Current Projects
Project Title: | Design and Development of Robust and Effective Battery Thermal Management Systems (BTMS) for Electric Vehicles (EVs) |
Principal Investigator: | Dr Mohd Kaleem Khan (PI)/Dr Manabendra Pathak(co-PI) |
Sponsoring Agency: | CRG, Science and Engineering Research Board, DST, Govt. of India |
Project Amount: | Rs. 63.36 lakhs |
Project Summary: |
Electric Vehicles (EVs) are currently the best alternatives to conventional vehicles to reduce greenhouse gas emissions when they run on the decarbonized grid. Li-ion batteries are predominantly used as power sources in EVs due to their higher energy density and low self-discharge rate. As Li-ion battery generates heat during charging and discharging, this heat needs to dissipate effectively to avoid a catastrophic thermal runaway where a chain of exothermic chemical reactions leads to fire or explosion. Batteries must be maintained at 20-50 °C, and temperature uniformity within the pack should be less than 5°C for optimal performance. A robust and efficient thermal management system for battery cooling is essential. The prominent cooling techniques utilized in the present EVs in the market majorly involve air and indirect liquid cooling. In forced air cooling, the ram air of a moving EV cools the battery. However, forced air cooling fails one or the combination of the following conditions are met: (a) during peak summers, (b) vehicle stuck in a traffic jam, and (c) aggressive drive cycle. Such a scenario might lead to a thermal runaway. In this project, an effective and robust battery thermal management system will be designed, fabricated, and tested.
Project Title:
Porous membrane based vapour venting technique for performance improvement in microchannel heat sink
Principal Investigator:
Dr Manabendra Pathak (PI)/Dr Mohd Kaleem Khan (co-PI)
Sponsoring Agency:
CRG, Science and Engineering Research Board, DST, Govt. of India
Project Amount:
Rs. 32.83 lakhs
Project Summary:
Phase change heat transfer in the microchannel is fundamentally essential for various thermal
management and energy conversion processes. Especially for thermal management of high power
density electronic devices where heat dissipation requirement has reached more than 1000 W/cm².
Flow boiling in microchannels is one of the best possible solutions for dissipating a large amount of
heat from a small space. However, heat dissipation through flow boiling in the microchannel is afflicted
by boiling instabilities due to explosive vapour growth in the channel, hindering the implementation of
microchannels as a heat sink for electronic devices. Flow boiling instabilities reduce the heat transfer
rate and critical heat flux limit of microchannel heat sinks. Although modification of channel geometry
has appeared as one of the prominent technique for mitigating flow boiling instabilities, it cannot
reduce the instabilities due to upstream compressible volume formed in the microchannel. Upstream
compressible volume forms due to periodic dryout and rewetting of the channels at very high heat flux
which significantly contributes for boiling instabilities deteriorating the heat transfer performance in
the microchannel heat sinks. In this proposal, a nanoporous membrane based vapour venting technique
would be introduced to curb the formation of upstream compressible volume for mitigating flow boiling
instabilities and enhance the heat transfer rate in a geometrically modified microchannel heat sink. A
hydrophobic nanoporous membranes would be introduced in the channel to repel the water and attract
the vapour phase. The separated vapour phase would be withdrawn through different passage from the
channel which would completely eliminate the compressible volume formation and reduce the boiling
instabilities. Further the nanoporous membrane would enable the formation of small bubbles with high
releasing frequency which would effectively address the boiling crisis at high heat flux, thus by
increasing the critical heat flux. The effects of different parameters of the porous membrane i.e.
hydrophobicity, pore size, permeability, physical dimensions and thermo-mechanical properties on the
vapour venting process and their consequence on the heat transfer performance of the microchannels
would be investigated in the proposal. A detailed understanding on the influence of the capillary
pressure on reducing the accelerated two-phase pressure drop at very high heat flux would be
explored. An effort would be also made to correlate the spatially varying temperature and pressure
fluctuations with capillary effects on nanoporous membrane. The proposal would provide a new
nanostructuring approach combined with geometric modification for mitigating flow boiling instabilities
and enhancing heat transfer coefficient and critical heat flux limit of the microchannel heat sinks.
Project Title:
Effect of burnup on ballooning and burst behavior of Zircaloy-4 cladding tubes under simulated LOCA
Principal Investigator:
Dr Mohd Kaleem Khan (PI) / Dr Manabendra Pathak (co-PI)
Sponsoring Agency:
Board of Research in Nuclear Sciences, DAE, Govt. of India
Project Amount:
Rs. 32.991 lakhs
Project Summary:
In the previous DAE projects undertaken at IIT Patna, the burst investigations were carried out on as-received and pre-hydrided Zircaloy-4 fuel claddings employed in Indian PHWR.
In the ongoing project, the burst experiments on the pre-oxidized fuel claddings have been carried out in the steam environment, a more realistic LOCA scenario.
Zircaloy-4 cladding tube are initially oxidized on its outer and inner surfaces to mimic extended burnup condition. The burst investigations are then performed on these pre-oxidized fuel claddings in the steam environment.
During normal reactor operation, the outer surface of cladding tube gets oxidized as it is exposed to coolant (water) while inner surface oxidation occurs due to the moisture present the fuel.
With the onset of LOCA sequence, the loss of coolant leads to steam generation with temperature and pressure inside cladding tube starts rising. The clad tube balloons and finally bursts.
Studies show that the effect of radiation induced defects gets annealed out at 600 ºC and ductility is restored back. So burnup effect on the ballooning and burst behaviour of the PHWR fuel cladding boils down to the effect of oxide layer and
the hydrogen picked up during service only.
Related Publications:
S.Sagar, M.K. Khan, M. Pathak, S. Banerjee, T. Sawarn, S.K. Yadav, and R.N. Singh, 2024, Zircaloy-4 fuel pin failure under simulated loss-of-coolant-accident conditions: Creep and rupture, Nuclear Engineering and Design, Vol. 428, p.113507. Click Here
Completed Projects
Project Title: | A self-adaptive electronic cooling system by enhanced pool boiling |
Principal Investigator: | Dr Manabendra Pathak (PI) / Dr Mohd Kaleem Khan (co-PI) |
Sponsoring Agency: | Science and Engineering Research Board, DST, Govt. of India |
Project Amount: | Rs. 35 Lacs (approx) |
Project Summary: |
The project mainly focuses on the development of a self-adaptive cooling system based on a closed-loop two-phase thermosyphon (CLTPT) with enhanced heat transfer in the evaporator and the condenser. The first part of the report explains heat transfer enhancement with structured surfaces, and the second part presents the temperature-controlled self-adaptive thermosyphon loop. A closed-loop two-phase thermosyphon (CLTPT) is a gravity-assisted heat dissipation device that works on the principle of evaporation and condensation to facilitate large amounts of heat transfer without any pumping device. An efficient heat transfer mechanism should act in the evaporator and the condenser to produce a sufficient buoyancy effect in the loop. In the first part of the work, an effort is being made to enhance the heat transfer in the evaporator section with a structured heating surface. A novel structured heating surface i.e. segmented finned microchannels has been used to enhance the heat transfer rate and its performance has been compared with that of plain heating surface. Compared to the plain heating surface, the segmented finned structured heating surface produces an enhancement of 157% in heat transfer coefficient whereas it produces 145% enhancement in the critical heat flux (CHF). The present structured surface also produces better heat transfer performance compared to similar works reported in the literature.
For heat transfer enhancement in the condenser a feedback control mechanism is introduced to produce an adaptive cooling in the condenser according to the temperature rise in the evaporator.
Compared to the ordinary CLTPT system, the CLTPT with feedback control mechanism produces a 68% enhancement in the heat transfer rate whereas it produces 12.5% enhancement in the critical heat flux (CHF) value.
Enhanced cooling in the condenser and higher pressure difference across the loop helps in better heat transfer performance in the modified loop compared to the ordinary loop.
Further better bubble dynamics, crossflow effects of coolant liquid, and better rewetting of the heating surface in the evaporator improve the heat transfer coefficient and CHF value in the modified CLTPT system.
Thus, in the present work an efficient closed-loop two-phase thermosyphon system has been developed that can provide adaptive cooling based on the temperature of the substrate.
Project Title: | Influence of Hydrogen Content on Burst Characteristics of Zircaloy-4 Cladding |
Principal Investigator: | Dr Mohd Kaleem Khan (PI) / Dr Manabendra Pathak (co-PI) |
Sponsoring Agency: | Board of Research in Nuclear Sciences, DAE, Govt. of India |
Project Amount: | Rs. 31.18 Lacs |
Project Summary: |
Zirconium alloys are widely used in nuclear power reactors as structural materials. Zircaloy, an alloy of
zirconium–tin, is extensively used as the nuclear fuel cladding material in water-cooled nuclear
power reactors due to its low thermal neutron absorption cross section, resistance to corrosion in high temperature and pressure conditions,
and high mechanical strength. Zircaloy-4 is used as the nuclear fuel cladding material in
the Indian Pressurised Heavy Water Reactors (IPHWRs). Although Zircaloy-4 nuclear fuel cladding has
shown satisfactory behaviour in service, its degradation due to waterside corrosion can limit the in-reactor
design life. The critical phenomenon is the precipitation of brittle hydride phase due to pickup of
a fraction of hydrogen produced during waterside corrosion. The degradation of mechanical properties
due to the presence of hydrides alters the creep performance, crack behaviour, and fracture procedure—
each phenomenon being crucial during the lifespan of the cladding. The present research work is carried
out to determine the effects of hydrogen/hydride in Zircaloy-4 fuel cladding tubes on (a) creep during
normal operation, (b) burst behaviour during the first phase of LOCA transient, and (c) crack instability
during spent fuel storage using both experimental and numerical techniques.
Related Publications: |
S. Suman, M.K. Khan, M. Pathak and R.N. Singh, 2018, Effects of hydrogen on thermal creep behaviour of Zircaloy fuel cladding, Journal of Nuclear Materials, vol.498, pp.20-32. Click Here
S. Suman, M.K. Khan, M. Pathak and R.N. Singh, 2018, Effects of delta-hydride precipitated at a crack tip on crack instability in Zircaloy-4, International Journal of Energy Research, vol.42, pp. 284-292. Click Here
S. Suman, M.K. Khan, M. Pathak and R.N. Singh, 2017, Investigation of elevated-temperature mechanical properties of delta-hydride precipitate in zircaloy-4 fuel cladding tubes using nanoindentation, Journal of Alloys and Compounds, vol.726, pp. 107-113. Click Here
S. Suman, M.K. Khan, M. Pathak and R.N. Singh, 2017, 3D simulation of hydride-assisted crack propagation in zircaloy-4 using XFEM, International Journal of Hydrogen Energy, vol. 42, pp.18668-18673. Click Here
S. Suman, M.K. Khan, M. Pathak and R.N. Singh, 2017, Effects of hydride on crack propagation in zircaloy-4, Procedia Engineering, vol. 173, pp. 1185-1190. Click Here
S. Suman, M.K. Khan, M. Pathak and R.N. Singh, 2016, Rupture behaviour of nuclear fuel cladding during loss-of-coolant accident, Nuclear Engineering and Design, vol. 307, pp. 319-327. Click Here
S.Suman, M.K. Khan, M.Pathak and R.N. Singh, J.K. Chakravartty, 2015, Hydrogen in Zircaloy: Mechanism and its Impacts, International Journal of Hydrogen Energy, Vol.40(17), pp.5976-5994. Click Here
Project Title:
Evaluation of Burst Criterion of Zircaloy Clad
Principal Investigator:
Dr Mohd Kaleem Khan (PI)
Sponsoring Agency:
Atomic Energy Regulatory Board, DAE, Govt. of India
Project Amount:
Rs. 25.45 Lacs (approx)
Project Summary:
The research work was undertaken with an objective to develop the burst criterion for zircaloy- clad tubes used in Indian pressurized heavy water reactors (PHWRs) in an outside inert environment. To serve this objective, an indigenous experimental clad burst facility was developed at IIT Patna. The clad specimens were heated at different heating rates (17 to 81 K/s) and at different internal overpressures (20, 40, 60 and 80 bar) until they burst. A total of 36 tubes were tested for burst for different combinations of heating rate and internal overpressure. The temperature, pressure and wall displacement were measured online. The offline measurements were also conducted on the burst specimen to determine the burst parameters like circumference and thickness at the burst location. These parameters were then used to determine the burst stress and burst strains.
The results of the burst criterion have been validated with the present and past data. It is worth mentioning that the proposed burst criterion model has also taken into account the effect of pressure rise during the heating of clad specimen. It has been found that the inclusion of rate of pressure-rise has a remarkable effect on the predicted burst parameters and has resulted in a better agreement with the experimental data.
Related Publications: |
M.K. Khan and M. Pathak 2014, Ballooning deformation of Zircaloy-4 fuel sheath, ASME Journal of Pressure Vessel Technology, vol. 136, pp. 031206-1-12. Click Here
Khan, M.K., Pathak, M., Suman, S., Deo, A., Singh, R., 2014, Burst Investigation on Zircaloy-4 Claddings in Inert Environment, Annals of Nuclear Energy, Volume 69, pp.292-300. Click Here
Khan, M.K., Pathak, M., Deo, A., Singh, R., 2013, Burst Criterion for zircaloy-4 cladding in an inert environment, Nuclear Engineering and Design, Vol. 265, pp. 886-894. Click Here
Alam,T., Khan,M.K., Pathak,M., Ravi,K., Singh, R. and Gupta,S.K., 2011. A Review on the Clad Failure Studies, Nuclear Engineering and Design, 241(9), pp. 3658-3677. Click Here