Dynamic Thermal Model Research Articles

Energy-efficient personalized thermal comfort control in office buildings based on multi-agent deep reinforcement learning

In a shared office space, the percentage of occupants with satisfied thermal comfort is typically low. The main reason is that heating, ventilation, and air conditioning (HVAC) systems cannot provide individual thermal environment for each occupant within the shared office space. Although personal comfort systems (PCSs) can be adopted to implement heterogeneous thermal environments, they have limited adjustment abilities. At this time, coordinating the operations of PCSs and an HVAC system is a good choice. In this paper, the coordination control problem of PCSs and an HVAC system in a shared office space is investigated to minimize the total energy consumption while maintaining comfortable individual thermal environment for each occupant. Specifically, we first formulate an expected energy consumption minimization problem related to PCSs and an HVAC system. Due to the existence of an inexplicit building thermal dynamics model and uncertain parameters, it is challenging to solve the problem. To overcome the challenge, we reformulate the problem as a Markov game with heterogeneous agents. To promote an efficient cooperation of such agents, we propose a real-time control algorithm based on attention-based multi-agent deep reinforcement learning, which does not require an explicit building thermal dynamics model and any prior knowledge of uncertain parameters. Simulation results based on real-world traces show that the proposed algorithm can reduce energy consumption by 0.7%–4.18% and reduce average thermal comfort deviation by 64.13%–72.08% simultaneously compared with baselines. • A Markov game for coordinating personal comfort systems and HVAC is formulated. • A multi-agent deep reinforcement learning based control method is proposed. • Real-world traces are used to verify the effectiveness of the proposed method.

Efficacy of 2-Hydroxyflavanone in Rodent Models of Pain and Inflammation: Involvement of Opioidergic and GABAergic Anti-Nociceptive Mechanisms.

The current work examined the pharmacological potential of a selected flavanone derivative 2-hydroxyflavanone as a promising remedy for the treatment and management of pain. The selected flavanone derivative (2-HF) was evaluated for its analgesic and anti-inflammatory potentials following standard pharmacological protocols including hot plate, acetic acid-induced writhing and tail immersion tests. Naloxone and pentylenetetrazol were used to evaluate the potential implication of GABAergic and opioidergic mechanisms. The anti-inflammatory potential of 2-HF was confirmed using carrageenan-, serotonin- and histamine-induced paw edema models as well as a xylene-induced ear edema model. Furthermore, the anti-neuropathic potential of 2-HF was tested using a cisplatin-induced neuropathic pain model. Our sample, at the tested concentrations of 15, 30 and 45 mg kg−1, showed considerable analgesic, anti-inflammatory effects, as well as efficacy against neuropathic pain. Naloxone and pentylenetetrazol at 1 and 15 mg kg−1 antagonized the anti-nociceptive activities of 2-hydroxyflavanone indicating the involvement of opioidergic and GABAergic mechanisms. In the static allodynia model, combination of gabapentin 75 mg kg−1 with 2-HF at 15, 30, 45 mg kg−1 doses exhibited considerable efficacy. In cold allodynia, 2-hydroxyflavanone, at doses of 15, 30 and 45 mg kg−1 and in combination with gabapentin (75 mg kg−1), demonstrated prominent anti-allodynic effects. The paw withdrawal latency was considerably increased in gabapentin + cisplatin treated groups. Moreover, cisplatin + 2-hydroxyflavanone 15, 30, 45 mg kg−1 showed increases in paw withdrawal latency. Likewise, considerable efficacy was observed for 2-hydroxyflavanone in thermal hyperalgesia and dynamic allodynia models. Our findings suggest that 2-hydroxyflavanone is a potential remedy for pain syndrome, possibly mediated through opioidergic and GABAergic mechanisms.

Compensation of Thermally Induced Errors in Five-Axis Computer Numerical Control Machining Centers Equipped With Different Spindles

Abstract Thermally induced errors are the dominant source of inaccuracy in machine tools today and are often the most difficult type of error to reduce. Software compensation of thermally induced displacements at the tool center point (TCP) is a widely employed error reduction technique due to its cost-effectiveness and ease of implementation. Transfer function (TF)-based compensation methods lead to promising results, as has been shown in previous studies. Furthermore, machine tool manufacturers frequently offer the same type of machine tool equipped with different spindle units. This leads to different thermal deformation behavior depending on the specific spindle unit mounted in the machine tool. To demonstrate this difference, experimental research is carried out on three five-axis computer numerical control (CNC) machining centers of the same type equipped with three different spindle units. The experimentally obtained thermal errors at the TCP of three machine tools with different mounted spindle units are compared, showing a significant variation in thermal errors in the Z-direction depending on the spindle unit. The research presented in this paper shows a dynamic approach to thermal error compensation of five-axis CNC machining centers considering different spindle units. System identification theory is applied to build dynamic thermal error models for three different spindle units based on calibration experiments. Subsequently, the evaluation of model performance through spindle spectrum tests shows that a reduction in thermal error of up to 85% was achieved in the Z-direction after compensation.

Dynamic Modeling of Alkaline Electrolyzer Based on Matlab Simulink Approach

Renewable energy as a backup energy source is becoming increasingly significant due to the world's environmental and ecological concerns. One of the most useful renewable energy methods used today is the production of hydrogen through electrolysis. When paired with solar-PV or wind energy, hydrogen produced by water electrolysis has the potential to play a key role as an energy carrier for future sustainable development. The inability to describe the internal operation of the process coupled with the flexibility issue is the main limitation of black box modelling. In this paper, an alkaline water electrolysis process was modelled dynamically. A stacked electrolyzer with each stack consisting of 21 series-connected steel cells and an electrolyte made of 30 wt% potassium hydroxide was employed. A dynamic thermal model for an advanced alkaline electrolyzer has been constructed based on basic thermodynamic and electrochemical reaction equations. The Matlab Simulink Model has this information. This approach provides more insight into the model dynamics and simulation based on the thermal and electrical approaches.

Considering transient UTCI and thermal discomfort footprint simultaneously to develop dynamic thermal comfort models for pedestrians in a hot-and-humid climate

A well-being and sustainable urban environment consist of a series of pedestrian walkways for either commuting, exercising, or leisure use. The environmental thermal condition, which affects a person's thermal comfort, of the linear walking paths will inherently influence people's usage probability. The outdoor thermal environment and the human physiological response are both important determinants of thermal comfort during the dynamic process of walking. The traditional assessment of thermal comfort is based on the heat balance of the human body with steady environmental conditions that are rarely true in the constantly changing outdoor environments due to the context of urban morphology. In this research, we propose a novel method by integrating the traditional static thermal comfort index with the dynamic thermal comfort footprint and taking the spatiotemporal variations of thermal comfort conditions during the walking activity into consideration to develop dynamic thermal comfort prediction models for pedestrians. On-site thermal walking experiments with both subjective thermal questionnaires and objective physical thermal condition measurements were conducted on a university campus in different seasons to help establish the models. The proposed models were afterward validated against the measured values and showed that they can predict the dynamic thermal comfort of the pedestrians with satisfactory accuracy. With the proposed model, one could assess the dynamic thermal comfort conditions of a particular walk path with the Universal Thermal Climate Index (UTCI) and help to seek strategies in designing a thermally acceptable pedestrian walkway.

Study of ultra-light modular phase change cooling clothing based on dynamic human thermal comfort modeling

Phase Change Cooling Clothing (PCCC) is a promising wearable device, which can reduce thermal discomfort and health risks associated with high ambient temperatures. However, most of the existing PCCC are developed for special types of work, with long cooling time but heavy weight, which are not suitable for daily life and work. Therefore, this study proposes a novel ultra-light modular phase-change cooling clothing for short-term thermal discomfort in daily life and work. Firstly, based on heat balance theory, the heat transfer process of people wearing PCCC is modeled, and a calculation method for the minimum charge of phase change material (PCM) is proposed. The weight of the PCCC is only 1390g for keeping thermal comfort over 30 min. Then, the modular structure is proposed to make the PCM solidification more convenient and the optimal arrangement of the PCM modules is determined. Finally, the thermal comfort before and after wearing the PCCC in different scenarios were tested. The cooling effects are significant and the average skin temperature of the subjects decreases by 1.35, 1.10 and 1.78 °C respectively after wearing the PCCC under three conditions of outdoor walking, indoor sitting and indoor walking. The proposed PCCC has the advantages of light weight, proper structure and good effect, which is suitable for people's daily life and work.

Trigger-Based K-Band Microwave Ranging System Thermal Control with Model-Free Learning Process

Micron-level accuracy K-band microwave ranging in space relies on the stability of the payload thermal control on-board; however, large quantities of thermal sensors and heating devices around the deployed instruments consume the precious inner communication resources of the central computer. Another problem arises, which is that the payload thermal protection environment can deteriorate gradually through years operating. In this paper, a new trigger-based thermal system controller design is proposed, with consideration of spaceborne communication burden reduction and actuator saturation, which guarantees stable temperature fluctuations of microwave payloads in space missions. The controller combines a nominal constant sampling PID inner loop and a trigger-based outer loop structure under constraints of heating device saturation. Moreover, an iterative model-free reinforcement learning process is adopted that can approximate the estimation of thermal dynamic modeling uncertainty online. Via extensive experiment in a laboratory environment, the performance of the proposed trigger thermal control is verified, with smaller temperature fluctuations compared to the nominal control, and obvious efficiency in system communications. The online learning algorithm is also tested with deliberate thermal conditions that deviate from the original system—the results can quickly converge to normal when the thermal disturbance is removed. Finally, the ranging accuracy is tested for the whole system, and a 25% (RMS) performance improvement can be realized by using a trigger-based control strategy—about 2.2 µm, compared to the nominal control method.

Effect of Lifting Gas Diffusion on the Station-Keeping Performance of a Near-Space Aerostat

During the long-endurance flight of a near-space aerostat, the characteristics of lifting gas diffusion have a great influence on the flight altitude adjustment and station-keeping performance. Thus, in this study, a lifting gas diffusion model and a dynamic model that consider thermal effects, which had not been studied in similar models before, were developed. The dynamic model and thermal model were validated by historic flight data, and the calculated lifting gas diffusion results were compared with the experimental data of other researchers. The variations in the flight endurance, flight altitude, lifting gas diffusion rate, and diffusion coefficient of a near-space aerostat were analyzed. The effects of the ratio of porosity to tortuosity and envelope radiation properties on the mass of the lifting gas and flight altitude were considered in detail. To analyze the effect mechanism of the ratio of porosity to tortuosity and the envelope radiation properties, the envelope and gas temperature, as well as the gas pressure, were studied. The results show that the lifting gas diffusion rate and diffusion coefficient are very sensitive to the change in the ratio of porosity to tortuosity and envelope temperature. The results obtained from the analysis of the lifting gas diffusion can lay a solid foundation for improving the flight performance of near-space aerostats and for providing improved design considerations for aerostats.

Improving thermal model predictions for naturally ventilated buildings using large eddy simulations

Natural ventilation involves complex flow and heat transfer processes that are challenging to model accurately and efficiently. Computational fluid dynamics (CFD) simulations can accurately represent the flow and heat transfer physics but are computationally expensive; while building thermal models are computationally efficient but they use reduced-order models to represent complex flow phenomena. In this study, we aim to use CFD to develop building-specific, accurate correlations for the flow and heat transfer rates in buoyancy-driven natural ventilation flow, such that these correlations can be used to improve the accuracy of a dynamic thermal model. First, a CFD model of an operational building is validated with full-scale experiments. Next, the validated CFD model is used to run nine large eddy simulations, from which correlations for the convective heat transfer and the natural ventilation flow rate and heat transfer are derived. The results suggest that standard correlations for these processes can differ significantly from the building-specific values. The CFD-based correlations are then used in a dynamic thermal model to improve its accuracy. The resulting CFD-informed dynamic thermal model accurately predicts indoor air temperature, surface temperature and heat transfer, while the model employing the standard correlations (without inputs from CFD) only predicts the indoor air temperature accurately, not the surface temperature and heat transfer. The fast yet accurate CFD-informed dynamic thermal model can be used to run many simulations in a short time, supporting uncertainty quantification to quantify the effect of variability in the operating conditions and real-time prediction of the natural ventilation process.

Dynamic thermal model of liquid-immersed shell-type transformers

The paper presents the dynamic thermal model of shell-type transformers. The data from heat run test and field operation of single-phase shell-type transformer 512 kV/13.8 kV/13.8 kV, 100/50/50MVA, with oil directed air forced (ODAF) cooling, and 9 built-in fibre-optics sensors, are used for the development and testing of the model. Starting model was standard IEC model with parameters determined from heat run test and transformer field operation data. For the computations supporting software in C# was developed, whereas Microsoft Solver Foundation (MSF) library was used for the estimation of the parameters from the recorded values during thermal transients. The following improvements of the IEC model were introduced: a)the dependence of the losses on the temperature, b)correction of top oil temperature rise based on ambient temperature and c)correction of hot-spot to top oil temperature difference depending on top oil temperature. The paper proposes a method based on the application of the safety margins, which guarantees the measured temperatures will be lower than calculated in high temperature region. The testing of the method was performed on one-year data set from transformer operation.© 2017 Elsevier Inc. All rights reserved.

Station-keeping for high-altitude balloon with reinforcement learning

The operating altitudes of the stratospheric balloons can reach near-space altitudes of more than 20 km, where the appearance of the quasi-zero wind layer follows the seasonal rule. As unmanned aerial vehicles with application potential, the effective flight control of balloon position is crucial. This research develops a station-keeping control approach based on reinforcement learning, and the control strategy also considers the characteristics of the local wind field. Firstly, an atmospheric environment model with an uncertain wind field is established according to the analysis of the historical wind data. The model serves as a training environment for the balloon station-keeping strategy training. Secondly, the thermal model, dynamic model, and altitude control model are introduced, and an environment based on historical real wind data is developed. Thirdly, the dueling double Q-learning deep network with prioritized experience replay method is applied to the station keeping of high-altitude balloons. The Priority Experience Replay based on High-Value Samples (HVS-PER) is developed to improve the stability of strategy training. Finally, the performance of the optimal network is evaluated by the total reward, horizontal displacement, and effective working time under the uncertain wind environment. The strategy analysis also has reference to exploiting appropriate initial positions and capturing the opportunity of releasing a balloon. This work confirms that the control strategy is viable in complex and variable wind field environments and is capable of long-duration flights.

Thermoelectric Generator as the Waste Heat Recovery Unit of Proton Exchange Membrane Fuel Cell: A Numerical Study

The proton exchange membrane fuel cell (PEMFC) is a prominent environmentally friendly alternative candidate to internal combustion engines in automotive applications. The recovery of the waste heat of light-duty diesel engines has been investigated recently, which is similarly relevant for PEMFCs. Thermoelectric generators (TEG) applied on the stack’s walls have been already proposed and tested as a cooling method for small scale applications of the PEMFC. For the medium scale usages of the PEMFC stack, TEG technology may be further used to recover heat lost through the cooling water required for stack thermal management, which was the focus of the present study. Using an agglomerate model for the PEMFC and a computational fluid dynamic (CFD) thermal model for the TEG heat exchanger unit, the operation and performance of the PEMFC stack and heat recovery unit were simulated, respectively. After validation, results indicated that the transferred heat from the PEMFC to the cooling channel increased the temperature of the coolant from room temperature to 330.5 K at the current density of 0.8 A/cm2. CFD analysis revealed that 37.7 W of the heated wasted by the PEMFC stack could be recovered by the currently available TEG material and geometry.

Моделирование гибридной системы, состоящей из фотоэлектрического преобразователя солнечной энергии и водонагревательного устройства

Abstract. The combination of a photovoltaic solar energy converter and a collector for heating water is an efficient system. Compared to well-known water heaters, this hybrid system has a number of advantages, including smaller dimensions, lower operating temperature of the coolant, significant increasing in system efficiency, while generating electricity and heating water for heating at the same time. When compared with other systems that combine a photovoltaic module and a water heating device, this system has a simpler structure, which greatly reduces production costs and maintenance of the system. Experimental data on the operation of a hybrid system — a photoelectric converter and a water-heating device mainly took into account stationary systems, which made it possible to obtain data on the characteristics of the system over a sufficiently long period, most often for a year or more. However, this approach does not allow taking into account constantly changing factors, such as illumination, water flows, etc. This article discusses a dynamic thermal model of a hybrid system — a photoelectric converter and a water-heating device, which can be applied for practical analysis of such a hybrid system. The proposed model makes it possible to evaluate the instantaneous characteristics of a hybrid system, to determine at any time the performance of the system, the state of its components, and, ultimately, under certain conditions, to carry out a comprehensive thermal calculation of the hybrid system. Relationships that can estimate the thermal and electrical efficiency of a hybrid system are obtained.

Thermal Stratification and Temperature Variation in Horizontal Electric Water Heaters: A Characterisation Platform

Electric water heaters, which have the capacity to act as thermal energy storage, are well suited to demand management strategies in smart grid applications. However, finding the balance between managing power load, reducing thermal energy losses, user’s convenience, and bacterial growth control, requires accurate modelling of the internal thermal dynamics of the tank, including stratification. As a black box, this unknown is dependent on a multitude of environmental factors (e.g., ambient temperature and inlet temperature), water draw patterns, scheduling, set temperatures and orientation of the vessel. The latter affects the stratification and temperature variation inside the tank, and therefore has a direct bearing on the balancing act of demand management. Although this has been assessed inside vertically oriented tanks, what happens inside the horizontal variety—ubiquitous in developing countries—is currently left to the guesswork. In this paper, we present the development of an embedded hardware and software platform with which the temperature variations inside a horizontal water heater can be characterised under numerous environmental and usage conditions. The importance of doing so is highlighted by the preliminary results, which clearly show the expected substantial temperature variation along the vertical axis, but also show interesting phenomena along the longitudinal and transverse axes, for both static (no water draw) and dynamic (with water draw) conditions. We conclude by highlighting potential for further research.

HOT-COMPRESSION DEFORMATION BEHAVIOR AND CONSTITUTIVE EQUATIONS OF LZ50 AXLE STEEL

A study of deformation behavior of LZ50 axle steel has great significance to the railway industry. Hot-deformation tests were performed using a Gleeble-3800 thermal mechanical simulator at temperatures of (900, 1000 and 1100) °C with strain rates of (0.1, 1.0 and 10.0) s–1 under different deformation degrees of 0.2, 0.6 and 1.0. True stress-strain curves were discussed to obtain hot-processing maps. Then hot-processing maps of LZ50 steel at different deformation parameters were discussed including safe zones and unsafe zones. Finally, thermal deformation constitutive equations and dynamic recrystallization models were established based on the experimental data. The results show that at a strain rate of 10.0 s–1, the peak value of the flow stress increases by approximately 40 MPa with a decrease in the temperature from 1000 °C 900 °C, which is larger than the value of 18 MPa obtained at a decrease from 1100 °C to 1000 °C. At deformation temperatures of 900–1000 °C, the peak value of the flow stress increases by approximately 37 MPa with the strain rate increasing from 0.1 s–1 to 1.0 s–1, while from 1.0 s–1 to 10.0 s–1, the increase is approximately 21 MPa. With an increase in the strain from 0.2 to 1.0, the instability area under the low deformation temperature expands due to a higher strain rate. The activation energy of dynamic recrystallization is 334.537 kJ/mol.

Temperature Dynamic Characteristics Analysis and Thermal Load Dissipation Assessment for Airliner Hydraulic System in a Full Flight Mission Profile

This paper deals with the modeling of the thermal load and the simulation of thermal dynamic characteristics for the hydraulic system of a large airliner in a full mission profile. Firstly, the formation mechanism of the thermal load in the hydraulic system is analyzed, and thermal dynamic modeling is conducted of the hydraulic components of an hydraulic system with an immersed heat exchanger employing the lumped parameter thermal node method and oil temperature and power loss of each key node within the hydraulic system within a full mission profile. Then, a thermal dynamic simulation model based on MATLAB/Simulink is established, and the temperatures at the nodes of different components and the absorptive capacity of the fuel heat sink in the thermal management module are calculated. The simulation results show that the thermal management scheme of the heat exchanger, located in the return oil pipeline of the hydraulic piston pump housing and immersed in the central fuel tank, can dissipate the thermal load of the system. This work is of important significance for temperature analysis and thermal load dissipation of the airliner hydraulic system.

The potential for indoor fans to change air conditioning use while maintaining human thermal comfort during hot weather: an analysis of energy demand and associated greenhouse gas emissions

Increasing air conditioner use for cooling indoor spaces has the potential to be a primary driver of global greenhouse gas emissions. Moving indoor air with residential fans can raise the temperature threshold at which air conditioning needs to be turned on to maintain the thermal comfort of building occupants. We investigate whether fans can be used to reduce air conditioner use and associated greenhouse gas emissions. We developed an integrated framework, featuring a dynamic adaptive thermal comfort model with a geographical information system-based spatially gridded map of Australia, further complemented with census data. We assessed the change in energy use and associated greenhouse gas emissions for five scenarios of air conditioner and fan use: an air conditioner-only scenario (no fans); and four fan-first scenarios with fans operating at speeds of 0·1 m/s, 0·3 m/s, 0·8 m/s, and 1·2 m/s, with air conditioning used only once the upper temperature threshold for thermal discomfort is exceeded. For each day of the selected case study year, we estimated the upper temperature limit for thermal comfort and the number of hours in which air conditioning would be switched on. The thermal comfort threshold was increased by the use of fans compared with air conditioner use alone. We found that widespread indoor fan use had the potential to reduce energy demand and greenhouse gas emissions attributable to air conditioner use, without compromising thermal comfort. Taking an annual perspective, the use of fans with air speeds of 1·2 m/s compared with air conditioner use alone resulted in a 76% reduction in energy use (from 5592 GWh to 1344 GWh) and associated greenhouse gas emissions (5091 kilotonnes to 1208 kilotonnes). A common strategy to cope with hot weather is the use of air conditioners, which feed a cycle of high electricity consumption, often delivered by fossil fuel power stations that in turn contribute to further increases in emissions. Moving air with electric fans could serve as a sustainable alternative, reducing air conditioner use and associated greenhouse gas emissions without sacrificing thermal comfort. Australian Research Council, New South Wales Department of Planning, Industry and Environment, and The University of Sydney.

Impact of the Vehicle Environment on the Thermal Behavior of the Electrical Wiring

<div class="section abstract"><div class="htmlview paragraph">The thermal behavior of wires within the electrical distribution system (EDS) has a strong impact on the conductor cross section, the type of insulation, the derating, and the fusing system, and therefore on weight, cost, and reliability. Consequently, significant efforts have been made to develop sound static and dynamic thermal models for single wires and wire bundles. However, these models are based on the simplifying assumption that the object is completely surrounded by air, where, with the exception of free convection, airflow can be neglected, and where no interaction with other objects is considered.</div><div class="htmlview paragraph">The approach presented in this paper takes into account the actual environment and routing within a vehicle, where some objects such as metal sheets can be considered as heat sinks and other objects, e.g. a motor block, as heat sources. For this reason, measurements were performed using an experimental set-up that allows any desired positioning and alignment of the DuT (device under test, here: wire, cable, bundle) and of two temperature-controlled heat source/sink objects. These objects are a large rectangular surface and a small sphere, in order to be able to emulate as many spatial configurations as possible. The overall set-up is protected against externally-induced airflows. Because the exact modelling of the heat transfer processes (radiation, conduction, and free/forced convection) would require time-consuming FEM calculations for the investigated complex geometries, a simplified and partially data-driven model is proposed. The paper describes the theory and the modeling approach, and presents initial simulation and measurement results.</div></div>

Gamma distribution excess minority carrier concentration model for solar cell performance modeling

Concentrated photovoltaic (PV) technology represents a growing market in the field of terrestrial solar energy production. As the demand for renewable energy technologies increases, further importance is placed on the modeling, design, and simulation of these systems. Given the cultural shift toward energy awareness and conservation, several concentrated PV systems have been installed across the world. This research presents a new model for carrier concentration within a solar cell. The goal of this innovation is to facilitate the determination of the steady-state operating temperature as a function of the concentration factor for the optical part of the concentrated PV system, to calculate the optimum concentration that maximizes power output and efficiency. This model will be shown to produce a more realistic estimate of the current through a solar cell, which will enable further research into dynamic thermal modeling.

Two-dimensional smoothed particle hydrodynamics (SPH) simulation of multiphase melting flows and associated interface behavior

ABSTRACT Heat transfer and phase change in multiphase media involve complex behavior such as multi-physics coupling, unsteady interfaces, and boundary generation/disappearance. The smoothed particle hydrodynamics (SPH) method is used to simulate multicomponent problems (initially solid material surrounded by a fluid) characterized by heat transfer, solid–liquid phase change, and multiphase flow. First, the interface behavior of the melted liquids and ambient fluids are simulated by a multiphase SPH model, where corrected algorithms and techniques are adopted to provide a stable simulation for the interface with a large density ratio. The wetting effect of the solid surface by melted liquids is considered by extending the continuum surface force model to three phases including solid, melted liquid and ambient fluid. Second, a thermal dynamics model is incorporated with the multiphase SPH model. The solid–liquid phase change occurs in a small temperature interval in which the latent heat is incorporated using the equivalent heat capacity. Third, the numerical model is validated using several benchmark examples. Five specially configured cases are simulated to demonstrate the robustness, adaptability, and stability of the model. The intriguing phenomena of evolution of the fluid interface of melted liquids, accumulation of thin-layer liquids, and melted droplet formation are reproduced.