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Pacific Gas and Electric Company

Emerging Technologies Program

Application Assessment Report #0706

Performance Study of a Mechanical Vapor

Recompression (MVR) Evaporation System

Issued: December 2007 Project Manager: Ryan Matley Pacific Gas and Electric Company Prepared By: Heschong Mahone Group 11626 Fair Oaks Blvd. #302 Fair Oaks, CA 95628

Legal Notice This report was prepared by Pacific Gas and Electric Company for exclusive use by its employees and agents. Neither Pacific Gas and Electric Company nor any of its employees and agents: (1) makes any written or oral warranty, expressed or implied, including, but not

limited to those concerning merchantability or fitness for a particular purpose;

(2) assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, process, method, or policy contained herein; or

(3) represents that its use would not infringe any privately owned rights, including, but not limited to, patents, trade marks, or copyrights.

© Copyright, 2008, Pacific Gas and Electric Company. All rights reserved.

Heschong Mahone Group, Inc. Pacific Gas and Electric Company

MVR Performance Evaluation

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TABLE OF CONTENTS 1. EXECUTIVE SUMMARY ...........................................................................................3

2. INTRODUCTION .........................................................................................................5

2.1 Background........................................................................................................5

2.2 Project Objectives ..............................................................................................5

2.3 Tomato Evaporation Technologies ....................................................................5

2.4 Host Site MVR and triple effect evaporation systems.......................................7

3. PERFORMANCE MONITORING AND EVALUATION...........................................9

3.1 Performance Monitoring....................................................................................9

3.2 Performance Evaluation.....................................................................................9

4. RESULTS AND DISCUSSION..................................................................................12

5. MVR PERFORMANCE MODEL...............................................................................18

6. CONCLUSIONS..........................................................................................................20

7. APPENDIX..................................................................................................................21

7.1 Performance Monitoring Data .........................................................................21

7.2 Screen Snapshots of the MVR Performance Model ........................................27

7.3 Reference .........................................................................................................30



ii

TABLE OF FIGURES Figure 1 Summary of MVR and triple effect energy consumption.......................................3

Figure 2 Illustration of evaporation process .......................................................................6

Figure 3 Schematics of a triple effect evaporation system ..................................................6

Figure 4 Schematics of a MVR evaporation system ............................................................7

Figure 5 Picture of the host site MVR system......................................................................8

Figure 6 Picture of the host site triple effect system............................................................8

Figure 7 Mass flow around a MVR evaporator.................................................................16

Figure 8 Energy flow around a MVR evaporator..............................................................16

Figure 9 Mass flow around a triple effect evaporator.......................................................17

Figure 10 Energy flow around a MVR evaporator............................................................17

Figure 11 Process flow diagram of the triple effect model ...............................................18

Figure 12 Process flow diagram of the MVR model..........................................................19



3

1. EXECUTIVE SUMMARY

PG&E Emerging Technologies Department sponsored this study to evaluate the energy savings potential of a mechanical vapor recompression (MVR) tomato evaporator, as compared to a triple effect evaporator.

The MVR system has three stages of evaporation, all operated at about 180 oF. On average, the tomato paste BRIX number was increased from 7.5 to 9.8 for cold break and from 7.3 to 9.3 for hot break. BRIX number is defined as the percentage of solid contents by weight. The energy input to the MVR system was from a compressor that was driven by a steam turbine. For each pound of water evaporated, the average energy consumed by the steam turbine was 50.2 Btu for cold break and 48.5 Btu for hot break.

In the triple effect system, the three evaporators were in operation at 113 oF, 153 oF, and 183 oF. Tomato paste concentration was increased from 10.3 to 18.4 BRIX for cold break and from 9.7 to 15.3 for hot break. Figure 1 provides a summary of energy consumption for both the MVR and triple effect systems. For each pound of water evaporation, the average steam input energy was 468 Btu for cold break and 441 Btu for hot break. Therefore, the MVR system required only 11% of the steam energy consumed by a triple effect system for evaporating the same amount of water, excluding other auxiliary power consumptions.

0

100

200

300

400

500

600

Hot Break Cold Break Hot Break Cold Break

MVR 3-effect

Btu

/lb o

f wat

er e

vapo

rate

d

CondenserEvaporation

Figure 1 Summary of MVR and triple effect energy consumption

MVR technologies are limited to evaporating tomato with low solids concentrations. Tomato paste with higher solids concentrations has lower thermal conductivity. It requires higher input steam temperature to achieve effective evaporation. Or, in other words, the evaporated water vapor needs to be compressed to higher pressure levels. Compression ratio for typical MVR compressors is limited to 1.6, which determines the maximum tomato paste output concentration. It should also be noted that the MVR technology still has large energy savings potential even with this limitation on tomato concentration. This is because concentrating tomato from 5.5 BRIX (raw tomato



4

concentration) to 10 BRIX (MVR limitation) represents roughly 50% of the total water removal for reaching final product concentration of 31% BRIX.

Steam condensate left evaporators at high evaporation temperatures of up to 183 oF. Compared to the city supply water temperature at 70 oF, the associated thermal energy was 113 Btu per pound of condensate. Also, the water quality was very good, since it was largely from water in tomatoes. The most practical approach for recovering the associated thermal energy is to use it as boiler feed water. At the host site, the steam condensate was not fully recovered for either the MVR or triple effect systems, due to the fact that condensate production was more than total steam demand.

Energy consumption related to recirculation pumps was similar for both systems and was estimated to be between 24 and 31 Btu per pound of water evaporation.

The study also developed energy performance models for the MVR and triple effect systems. An EXCEL spreadsheet tool was built to estimate MVR energy savings based user inputs of key MVR and triple effect parameters.



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2. INTRODUCTION

2.1 Background The PG&E Emerging Technology Department has identified the MVR system as a promising energy efficient technology for food evaporation processes and sponsored this study to investigate the performance of a MVR system at a tomato processing plant.

California produces more than ten million ton of tomato every year, representing 95% of the total US production. Tomato concentration through evaporation is an important step in tomato processing. There are 15 major tomato processors with 18 major processing facilities in California, providing more than 1.7 million lb/hr processing capacity. This large tomato processing industry consumes substantial amount of energy every year. For example, the 2007 industry-wide tomato production was 12 million tons. With typical triple effect evaporation systems, which take about 450 Btu for evaporating one pound of water, the annual industry-wide fuel energy consumption would be about 105 million therms. Application of energy efficient technologies in this area could lead to significant energy savings.

2.2 Project Objectives The objective of this field performance monitoring study is to assess the energy consumption characteristics of a MVR system and a triple effort system for tomato processing. The study will also develop a model for estimating energy savings of MVR systems, as compared to triple effect systems. This model is validated by the field performance monitoring results.

2.3 Tomato Evaporation Technologies Figure 2 through Figure 4 illustrate several evaporation systems. In general, an evaporator consists of a calandria, where tomato paste is heated by steam, and a separator, where water vapor is separated from the tomato paste. Evaporation processes keep the tomato paste at a constant temperature, determined by the tomato paste pressure. Similarly, steam stays at a constant temperature as it is cooled by the tomato paste and condenses into liquid water. As a result, the temperature difference between steam and tomato paste is held constant through the evaporation process. The industry often used the measure of steam economy to gage evaporator efficiency, which is defined as the ratio of water evaporation to steam input by weight.

In a single effect evaporation system (Figure 2), water vapor from the tomato paste is not used for further evaporation. The latent heat carried by the vapor is wasted if it is condensed through a condenser. Under typical evaporation conditions, this system takes about 1000 Btu to evaporate one pound of water, assuming the steam economy is 100%.



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Figure 2 Illustration of evaporation process

A multiple effect evaporation system has more than one evaporator. As shown in Figure 3, water vapor from one effect is used to drive the next stage of evaporation, at a lower temperature. The result is that the latent heat from the steam input is used several times and the total steam consumption is greatly reduced. For example, a triple effect system would ideally use 1/3 of the steam required by a single effect system. Since each succeeding effect has to be operated at lower pressures and temperatures, the number of effects that can be achieved is limited by the initial tomato temperature.

Figure 3 Schematics of a triple effect evaporation system

2nd Effect 3rd Effect

17% 1st Effect

Further evaporation

12.5% 9.9%

Steam Condensate

Steam Input

35,300 lb/hr

Condenser

Calandria

Separator

Recirculating Pump

Condensate

Tomato Paste Input

Steam Input

Vapor Output

Tomato Input

191,800 lb/hr

7.3%



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Thermal vapor recompression (TVR) uses high-pressure steam to compress water vapor to recycle latent heat. Due to the inherent thermodynamic effect, not all vapor is recompressed and steam input is still required. The advantage of a TVR system is its simplicity, therefore, lower cost. A TVR system can achieve similar energy efficiency as a multiple effect system, but with a smaller number of effects.

Figure 4 Schematics of a MVR evaporation system

In the MVR system shown in Figure 4, water vapor from tomato paste is compressed by a compressor or fan to a higher a pressure and temperature so that it can be used by the same evaporator. No additional steam is required except during the process startup. Effectively, latent heat from the initial steam is recycled as long as the process is not stopped. Since the compression power is less than the latent energy carried by the water vapor, energy consumption per pound of water evaporation is much smaller than multiple effect systems.

2.4 Host Site MVR and triple effect evaporation systems The host plant had two independent tomato processing systems. One of them utilized MVR technology and the other utilized triple effect technology. Figure 5 shows a picture of the MVR system and Figure 4 provides the process diagram. Tomato paste was concentrated from 7.3% to 10% through three stages of evaporation, all at 180 oF. Water vapor from all three stages was compressed by a steam turbine driven by a compressor. The compressor discharge pressure was about 12.2 psia, which corresponded to a saturation temperature of 203 oF.

Figure 6 shows a picture of the triple effect system and Figure 3 provides the process diagram. Tomato paste was concentrated from 7.3% to 17%. By the third stage, evaporated water vapor was no longer used and was sent to a condenser.

MVR 3 MVR 2 Tomato Input

195,069 lb/hr

~180 ºF

7.3%

MVR 1

Compressor

Further evaporation

8.6% 9.1% 10.0%

Vapor

51,515 lb/hr

Steam Turbine

280 psi Steam

Steam Condensate



8

Figure 5 Picture of the host site MVR system

Figure 6 Picture of the host site triple effect system



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3. PERFORMANCE MONITORING AND EVALUATION

3.1 Performance Monitoring The primary energy input for the MVR system was steam, which was used to drive the compressor and three recirculation pumps. The triple effect system consumed steam for evaporation and for driving three recirculation pumps. It also consumed electric power for the corresponding condenser sub-system. The host site did not have any steam flow measurement. It was also not possible to install any inline flow meters during the monitoring period, which occurred during the tomato harvesting season and thus the host site was operating continuously. The project team did not believe that the strap-on ultra-sonic type flow meters could provide reliable steam flow measurements. The host site did have flow meters for all steam condensate flows, however, which should be equal to the corresponding steam flow. Some of those meters did not work, however, and for those meters that worked, the measurements were not very accurate.

With the help from the host site, we monitored the product mass flows and concentrations. At the end of the production lines, the final product was carefully weighed and packaged for sale. The concentration of the final product was also carefully controlled. This provided an accurate tracking of system mass flow. The host site conducted special sampling and concentration measurement at each stage of evaporation, so that tomato paste concentrations before and after each evaporator were monitored. The project staff also obtained MVR compressor inlet and discharge parameters, which were monitored by the plant control system.

For both the MVR and the triple effect system, evaporator recirculation pumps were driven by steam turbines. Monitoring of their actual power consumption was almost impossible since reliable measurement of steam flow was not available. Rated power for the three recirculation pumps used in the MVR system were 105 HP, 92 HP, and 88 HP, respectively. Rated power for triple effect recirculation pumps were not available. The project team developed a simple model to estimate the recirculation pump power in the triple effect system.

The condenser in the triple effect system required additional electric power and steam. There were two cooling water recirculation pumps, each rated at 150 HP. The rated fan power at each cell of the cooling towel was 150 HP. Normally, one cooling tower cell was operating, using about 45% of the rated fan power. The condenser vacuum was maintained by an ejector, which consumed about 1500 lb/hr of steam at 150 psig.

3.2 Performance Evaluation Evaporation Rate and Steam Flow At each evaporator, the amount of water evaporation can be calculated as:

After

ContentSolid

Before

ContentSolidnevaporatio C

mC

mm

&&& −=



10

)11(PrAfterBefore

FinaloductFinal CCCm −⋅⋅= &

where

FinalC is measured the final product concentration;

BeforeC is the measured product concentration entering an evaporator;

AfterC is the measured product concentration leaving an evaporator;

oductFinalm Pr& is the product mass flow measured at the end of the production line;

ContentSolidm& is the tomato solid content mass flow. It was constant, since there was no tomato paste loss during the process.

For the MVR system, all evaporated vapor was compressed and recycled back into the three evaporators. Therefore, steam flow for the compressor was:

321 MVRnEvaporatioMVRnEvaporatioMVRnEvaporatioCompressor mmmm &&&& ++=

For the triple effect system, the first effect steam input was calculated estimated as:

st

stnEvaporatioeffectSteam mySteamEcono

mm

1

13

&& =

Where

stnEvaporatiom 1& is the first effect evaporation rate;

stmySteamEcono 1 is the first effect steam economy.

The study assumed that the first effect steam economy was constant and the same as the design value of 0.86.

Steam energy input for the MVR compressor The MVR compressor power was calculated as:

)( inletdischCompressorCompressor hhmP −⋅= &

Where

dischh is compressor discharge enthalpy and it was determined by the measured compressor discharge temperature and pressure;

inleth is compressor inlet enthalpy and it was determined by the measured compressor inlet temperature and pressure.

Steam energy input for the triple effect system



11

The triple effect energy input was calculated as:

LatenteffectSteameffect hmE ⋅= 33 &&

Where

Latenth is the latent heat of the input steam and is determined by the measured steam temperature, assuming that the steam was saturated.

Evaporator recirculation pump power

pump

pastepastetomatopump

hmP

η∆⋅

=&

Where

pasteh∆ is the increase in tomato paste enthalpy. Without knowing the detailed property of tomato paste, which was largely water anyway, water property was used. According to the MVR manufacturer, the pressure increase by the recirculation pump was about 30 ft. The corresponding enthalpy increase was about 0.04 Btu/lb;

pumpη is the pump efficiency and was assumed to be 60%;

pastetomatom& is the tomato paste flow through the pump. According the MVR manufacturer, the recirculation was about 30 ~ 40 time of evaporator input flow.

The above model provided an estimated pump power that was about 50% higher then the rated power. The pump power for the triple effect system was estimated in a similar way using the same enthalpy and efficiency parameters.

The recirculation pump power was much smaller than the total steam energy. The purpose of this estimation was to demonstrate the order of magnitude of the pump power. Therefore, the large estimation error was tolerable.

Steam and water properties All steam and water property was calculated with a National Institute of Standard Technologies (NIST) software tool.



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4. RESULTS AND DISCUSSION

The host site performed both cold break evaporation and hot break evaporation during the assessment. In the cold break method, the tomato paste had low pectin and was less dense; therefore, it had better heat transfer characteristics and was easy to evaporate. In the hot break method, the tomato enzymatic process was deactivated. The tomato paste was more dense and harder to evaporate. Both processes were run under steady state. For each process, the host site collected two days of data at a two hour interval. The raw data is provided in the appendix 7.1. Table 1 shows the performance evaluation results:



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Table 1 Field Performance Evaluation Results

MVR Triple Effect

Cold Break Hot Break Cold Break Hot Break

Average Steam Energy

(Btu/lb of water evaporation)

50.2 48.5 468 441

Recirculation Pump Power (Btu/lb of water

evaporation)

23.5 30.9 28.5 31.3

Condenser Powers

(Btu/lb of water evaporation)

NA NA 21 23

Condensate Heat Recovery

Potential (Btu/lb of water

evaporation)

81.8 80.2 84.7 81.2

Concentration Change (BRIX)

2.3

(7.5 to 9.8)

2.0

(7.3 to 9.3)

8.3

(10.3 to 18.4)

5.6

(9.7 to 15.3)

Average Evaporation Rate (lb/hr)

44676 39756 117924 104829

Average Steam Flow (lb/hr) NA NA 50454 427591

The monitoring data indicates that both the MVR and the triple effect system were running at a steady state. The MVR evaporator was operated within the temperature range of 176 oF to 187 oF, the corresponding vapor pressure was in the range of 6.7 to 7.7 psia. The compressor had a compression ratio of 1.6. The compressor discharge pressure was 11 to 12.3 psia and discharge temperature was 277 to 293 oF. The calculated compressor efficiency was about 73%.

Figure 7 through Figure 10 illustrate the mass and energy flow around a MVR and a triple effect evaporator. For better comparison, all energy consumption terms are

1 The triple effect steam flow was estimated from the evaporation rate and the steam economy. Without accurate field

measurement data, same values of steam economy, 0.86, were used for both the hot and cold break.



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normalized by the evaporation rate. On average, the MVR system consumed 48.5 and 50.2 Btu of steam energy for evaporating one pound of water in hot and cold break processes respectively. By contrast, the triple effect system required 441 and 468 Btu of steam energy per pound of water evaporated. In this example, the MVR system only used about 11% of the steam energy consumed by the triple effect system.

For the triple effect system, the steam energy consumption was between 46 and 49% of the steam latent heat of 954 Btu/lb. This is greater than one-third of the energy to evaporate water that would be required if each effect had a steam economy of 100%.

Table 2 compares the MVR seasonal energy consumption to what a triple effect system would consume. The estimation was based on energy consumption data from Table 1. The seasonal operation length was assumed to be three month long, with 50% hot break and 50% cold break. The MVR system saved about 39000 MM Btu of energy in one season!

Table 2 Seasonal Energy Savings Achieved by the MVR system

MVR Triple Effect

Tomato processed Ton

6.3 X 105

Total water evaporation lb

9.1 X 107

Steam Energy MM Btu (MM therms)

4500

(0.045)

41500

(0.415)

Condenser Energy MM Btu (MM therms)

NA 2000

(0.02)

Total seasonal savings MM Btu (MM therms)

39000

(0.39)

The results for the tomato paste recirculation pump powers were based on a simplified model, discussed in the previous section. These estimated results show that the recirculation pump power was smaller than the steam energy, especially in the triple effect system. This model did not have enough accuracy to demonstrate which system used less power for recirculation. The power consumption probably depends more on the calandria design. If the calandria has smaller effective surface and higher recirculation speed, higher pump power, would therefore be required to achieve effective heat transfer.

The triple effect system also required additional energy for the condenser operation. The normalized power consumption indicated that it was almost equivalent to the evaporator recirculation pump power.

Steam condensate left the evaporators at high temperatures. For the MVR system, it was at about 180 oF. For the triple effect system, it ranged from 130 oF to 180 oF. If the



15

condensate could be used as boiler feed water a large amount of thermal energy could be recovered. This energy savings opportunity is evaluated by comparing condensate enthalpy to that of city supply water, at about 70 oF. Table 1 indicates that the energy recovery potential is very large. It is also worth mentioning that the condensate also had very good water quality, since it was from steam or tomato water vapor. The host site used one third of the condensate as boiler feed water in the triple effect system. For the MVR system, condensate was not used since no live steam was required. Full recovery of condensate was challenging since the more condensate was produced than the total steam demand.



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Figure 7 Mass flow around a MVR evaporator

Figure 8 Energy flow around a MVR evaporator

MVR1 Evaporator

Tomato paste input ~ 140 time of steam flowBRIX = 7.3 %

Recirculation flow~ 33 time of paste input flow

Steam flow ~ 18000 lb/hr ~ 0.7% of tomato paste flow

Compressor Steam Turbine Attemperation flow

Tomato paste output BRIX = 8.0 %

Condensate

Hot Break

To MVR2 & 3 Vapor from MVR2 & 3

MVR 1 Evaporator Tomato paste input

BRIX = 7.3%

Recirculation pump power~ 2.5% of steam energy

Steam energy ~ 18 million Btu/hr

Compressor

Condensate ~ 10% of steam energy

Surface Heat losses

Tomato paste output BRIX = 8.0%

~288 oF

180 oF

Hot Break

Steam Turbine ~ 48.5 Btu/hr, ~ 5% of steam energy



17

Figure 9 Mass flow around a triple effect evaporator

Figure 10 Energy flow around a MVR evaporator

Evaporator Tomato paste input ~ 48 time of steam flow

Recirculation flow~ 33 time of paste input flow

Steam flow ~ 37000 lb/hr ~ 1.8% of tomato paste flow

Tomato paste output

Condensate

Hot Break

To the next effect or a condenser

Evaporator Tomato paste input

Recirculation pump power~ 2.0% of steam energy Steam energy

~ 51 million Btu/hr (1st effect) ~ 43 million Btu/hr (2nd effect)~ 37 million Btu/hr (3rd effect)

Condensate 4% ~ 10% of steam energy

Surface Heat losses

Tomato paste output

Hot Break

Steam latent heat reused after the 1st and 2nd effect Release into the atmosphere after the 3rd effect



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5. MVR PERFORMANCE MODEL

An EXCEL based software tool was developed to assess the potential savings from using MVR evaporation technology, instead of a multi-effect system. The snapshots in the following figure illustrated the inputs and outputs of the tool. In addition to energy consumption, the tool also estimates the energy savings potential for recovering steam condensate and steam turbine exhaust. As discussed in the last section, these two items could be significant compared to the primary energy inputs.

Figure 11 and Figure 12 provide the process flow diagram of the model. Detailed calculation formula was provided in previous sections.

Figure 11 Process flow diagram of the triple effect model

Steam Input Parameters

Input Steam input flow

Or First effect steam economy

& input concentration

Evaporator Parameters

Input Evaporation Flow:

Total Evaporation Flow Or

End Product Information: Mass flow & concentration

Input First effect output

concentration & last effect input concentration

Input Condenser related

power & steam consumption

Steam input flow

Total Evaporation

flow

Input Input steam

pressure, temperature,

quality

Total Steam energy

Steam consumption per pound of water

evaporation

Electric power consumption per pound of water

evaporation



19

Figure 12 Process flow diagram of the MVR model

Compressor/Fan Parameters

Input Compressor/fan performance:

Compression ratio & efficiency Or

Exhaust Conditions: Temperature & pressure

Evaporator Parameters

Input Evaporation Flow:

Total Evaporation Flow Or

End Product Information: Mass flow & concentration

Input Input & Output Concentration

Input Evaporation TemperatureCompressor

inlet pressure & enthalpy

Compressor discharge

pressure & enthalpy

Input Gear box efficiency

Compressor shaft Power

Evaporation flow

(Compressor flow)

Is the compression

steam driven? Input Motor

efficiency

Electric Power

Consumption Steam energy Consumption

Steam consumption per pound of water

evaporation

Electric power consumption per pound of water

evaporation



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6. CONCLUSIONS

This field performance monitoring study successfully assessed energy consumption of a MVR and a triple effect evaporation system. The MVR system was proven to be much more efficient than the triple effect system. For evaporating one pound of water, the MVR system used from 48.5 to 50.2 Btu of steam energy, which was only about 11% of what the triple effect system consumed. It should also be note that the MVR technology is usually used for tomato paste at low relatively concentrations. To evaporate more concentrated tomato paste higher steam temperatures are required. This, in turn, requires a higher compression ratio. It is difficult to cost effectively achieve compression ratios of more than 1.6.

The recirculation pumps in both system used fair amount of energy, about 24 to 31 Btu per pound of water evaporation. However, this is small compared to the steam energy input in the triple effect system. The difference between the MVR and the triple system can almost be neglected, compared to the steam energy difference. In the triple effect system, the energy consumed by the condenser system was about 21-23 Btu per pound of water evaporation.

The study also developed models for estimating energy consumption of a MVR or a multiple effect system based on some basic design parameters. The models were implemented in an EXCEL based software tool that could help a user estimate energy savings from using a MVR system vs. a multiple effect system.



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7. APPENDIX

7.1 Performance Monitoring Data Table 3 Raw data for the MVR system

Hour MVR 1 Input Brix

MVR 1 Output Brix

MVR 2 Output Brix

MVR 3 Output Brix

End Product flow (lb/hr)

End Product Brix

MVR Evaporation Temp, F

COMP. Inlet PRES, PSIA

COMP DISCH PRES, PSIG

COMP. INLET TEMP, F

COMP DISCH TEMP, F

Cold break, Day 1

0000 7.5 8.2 8.7 9.6 40,961 36.9 181.5 7.6 12.2 180.6 290.3

0200 7.6 8.4 8.7 9.7 38,049 37.0 180.8 7.5 12.0 180.0 288.9

0400 7.6 8.3 8.7 9.6 40,989 36.9 179.7 7.3 11.8 178.8 286.6

0600 7.7 8.2 8.9 9.2 38,049 36.9 181.4 7.5 12.2 180.6 288.6

0800 7.4 8.2 8.6 9.3 39,482 36.8 182.2 7.7 12.3 181.4 291.2

1000 7.4 8.2 8.6 9.2 39,466 37.2 181.7 7.6 12.2 180.9 292.8

1200 39,521 37.3 180.5 7.4 11.9 179.6 290.7

1400 7.1 8.5 9.0 9.5 33,660 36.7 180.1 7.3 11.8 179.1 290.1

1600 7.3 8.1 8.5 10.2 36,587 36.9 180.2 7.3 11.8 179.2 289.1

1800 7.6 8.2 9.2 10.3 36,589 37.0 181.1 7.4 12.0 180.1 289.9

2000 7.5 8.0 8.5 9.2 36,593 37.0 179.7 7.0 11.7 178.7 286.2

2200 7.3 8.9 9.5 10.4 35,161 37.0 179.4 7.1 11.7 178.4 285.0

Cold break, Day 2

0000 7.5 8.2 9.0 10.0 35,144 37.2 179.9 7.2 11.8 178.9 285.5



22

0200 7.3 8.1 8.8 10.2 38,069 37.1 180.7 7.4 12.0 179.7 287.2

0400 7.4 8.0 8.6 10.3 38,075 36.9 179.8 7.3 11.8 178.8 283.6

0600 7.0 7.7 8.4 9.6 38,053 37.4 180.3 7.3 11.9 179.2 283.0

0800 7.4 8.0 8.8 9.5 38,057 37.1 180.1 7.3 11.8 179.1 282.1

1000 7.2 7.9 8.5 9.5 40,887 37.1 180.7 7.4 12.0 179.7 283.8

1200 7.5 8.2 8.8 9.5 38,095 37.0 179.7 7.3 11.8 178.6 281.5

1400 7.8 8.5 9.5 10.2 39,509 37.0 179.6 7.2 11.7 178.4 280.8

1600 7.6 9.3 9.0 10.4 40,937 36.9 180.1 7.3 11.9 178.9 281.6

1800 7.5 8.2 8.4 9.5 38,075 36.9 181.0 7.3 12.1 179.9 282.8

2000 7.6 7.8 8.7 9.4 38,072 37.0 180.3 7.3 11.9 179.2 281.6

2200 7.6 8.8 9.3 10.4 39,560 37.1 181.0 7.3 12.1 180.0 284.2

Hot break, Day 1

0000 6.7 8.7 9.2 10.1 54,684 26.1 181.2 7.1 11.6 178.3 282.5

0200 6.8 8.7 9.2 10.3 56,154 26.1 181.0 7.1 11.5 178.0 282.8

0400 7.5 8.9 9.0 10.2 51,840 26.1 181.1 7.2 11.6 178.3 282.7

0600 6.9 7.6 8.5 9.0 54,696 26.0 181.2 7.2 11.6 178.5 283.1

0800 7.0 7.4 8.0 8.7 54,652 26.0 180.3 7.2 11.4 178.2 281.0

1000 6.7 7.0 7.7 8.3 50,351 26.0 180.9 7.2 11.7 178.6 284.3

1200 6.7 7.2 8.0 8.5 50,328 26.0 180.6 7.2 11.6 178.2 285.6

1400 7.5 8.5 8.2 8.6 50,355 26.1 181.5 7.3 11.8 179.2 286.5

1600 8.9 8.9 8.5 9.8 54,666 26.4 179.8 7.0 11.4 177.3 285.5

1800 8.1 8.7 8.8 9.4 51,778 26.2 181.7 7.3 11.8 179.2 287.0



23

2000 6.6 7.4 8.2 8.7 51,797 26.0 181.0 7.2 11.6 178.5 286.6

2200 7.8 8.0 8.8 9.5 53,259 25.9 180.4 7.1 11.5 177.7 284.8

Hot break, Day 2

0000 8.7 8.6 10.1 10.4 51,774 26.1 180.3 7.1 11.5 177.8 283.2

0200 7.2 8.4 9.0 9.8 53,216 25.9 181.2 7.2 11.7 178.7 285.3

0400 7.5 8.1 9.5 9.3 51,840 26.1 181.1 7.2 11.6 178.5 285.8

0600 7.8 7.8 8.5 9.1 53,233 26.1 180.6 7.1 11.5 177.9 285.5

0800 7.1 7.5 8.2 8.5 51,792 26.1 181.0 7.2 11.6 178.4 286.0

1000 7.0 7.6 8.1 9.0 53,216 26.1 181.4 7.3 11.8 179.1 288.0

1200 7.2 8.1 8.4 9.1 54,603 26.1 181.1 7.2 11.6 178.6 288.8

1400 7.2 8.0 8.1 8.9 47,477 26.2 181.1 7.2 11.7 178.6 288.6

1600 7.2 7.8 7.9 9.2 50,233 26.1 179.8 7.0 11.4 177.3 285.1

1800 7.5 8.0 8.6 9.5 47,494 26.0 178.6 6.8 11.1 175.8 279.6

2000 7.1 7.6 8.3 9.8 50,361 26.0 178.3 6.7 11.0 175.3 277.1

2200 7.2 8.5 8.5 9.5 48,948 26.0 180.2 6.9 11.4 177.4 278.4



24

Table 4 Raw data for the triple effect system

Hour

3rd Effect Input Brix

3rd Effect Output Brix

2nd Effect Output Brix

1st Effect Output Brix

End Product flow (lb/hr)

End Product Brix

1st Effect Steam Temp, F

1st Effect Vapor Temp, F

2nd Effect Vapor Temp, F

3rd Effect Vapor Temp, F

Cold break, Day 1

0000 9.7 11.5 13.7 17.9 68,274 36.9 238 181 155 119

0200 9.7 11.3 13.7 18.2 71,569 37.0 238 181 155 119

0400 9.7 11.3 13.6 18.2 72,466 36.9 238 181 155 119

0600 9.8 12.0 14.3 18.5 72,612 37.0 238 179 154 119

0800 9.7 11.8 14.1 19.1 76,571 37.2 231 173 152 123

1000 12.4 44,258 37.0 171 146 135 130

1200 10.8 13.7 16.2 20.1 80,459 37.0 226 173 150 117

1400 12.0 12.8 14.1 18.2 75,779 36.7 233 176 153 118

1600 11.5 12.5 15.9 18.5 75,026 37.1 237 179 155 119

1800 11.6 12.4 15.1 18.1 70,479 37.0 237 181 155 119

2000 10.5 12.4 15.0 18.1 70,528 37.1 238 181 155 119

2200 9.9 11.5 13.7 18.2 70,529 36.9 238 182 155 118

Cold break, Day 2

0000 10.0 11.8 13.8 18.4 70,382 37.1 238 182 155 118

0200 10.7 11.7 14.2 18.5 74,857 37.0 238 181 155 118



25

0400 10.0 11.5 13.8 18.4 73,434 37.1 239 181 155 119

0600 9.9 12.3 13.9 18.4 73,304 37.2 238 181 155 119

0800 10.2 12.4 14.0 18.3 73,045 37.2 238 181 155 119

1000 9.6 11.6 14.2 18.3 78,448 37.2 238 180 156 119

1200 9.6 11.5 14.2 18.3 74,876 37.1 238 180 155 119

1400 10.4 11.6 14.0 18.3 74,282 37.1 238 179 155 119

1600 10.4 11.4 13.8 18.2 71,556 37.0 237 179 154 119

1800 10.3 11.2 13.6 18.1 69,249 36.9 238 180 155 119

2000 10.2 11.3 13.6 18.0 73,469 37.0 238 180 155 120

2200 9.7 12.8 15.0 19.3 72,154 36.7 238 180 154 120

Hot break, Day 1

0000 9.5 12.0 13.3 16.0 107,342 25.6 236 184 158 119

0200 10.6 12.2 13.0 15.1 110,233 25.9 238 185 158 119

0400 10.2 11.9 12.5 15.2 110,205 25.9 239 185 158 119

0600 10.4 12.0 12.5 15.0 103,064 25.6 239 186 158 119

0800 9.6 11.9 12.5 15.1 105,899 25.6 239 186 158 119

1000 9.4 11.8 12.6 15.2 103,036 26.0 239 185 157 119

1200 9.7 12.2 13.0 15.8 105,882 26.2 239 185 157 118

1400 9.4 10.8 12.7 15.1 105,909 26.2 239 184 157 118

1600 9.2 11.8 12.8 15.2 102,978 26.0 239 185 157 119



26

1800 9.4 10.3 12.4 15.1 97,259 26.0 239 185 157 119

2000 9.6 10.1 12.3 15.1 107,394 26.0 239 185 158 119

2200 9.7 10.6 12.4 15.2 107,349 26.0 239 185 157 119

Hot break, Day 2

0000 10.1 12.1 12.6 15.4 104,527 26.0 239 185 158 119

0200 9.7 11.8 12.6 15.2 102,792 26.1 239 185 158 119

0400 10.6 11.9 12.7 15.2 105,957 25.8 239 185 157 119

0600 9.1 10.9 12.5 15.2 107,375 26.0 239 185 158 120

0800 9.1 10.6 12.6 15.2 104,418 25.9 239 185 158 120

1000 9.7 11.5 13.0 15.5 107,300 26.0 239 185 158 119

1200 9.6 11.2 13.1 15.6 111,614 26.2 239 186 159 120

1400 9.7 11.2 13.1 15.8 108,671 26.3 239 185 158 120

1600 9.6 10.9 13.0 15.6 104,388 25.9 239 186 158 119

1800 9.7 11.7 12.8 15.4 102,962 26.2 239 185 158 119

2000 9.5 11.5 12.0 15.2 103,020 26.0 239 185 158 120

2200 9.0 11.8 12.9 15.1 104,417 26.2 239 185 157 120



27

7.2 Screen Snapshots of the MVR Performance Model



28



29



30

7.3 Reference 1. “Energy Use In Tomato Paste Evaporation”, T. R. Rumsey, T. T. Conant, T. Fortis, E.P. Scott, L. D. Pedersen, W. W. Rose, Journal of Food Process Engineering, Volume 7 Issue 2 Page 111-121, April 1984

2. “Evaporation Technology”, GEA Wiegand GmbH

3. “Revised Release on the IAPWS Industrial Formulation 1997, for the Thermodynamic Properties of Water and Steam”, The International Association for the Properties of Water and Steam, Lucerne, Switzerland, August 2007

pacific gas and electric company emerging technologies … · 2020-01-02 · figure 8 energy flow...

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