Process Heating Dan Zhou CREST Loughborough University Research - PowerPoint PPT Presentation

Thermal Energy Storage for Medium Temperature Industrial Process Heating Dan Zhou CREST Loughborough University

Research Proposal • Heat storage media: Material preparation, thermal property measurement, thermal stability and reliability test, chemical stability test; • Heat storage system design and build up Heat storage tank, heat transfer method, high temperature heat exchanger, high temperature oil pump, flow meter and other equipment; • Heat charging and discharging analysis: Experimental and numerical; • Valuation of the heat storage system and improvement: Cost, running efficiency and heat transfer enhancement.

Binary system of molten salts • A binary system of LiNO 3 and NaCl (87mol%/13mol%) is selected as the heat storage medium because of its high phase transition enthalpy. • Thermal properties by DSC: The samples were heated from 50 ° C to 260 ° C then cooled down to 50 ° C at a heating/cooling rate of 10 ºC/min and 15 ºC/min. • Thermal stability and reliability by DSC and TGA: 11 heating/cooling cycles by DSC 5 heating/cooling cycles by TGA at a heating/cooling rate of 10 ºC/min

Binary system of molten salts

Binary system of molten salts • Weight loss vs temperature tested by TGA: 5 cycles. • Corrosion test Copper Alloy Steels Austenitic. Grade 304 Austenitic. Grade 316

Heat Storage System Charging temperature at 280 ° C Discharging temperature at 160 ° C

Heat Storage System 0.2 m 𝑬 : Diameter of the tank; 0.2m 0.4 m 0.14 m 1.5 d o 𝒆 𝒑 : Outside diameter of the heat transfer tube; 0.015m H: Tank height; 0.5m O.D 0.015 m F: Coil height; 80% of the tank height; 0.4m C: Top height; C=(H-F)+0.1=0.5- 0.4+0.1=0.2m A: Coil gap; A=1.5 𝒆 𝒑 =0.022m r: Radius of the coil; 0.07m Heating power: Q=1.5kW Charging/ discharging time (approximately and ideally): 1.5 hour

Heat Storage System • • High temperature oil pump (Turbine Multifunction Data Acquisition pump) National Instruments USB-6225 STM Series, Low flow and high head; stainless steel 316L; capacity can up to 10 m 3 /h; head is up to 80 m Operating temperature: 300 ° C • High temperature heat exchanger • IC-LPM industrial paddle wheel Tube-in-tube heat exchanger (high series flow meter: temperature, high pressure and low flow) Flow range: 2-20 L/min Material: stainless steel 316L Operating temperature: 350 ° C Heat transfer rates to 29 kW Material: 304 stainless steel Liquid flows to 38 L/min Out/Display: IC-MV-AN analogue 4/20mA out put module Repeatability: 0.1% of reading Linearity: 0.5% FSD