Hi
I am onboard a ship where we have 5 engine.
I can choose to run 1 engine alone or 2 engines runnings, or 3,4,5
But I wont to know how I can calculate, by knowing the kW I shall use, which configuration of engines I shall use.
I If only shall use 2000 kW the excel shall tell me, it is better to run engines no 2 and no 3 in 70 % load.
Get most kW for less fuel
See attached excel
Are you limited to 5% increments or can you set any %?
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Hi
I have only collect date for each 5%, but if it is necessary i can write some numbers between.
Uppmatingar.xlsx
When the engines are running, they are all loaded with the same %.
DG 1 = 60 %
DG 2 = 0 %
DG 3 = 60 %
DG 4 = 60 %
DG 5 = 0 %
Thanks! I think I have enough data, I will solve this later tonight.
see attachment,
in the 1st result I didn't know the running engines were all loaded with the same %
the 2nd result does do so.
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I forgot do tell you, if the generator is loaded more than 85% the next generator will start.
Is it possible to add one cell, where i can insert an value, that say how much it cost to run a engine pr hour ? Cost in maintenace + luboil
So if the generator has a max load on 80 %
see attachment
Looks good.
But can i get an explanation how you made all the calculation from AA-AH ?
see attachment.
I added a price for your fuel in E23 and a price for other variable costs pr hour for each of your 4 motors in A12:A16. You'd better chang those numbers to something more realistic, because i didn't know what to write there.
Then I added a green commandbutton, so if you press on that one, the macro "InStappen" runs (see statusbar at the bottom of your screen) and after a minute you get a new table with your results.
That is really impressive, bsalv!
This task is not as innocent as it looks...
thanks and good luck with your engines !
someone noticed me that excel sometimes swapped between 2 equal motors, for example engine 1 and 5. They have the same power and consumption and most of the time, if only one of both motors must run he chooses engine5 and occasionally he chooses engine1.
Because of the high precision of the calculation in excel (15 digits), the combination with engine1 is 1e-14 liter(a tiny tiny fraction of a drop) cheaper then the combination with engine5.
With the improvement in the macro, the gain in consumption must be greater then 0.0001 liter (that's a fraction of a drop).
It lock great.
I have been some busy this last days.
If i change the fuel consumption, will it then calculate the "setup" auto, or do i need to do some changes. ?
I have also been working with one idea. Attach
Still i need some information from the ship engine and ship speed
If you change the consumption, you must run the macro again to recalculate all the combinations.
Your file as attachment
note: I used matrixformulas (those "{}" around the formula), so you must use SHIFT+CTRL+ENTER instead of the normal ENTER if you edit a formula.
Hi again
I have made some works on my excel, but under the "cost consumption" is it possible to add this criteria, "next gen starts at 85%" ?
I have change it from "fuel consumption" to "cost consumption", so I get the total prise for a running mode, Fuel+NOx+Service
Attached "samla 24-02-2014.exl"
I think I have an solution
so it chooses the dieselgenerator 24 or 28 at 85% or 32 between 70-80% ??
You already have a solution, so solved ?
Yes, solved.
I used a If function inn all mode from 80% to 100%, but not the running mode where all engines are inn.
If the startup % is higer then 80-100%, then the value shall show zero.
So i think the excel program is finish.
All i need know i the right numbers from the ship.
All number in yellow are just some guesses.
Your help have been greatfull
Mayby one thing I will add. A graf that show ****/fuel in electric mode and on that show diesel mode.
1 KW cost in average 0.953 kr, see attachment tabs "summary" and "grafiek1".
There you also see that there are only 15 combinations that matter (see pivottable that starts in L3)
You see there the 3 cheapest combinations per KW in the table on your left.
Hi again
That grad you made did not stop with 85%..
But, I have made it all from scrats again, but i can not get the cost calculation to work.
have try to make it just like the old one, but with no luck
Have also made some define names "kilowats" and "kr"
See attached
Einar
don't you make it too complicated ?
I have uploaded the wrong file.
"Nytt yvirlit - stril merkur" is the new
I have made it new, to make it less complicated.
And i do not want any macro.
I think that it will soon work, when the cost calculation is working
Just noties, that the I column is "hide" in "cost" sheet. It shall not be hide. Just you know
Last edited by einar.a.petersen; 03-16-2014 at 03:30 AM.
I'm a little bit disappointed that you don't like macros. They can do a big job here.
I don't understand why some motors stop at 75%, others goto 90%, those who stop remain there power with 0 fue
See columns AM:AW :
AM = find the column with greatest power <= desired power
AN = boolean, column found.
AO:AP = power smaller and greater
AQ:AR = fuel smaller and greater
AS:AT = percentage smaller and greater
AU = real percentage
AV = real fuel
AW = ranking.
Number 1 = cheapest !
you should learn sumproduct, Vlookup and index-formulas, to make everything less complicate.
Hi again
The reason i do not want macro, is that i am not so good to macro and cant see the whole picture, if i dont understand how it works.
If i had know how to build a macro, I may have used it.
If i run one engine and it load will raise above 85% in more than 8 sec the next generator will start and the load will fall under 85%. If i need more power and those two engine which are running, are loaded more the 85%, the next generator will start. This will go on, until all engine "dg1-5" are running, then it is possible to load the generator up to 100%
The engines do not stop at 75% as your wrote, it is just another engine which is starting up and take some load from the running engine.
Which sum-product to you have in mind ?
I used Dmin and Dmax to get the Cost calucaltion to work. Mayby not the smartest way, but it works.
See attched "Stril merkur ver 1"
with modified tab "cost"
In cell W1 choose your power and in the table below you get (max 10) all possible combinations.
All combinations are allowed between 35 and 85%, the last untill 100% (columns I:J)
The real cost and load are calculated with interpolation, so if cost and load are lineair in the whole range, you don't need those 500 rows of calculations in "Yvirlit".
For example, suppose that all functions are lineair within 30 and 100% for DG1 (even outside that range), I only need those 2 rows with 30% and 100%.
So I deleted all the rest for DG1 in "Yvirlit". I hope you didn't need them somewhere else in your worksheet.
Hi
The fuel consumption is not linear"kw/(fuel consumption)" is not a constant.
I have made it that i can choose that one or several engine are not available or that some engines are preferred.
where ?I have made it that i can choose that one or several engine are not available or that some engines are preferred.
Fuel consumption isn't linear, you have the consumptions in columns AC:AQ in steps of 5 percent, so the smaller steps of 1 % aren't necessary.
DG4 65% and 75% are smaller then 60% and 70%, seems not logic.
engines are preferred.
Frontpage. K9:K13
The numbers in "cost" column C:G will change
DG 4 fuel
These number was wrong.
We do have a IAS which tell us the Fuel consumption at the moment, but i choose to write from 30% upp to 100% in 5% step.
The numbers 31,32,33,34 are linier to 30% and 35%.
The numbers 56,57,58,59 are linier to 55% and 60%
But numbers 30,35,40,45,50,55,60,65,70,75,80,85,90,95,700 are not linier
see attachment,
result is almost the same.
Now only those 5% steps are in your table1, the rest wasn't necessary.
In row2 of "Cost" are your available motors(column J of frontpage), something similar could be done for preferred but I don't understand "preferred" versus "available".
Now you get the possible combinations in the table.
All those number in yellow are demo numbers, have not yet got the right number.
Mayby it is best I first get those numbers, then we can see if only 30,35,40.... % are needed or when shall used 30-100%
On this trip engine no 2 is not working.
So DG 2 available is NO
We shall have a top overhaul on DG2 and DG3 next trip, so we want to run as much as possible with those two
So DG 3 preferred is Yes "DG2 is not available"
don't make it more difficult ! Fuelconsumption is liniar, see the graph in tab "grafiek"
Those regressions have a R2>=.98.
I suppose that if you use those regressions, the error on the results 'll be minor.
For example fuelconsumption DG5 = 121.43 * %load + 7.54
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