Energy Assessment on Cooling Systems in Wine Industry

Case Study in Ervideira Winery João Leal da Costa M. Correia1, Miguel Cavique Santos2 and António José Freire Mourão3

1Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Campus de Caparica, 2829-516 Caparica, Portugal2UNIDEMI_CINAV & Naval Academy, Base Naval de Lisboa – Alfeite 2810-001 Almada

3UNIDEMI & Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Campus de Caparica, 2829-516 Caparica, Portugal

Introduction

• Wine industry have changed in the last thirty years. The technology is improving and the wine consumers demand more. It is crucial to have a rigorous control over the production.

• The study conducted at the Ervideira Winery in the South of Portugal allowed to define a model of the heat transfer and the heat generated in a real winery.

• Can help defining the main sinks of heat in the production of wine, and to establish the cooling needs of the central cooling producer.

• The need to present improvement measures that justified not only their application but could increase the quality of the production conditions in order to have a better product.

Structure of the work

Introduction Wineproduction

Understand the parameters of the

fermentation

Heat transfer to thetanks due to environment

conditions

To fermentation

tanks

To maturation

tanks

Sum of allenergysources

Analyse of energy

generated in fermentation

Improvementmeasures

Conclusions

Wine production

Receptiongrape tank

Crush and destemming

Fermentation tankand maceration

Must follows to fermentation tank

Solid parts are pressed

Alcoholicfermentation

Malolacticfermentation Maturation

Filtration and fining

Botling and commercialization

24 ᵒC

15 ᵒC

18-20 ᵒC

<20 ᵒC

FermentationOrigin of the heat

• Enthalpy• El Haloui et al. (1988) → correlations

• A. López and P. Secanell• = 0,99109. − 2096,3. + 2078

• The heat released is calculated by:

• = ∆

450 ≤ ∆ ≤ 650 /

= 1,85 + 2,7= 2088,7 − 2070,7

Heat released

0

20

40

60

80

100

120

140

160

180

200

12 60 108

156

204

252

300

348

396

444

492

540

588

636

684

732

780

828

876

924

972

1020

1068

1116

1164

1212

1260

1308

1356

1404

1452

1500

dQ/d

t [kJ

/L]

Time [h]

Sum of heat released from all tanks

-1

0

1

2

3

4

5

6

7

8

9

10

12 36 60 84 108132156180204228252276300324348372396420444468492516540564588

dQ/d

t [kJ

/L]

Time [h]

Heat released in a white wine grape

The heat transfer analysis to the tanks due to environment

• Ervideira winery is open to the exterior on the North and East bounds.

• Covered by a non-insulated white metal sheet.

• The tanks are therefore at atmospheric conditions, subjected to radiation from the cover and to direct radiation from the East area.

• A refrigeration water network with a central chiller of 149 kW allows removing the heat gained by the tanks due to the chemical process and to the heat transfer.

Methods

• Sf• Calculate the heat convection coefficients inside

and outside of the tanks to determine the heatflow at any hour, considering natural convection.

• Calculate the Nusselt number, Nu, to determine the heat convection, according to:

• = = ×

• It was estimated temperatures of the walls and then an iterative method was performed to calculate the real temperature of the walls through the calculation of heat flux according to Fourier’s Law.

• The convection coefficients were found based on the same method after knowing the real temperatures of the wall.

Heat transfer result• The global energy generated since May to October is represented in the chart.

0

20000

40000

60000

80000

100000

120000

140000

160000

Potê

ncia

(W)

Time (Horas)

The global energy generated to fermentation and maturation tanks

Two different analysis

0

10

20

30

40

50

60

70

Convection andconduction

Fermentation Direct radiation Radiation from theroof

Heat dissipation

Perc

enta

ge [%

]

Source of energy

Percentual balance

86%

6% 8%

Red Wines

37%60%

3%

White wines

Comparison to the real case

• In most cases the energy consumption at a winery in fermentationtime is circa 60-70% of total annual consumption. Regarding to Adega da Ervideira it corresponds to 81 MWh/a.

• What concerns with this study the total refrigeration needs are: 96,2 MWh/a per year.

• EER of the chiller of 2,58 → 37,3 MWh/a (electricity use).• The 37,3 MWh/a corresponds to 46% of the 81 MWh/a (Adega da

Ervideira).• With the consumption of the pumps it can be 43,8 MWh/a which is

54% of total energy use of the year.

Improvement measures

Not Quantified Quantified

Close the interior with masonry wall Insulation of the tanks

Application of nebulizers Insulation of cover metal sheet

Replacement of the lighting to led systems

Vertical wall plants to cover the radiation

Insulation of the pipe system

Results• The application of insulation to all tanks is the more effective

measure.

Total thermal charge[kWh]Total [kWh]

Total electricalconsumption

[kWh]Fermentation Maturation

No insulation 22036 74185 96221 37295

With insulation 16261 32632 48893 18951

Savings of cooling energy 5775 41553 47328 18344

Conclusions• With hot temperatures during the summer, it is important to reduce the heat

transfer to the tanks in order to decrease the energy spending and to achieve better production conditions.

• The electricity for wine production totals 43.8 MWh/a, therefore about 5.5 MWh/a per 100.000 bottles.

• About 2/3 of the energy use concerns the process of maturation and fermentation.

• It needs a maximum cooling power of 136 kW, accomplished by a chiller of 149 kW, or less than 20 kW to produce 100.000 bottles.

• The application of insulation can represent an annual saving of 2385€ corresponding to 10% of total energy use in a year.

• The use of these indexes can help defining the power and energy use for other producers, and to allow the oenologist to check the availability of cooling power to produce different types of wines.

Energy Assessment on Cooling Systems in Wine IndustryCase Study in Ervideira Winery

Thank you

João Leal da Costa M Correia