Downloaded from orbit.dtu.dk on: Oct 05, 2018 Extending MFM Function Ontology for Repreenting Separation and Converion in Proce Plant Zhang, Xinxin; Lind, Morten; Jørgenen, Sten Bay; Wu, Jing; Karnati, Pardhaaradhi Publihed in: Proceeding of 7th International Conference on Water and Flood Management Publication date: 2018 Document Verion Peer reviewed verion Link back to DTU Orbit Citation (APA): Zhang, X., Lind, M., Jørgenen, S. B., Wu, J., & Karnati, P. (2018). Extending MFM Function Ontology for Repreenting Separation and Converion in Proce Plant. In Proceeding of 7th International Conference on Water and Flood Management General right Copyright and moral right for the publication made acceible in the public portal are retained by the author and/or other copyright owner and it i a condition of acceing publication that uer recognie and abide by the legal requirement aociated with thee right. Uer may download and print one copy of any publication from the public portal for the purpoe of private tudy or reearch. You may not further ditribute the material or ue it for any profit-making activity or commercial gain You may freely ditribute the URL identifying the publication in the public portal If you believe that thi document breache copyright pleae contact u providing detail, and we will remove acce to the work immediately and invetigate your claim.
Extending MFM Function Ontology for Repreenting Separation and Converion in Proce Plant Xinxin Zhang xinz@elektro.dtu.dk Jing Wu jinwu@elektro.dtu.dk Morten Lind mli@elektro.dtu.dk Pardhaaradhi Karnati Eldor Technology AS Stavanger, Norway karnati@eldor.no Sten Bay Jørgenen Department of Chemical Engineering bj@kt.dtu.dk Abtract Thi paper intend to extend the Multilevel Flow Modelling ontology by defining eparation and converion function for repreenting ma balance in the phyical ytem uch a proce plant. Two modelling example are provided in order to demontrate how to ue the two new ma flow function and their caual role in relation to other function. Keyword functional modelling, multilevel flow modelling, function ontology. I. INTRODUCTION Multilevel Flow Modelling (MFM) i applied to model the proce plant in the perpective of the goal and function. MFM ontology define the concept of a function from everal different perpective. One of the apect that an MFM function addree i that a function can be viewed from both a tatic and a dynamic perpective. The tatic view of a function center on the actor (role i.e. commodity and in the context of proce plant) that are involved in realizing the function. The dynamic view of a function involve the actual action thoe actor (role) hould perform. The ix baic MFM function defined in the MFM ontology [1] can decribe a relatively broad range of action that are commonly applied in proce plant: the material that through the ytem can be provided (repreented by ource function), tranported (repreented by tranport function), tored (repreented by torage function), balanced (repreented by balance function), barred (repreented by barrier function), and dicharged (repreented by ink function). The ame action can apply to the energy, which i normally carried by and exchanged between material. While thi et of function i adequate to repreent the total ma and energy balance in a variety of proce plant, they often fall hort of repreenting ome of the production goal that heavily rely on the propertie of the material. For thi reaon, everal ad hoc pecial function have been ued during the modelling practice uch a in [2][3] to repreent the detailed apect of change in material and it effect on the plant production and control goal. The pecial function are named, following the nature of the property change, a eparation, mixing, ditribution, and converion. The name alo comply with indutrial convention. The aim of thi paper i to formally define and integrate two of the new function ma eparation and ma converion into the exiting MFM ontology with clear definition and caual rule. The definition and caual rule are introduced in Section 2. Two modelling example, one for each function, are provided for demontration purpoe in Section 3. Section 4 offer dicuion regarding MFM ontology extenion and concluion. II. MASS SEPARATION AND CONVERSION The author aume that the reader already have obtained a baic undertanding of MFM through a variou election of MFM literature uch a [1], [4] and [5]. Here on forward, MFM terminology i ued directly without further reference. A. MFM Flow Function The concept of a flow function defined in MFM ontology i in relation to it placement in the mean-end tructure (Fig.1). From the dynamic perpective, an action ha to be performed for the function to be able to achieve an objective. Therefore, the role that involved in an action ha to be fulfilled o that the function can be realized. The mot baic action role are the agent that act) and the object (that i acted upon) [5]. Take MFM ma tranport function a an example (alo illutrated in Fig.1), the function repreent a tream of ma that i tranported. The agency of the tranportation i provided by a combination of either the three poible ource: 1) the agency propagate from the ma flow uptream or downtream through caual relation, 2) the agency propagate from other ma or energy though mean-end relation, and 3) the agency i provided by a phyical tructure or. All ix MFM flow function are defined in an analogou manner; uch that caual reaoning rule can be ytematically derived. Change of the performance of the agent will influence the change of tate in the object. XXX-X-XXXX-XXXX-X/XX/$XX.00 20XX IEEE
Function Objective Tranformation (action) agent object from up/down tream MFM tranport function mixture compoiti on tra1 Object influence from uptream S tra2 from uptream (inlet tranport & eparation) comp. com. from other from Phyical Structure Fig. 1. Mean-end tructure and MFM ma tranport function The obervable realization of a function i the tate of the object; naturally, thi i ued to evaluate the tate of the function performance. Since MFM model i a qualitative model, the function tate are alo qualitative tate. For example, a tranport function can have high flow rate or low flow rate comparing to it normal performance, and a torage function can have high level or low level tate. Through the analyi depicted in Figure 1 above, the apect to be conidered when defining a MFM flow function can be ummarized a follow: 1) the tranformation (action) of the function.; 2) the object role and agent role of the function; 3)what model element can provide the required agency; and 4) the tate of the object. Thee four point are addreed in the following ection when defining new MFM function. B. Ma Seperation Function Separation procee, or procee that ue phyical, chemical, or electrical force to iolate or concentrate elected contituent of a mixture, are eential to the chemical, petroleum refining, and material proceing indutrie [7]. MFM model can repreent ytem within the abovementioned indutrie [2]. On an abtract level, the action involved in a eparation proce can till be decribed by uing the baic MFM balance, tranport, and torage function. In that cae, the total ma balance between the mixture inlet and the total outlet of the eparated tream are repreented in the MFM model. However, the nature of the eparation function itelf i not repreented pecifically. To introduce the eparation function, a imilar analyi for MFM eparation function a in the previou ection i illutrated in Fig. 2. The mot ignificant difference between a eparation and a normal MFM balance function i the requirement on the tranformation of tream compoition during the eparation, which mean that there exit condition for the material to erve a object role in the eparation function, and alo in it uptream and downtream tranport. The normal balance function ha two caual ignature. One i to pa the agency from uptream to downtream or vice vera; the other i to balance different flow branche connected to it uptream or downtream. The eparation function, in comparion, ha only one uptream inlet flow. The total inflow and outflow are till balanced by the eparation (the ame a a balance function), but the ditribution of after eparation depend on: 1) the eparation condition, and 2) the compoition of the through the eparation (which i paed down from the inlet). from other from tra3 Fig. 2. Separation function and it connected tranport function object role Draw from thi analyi, the eparation function can be defined in the ame manner a other MFM flow function. Definition: The (binary) ma eparation function in MFM repreent a ytem a a eparator of two ma. The function i characterized by a tate variable indicating the quality of ma eparation, the low quality mean the purity of the downtream object i low. Note that only a low tate i defined a an abnormal tate. Each eparation function can have one and only one uptream inflow, and at leat two downtream out. The tate of the object role around eparation function are the key element that will actually influence the proce. The condition of the object role ha to be pecified. 1) Uptream tranport to a eparation function ha an object role that pecify the condition of the mixture to be eparated 2) The downtream tranport from a eparation function alo have mixture a object, however, they hould each ha one predominate contituent compare to the uptream tranport function. Baed on the definition and the pecification of the object role involved, caual reaoning rule can be defined a follow. Firtly, MFM eparation function hould have the ame acro balance rule a normal balance function. Secondly, a low amount of a certain in the uptream tranport function object role will caue a low flow to a certain tranport function that repreent thi dominant flow at the downtream ide. Thirdly, MFM a eparation function can be connected through mean-end relation and producer-product relation a function target, the mean function in thi relation hould contribute to the quality of the eparation. Fourth, the quality of the eparation influence the object role purity tate of the two downtream tranport. All the influence are indicated in Fig.2. C. Ma Converion Function Converion function i firtly introduce to MFM model a energy converion function and it i till being invetigated by the author reearch group. Converion function can alo apply to ma flow, where it indicate a chemical reaction. Chemical reaction engineering i a field of reearch of it own, however, ince it i commonly ued in the proce plant, not only to
produce chemical compound, but a briefly mentioned in the previou ection, can alo be ued a mean for eparation. By uing the ame analyi a in Fig. 1, we can define the MFM ma converion function a follow: Definition: The ma converion function in MFM repreent the ue of a ytem a a reactor of ma according to a pecified toichiometry. The function i characterized by a tate variable indicating the rate of reaction; low reaction rate mean the downtream object tate (product concentration) i low, and high reaction rate mean the downtream object tate i low. Each eparation function can have one or more uptream in flow(), and one downtream out flow. Pleae note that chemical reaction may have multiple product; however, ince the eparation function ha been defined in the previou ection the reaction product can be eparated further downtream. Again, it i important to analyze the object role around the ma converion. 1) Uptream tranport() to a ma converion function ha an object role that atify the condition of a reactant mixture. 2) The downtream tranport() to a ma converion ha the reacted mixture a object, the reaction productha to have an increed concentration. Baed on the definition and the pecification of the object role involved, caual reaoning rule are defined for ma converion a follow: Firtly, a MFM ma converion function hould have the ame caual reaoning rule a normal torage function. Secondly, low flow of a limiting reactant will lead to a low product content in the downtream tranport. Thirdly, ma converion function can be connected through mean-end relation producer-product a function target, the mean function in thi relation hould contribute to the rate of the reaction (thi can be catalyt, temperature or any other reaction condition). Fourthly, the rate of the reaction influence the downtream tranport depending on whether it ha an influencer relation to the downtream. reactant from other from Fig. 3. Separation function and it connected tranport function C from up/down tream Object influence from up tream mixture object role Fig. 4. Proce heet and ma flow tructure for a three-phae eparator. III. MODELING EXAMPLE To demontrate the uage of the ma eparation and converion function, two modelling cae are preented in thi ection. The ma flow tructure for a three-phae eparator i preented for eparation function, and the ma flow tructure for a chemical deaeration proce i preented to demontrate the ma converion function. A. Three-phae Separator The three-phae eparator ha been modeled by uing MFM model in [6]. A the MFM function of eparation wa properly defined prior to thi paper, the model preented here will be different from that how in [6]. The caual influence now can be decribe more preciely. Due to the limitation of the paper, only a ma flow tructure for the three-phae eparator i preented. The preure and temperature influence are not hown. The ytem and the MFM model are hown in Fig. 4. Function ou2 repreent the ource of the mixture, function tra8 repreent the inlet mixture, and ep1 i the eparation function. The ma flow i eparated into three different phyical pace within the eparator: to7 repreent the ga torage on top of the eparator tank, to8 repreent the water torage, to5 repreent the oil remained on top of the water chamber, and to6 repreent the oil tored in the oil chamber. Function tra3, tra11, tra15 and their downtream ink function repreent the ga, oil and water outlet repectively. Function bar2 repreent the afety preure valve that i cloed during normal operation. By uing reaoning rule defined in Section II, we can analyze how change in the compoition of the mixture can lead to deviation in the downtream. For example, low level in to6 indicate a low oil level. One of poible caue i low flow from the inlet tra8, another poible caue i a low oil content in the inlet mixture. In the two different cenario, if the tra8 i
low, then the water and ga inlet tra12 and tra14 are alo low; if tra8 i normal, the oil content i low, then the water and ga inlet tra12 and tra14 hould be higher than normal ituation. In thi way, it i poible to ue a MFM model to identify abnormal tate due to the property of the amterial on top of the normal total ma balance. B. Chemical Scavanger Deaeration Proce The econd model ubject i a chemical deaeration proce. It i the final tep for Oil and Ga platform injection water treatment. Both the ytem diagram and the MFM ma flow tructure are hown in Fig. 5. In thi proce, the ea water i being treated by adding an oxygen cavenger to remove the remaining oxygen in the water. However, no eparation i required after the reaction, o we can view the ma converion function without a downtream eparation. In the MFM model, ma flow converion repreent the reaction between the cavenger and the diolved oxygen. Function ou1 and tra1 repreent the inlet of the diolved oxygen in the ea water; function ou2 and tra5 repreent the oxygen cavenger inlet. Function tra3 and in1 repreent the outlet of the reaction product and remaining reactant leaving the ytem with the ea water dicharge. The ea water ma flow repreent the water flow. It mediate the tranportation of the reactant and the product. The object role for tra1, tra5, and tra2 are erved by oxygen (reactant), oxygen cavenger (reactant), and mixture of the reactant and the produced chemical compound (all diolved in the ea water). Function tra10 and tra3 ha the ame object role a tra2 ince no converion or eparation happen between thoe tranport. The reactant flow rate will influence the tate of the reaction, then it will further influence the tate of the object role aociated with tra2. A low level in the eawater flow will reult in a longer reaction time, which will alo influence the tate of the reaction and the tate of the object role in tra2. IV. DISCUSSION AND CONCLUSIONS Thi paper preented two example of how MFM function ontology can be extended. Both the dynamic and tatic apect of a function have to be taken into conideration. Even though the function are defined motly by the dynamic part, namely the tranformation (action), the condition for phyical commodity or to erve required action role (the tatic view) are equally important. Only by analyzing the function role, the caual relation between new function and exiting function can be properly undertood. The reaction proce elected in thi paper i very imple, which only involve two reactant. The reaction itelf can happen without catalyt and the energy change caued by the reaction i alo negligible. More modelling cae are required for finalizing the reult from thi paper. By uing a imilar analyi, more function regarding change of the object role property can be defined. The already developed function uch a ma mixing, ditribution, and energy converion hould be tudied afterward. The caual reaoning rule involving object role ha not been fully implemented in the DTU developed rulebaed reaoning ytem. The work in thi paper will be continued and teted by uing model and data collected from real proce ytem. ACKNOWLEDGMENT The author would love to thank The Danih Hydrocarbon Reearch and Technology Centre for upport the preented reearch reult. The author would alo love to thank the colleague working together in the DTU MFM reearch group. Fig. 5. Proce Flowheet and ma flow tructure for a chamical deaeration. REFERENCES [1] M. Lind. An Introduction to Multilevel Flow Modeling. Nuclear Safety and Simulation vol. 2. iue 1. 2011, pp. 22 32. Print. [2] W. Jing, L. Zhang, M. Lind, W.Liang, J. Hu, S. B. Jørgenen, G. Sin, and Z. U. Khokhar. Hazard Identification of the Offhore Three-Phae Separation Proce Baed on Multilevel Flow Modeling and HAZOP. Proceeding of the 26th International Conference on Indutrial, Engineering Other Application of Applied Intelligent Sytem (Iea/Aie). Springer, 2013, pp: 421 430. [3] X. Hua; Z. Wu, M. Lind, J. Wu, X. Zhang, J. Frutiger, G. Sin. Uing MFM methodology to generate and define major accident cenario for quantitative rik aement tudie. Computer-aided Chemical Engineering, ed. A. Epuña; M. Graell; L. Puigjaner. Vol. 40 1. Elevier, 2017, pp: 589-594. [4] M. Lind and X. Zhang. Multilevel Flow Modelling: A Tutorial, OECD Halden Reactor Project, HWR-1102, 2017. [5] X. Zhang. Aeing Operational Situation. Technical Univerity of Denmark,. 2015. [6] M. Lind and X. Zhang. Applying Functional Modeling for Accident Management of Nucler Power Plant. In: Nuclear afety and imulation, Vol. 5, No. 3, 2014, pp: 186-196. [7] National Academy of Science, Separation Technologie for the Indutrie of the Future. National Academie Pre. Wahington, D.C. 1998.