Weekly/daily production schedule optimization

GAMS
1

I’m trying to optimize a furnace (melting iron) weekly production scheduling.
I have 168 hours with 168 hourly prices, and I need to choose the best daily hours to schedule my melting process
The melting process is 1 hour loading the furnace and 3-hour melting. 4 hour melting block in total.
Loading the furnace, the electrical demand is 0 MWh, melting the electrical demand is 10 MWh for each individual hour

Weekly load schedule
Day1 3 loads
Day2 4 loads
Day3 3 loads
Day4 4 loads
Day5 3 loads
Day6 2 loads
Day7 1 load

Objective function is to minimise energy costs (demand X price)

How to interlink several hours as a block?
Do you have any example like this problem?

Thanks
Paulo


Hand made optimization for 2 loads day (day6)

Hour Price Demand
1 76.87 0 Load Block1
2 55.07 10 Melt Block1
3 51.64 10 Melt Block1
4 47.47 10 Melt Block1
5 56.56 0
6 59.69 0
7 61.87 0
8 51.00 0
9 50.34 0 Load Block2
10 47.97 10 Melt Block2
11 55.03 10 Melt Block2
12 43.43 10 Melt Block2
13 85.97 0
14 117.26 0
15 102.47 0
16 115.36 0
17 193.86 0
18 281.69 0
19 279.29 0
20 153.87 0
21 91.56 0
22 54.09 0
23 103.08 0
24 81.64 0

2

Hi,

I guess you need sth. like a maping from start hours to melting hours, e.g.

set h hours / h1 * h168 /
    hhMelt(h,h) map start hour to melting hours
;
alias (h,h1,h2);
hhMelt(h1,h2) = ord(h1)<ord(h2) and ord(h1)+3>=ord(h2);
option hhMelt:0:0:1; display hhMelt;

I hope this helps!

Fred