Development of a concept for themodular design and sizing of a PV ice-making shipping container for ruralapplications

by:Ricardo Faerron Guzmán

In collaboration with:

Outline1. Introduction to refrigeration in rural

environment

2. Commercial Ice-making Machine

3. Model for Prediction of Ice-making with a PV power supply

4. Design of an Ice-making Container

5. Results and Economic Analysis

6. Comparison of Systems

7. Limitations and Conclusions

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Introduction to Rural Refrigeration

Approximately over 1.4 billion people live without the benefits of electricity [1]

The basic element for the preservation and safe consumption of food and storage of vaccines and other medicines is the use of refrigeration

Refrigeration can provide a means of income, when the increase yield of food stuffs can be then sold to the market.

The project consisted of a technical solution for the production of ice through a solar driven ice-making machine

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Income Generating Applications of Ice for Rural Developmento The cold chain makes it possible to bring food products from far away and in

premium condition.

o The result of spoilage of food is financial loss and constrained economic and social development.

o Increasing produce yield also leads to jobs for transport and distribution

o For the rural environment it has been recommended to have 2 kgice / kgfish and 0.5 kgice / kgmilk (per day)

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Fish sale at market [8]Transportation of chilledMilk [7]

Existing Case Studies

System in Chihuahua, Mexico [2]

-Fishing village-Ice-maker-2.4 kWp PV-24Vdc 2200Ah-About 75kg ice per day-1999 Cost of approx.: $38,000

ISAAC System [3]

-20 Systems in 7 countries-125ft ^2 collector-Ammonia absorption cycle-About 50kg ice per sunny day-Cost of approx.: $17,000

Contained Energy

System[4]-Cold storage for fish-10kWh VRLA-6.4 kWp PV-20m^3 storage room-500kg at -2°C-Phase change material

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The ILK Ice-making Prototype6

[5]

The ILK Ice-making Prototype

o 5.1 kWp PV with estimated 300 kg of ice produced under 6.5kWh/m2/day

o Variable frequency drive of the refrigeration compressor allowsit to work during the day

o Ice-making machine, electronic and control system are madein-house by ILK

o Containers are intended to be custom made to costumerspecifications

o Cost estimates are in the range of €100,000

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Why search for a new approach?o Design process can be a lengthy one for a customized solution

o The cost of such a customized system presents a great barrierfor their sales

o There is no available comparison of the ILK system with marketavailable ice-makers

o A standard product can provide the potential user with a systemwith known performance and characteristics

o Cost reduction through modular design possibilities:o Use market available electronics (inverter, charger, batteries)o Use commercially available ice-making machineo Minimize machining needed to modify container

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Commercial Ice-making Machines

o The Consortium for Energy Efficiency (CEE) list of high efficient ice machines was analyzed

o Findings:o In general smaller machines are less

efficient

o The energy efficiency does not make a correction for ice hardness

o Flake ice contains part of its mass as water (30%), so does nugget ice (20%)

o Water consumption is also an issue to consider

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[6]

[6]

Coefficient Of Performance (COP) of Ice-machines

Machine Model

Compressor Type of ice

Temps of COP

calculation

Ice Production*

Energy Use*

Average power

Cooling Energy

to -5°C **

Calculated overall COP **

Hoshizaki Tair / Twater (°F/°F)

(lbs/24 hrs)

(kWh/100lb) (kW) (kW)

F-801MAH Joint Flake ice

70/50 823 3.20 1.097 1.207 1.100

90/70 599 4.50 1.123 1.037 0.923

F-801MAH-C Joint Cubelet

70/50 752 3.50 1.097 1.239 1.130

90/70 552 5.10 1.173 1.055 0.900

KM-515MAH Joint Crescent

70/50 501 4.70 0.981 1.007 1.027

90/70 435 6.00 1.088 0.989 0.910

KM-650MAH Joint Crescent

70/50 589 4.50 1.104 1.184 1.072

90/70 512 5.80 1.237 1.165 0.941

KM-901MAH Joint Crescent

70/50 874 4.40 1.602 1.757 1.097

90/70 732 5.60 1.708 1.665 0.975

KM-1340MAH Joint Crescent

70/50 1325 3.80 2.098 2.664 1.270

90/70 1167 4.70 2.285 2.654 1.161

KM-1601SAH Joint Crescent

70/50 1462 4.03 2.455 2.939 1.197

90/70 1343 4.70 2.630 3.055 1.161

* Not corrected for ice hardness* * Corrected for ice hardness

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Daily Model for Ice-making

Output Ice

Battery bank

η = 63%

PV ModulesPR = 70%

ηpv_module = 13.7% @ STCPV Area

Inverterη = 94%

MPPT Chargerη = 96%

Solar RadiationAir Temperature

Water TemperatureHourly

simulation for one day

Loads

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[6]

Water pumpLights

Ice-making machine

Results• Seven Machines where modeled• Simulation was run for meteorological data for 4 typical days in Durban, S.A.

Procedure1. First, the ideal situation where all energy provided by the battery was restored by

the PV modules was analyzed2. This leads to different hours of operation for each of the 4 different days3. The minimum hours of operation was taken4. These minimum number of hours were then fixed for all 4 days simulated

* Corrected for ice hardness

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Ice Production ( corrected for ice hardness) [kg]

Machine Model

Type of ice

Hours of operation

4.6kWh/m^2

/day @ 15.3°C

Avg *

5.6kWh/m^2

/day @ 22.9°C

Avg *

4.9kWh/m^2

/day @ 14.2°C

Avg *

5.0kWh/m^2

/day @ 26.4°C

Avg *

Average*

KM-515-MAH Crescent 8.6 81.6 74.2 82.5 71.0 77.4KM-650-MAH Crescent 7.7 85.7 78.0 86.6 74.8 81.3KM-901-MAH Crescent 5.3 88.1 77.8 89.3 75.5 82.7KM-1340-MAH Crescent 3.3 85.5 77.5 85.9 75.3 80.6KM-1601-SAH Crescent 2.8 80.8 76.0 80.7 73.2 77.7

F-801-MAH Flake 8.41 95.2 77.0 98.1 72.1 85.6F-801-MAH-C Cubelet 8.15 97.4 78.3 100.3 72.9 87.2

Daily Ice Production Prediction

Container Designo Once the selection of a machine has been made, then the rest of the

system can be designed, and costs estimations made

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Electronic Component Design

Sub-systems in the container design

Economic Analysis

Day

Solar irradiation

Average temperature

Predicted possible ice production

Days

Totals

(kWh/m^2/day) (°C) (kg) (kg)

37 5.6 22.9 78.3 Jan-March 90 7,047

168 4.6 15.3 97.4 April-June 91 8,863

185 4.9 14.2 100.3 July-September 92 9,228

350 5.0 26.4 72.9 October-December 92 6,707

Year Total 31,845

Availability 85%

20 year total 541,362

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Yearly Ice Production Prediction

Comparison of Systemso An fair comparison is difficult. No standard testing conditions

(different irradiations, air and water temperatures, icehardness)

o Under the different test conditions ILK seems to still presentthe system with highest ice production and lowest lifetimecost of ice

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Preliminary Comparison

Limitations of study Control System: fixed amount of hours through a day

Other costs: water supply and shipping

Daily model vs. Yearly simulation

Non-technical and financial aspects Funding Training Technical SupportMaintenance

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Conclusions

COP of analyzed ice-machines are in the range of 1

Largest cost for Investment and NPV is that of the ex-works (62% and 40.3% respectively)

ILK system is more efficient and produces ice at a lowercost but, by assembling onsite, the proposed system canclose this gap

System would also benefit from an organizationdedicated to providing funding, training, supervision andmaintenance for systems for rural applications

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Thank you for your attention

Question?

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Bibliography

1. The World Bank. Worldbank.org. Energy - The Facts. [Online] 2011. [Cited: 02 01 2013.] http://web.worldbank.org/WBSITE/EXTERNAL/TOPICS/EXTENERGY2/0,,contentMDK:22855502~pagePK:210058~piPK:210062~theSitePK:4114200,00.html.

2. Rudischer, R.; Waschull, J.; Leupolt, H.; Prastka, F. Abschlussbericht Produktenwicklung PV-Eirerzeuger. Dresden : ILK-AB-32/05-247, 2005. Internal document.

3. Estrada, L.; Foster, R.; Cota, A.D. .First Year Performance of the Chorreras PV-Hybrid Ice making System in Chihuahua, Mexico. Mexico : ISES Forum, 2000. DSA 09-03.

4. Ericson, C. Rural Milk Collection Centers ISAAC Solar Icemaker. Nairobi, Kenya : s.n., 24 May 2005. East and Southern African Dairy Association Conference. http://www.dairyafrica.com/html/conferences/pdf/conf01_presentations/Session%208/Carl%20Erickson%20-%20Rural%20Milk%20Collection%20Centers.pdf.

5. Contained Energy. Containedenergy.com. Contained Energy Solar Powered Cold Storage Systems. [Online] 2012. http://www.containedenergy.com/CE_Solar_Powered_Cold_Storage_System_1.01.pdf.

6. Hoshizaki America. Hoshizakiamerica.com. F-801M_H-C Modular Cubelet Ice Machine. [Online] [Cited: 02.01.2013] http://www.hoshizakiamerica.com/color-specs/F801MHC.pdf.

7. ISAAC Solar ICE Maker. http://solaricemaker.com/. Phtograph of website from: Solar Ice Company, Annapolis, Maryland. [Online] [Cited: 31.01.2016] http://solaricemaker.com/

8. Fish Consulting Group. http://fishconsult.org/ Photograph from article: Marketing and consumer preference in Lao PDR [Online] [Cited: 31.01.2016] http://fishconsult.org/?p=12635

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Special Thanks

Russom SemereDirk Gutzeit

Tobias Zwirner

Hans HoltorfDaniela Vega

Dr. Jörg WaschullWolfgang Hernschier

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