Preheating analysis on molten salt storage tank based on CFD method

doi:10.3969/j.issn.1674-1951.2021.07.012

Abstract

Abstract:

Construction a modern power system to pursue carbon neutrality need the support of energy storage technology. The preheating for molten salt storage tanks is an important link to ensure the safe operation of thermal storage system in CSP plants. Taking the molten salt storage tank of a CSP plant as the research object, the temperature distribution in the tank during the equal-step preheating process is numerically simulated based on the computational fluid dynamics （CFD） method. The influences of the preheating gas injection angle and tank size on the preheating process are explored. The results show that the temperature at the junction of the bottom plate and the side wall is the lowest during preheating. Decreasing the vertical injection angle of preheating gas or increasing its circumferential angle can effectively shorten the preheating time of the storage tank. Under the same preheating gas inlet and outlet conditions, the increase in the inner diameter of the storage tank can result in a substantial increase in the preheating time.

Key words: CSP plants, heat storage system, molten salt storage tank, preheating, numerical simulation, heat loss, carbon neutrality, energy storage

CLC Number:

TK514

WANG Ding, XIAO Hu, CHEN Yuxuan, YUE Song, ZHANG Yanping. Preheating analysis on molten salt storage tank based on CFD method[J]. Huadian Technology, 2021, 43(7): 75-81.

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项目	罐体材料	保温材料
密度/(kg·m^-3)	7 750	128
比热容/[J·(kg·K)^-1]	309.3+0.437 3T	640
导热率/[W·(m·K)^-1]	73.857-0.043 0T	0.042+0.000 2T

进风时间/h	预热气体温度/℃	预热气体流量/(m³·h^-1)
0~9	150	6 000
10~21	200	6 430
22~40	250	6 890
41~54	300	7 320
55~79	350	7 750
80~104	400	8 180
105~128	450	8 600
129~172	500	9 050
173~245	550	9 480

预热时间/h	实际罐体温度/℃	模拟罐体温度/℃	相对误差/%
25	76.56	89.32	16.67
50	111.63	132.59	18.78
75	156.44	172.12	10.02
100	183.75	206.73	12.51
125	223.31	239.57	7.28
150	258.35	273.94	6.03
175	269.04	297.48	10.57
200	312.43	323.94	3.68

罐体平均温度/℃	不同竖直角下的预热时间/h
罐体平均温度/℃	35˚	45˚	55˚
50	3.3	3.4	3.4
100	7.8	8.2	8.1
150	14.2	15.1	14.9
200	22.8	24.5	24.0
250	33.3	35.9	35.0
300	45.5	49.4	48.4
350	59.1	65.3	64.4
380	66.5	72.9	73.1

罐体平均温度/℃	不同周向角下的预热时间/h
罐体平均温度/℃	30˚	40˚	50˚
50	3.4	3.4	3.2
100	8.3	8.2	7.8
150	15.6	15.1	14.4
200	24.9	24.5	22.8
250	36.2	35.9	33.3
300	49.9	49.4	46.2
350	66.1	65.3	61.4
380	73.8	72.9	69.7