Optimal study on parameters of rotational molding process heated electrically for making liner of hydrogen cylinder

doi:10.19491/j.issn.1001-9278.2024.01.011

Abstract

Abstract:

On basis of the static bed model， a heat transfer model was established for the rotational molding process heated electrically by a control mode of PID to make the liner of a hydrogen cylinder. The temperatures at the mold surface and inside mold， heating time， and electrical energy were simulated by means of the FLUENT software. These simulated results were in good agreement with the experimental results， indicated that the heat transfer model established in this study was validated. The heat transfer model was then applied to calculate the temperature inside the mold when the heating was stopped， heating time， and electrical energy in 16 cases. A grey relational analysis was conducted to investigate the trigger temperature of the PID mode and the percentage of initial heating power affecting heating time and electrical energy. The results indicated that temperature inside mold after stopping the heating varied with the percentage of initial heating power slightly， and however， it decreased with an increase in the trigger temperature. Both heating time and electrical energy decreased as the trigger temperature increased. The optimal process parameters were determined to be a trigger temperature of 250 ℃ and an initial heating power percentage of 90 %. In addition， the affecting extent of trigger temperature on heating time and electrical energy was larger than that of the percentage of initial heating power.

Key words: electrical heating, rotational molding process, heat transfer model, liner of hydrogen cylinder, FLUENT simulation, grey relational analysis

CLC Number:

TQ320.66

LIU Xuejun. Optimal study on parameters of rotational molding process heated electrically for making liner of hydrogen cylinder[J]. China Plastics, 2024, 38(1): 79-85.

Figures/Tables 14

References 18

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项目	加热时间/s	加热电能/kW•h	模内最高温度/℃
实测值	1074	1.563	206.3
仿真值	1112	1.599	194.7
相对误差/%	3.5	2.3	5.6

项目	加热时间/s	加热电能/kW•h	模内最高温度/℃
实测值	1074	1.563	206.3
仿真值	1112	1.599	194.7
相对误差/%	3.5	2.3	5.6

实验次序	PID模式的触发温度/℃	初始加热功率的百分比/%	加热时间/ s	加热电能/ kW•h
1	220	70	1 394	1.841
2	230	70	1 238	1.754
3	240	70	1 133	1.700
4	250	70	1 052	1.659
5	220	80	1 376	1.851
6	230	80	1 187	1.741
7	240	80	1 054	1.676
8	250	80	974	1.637
9	220	90	1 307	1.822
10	230	90	1 139	1.730
11	240	90	1 014	1.667
12	250	90	925	1.625
13	220	100	1 329	1.890
14	230	100	1 155	1.796
15	240	100	1 027	1.733
16	250	100	930	1.686

实验次序	PID模式的触发温度/℃	初始加热功率的百分比/%	加热时间/ s	加热电能/ kW•h
1	220	70	1 394	1.841
2	230	70	1 238	1.754
3	240	70	1 133	1.700
4	250	70	1 052	1.659
5	220	80	1 376	1.851
6	230	80	1 187	1.741
7	240	80	1 054	1.676
8	250	80	974	1.637
9	220	90	1 307	1.822
10	230	90	1 139	1.730
11	240	90	1 014	1.667
12	250	90	925	1.625
13	220	100	1 329	1.890
14	230	100	1 155	1.796
15	240	100	1 027	1.733
16	250	100	930	1.686

实验次序	信噪比		无量纲的信噪比		灰色关联度
实验次序	X	Y	X	Y	X	Y
1	-62.885	-5.301	0.000	0.174	0.333	0.377
2	-61.854	-4.881	0.289	0.494	0.413	0.497
3	-61.085	-4.609	0.506	0.701	0.503	0.626
4	-60.440	-4.397	0.686	0.863	0.615	0.785
5	-62.772	-5.348	0.032	0.138	0.341	0.367
6	-61.489	-4.816	0.392	0.544	0.451	0.523
7	-60.457	-4.486	0.682	0.795	0.611	0.710
8	-59.771	-4.281	0.874	0.951	0.799	0.911
9	-62.326	-5.211	0.157	0.243	0.372	0.398
10	-61.131	-4.761	0.493	0.586	0.496	0.547
11	-60.121	-4.437	0.776	0.832	0.691	0.749
12	-59.323	-4.217	1.000	1.000	1.000	1.000
13	-62.471	-5.529	0.116	0.000	0.361	0.333
14	-61.252	-5.084	0.459	0.340	0.480	0.431
15	-60.231	-4.774	0.745	0.576	0.662	0.541
16	-59.370	-4.537	0.987	0.756	0.974	0.672