HEAT STORAGE CONSIDERATIONS IN HEAT INTEGRATED BATCH PLANTS

HEAT STORAGE CONSIDERATIONS IN HEAT INTEGRATED BATCH PLANTS.

TABLE OF CONTENTS. 03. 01. 02. 04. 05. How is this problem is effectively being solved.

Chemical Engineering for Non-Chemical Engineers | AIChE.

Energy usage in South Africa. Sales Transportation Industry Residential Commercial Other 0.01 0.48 0.24 0.17 0.1.

02. Travel Photography Aesthetic Filter Edit Paris France Museum Clock Time Tower Black and White … | Aesthetic photography, Aesthetic filter, Black and white aesthetic.

Background into Batch Processes. Pre-defined sequencing of tasks Strongly dependant on time and scheduling aspects.

Background into Process Integration. Process optimization = largest production, greatest profit and reduction in raw materials and utilities.

Energy optimization techniques. Heat Integration.

Solution Procedure. 03. GAMS - Cutting Edge Modeling.

Solution Finding Process. Scheduling model. Heat Integration model.

Mathematical formulation. cold Utility Hot Unit Hot Unit cold Utility 2 Storage Vessels Hot Utility Cold Unit cold Unit Hot Utility.

Sets Variables Parameters. in. in in in in. (d •Zs)nw.

Duties of tasks and heat storage vessels. Allocation.

Temperature. out in T sjh,p =Tts;;. in in T sjh,P.

Challenges. Constraints continued. Utility usage by tasks.

Constraints continued. Time. ((d'a'0urs z ' ors) JJ d J s z— d' VCs d 'a' d' qrs u! u! u! u!.

Objective function. hr/ yr , p)huc ). Profit = Revenue from products- cost of external cold utility – cost external hot utility – capital cost of the heat storage vessel.

04. Case study. Feed C Feed B Feed A Heat product I Distillation Column Reactor 2 Product 2 Reactor I.

Feed A 0.4 sl Feed B 0.5 (s4) 02 Product I 0.4 0.6 (0) 0.6 Feed C 0.1 0.8 0.9 SIO Product 2.

GAMS coding. Sets 5 6 s Sj in_h Sj in_c 9 Sj in Sin Sout 12 SinEt 13 pr 17 parameters alpha_sto beta_sto alpha_Sjin beta_Sjin 22 23 20 theta 25 26 27 Cpw 2B 29 cu_c hu_c 32 hr-yr 33 Ts_Sjin_c 35 Tt_Sjin_h Tt_Sjin_c 37 39 TUP delta_TL ae_L oe_u SP(S) vu(j) Qi(S) nx(S) tou(SinEf) taw(SinEf) beta(SinEt) rho(Sin) time point units cold processing unit requires hot processing unit any state task wtlich needs cooling task 'atlich needs heating state in state in state out effective state any product Heat storage vessel fixed cost of heat storage heat /p1.p5,' /U1*U4/ S22, S23, S32, S33, S42, so, S52, S53, S62, so, S72, S73, "2 , S83, S92, S93/ /S6, S62, S63, S9,' /SI, S8, S82, "3/ / n, s2, s3, so, ss, so, ss, s9, s22, s23, s32, s33, s42, s43, s52, ss3, s62, s63, s82, s83/ / Sl, S2, S3, SO, SS, SO, SS, sy, S22, S23, S32, S33, S42, S4J, S52, S53, S62, S63, "2, S83/ /S5, SO, ST, S9, SIB, S62, S63, S72, sea, SBJ, S92, S93, /SI, s22, s23, s02, s63, SSZ, , s9/ /s5, so, , se, sy, s62, Så3, s72,s73, s82, s83, s92, s93, s84/ /Vi*V5/ vessel variable cost of heat storage vessel coefficient of conatant term for processing time of a task coefficient of variable tern for processing time of a task annual tractional interest rate cost function exponent specific heat capacity ot a cold task specific heat capacity ot a hot task specific heat capacity ot heat transfer medium Cost of cold utility Cost ot hot utility Any large number lifespan ot heat storage vessels in years operational time inlet temperature of a hot task inlet temperature of a cold task outlet temperature of a hot task outlet temperature of a cold task lower bound for initial temperature of a heat storage vessel Upper bound tor initial temperature of a heat storage vessel minimum allowable temperature difference lower bound tor size ot a neat storage vessel upper bound tor size ot a neat storage vessel lower bound tor amount ot neat transferred between two tasks upper bound tor amount ot heat transferred between two tasks Selling price ot sate time horizon ot interest Capacity ot unit j initial amount ot state s stored maximum amount ot state s stored within the time horizon of interest mean processing time of state stored portion of state consumed by a task.

Results. Rxn I 2 Rxn I Rext« 1 Rxn 2 Rxn 3 Rxn 2 33.7 Rsn 284 Rxn 3 17.7 Rxn 2 10.

storage Objective (c. u) Cold utility (MJ) Hot utility (MJ) Discrete variables Continuous variables Time points CPU time (s) No integration 465.2x103 21.0 16.6 72 337 5 3 One heat vessel 2,5x106 15.6 143 639 5 6000 Multiple heat storage vessels 2,9x106 236 1035 5 6000.

More robust objective function. the transfer times of materials.

Question and answer session. 06.

Question 1. Question 2. Question 3. Question 4. Question 5.

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