The quantitative calculation of resource consumption is based on the resource consumption demand model and combined with the field records in the actual production process to obtain relevant data. It is mainly considered from three aspects: material resources, energy resources and human resources.
The energy consumption per unit casting can be obtained by energy consumption calculation formula. Among them, the energy consumption per ton of molten iron is obtained by referring to the data in the electric furnace power consumption statistics of sand casting enterprises in August 2019. When the production condition is A1, the medium frequency furnace produces 6250kg molten iron per furnace, 45% of the production capacity is used to produce the casting, the discharge temperature is 1470 ℃, the pouring temperature is 1380 ℃, and the power consumption per ton of molten iron is 550.3kw · h; When the production condition is A1, the medium frequency furnace produces 8500Kg molten iron per furnace, and 65% of the production capacity is used to produce the casting. The discharge temperature is 1470 ℃ and the pouring temperature is 1380 ℃. At this time, the power consumption per ton of molten iron is 506.808kw · H.
Among them, the real-time energy consumption of sand mold 3D printing process can be obtained through LabVIEW Ni data acquisition card. The printing environment and energy consumption measurement device are shown in Figure 1. The equipment energy consumption of other casting processes is obtained through the conversion of equipment average power and operation time or workshop electricity meter statistics.
Figure 2 shows the Gantt chart of casting process flow of three casting methods under A1 production conditions, and the sub coordinate represents the power of corresponding auxiliary equipment in each casting process. The casting process in the figure starts from sand mixing and ends with shot peening, which is regarded as the completion of casting production. Among them, the traditional pattern modeling needs to complete the production of wood pattern, and the effective working time of carpenters is taken as the production time of wood pattern, so the casting time is calculated from 100800s. When the production condition is A1B1, the curing time of molding sand and the cooling time after pouring are equally divided into 864s according to the number of castings. The sand mixing process of sand mold 3D printing is carried out intermittently during the printing process. In the figure, the sand mixing time is summarized according to the sand mixing times.
According to the main material consumption list of unit casting production and the production energy consumption of unit casting, the material carbon emission and energy carbon emission values can be obtained respectively. Undesired carbon emission is related to slag, waste treatment and molding sand exhaust. It is also converted according to specific material consumption, waste treatment power consumption and gas carbon coefficient of molding sand materials. Take the carbon emission calculation of sand mold 3D printing process under A1 production conditions as an example:
The material carbon emission in the sand mold 3D printing process is calculated as follows:
The energy and carbon emission of sand mold 3D printing process is calculated as follows:
The unexpected carbon emission of sand mold 3D printing process is calculated as follows:
To sum up, the total carbon emission of sand mold 3D printing process under A1 production conditions is:
