plate heat exchanger for milk pre-cooling. However, in an open loop system, this resulted in a 41% increase in parlour water consumption. Electricity consumption was found to be largely associated with milk production, herd size (total dairy cows) and the number of lactating cows. Water consumption was found to be largely correlated with milk production and moderately correlated with herd size and the number of lactating cows. Decreased correlation strengths for water consumption compared to electricity suggests consumption is less dependent on milk production and stock numbers and more dependent on managerial processes, environmental conditions and farm infrastructure. Results and methodologies from this analysis will facilitate the development of adaptive predictive and optimisation methodologies for dairy farming electricity and water consumption.