Thermal Discharge Research Articles

A comparative evaluation on energy consumption of a building using bio-based and paraffin-based phase change materials integrated to external building envelope

Using thermal energy storage such as phase change materials (PCMs) is a suitable solution to reduce energy consumption in order to maintain thermal comfort conditions inside the building. There is a wide range of phase change materials according to their different characteristics such as melting temperature, freezing temperature, latent heat capacity, specific heat value of solid and liquid phase, thermal conductivity coefficient, and charge and discharge range, which makes it difficult to choose the right PCM. In this research, two common groups of phase change materials that are used commercially are studied and after performing a sensitivity analysis on them, a suitable temperature range is selected. Then the selected PCMs are placed in different parts of the external envelopes of the building and various parameters such as air conditioning system energy consumption, thermal comfort, heat balance, etc. are examined. It should be noted that in this study, the use of PCMs in buildings with cooling and heating systems is investigated. In order to carry out the simulation, a two-story office building located in Arak, Iran was modeled in Design Builder software along with all the details. The outputs show that if Bio PCM is used in the outer layer of the wall in the summer season, it is possible to save up to 154 w/m2 in the energy required for cooling the building. While the use of Bio PCM M91 Q21 material in the inner layer of the wall will reduce the load of the cooling system by 246.15 Wh/m2. Also, if RT PCM is used, it is possible to reduce the heat load by 80%. Furthermore, by analyzing the optimal cases, it can be concluded that increasing the thickness of the PCM layer cannot effectively improve the thermal performance of the building. On the contrary, their reduction in some cases leads to a reduction in energy demand in the building. Finally, in order to generalize the results, the optimal situation was compared with two similar climates of Arak city.

Investigation on the effect of physical parameters of PCMs on the exothermic properties of energy storage units of bilayer tubes

Based on the structure of bilayer tube energy storage unit (ESU), the study investigates the effects of physical parameters and arrangement combinations of phase change materials (PCMs) on the heat storage and exothermic performance of the ESU. The control variable method is used to focus on a single physical parameter of the phase change material to analyze its influence on the heat storage and exothermic performance. Use of experimental and numerical modelling, we firstly analyze the influence of the thermal conductivity of PCMs on the thermal storage and discharge performance, and then study the influence of the latent heat value of PCMs on the thermal storage and discharge performance, and compare and analyze its thermal performance parameters with those of traditional ESUs. Studies have shown that the thermal conductivity of the bilayer ESU can be minimized by up to 26.9% and the heat release time can be increased by up to 23.8% compared with the conventional ESU. The latent heat value of the bilayer ESU can be minimized by up to 28.1% and the heat release time can be increased by up to 35.3% as opposed to the conventional ESU. Obviously, the selection of PCMs must be considered for each parameter, and the selection of PCMs with appropriate parameters plays a crucial role for different energy storage conditions.

Computational modelling and experimental investigation of micro-electrochemical discharge machining by controlling the electrolyte temperature

Glass vias are emerging as a favourable option for radiofrequency-based micro-electromechanical system packaging. For the micromachining of glass, electrochemical discharge machining (ECDM) could be the most suitable technique if issues pertaining to the process stability are addressed thoroughly. The electrolyte temperature has immense influence on the viscosity and conductivity of the electrolyte, which percolate the stability of the ECDM process. Therefore, this article investigates the effects of the electrolyte temperature and applied voltage on the performance characteristics of ECDM for the micromachining of borosilicate glass. The machining rate (MR) and hole overcut (HOC) of the machined microholes are considered as performance characteristics. A 3D thermal-based finite element model (FEM) was developed for the thermal analysis in the machining zone. In the thermal analysis, the heat flux by thermal discharge was assumed to have Gaussian distribution, and accordingly, temperature profiles in the thermal zone were analyzed by controlling the electrolyte temperature and voltage at various levels. Further processing of temperature profiles in the thermal zone was utilized in the estimation of MR and HOC. Electrostatic-based FEM was utilized to assess the intensity of the electric field in the proximity of the tool electrode to analyze the probable locations of thermal discharge and its impact on the geometrical characteristics of the machined microholes. The simulation outcomes were validated experimentally, and show good agreement. A field emission electron microscope with energy dispersive spectroscopy was used for the characterization of the machined surface to observe the effect of the electrolyte temperature.

Mixing behavior equations created by a buoyant jet in wavy crossflow environments

The understanding of mixing behaviors of submerged effluent discharge in buoyant jet flows within coastal dynamic environments remains incomprehensive. This study explores the mixing behaviors of buoyant jets in wavy crossflow environments by utilizing dimensional analysis and an integral model. We examine physical mechanisms underlying the linear uplift of buoyant jets and establish three semi-empirical equations pertaining to the vertical location of the cross-sectional minimum dilution, cross-sectional minimum dilution, and visible diffusion area. These equations quantify the influence of waves and buoyancy on the mixing behaviors of buoyant effluent discharge in wavy crossflow environments. The dimensional analysis demonstrates that the proposed mixing behavior equations are closely related to the buoyant characteristic length scale. We validate the reliability of these equations with that of existing ones for non-buoyant jets in wavy crossflow environments. Furthermore, this study extends the application of buoyant jet equations, evaluating their suitability by comparing them with data from cases involving buoyant jets in wavy crossflow environments. This study highlights the positive effect of wave height and buoyancy on the initial dilution of effluent discharge. Future studies can implement our semi-empirical equations on the near and far zone coupling simulations of wastewater and thermal discharges.

Effects of air gap and compression on the dual performance of multilayer thermal protective clothing under low radiant heat

An air gap in thermal protective clothing (TPC) plays an important role in determining heat transfer, but it may also increase the amount of stored thermal energy that would discharge to the skin after exposure, especially when the TPC suffers compression. To investigate the effect of air gap and compression on the dual thermal protective performance (TPP), thermal hazardous performance (THP) and overall thermal protective performance (OTPP) of TPC, nine air gap configurations with different sizes and positions and five compression levels were designed in this study. Regression models were established to explore the relationships among air gap size, compression and THP for different air gap positions. The results demonstrate that increasing the air gap size without exceeding 12 mm not only significantly enhances the TPP by impeding heat transfer from the heat source to the fabric system during exposure but also decreases the THP by reducing heat discharge from the fabric system to the sensor even when compression is applied. Although an inner air gap contributes more to increasing the TPP during exposure than an outer air gap, it may also bring about severe stored energy discharge when compression is applied. It suggests that a larger air gap size should be divided into individually separate air gaps within different fabric layers to reduce the heat transfer during exposure as well as lower the stored thermal energy discharge after exposure.

Rapid detection of aflatoxin B1, zearalenone and ochratoxin A in grains by thermal desorption dielectric barrier discharge ionization mass spectrometry.

Dielectric barrier discharge ionization is increasingly used for rapid detection in ambient mass spectrometry, although more often for gaseous and highly volatile samples than for solids and liquids. In this project, we present a rapid and sensitive method for detecting mycotoxins and demonstrate its capability for the detection of aflatoxin B1, zearalenone, and ochratoxin A in food samples. Our method is based on thermal desorption coupled to dielectric barrier discharge ionization mass spectrometry (TD-DBDI-MS), which we show generates minimal interferences and produces almost exclusively molecular ions. We detected mycotoxins in various food samples, including corn, peanuts, millet, and rice. Our method has a linear dynamic range of 1 μg kg-1 to 100 μg kg-1 for all three mycotoxins and a limit of detection (LOD) of 0.31 μg kg-1, 0.28 μg kg-1 and 0.43 μg kg-1, respectively. It is simple, rapid, reduces the pretreatment steps and has significant potential for practical applications.

Enhancing Battery Thermal Management in Li-ion-Powered Electric Vehicles using Phase Change Material-based Systems: A Multi-Scale CFD Simulation Study

Electric cars (EVs) and hybrid electric vehicles (HEVs) are propelled by Li-ion batteries for a clean and sustainable future. Under harsh and abusive conditions, a battery pack generates a lot of heat, which could result in a disastrous thermal runaway. The current work suggests a Battery Thermal Management System (BTMS) based on Phase Change Material (PCM) to prevent thermal runaway. Using ANSYS's multi-scale, multi-dimensional Newman, Tiedemann, Gu, and Kim (NTGK) model, a 3D simulation of a single battery with PCM, is carried out. The thermal performance and discharge behavior of the battery pack is analyzed by the NTGK model. The solidification and melting model is combined with the NTGK for PCM-based BTMS. Under harsh and abusive circumstances, the effect of different discharge rates on the thermal performance of 26650 Li-ion cell with and without PCM is investigated. The PCM-based BTMS reduces the maximum battery temperature by 2.243 K ,1.44 K, and 2.5 K and increases temperature uniformity at 0.5C ,1C and 1.5C discharge rates, respectively. The data available from this research will be useful in the development of passive BTMS for EV applications.

Thermal energy storage with flexible discharge performance based on molten-salt thermocline and thermochemical energy storage

Thermocline sensible thermal energy storage has prospects in cost-effective thermal energy storage. In this study, we combined a molten-salt thermocline with thermochemical energy storage to improve the flexibility of thermal discharge performance. For the thermochemical energy storage material, a composite was synthesized using calcium hydroxide and silicon-impregnated silicon carbide foams with an energy capacity of 1.8 MJ (0.50 kWh) and volumetric energy density of 0.79 MJ L-material−1. The composite was loaded onto an indirect fixed-bed reactor that used molten salt as the heat transfer fluid. The temperature of the composite reached 637 °C at a hydration pressure of 812 kPa. The thermochemical energy storage reactor exhibited a variable maximum outlet temperature of the heat transfer fluid in the range 524–583 °C and maximum discharge power of up to 0.6 kW (discharge power density up to 0.25 kW L-material−1) on changing the hydration pressure and flow rate of the heat transfer fluid. The results confirm the significance of thermochemical energy storage to the system in boosting the temperature of the thermocline and variable discharge performance. The novel hybrid system has a superior discharge performance compared with that of the conventional thermocline thermal energy storage, and it is a promising option for flexible large-scale energy storage and power generation driven by renewable energy.

Plasma Analyzer for the Chinese FY-3E Satellite: In-Orbit Performance and Ground Calibration

The plasma analyzer (PMA) on the Fengyun-3E (FY-3E) meteorological satellite series is a critical sensor of the space environment monitoring package that is capable of the comprehensive in situ detection of the thermal plasma environment and surface discharge effects. In this paper, we conducted a thorough evaluation of the PMA’s performance and reliability through a combination of ground-based laboratory calibration and in-orbit testing. During the ground-based calibration, the PMA underwent assessments for the energy range, field of view (FOV), and measurement accuracy, and obtained the detection accuracy and the geometric factors. During the in-orbit testing, the PMA successfully obtained the typical distribution characteristics of low-energy ions and electrons in orbital space regions, as well as the precipitating particles in the middle and high latitudes of both hemispheres. Notably, the PMA observed an expansion of the particle distribution in the high-latitude regions during a moderate geomagnetic storm. The results from both the ground-based calibration and in-orbit testing demonstrated that the PMA met the requirements for thermal plasma detection, with reliable and scientifically valid in-orbit detection data. These results provide a crucial foundation for studying spatial weather variations, improving the accuracy of space environment forecasts and enhancing disaster detection and monitoring capabilities.

Comparative analysis of thermal and non-thermal discharge modes on ultra-lean mixtures in an optically accessible engine equipped with a corona ignition system

Radio-Frequency corona-based ignition systems are currently being investigated by the engine research community for their capability to ensure robust combustion at challenging operating conditions such as lean mixture and/or high exhaust gas recirculation (EGR) dilution. The low-temperature plasma (LTP) produced by the corona discharge accelerates the early flame development thanks to the production of combustion precursors like radical and excited species. Plasma benefits can be maintained with extensive management of the control parameters, preventing the transition from the non-thermal discharge mode to a thermal one.However, under ultra-lean conditions, where the ignition probability significantly decreases, the LTP discharge may not be suitable for promoting the combustion process because of insufficient thermal energy transfer and scarcity of available fuel, which is essential for radical production. Therefore, it may be necessary to increase the volume in which the plasma interacts to ensure robust ignitions and stable flame propagations. For this reason, the present work aims to assess and quantify the differences, in terms of combustion performance, between a corona igniter operating at LTP mode and with electric arcs occurring, at ultra-lean operating conditions. In arc-mode, the igniter produces volumetric discharges, facilitating extensive mixing of the mixture and resulting in advantageous effects on kernel formation and propagation. Tests were carried out in a single-cylinder optical access engine under low load and low speed, using gasoline as fuel. Close to the leanest stable limit found, the LTP mode shows a lower cycle-to-cycle variability. Above such a threshold, the thermal discharge can guarantee stable combustion events while the LTP discharge leads to unstable working conditions. Indicating, imaging, and pollutant emission analysis are carried out to evaluate the effects of thermal and non-thermal plasma modes on combustion characteristics and their environmental impact.

Spatial and temporal distribution of fish egg communities in the adjacent waters of Daya Bay nuclear power plant and their relationship with environmental factors

The thermal discharge of Daya Bay Nuclear Power Plant has a certain impact on the ecological environment of the adjacent waters. In order to understand and evaluate changes in the fish egg community structure in the adjacent waters of Daya Bay Nuclear Power Plant and their relationship with environmental factors, four surveys were conducted to investigate fish eggs in January (winter), March (spring), August (summer) and November (autumn) of 2020. A total of 100,985 fish eggs were collected and 17 taxa were identified, belonging to five orders, 14 families and 17 genera. Among them, Perciformes and Clupeiformes were the main contributing taxa to fish egg species and abundance in the waters adjacent to Daya Bay Nuclear Power Plant. The number of fish egg species ranged from high to low was summer, spring, autumn and winter; the average abundance ranged from high to low was spring, summer, winter and autumn. The results showed that except in winter, the average abundance of fish eggs was greater in northeast area than in southwest area. The Shannon-Weiner species diversity index (H’), Pielou evenness index (J’) and Margalef richness index (d) were significantly different between seasons, but none were significantly different between areas. The results of NMDS analysis showed that there were significant differences in fish egg communities between seasons. Surface seawater temperature the average abundance of fish eggs was positively correlated in the results of all four seasons. Although the entrainment effect of nuclear power plant water intake and thermal pollution of partial waters owing to thermal discharge can cause some loss of fish eggs, fish resources can still be effectively maintained.

Mass spectrometry analysis of drugs using an integrated thermal desorption corona discharge ionization device

In this study, we introduce the design, characterization, and application of an integrated thermal desorption corona discharge ionization (TD-CDI) device, which was developed for direct mass spectrometry (MS) analysis of drugs in solid or liquid samples. The structure and operational parameters of the TD module were optimized through simulation and experimental investigations. For the CDI module, a hollow needle was used as the discharge electrode and sample inlet, allowing self-aspiration and efficient ionization of the desorbed samples. The TD-CDI device was tested and characterized using different mass spectrometers, exhibiting satisfactory stability and quantitative performance. Owing to its compact structure, it can be coupled to a miniature MS instrument to implement rapid identification of various drugs in urine solutions.

Numerical Simulation Calculation of Thermal Discharge Water Diffusion in Coastal Nuclear Power Plants

Coastal areas have become the primary location for nuclear power plant sites due to the convenience of seawater cooling. In China, the diffusion range of thermal discharge water has always been a hot research topic as the basis for sea use areas. The main physical process of heat loss in the numerical simulation of thermal discharge from power plants is heat exchange between the water surface and air. Currently, the methods for calculating this heat loss include the heat flux method and the water surface heat exchange coefficient method. Taking a power plant in Zhejiang as the research object, the MIKE 3 temperature–salinity module (heat flux method) and MIKE ECO Model (water surface heat exchange coefficient method) were used for modeling, and the diffusion of thermal discharge water under different modules was compared and analyzed. The results show that the calculated area of the water temperature rise envelope between the two modules differed significantly under the same conditions. The surface 4 °C temperature rise area, as calculated using ECO Model, was 45.8% smaller than that of the temperature–salinity module. The MIKE 3 temperature–salinity module can simulate the heat accumulation of water under thermal buoyancy, producing a significant thermal stratification phenomenon; the ECO module does not accurately represent the heat exchange process between the water surface and the air, and it does not adequately capture the significant vertical stratification that occurs in real-world scenarios. On this basis, this study not only lays a foundation for further exploring the impact of thermal discharge water from this powerhouse on the structure of surrounding marine biological communities and dissolved oxygen content in water bodies but also provides scientific evidence for the selection of modules when simulating thermal discharge water with the MIKE model.

Study of Lithium-Silicon Anode Materials for Thermal Batteries

Thermal batteries are constructed from a molten salt electrolyte which is solid at room temperature, a FeS2 positive electrode and a lithium-silicon negative electrode. The typical operating temperature of the battery is between 350 to 500°C. Thermal batteries use an inorganic salt as the electrolyte such as binary or ternary alkali halide eutectics. For example, LiCl-KCl and LiF-LiCl-LiBr. At a composition of 44.8 LiCl and 55.2 KCl wt%, the melting point is around 353°C for LiCl-KCl. Molten salts have a very high electrical conductivity, so thermal batteries have a higher power density than room temperature batteries. In this work, LiCl-KCl eutectic was used for electrochemical testing. The performance of an electrode can be studied in single-cell discharge tests where a discharge profile is obtained. The tests were carried out in a cell testing rig inside an argon glovebox. The cells were made from pellets which were placed in a Swagelok casing. The cells were made from 0.15g of FeS2 mixed with 0.05g LiCl-KCl as the positive electrode, 0.2g of LiCl-KCl with 35% wt MgO as the electrolyte and 0.2g of Li13Si4 as the negative electrode. Lithium silicides were made using solid state synthesis in a tube furnace. The electrochemical tests show that the Li13Si4 is a better negative electrode material than Li7Si3 (Figure 1). In addition, powder neutron diffraction was used to probe the lithium silicides with increasing temperature. The high-temperature behaviour of Li13Si4 and Li7Si3 was studied in March 2020 by the JTSI group at the ISIS neutron source, Rutherford Appleton Laboratory, UK. The data gives information on structural changes in Li13Si4 and Li7Si3. The results indicate that Li13Si4 and Li7Si3 remain remarkably stable at 500°C. There are no phase transitions in the materials from room temperature to 500°C and the materials remain crystalline. These findings give a clearer understanding of thermal battery discharge processes. Figure 1

Data-Driven Integrated Decision Model for Analysing Energetic Behaviour of Innovative Construction Materials Capable of Hybrid Energy Storage

Aligning the European Union goals for climate neutrality by 2050 and the ambition for carbon equivalent emissions reduction to almost half by 2030 demands the exploration of alternative decarbonisation pathways. Energy consumption across all sectors is identified as a crucial contributor to this challenge, with a number of legislative and regulatory frameworks and commitments to be introduced every year. In response to these trends, the concept of exploiting a building’s thermal mass through the integration of phase change materials (PCMs) enhances the ability of building elements to reserve and deliver large amounts of energy during phase transitions. However, the incorporation of PCMs into building elements requires the thorough understanding of their thermal behaviour. This study evaluates and predicts the thermophysical properties of mineral particles carrying PCMs and coated with a cementitious layer able to be utilised as fillers in construction applications. By employing deep learning and predictive modelling techniques, the numerical data-driven model developed in this paper enhances accuracy and efficiency in property estimation and prediction, facilitating material selection, system design, and optimisation. A model in a MATLAB simulation environment is presented, evaluating and predicting the thermophysical properties of semi-organic particles able to enhance building envelope thermal mass as a hybrid energy storage solution. These findings show the time needed for a building block to undergo cooling, demonstrating a clear upgrade in the thermal discharge of the walls. Substituting traditional EP with PCM-enhanced EP leads to a minimum reduction of 1 °C per hour in the discharge rate, thereby extending the comfort duration of indoor spaces without necessitating additional space heating. These models offer the potential for assessing diverse material compositions and usage scenarios, offering valuable insights to aid decisions in optimizing building energy efficiency.

Analysis of the Plasma Discharge Phenomena for Ceramic Metal Halide Lamps Using Finite Element Method

Metal halide (MH) lamps comes under the category of high intensity discharge (HID) lamps, which involves high intensity thermal plasma discharge phenomenon. In this paper we have considered ceramic MH lamps. The plasma discharge in MH lamps is different from other plasma discharge by the velocity of all the discharge obeys Maxwellian distribution, the excited energy states are occupied by Boltzmann distribution, and composition of the plasma can be derived from local chemical equilibrium. This paper explores the temperature distribution and the immediate effects towards the life of MH lamp. The temperature profile for the MH lamp is numerically investigated using WELSIM 2.0, considering the lamp plasma model mathematical equations. Since electrode plays a significant role, influencing MH lamp life, it becomes imperative to understand the electrodes. In this context, the energy balance equation is taken into consideration. The equations are solved using finite element method. The necessary boundary condition for solution of the equation is the plasma boundary layer for the cathode heat conduction. The analysis provides the temperature distribution inside the lamp for different electrode geometry. The solutions to the equations have been pictorially investigated for the lamp starting phenomena and E/N ratio. For HID lamps in general, the improvements in HID technology are all linked to the performance of the arc tube, and within that tube, the chemical reaction, the pressure, and the temperature of the reaction. Another feature in the case of MH lamps that is worth mentioning in the determination of lamp life is the ratio between electric field to gas number density. From the above, we can draw the following conclusion that the radiation transport mechanism of the HID lamps plays a pivotal role apart from other parameters influencing the lifetime of HID lamps. The paper envisages all these aspects using PDEs, the solutions of which provide an insightful understanding of the phenomena substantially.

The impact of thermal aging on the degradation of technical parameter of a dynamic latent thermal storage system

A dynamic latent thermal storage (DLTS) system operates at elevated working temperatures to maximize the operation of the thermal system. It potentially deteriorates the phase change material (PCM) after specific cycles due to thermal aging. The present work assesses the impact of thermal aging of wax-based PCM (paraffin and beeswax) toward the technical parameter of a DLTS system. After thermal aging treatment, the charge and discharge performance for both PCM are degraded. The discharge rate of beeswax (BW) decreases by 23.2%, reducing the effective power rate and storage efficiency by more than 50%. The aged paraffin wax (PW) also experiences performance degradation, where the discharge and power rates decrease around 14.7% and 18.7%, respectively. However, the aged PW maintains sufficient efficiency (67.2%) compared to BW (41.1%), implying that the aging effect can vary for different PCM. Surface observation for the aged PCM demonstrates a fracture profile and microvoids which are probably affected by thermal stress that leads to physical deformation at the molecular level. The decomposition curve is also changed for the aged PCM, making thermal stability an important parameter in choosing a suitable PCM for long-term operation. The study demonstrates the urgency to consider suitable PCM and adjustment on the operation protocol of the DLTS system after a certain cycle operation to minimize the degradation of performance parameters of the thermal system.

Partial Oxidation Synthesis of Prussian Blue Analogues for Thermo-Rechargeable Battery

A thermo-rechargeable battery or tertiary battery converts thermal energy into electric energy via an electrochemical Seebeck coefficient. The manufacturing of the tertiary batteries requires a pre-oxidation step to align and optimize the cathode and anode potentials. The pre-oxidation step, which is not part of the secondary battery manufacturing process, makes the manufacturing of tertiary batteries complex and costly. To omit the pre-oxidation step, we used partially oxidized Prussian blue analogs, i.e., NaxCo[Fe(CN)6]yzH2O (Co-PBA) and NaxNi[Fe(CN)6]yzH2O (Ni-PBA), as cathode and anode materials. The modified tertiary battery without the pre-oxidation step shows good thermal cyclability between 10 ∘C and 50 ∘C without detectable deterioration of the thermal voltage (Vcell) and discharge capacity (Qcell).

Assessment of thermal water and energy recoverable rate based on express method: A case study of Reshuiwei geothermal field

Assessment of geothermal resources is the vital and difficult work during geothermal resources utilization. The aims of this study are to: (1) estimate the natural thermal water discharge and the mass flow rates of recoverable thermal water in boreholes by using “express method”. (2) evaluate the geothermal water and energy resources through estimating the convective heat and mass discharge/deep recharge of this geothermal field based on the calculation results. Results show that this geothermal field should be divided into three sections to calculate hot water resources: Reshuiwei section, Miaowan section and Dongqingshu downward section. Main controlling fault zones are F3, F6 and F7 fault zones, respectively. The total reached mass flow rates of recoverable thermal water are 49.32 kg/s. Reshuiwei section is a suitable area for underground hot water comprehensive utilization. The reached recoverable heat rates are 15.031 MW. In addition, the reservoir temperature potential of Reshuiwei geothermal field would be about 182.95 °C, the conceptual model of this geothermal field formation is summarized. Conclusions drawn from this study would provide reference for geothermal resources assessment of all geothermal fields.

Long-term observation of global nuclear power plants thermal plumes using Landsat images and deep learning

Thermal discharge from nuclear power plants poses a threat to the received natural water bodies, but the long-term extent and intensity of their surface thermal plumes remain unclear. In this study, we proposed a method to determine the background area for each drainage outlet and delineate the mixed surface thermal plumes based on 7,172 Landsat thermal infrared images. We further used a deep convolutional neural network integrated with prior location knowledge to extract core surface thermal plumes for 74 drainage outlets of 66 nuclear power plants worldwide. Our final model achieved a mean Intersection over Union (mIoU) of 0.8998 and an F1 score of 0.8886. We found that the mean maximal water surface temperature (WST) increment of the studied plants globally was 4.80 K. The Tianwan plant in China experienced the highest WST increase (8.51 K), followed by the Gravelines plant in France and the Ohi plant in Japan (7.91 K and 7.71 K, respectively). The Bruce plant in Canada had the largest thermal-polluted surface area (7.22 km2). We also provided the dataset, Global Coastal Nuclear power plant Thermal Plume (GCNT-Plume), to describe the long-term occurrence of water surface thermal plumes. Three influencing factors of the water surface thermal plume were further analyzed in this study, including total capacity, drainage type, and location type, which were associated with operating power, drainage method, and geographical features, respectively. Total capacity was more statistically related to the maximum of WST increment under shallow drainage condition. The mean WST increment of shallow drainage was 1.22 K higher than that of deep drainage. Surface plumes larger than 4 km2 frequently occurred in the Great Lakes, while small surface thermal plumes (< 1 km2) were primarily found in estuaries. The proposed method provides an important framework for future operational water surface thermal plume detection using remotely sensed observations and deep learning.