GEA Bock Software in VAP...Adaptation of breadcrumb navigation VAP 11.5.0 (online) for stationary...

GEA Bock Software

VAP 11.5.0 for stationary applications

NEW IN THIS VERSION

• HA44e

• HGX2+34+46 CO2 T optimized

• HGZX7 R448A/R449A

New compressor types

2

• New semi-hermetic air-cooled 4-cylinder

compressor series GEA Bock HA44e

• The HA44e series of compressors uses state-of-

the-art technology to replace the existing HA4

compressors

• Performance data (including R448A and R449A),

documentation and other information and can be

found in the software

New compressor series: GEA Bock HA44e

3VAP 11.5.0 (online) for stationary applications - New in this version 06/2018

• The extensively optimized transcritical CO2 compressor series GEA Bock

HGX2 + 34 + 46 CO2 T can now also be found in the offline version of the

software

Optimized transcritical CO2 compressor series:GEA Bock HGX2 + 34 + 46 CO2 T


• New semi-hermetic 2-stage compressor series GEA

Bock HGZX7 R448A/R449A

• The proven 2-stage compressor series HGZ7 is now

also available for the two low-GWP refrigerants

R448A and R449A

Extension 2-stage compressor series:GEA Bock HGZX7 R448A/R449A


New software features

• Implementation reference temperature for zeotropic refrigerants

• Buttons for setting standard operating conditions

• Performance data table: Decimal places for to and tc

6

• To compare zeotropic refrigerants (with temperature

glide) with azeotropic refrigerants (without

temperature glide, e.g., R134a), reference is made to

the use of the medium temperature (rather than the

dew point temperature) for the evaporating and

condensing temperature (see e.g. ASERCOM-Guide

Refrigerant Glide and Effect on Performances

Declaration).

• If a zeotropic refrigerant is selected in the VAP, it is

now possible to select the reference temperature for

the evaporating and condensing temperature:

dew point temperature (default setting) or medium

temperature.

• In the appendix of this presentation you will find

further explanations.

Implementation reference temperature for zeotropic refrigerants


http://asercom.org/sites/default/files/en_guideline_glide_effect_sept_2015.pdf

• The setting of standard operating

conditions for the three standard freezing,

normal cooling and air conditioning via

buttons are now also available in the

calculation screen

Buttons for setting standard operating conditions


• In the table performance data, the basic values can now be set to one decimal place:

Performance data table: Decimal places for evaporating and condensing temperatures


Adjustments and bug fixes

• Adaption of the menu structure for EX-HG HC compressors

• Navigation bar - All compressor types of the series selectable

• Search function - Keeping adjusted operating conditions

• Installation Offline-VAP in the user directory

• Condensing units – Warning note regarding max. permissible ambient temperature

• Adapting the note regarding reduced suction gas temperature

10


Adaption of the menu structure for EX-HG HCcompressors

• Until now the special ATEX

compressors for hydrocarbons

EX-HG HC compressors have

been combined with the ATEX

compressors for standard

refrigerants








refrigerants

• In the new software version, these

compressors can now be selected

from a separate section

HG HC ATEX compressors








refrigerants

• In the new software version, these

compressors can now be selected

from a separate section

HG HC ATEX compressors

• In addition, these compressors can

also be found under the topic

HG HC compressors.


• In the upper area of the selection

software there is (in addition to the

selection menu on the left) a

navigation bar which can be used

to switch to another type of

compressor or compressor series.

Adaptation of the navigation bar







compressor or compressor series

• So far only compressors of the same

compressor type (for example

HG44e) could be selected via the

included dropdown box

Adaptation of breadcrumb navigation







compressor or compressor series

• So far only compressors of the same

compressor type (for example

HG44e) could be selected via the

included dropdown box

• Now all compressors of the entire

series (e.g. HG standard

compressors) can be selected via

the dropdown box

Adaptation of breadcrumb navigation

Individual adjusted operating conditions

• In former version’s search mask, individual

adjusted operating conditions were

automatically reset to the standard operating

conditions when e.g. the type of refrigerant was

changed.

• In the new software version, the individual

adjusted operating conditions are kept now

unchanged, as long as the set operating point

is compatible with the newly set refrigerant

Search function - Keeping adjusted operating conditions


• Parts of the offline VAP are now installed in

the user directory (instead of the program

directory).

• The user directory does not normally require

admin rights, so the software can be installed

directly by the user.

• The prerequisite for this is that the required

Add-in Microsoft .NET Framework 4.6 or higher

is already installed on the computer. Admin

rights are still required for installing this Add-in.

Installation Offline-VAP in the user directory


• For the semi-hermetic condensing

units, the max. permissible ambient

temperature of the compressor is

now considered

• If the set air inlet temperature

exceeds the max. permissible

ambient temperature of the

compressor, a corresponding

warning note is displayed

Condensing units – Warning note regarding max. permissible ambient temperature


• Depending on the type of compressor and the

refrigerant, there is an extended range of the

operating limit diagram (light blue area) where

(amongst others) a reduced suction gas

temperature is required.

• Up to now a note informing about this

requirement has always been displayed as

soon as the set operating condition was within

the extended application limits range.

Adapting note regarding reduced suction gas temperature


• Depending on the type of compressor and the

refrigerant, there is an extended range of the

operating limit diagram (light blue area) where

(amongst others) a reduced suction gas

temperature is required.

• Up to now a note informing about this

requirement has always been displayed as

soon as the set operating condition was within

the extended application limits range.

• Now, if the requirement of a reduced suction

gas temperature is fulfilled by adjusting the

suction gas superheat or suction gas

temperature accordingly, this note is no longer

displayed.

Adapting the note regarding reduced suction gas temperature


Comments regarding reference temperature:

Dew point vs. Mean temperature

Appendix

22

• With zeotropic refrigerants, in the log p,h-diagram

lines of constant temperatures (isotherms) are showing

a declination within the wet vapor region. This also

means that they are not going parallel with the lines of

constant pressure (isobars).

• This results into a so-called temperature glide during

the isobaric evaporation and condensing.

• The level of the temperature glide is depending from the

type of refrigerant and the operating condition.

• Examples of zeotropic refrigerants:

All R400 refrigerants, e.g. R407C

• Examples of azeotropic refrigerants:

R134a, R744 (CO2), R500 refrigerants

Zeotropic refrigerants (with temperature glide)


Pre

ssure

Enthalpie

t= c

on

st.

p = const.

• The temperature glide influences the performance data of the

condenser and evaporator and thus also the performance data

of the compressor.

• The sketch on the right shows schematically the course of the

temperatures along a water or air cooled condenser.

• After desuperheating the condensing temperature at dew line

tc,dew is reached at the condenser. With a zeotropic refrigerant,

from there the condensing temperature is decreasing (dashed

line), while it remains constant (solid line) for a azeotropic

refrigerant.

• Due to this temperature glide of the zeotropic refrigerant the

mean temperature difference m,zeotropic , which among others

drives the heat transfer, between refrigerant and air/water is

smaller (yellow marked area) compared with a azeotropic

refrigerant.

• At the evaporator the case is opposite when the evaporation

temperature is referred to dew line. Here the mean temperature

difference m,zeotropic is larger with zeotropic refrigerants

compared to azeotropic refrigerants.

Reference temperature: Dew point

24VAP 11.5.0 (online) for stationary applications - New in this version 06/2018Tem

pe

ratu

re

Condenser surface

Condenser

tc,dew

m,azeotropic > m,zeotropic

azeotropic

zeotropicwater/air

• This temperature glide makes a comparison of the

performance data between zeotropic and azeotropic

refrigerants or between zeotropic refrigerants with

different temperature glides inaccurate when the

evaporation and condensing temperature is related to

the dew line.

• If the evaporating and condensing temperature of

zeotropic refrigerants are related to the so-called mean

temperature, similar mean temperature differences

between different refrigerants result (the yellow-marked

areas cancel each other out).

• Performance data of different refrigerants give more

comparable results with the reference temperature

mean temperature.

• For azeotropic refrigerants, the reference temperature

does not matter because the dew point and mean

temperature are identical.

Reference temperatur: Mean temperature

25VAP 11.5.0 (online) for stationary applications - New in this version 06/2018Tem

pe

ratu

re

Condenser surface

Condenser

tc,dew

m,azeotropic m,zeotropic

tc,mean

azeotropic

zeotropicwater/air

• In the software you will find the menu for setting the reference temperature in the following places:

Setting reference temperature in the software


Calculation form:Search form:

• The two following examples with the zeotropic refrigerant R407C aims to clarify the difference

between the two reference temperatures dew point and mean temperature.

• In each case identical values are set for the operating conditions.

• The following values are assumed for the operating conditions:

Compressor model: HGX56e/995-4

Compressor frequency: 50Hz

Evaporation temperature to (SST): -10°C

Condensing temperature tc (SDT): +45°C

Suction gas superheat: 10K

Subcooling: 0K

• In the first example, the reference temperature is set to dew point, in the second to mean

temperature.

Example reference temperature


28VAP 11.5.0 (online) for stationary applications - New in this version

tc,D = 45°C

to,D = -10°C

tc,B = 40.2°C

to,in = -14.1°C

tc,m = 42.6°C

to,m = -12.1°C

• Reference temperature:

Dew point

• Corresponds to mean

temperature:

• to,m = -12.1°C

• tc,m = 42.6°C

Example: Reference temperature Dew point

29VAP 11.5.0 (online) for stationary applications - New in this version

tc,D = 47.4°C

to,D = -8.0°C

tc,B = 42.6°C

to,in = -12.0°C

tc,m = 45°C

to,m = -10°C

• Reference temperature:

Mean temperature

• Corresponds to dew point

temperature:

• to,D = -8.0°C

• tc,D = 47.4°C

Example: Reference temperature Mean temperature


43,1 kW

18,4 kW

2,34

89,9 °C

45,5 kW

19,6 kW

2,32

91,5 °C

Qo

P

COP

tv2

HGX56e/995-4, R407C @ -10°C / +45°C10K superheat, 0K subcooling, 50Hz

Dew line Mean temperature

• The diagram shows the comparison

of the performance data between

the two reference temperatures of

the previous example.

• The result shows the following

trends:

Refrigeration capacity:

Qo,Tau < Qo,Mittel

Power consumption:

PTau < PMittel

Coefficient of performance:

COPTau > COPMittel

Discharge end temperature:

tv2Tau < tv2Mittel

• Those trends are similar in other

operating conditions and refrigerants

with temperature glide.

Comparison of performance data - Absolute values


Difference in mean temperature values compared to dew point values

-2,0% -1,0% 0,0% 1,0% 2,0% 3,0% 4,0% 5,0% 6,0% 7,0%

Qo

P

COP

tv2

HGX56e/995-4, R407C @ -10°C / +45°C10K superheat, 0K subcooling, 50Hz

• The diagram shows the relative

difference of the performance data in

percent between the mean

temperature and the dew point.

• If the evaporation and condensing

temperature is related to the mean

temperature, the refrigeration

capacity Qo will increase by approx.

5.6% and the power consumption P

by ca. 6.5% compared to the

reference temperature dew point.

• This result into a slightly lower COP

(reduction by 0.9%).

• The discharge end temperature tV2 is

slightly increased by 1.8%.

Comparison of performance data - Relative values


tv1h = 10 K

tv1h = 10 K

Reference temperature Mean temperature

Reference temperature Dew point

• In the software, the suction gas superheat is always

related to the dew point evaporation temperature.

• This means that even if the reference temperature is

set to the mean temperature, the set suction gas

superheat refers to the dew point.

• In the previous example, a suction gas superheating of

10K was set in each case.

• At reference temperature dew point this corresponds

to a suction gas temperature of: 0°C ((-10°C) +10K).

• At reference temperature mean temperature this

corresponds to a suction gas temperature of:

+2°C ((-8°C) + 10K).

Suction gas superheat in the software:

Always related to dew point evaporation

temperature: tv1h = tv1 – to,D

Definition of suction gas overheating in the software

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