Estimation of Energy Consumption in Manufacturing

1. Estimation of Energy Consumption in Manufacturing P M V Subbarao Professor Mechanical Engineering Department Models for Development of Future Eco-Factories…

2. Introductory Remarks • The integration of environmental sustainability and energy-efficiency is the goal for future eco-factories. • This has been recognized as a means to foster: • Economic and environmental performance, • Increase competitiveness & • Use it as a lever to spur innovation. • Green Norms for Eco-factory: • Integrating green technologies in the manufacturing system. • Putting environmental goals on the company agenda. • Pursuing green norms and directives. • the question is: quo vadis eco-factory?

3. Energy assessment framework for machining worksh

4. Energy considerations at different manufacturing levels

5. Model for Specific Work during Cutting • Based on model, the specific work consumption is:

6. The Product: Wheel&Axle

7. The sub-Product: Axle

8. The sub-Product : Wheel

9. The sub-Product : Wheel

10. Energy Consumption @ Workpiece Level • Energy Consumption Allowance (ECA): • The ECA of a workpiece is the reasonable quantity criterion of the energy consumption of the whole machining process of a workpiece. • ECA is an index related to the technology and management of a manufacturing process/system. • Acquiring and integrating the energy consumption at each level in workpiece machining/processing generates the energy consumption of a workpiece. • Energy Consumption Step for ECA is used from the perspective of the workpiece movement to uniformly describe various types of energy consumptions of every procedure.

11. Traditional step Vs ECS • Process refers to a machining process over one workpiece or several workpieces that are continuously completed by one or a group of workers at the same work station. • A process step refers to a machining process that is continuously completed without changing the cutting tool or the workpiece surface. • This process step is called the traditional step. • ECS refers to a time segment procedure in which some energy is consumed under the same operating environment. • Complex ECSs can be continuously decomposed into multiple sub-ECSs until the basic energy consumption- step (BECS). • The BECS is an energy-consumption procedure with the same environment, rules and sources of energy consumption.

12. Structure of ECS The Transportation Basic Energy Consumption Step The Basic Machining Energy Consumption Step The Storage Basic Energy Consumption Step

13. The Machining Step : Level-1

14. The Machining Step : Level-2

15. The Storage Step

16. The Transportation Step : Level -1

17. The Transportation Step : Level -2

18. BECS: Turning Operation

19. BECS: Turning Operation

20. BECS: Turning Operation

21. ECS Model for Machining • The machining ECSs are complex and various. • They can all be decomposed into several machining sub-ECSs. • Further these are divided into multiple BECSs. • Energy consumption of BECSs are computed as minimum work or minimum energy models. • Add BESCs to obtain the energy consumption of machining ECSs. • It is clear that the whole machining ECS may contain more than one sub-ECS.

22. The ECS Model The energy-consumption model of machining ECS is: EM: Energy consumption of machining ECS EMM: Energy consumption of machining sub-ECS EWorkshopM: Allocation energy of energy consumption of workshop auxiliary production system according to the time of this machining ECS

23. The ECS Model The energy-consumption model of machining ECS is: QMM: Number of machining sub-ECSs in the machining ECS EWorkshop: Energy consumption of the workshop auxiliary production system TM: Ratio of the energy consumption of the workshop auxiliary production system

24. The ECS Model The energy-consumption model of machining ECS is: ER: Energy consumption of standby BECS in this machining sub-ECS ES: Energy consumption of starting BECS in this machining sub-ECS EI: Energy consumption of idling BECS in this machining sub-ECS EA: Energy consumption of air-cutting BECS in this machining sub-ECS EC: Energy consumption of cutting BECS in this machining sub-ECS

25. Data Collection • The data for calculating the EC of standby, starting, idling, air-cutting and cutting BECS can be divided into two categories. • One is fundamental energy consumption data. • These data are related only to the equipment and have nothing to do with the machining process. • Ex: Starting energy consumption, idling power consumption, and additional load coefficients. • These data are from databases established through a number of experiments at each spindle speed of each machine tool. • Another type of data is supporting energy consumption data. • These are interrelated to the machining procedure, workpiece and process parameters. • Ex: The size of the work-piece, the spindle speed etc.

26. The ECS Model : Maching The energy-consumption model of machining ECS is: QR: Number of standby BECSs in this machining sub-ECS QS: Number of starting BECS in this machining sub-ECS QI: Number of idling BECS in this machining sub-ECS QA: Number of air-cutting BECS in this machining sub-ECS QC: Number of cutting BECS in this machining sub-ECS.

27. Method of Acquisition : EC of Standby • The energy consumption of standby BECS ER =PRTR • PR is the experimental measurement power of the machine tool in a standby state. • TR is the duration of the machine tool in a standby state. • The data of PR are from a standby fundamental energy consumption database, and the data of TR are the empirical mean values.

28. Method of Acquisition : EC of Starting • The energy consumption of starting BECS, ES is the experimental measurement energy of machine tools in a starting state. • It is taken from starting fundamental energy-consumption database.

29. Method of Acquisition : EC of Idling • The energy consumption of idling BECS, EI = PITI. • PI is the experimental measurement power of a machine tool in an idling state. • PI is taken from the idling fundamental energy consumption database. • TI is the duration for which the machine tool is in an idling state. • TI can be determined by the work piece size and the process parameter.

30. Method of Acquisition : EC of Air-Cutting • The energy consumption of air-cutting BECS, EA = PATA. • PA is the power of the machine tool in air-cutting state. • PA is taken from the air-cutting fundamental energy-consumption database. • TA is the duration of the machine tool in an air-cutting state. • TA can be determined by the workpiece size and the process parameter.

31. Method of Acquisition : EC of Cutting • The energy consumption of cutting BECS, EC. ECCdepicts cutting energy consumption ECIdepicts air-cutting energy consumption ECAis additional load energy consumption is the additional load coefficient in the cutting procedure

32. The energy-consumption model : Transportation Transportation ECS can be decomposed into several sub-ECSs and further into BECSs. ETR: Energy consumption of transportation ECS EL: Energy consumption of loading sub-ECS ET: Energy consumption of horizontal sub-ECS EU: Energy consumption of unloading sub-ECS QL: Number of loading sub-ECS QT: Number of horizontal sub-ECS QU: Number of unloading sub-ECS

33. Decomposition of Transportation Sub ECs Leading sub EC for Transportation can be further decomposed into several sub-ECSs ENH: Energy consumption of no-loading rising BECS END: Energy consumption of no-loading decline BECS ELH: Energy consumption of loading rising BECS ELD: Energy consumption of loading decline BECS ETN: Energy consumption of no-loading horizontal BECS ETL: Energy consumption of loading horizontal BECS.

34. The energy-consumption model: Storage ECS • Storage ECS can also be decomposed into several storage sub-ECSs and further into multiple BECSs. • These are auxiliary facilities, such as lighting, always work in the rated condition. • There are other facilities, such as fans and air-conditioners, usually work in the rated condition.

35. The energy-consumption model : workshop auxiliary production system • The workshop auxiliary production system includes air-compressor, lighting, ventilation, heating, air-conditioner, and other auxiliary production facilities. • This energy consumption is to maintain the appropriate production environment and production conditions. • The energy consumption data of one auxiliary production facility within a period of time can be obtained by measurements. • The model is as follows:

36. Case Study • A primary ECA of a workpiece is established in a real workshop using the proposed model. • the practicability of the model is demonstrated by comparing the computed value to the actual measured value. • Major steps: • Establishing a fundamental energy-consumption database • Preparing the energy-consumption data • Calculating energy consumption for ECA • Analysis

37. The Selected Work Piece The case workpiece is an exhaust plate, one component of an electromagnetic valve product.

38. Energy Consumption Calculations for ECA Energy consumption of standby BECS Energy consumption of starting BECS Energy consumption of idling BECS

39. Energy consumption of air-cutting BECS Energy consumption of cutting BECS

40. The energy consumption of the machining ECS

41. The energy consumption of the workshop auxiliary production system

42. The energy consumption of one exhaust plate The ECA of the exhaust plate is 1.518 kWh The actual value measured by the HIOKI 3390 power analyser is E0MM = 1.637 kWh. The error of the calculated energy consumption is error 7.839%