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Analysis of Thermodynamic Processes with Full Consideration of Real Gas Behaviour Analysis of thermodynamic processes with full consideration of real gas behaviour engineering your visions © by B&B-AGEMA, No. 1 Contents • What is TDT 2 ? • How does it look like ? • How does it work ? • Examples engineering your visions © by B&B-AGEMA, No. 2 Introduction What is TDT ? TDT is a Thermodynamic Design Tool, that supports the design and calculation of energetic processes on a 1D thermodynamic approach. The software TDT can be run on Windows operating systems (Windows XP, Windows Vista, Windows 7 and Windows 8). engineering your visions © by B&B-AGEMA, No. 3 TDT2 Features TDT2 Features 1. High calculation accuracy: • real gas properties are considered on thermodynamic calculations • change of state in each components is divided into 100 steps 2. Superior user interface: • ease of input: dialogs on graphic screen • visualized output: graphic system overview, thermodynamic graphs, digital data in tables 3. Applicable various kinds of fluids: • liquid, gas, steam (incl. superheated, super critical point), two-phase state • currently 29 different fluids • user defined fluid mixtures engineering your visions © by B&B-AGEMA, No. 4 How does TDT2 look like ? engineering your visions © by B&B-AGEMA, No. 5 TDT2 User Interface Initial window after program start: start a “New project”, “Open” an existing project, open one of the “Examples”, which are part of the installation, or open the “Manual”. engineering your visions © by B&B-AGEMA, No. 6 TDT2 Main Window Structure tree structure action toolbar notebook containing overview and graphs calculation output On the left hand side of the window the entire project information is listed in a tree structure. The right hand side has three areas: the action toolbar (with buttons to start calculations and, the notebook (containing the overview, graphs and diagrams) and the calculation output at the bottom. engineering your visions © by B&B-AGEMA, No. 7 TDT2 Detailed Part Information engineering your visions © by B&B-AGEMA, No. 8 TDT2 Ease of Input Currently, 9 different types of parts are available in TDT2: Compressor: component to increase the pressure of a compressible fluid Pump: component to increase the pressure of an incompressible fluid Turbine: component to expand either compressible or incompressible fluids; this component also covers so-called expanders Combustor: component to calculated simple combustion of gases Condenser: cools a fluid, so that liquid state is reached at the outlet Heat exchanger: general component to put heat into the fluid or to cool a fluid Pressure loss element: component to consider pressure losses e.g. in pipes Process branch: splitting and mixing of fluid flows Interface: used to create a connection between 2 heat exchangers engineering your visions © by B&B-AGEMA, No. 9 TDT2 Available Fluids Applicable various kinds of fluids The current version of TDT2 can calculate the properties of 29 different fluids in the liquid, gas (super-heated and super-critical) and two-phase state. ◦ pure fluids: ◦ alkanes: Air (as a pure fluid) Methane (CH4) Water (H2O) Ethane (C2H6) Steam (H2O) Propane (C3H8) Carbon monoxide (CO) Butane (C4H10) Carbon dioxide (CO2) Isobutane (C4H10) Hydrogen (H2) Pentane (C5H12) Oxygen (O2) Hexane (C6H14) Nitrogen (N2) ◦ aromatic hydrocarbons: Ammonia (NH3) Toluene (C7H8) ◦ inert gases: ◦ refrigerants: Helium (He) R11 (Trichlorofluoromethane, CCl3F) Neon (Ne) R12 (Dichlorodifluoromethane, CCl2F2) Argon (Ar) R123 (Dichlorotrifluoromethylmethane, C2HCl2F3) Krypton (Kr) R1234YF (Tetrafluoropropylene, C3H2F4) Xenon (Xe) R134 (Tetrafluoroethane, CH2FCF3) R245CA (Pentafluoropropane, C3H3F5) R245FA (Pentafluoropropane, C3H3F5) engineering your visions © by B&B-AGEMA, No. 10 TDT2 Definition of Mixtures Definition of mixtures available, e.g.: • furnace gases • alkane mixtures • special gas compositions Fluids are defined by selecting components and assigning volume or mass fractions and additional humidity. 3 fluid mixture types: • Dry mixtures: no water content • Humid mixtures: water content, with condensation calculation • General mixtures: water allowed, no condensation is calculated engineering your visions © by B&B-AGEMA, No. 11 How does TDT2 work ? engineering your visions © by B&B-AGEMA, No. 12 TDT2 Calculation of Change of State Critical point Various states possible in TDT: ・liquid ・vapor (super-heated, super-critical) ・two-phase state Calculation of change of state v p Isentropic volume coefficient: k v (compression & expansion) p v s n 1 n v 1 Polytropic head: y Z RT v n v 1 Isentropic temperature coefficient: k p 1 1 n 1 T p v 1 T T ps nT 1 n T n 1 k 1 1 p k 1 Outlet temperature: T2 T1 Polytropic volume coefficient: v v T n v k v p k T n 1 ZR1 k 1 with pressure ratio , real gas coefficient Z, Polytropic temperature coefficient: T p T n c k specific heat cp and polytropic efficiency p T p p T Reference: K. H. Lüdtke: “Process Centrifugal Compressors – Basics, Function, Operation, Design, Application”, Springer-Verlag Berlin Heidelberg, Germany, 2004 engineering your visions © by B&B-AGEMA, No. 13 TDT2 High Calculation Accuracy High calculation accuracy • change of state in each component is divided into 100 steps • real gas properties determined in each step Entropy Differences of a Real and Isenthalpic Change of State** ** D. Bohn/H.E. Gallus , Energy Conversion Machinery engineering your visions © by B&B-AGEMA, No. 14 TDT2 Visualized Output Thermodynamic diagrams • h-s diagram: Enthalpy over Entropy • p-s diagram: Pressure over Entropy • T-s diagram: Temperature over Entropy • p-h diagram: Pressure over Enthalpy • p-T diagram: Pressure over Temperature Q-T diagrams • Evaluation of heat transfer in interfaces • Inlet & outlet temperatures • Pinch point determination engineering your visions © by B&B-AGEMA, No. 15 TDT2 Example of Properties Table (Air) engineering your visions © by B&B-AGEMA, No. 16 TDT2 – Features Summary . Real gas properties 29 fluids (e.g. air, steam, CO2, hydrogen, helium, argon, methane, ethane, refrigerants) Consideration of changing properties during compression / expansion Export of properties into tables User-defined fluid mixtures . Implemented components Compressor Heat exchanger Pump Pressure Loss Turbine Process Branch Combustor Interface Condenser . Few input parameters necessary Efficiency (polytropic or isentropic) Outlet pressure (as ratio or fixed) Leakage (absolute or relative) Pressure loss (absolute or relative) . Combined cycles Interaction of energy conversion cycles with different fluid: CCGT, ST+ORC, … . Thermodynamic diagrams & QT-diagrams engineering your visions © by B&B-AGEMA, No. 17 Examples engineering your visions © by B&B-AGEMA, No. 18 TDT2 – Examples Combined Cycle Gas & Steam CO2 Compression with Intercoolers Organic Rankine cycles engineering your visions © by B&B-AGEMA, No. 19 TDT – Combined Cycle Gas & Steam T-S Diagram QT Diagram engineering your visions © by B&B-AGEMA, No. 20 TDT – CO2 Compression with Intercooling Comparison: 8 vs. 4 Compression steps 4 Compression steps 8 Compression steps P=36.2 MW P=31.3 MW engineering your visions © by B&B-AGEMA, No. 21 TDT - ORC design industrial waste combined electricity solar thermal geothermal heat production • Process design • Fluid study Organic Rankine Cycle • Process optimization • Design parameter Different application areas require individual process design, parameter studies, analyses of fluid variations, … TDT efficient and fast thermodynamic process configuration and calculation of ORC’s consideration of real gas properties of various fluids evaluation of state variables database of fluid property tables engineering your visions © by B&B-AGEMA, No. 22 TDT2 – Example: Helium & ORC Combined Cycle engineering your visions © by B&B-AGEMA, No. 23 TDT2 - ORC process configuration and parameter study Example: Process configuration for industrial waste heat utilization design of multiple types of processes within definition of boundary one file for study of various parameters or conditions as fluids transferrable heat, upper and lower temperature ranges, etc. T-s, h-s, p-T, etc. diagrams definition of component efficiencies, pressure losses, leakage, … inlet/outlet state variables and component specific results engineering your visions © by B&B-AGEMA, No. 24 TDT2 – combined cycle configuration for ORC Example: Combined cycle configuration of recuperated air turbine with water cooled intercooler and ORC with isobutane as working fluid Evaluation of Process chart - required water mass flow for intercooler (e.g. for presentation) - configuration of ORC cycle for waste heat utilization of air turbine - parameter study of air cycle and ORC for highest efficiencies and/or highest power output - Q-T-diagrams for heat exchangers - generate thermodynamic state variables for component design consideration T-s-diagram for each process Q-T-diagram of heat exchanger interfaces engineering your visions © by B&B-AGEMA, No. 25 Thank you very much for your attention! engineering your visions © by B&B-AGEMA, No. 26 .
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