High-efficiency Heat Research Articles

Polyurethane Foam with High-Efficiency Flame Retardant, Heat Insulation, and Sound Absorption Modified By Phosphorus-Containing Graphene Oxide

Polyurethane Foam with High-Efficiency Flame Retardant, Heat Insulation, and Sound Absorption Modified By Phosphorus-Containing Graphene Oxide

Numerical Analysis of Fluid Flow and Heat Transfer Characteristics of Novel Microchannel Heat Sink

Microchannel heat sinks have gained prominence in the field of thermal management, offering compact and efficient solutions for dissipating heat flux from high performance electronic devices. Escalating heat flux in modern electronic devices, such as those found in telecommunication equipment, industrial automation equipment, solar devices, and data centre servers has driven the continuous development of microchannel heat sink to achieve efficient thermal management. The critical challenge in thermal management for these devices is to develop a microchannel that enhances heat transfer performance and minimises pressure drop. Heat transfer and pressure drop are two competing factors that determine the practicability of the design for real world application. Improvement in heat transfer performance usually results in an increase in pressure drop and pumping power. This study addresses the challenges of designing microchannel through comprehensive numerical analysis of fluid flow and heat transfer characteristics of a novel design that combines ribs, secondary channels, and tertiary channels. The numerical results showed that the novel microchannel design achieves a favourable balance between heat transfer and pressure drop, demonstrating its potential to be used in application where high heat transfer and efficiency are paramount. To assess the performance of the microchannels, thermal resistance, a measure of system’s resistance to heat transfer is used. At the same pumping power, thermal resistance in the new design is consistently lower compared to other designs.

Enhanced solar absorbance and infrared emittance in Co-doped BaTiO3

Broadband absorber materials with high solar absorptivity and infrared emissivity are conducive to high-efficient and cost-effective heating technology in the civil and industrial field. The BaTi1-xCoxO3 ceramics are prepared by sol-gel method, showing mixed tetragonal/hexagonal phases. Co doping slightly reduces the phase transition temperature of BaTiO3. Meanwhile, BaTi1-xCoxO3 ceramics present a composite Mott/charge transform band nature and the Co-3d impurity level and oxygen vacancies level lead to a narrowed bandgap. The enhancement of the absorption induced by free carriers, impurity level and lattice vibration promote the UV-Vis-NIR absorption and mid-infrared radiation of BaTi1-xCoxO3 ceramics. In conclusion, the optimized BaTi0.95Co0.05O3 ceramic achieves a high solar absorptivity (0.88) in 0.25–2.5 µm and a high infrared emissivity (0.83) in 8–14 µm. The radiative performance presents good temperature stability, unaffected by phase structure and lattice thermal expansion, which provides prospective applications in solar energy conversion and infrared radiation heating.

Thermal energy storage system based on nanoparticle distribution optimisation for enhanced heat transfer

As a new type of heat transport medium with high efficiency and high heat transfer performance, nanofluids can effectively improve the heat transfer performance of thermal systems. In this paper, a lattice Boltzmann method is employed to propose a novel thermal storage system with optimised nanoparticle distribution using spacer-separated nano-enhanced PCM with spacer arrangement. The thermal energy storage units are separated by thermal insulation and heated by means of thermally conductive fluid channels. The effects of Rayleigh number, volume fraction and layout pattern are investigated. It is shown that the larger the Rayleigh number is, the more intense the reaction of the heat storage system is; it is concluded that the strong convection phenomenon in the upper left side region is more than that in the lower left side, and the volume fraction in the lower left side can be reduced to enhance the efficiency of this heat transfer in order to achieve a faster melting rate. The various distributions studied in this paper all have the effect of accelerating the melting rate to varying degrees compared to Type 1. The present study shows that increasing the volume fraction of phase change material in the upper left side of the square cavity has a promoting effect on the melting rate when compared to the lower side, and the larger the difference between the two, the better the effect is.

Active generation and control of radial electric field by local neutral beamlets injection in tokamaks

The radial electric field plays an important role in plasma confinement in tokamaks and can be generated through neutral beam injection. In this study, we propose a model for calculating the radial electric field resulting from tangential local neutral beamlet injection, aiming to externally control and improve plasma confinement. The Neutral beamlet ion and Energetic particles Orbit mover and Electric field solver code has been developed to analyze this issue, and its simulation results have been validated against results from other codes as well as measurements from correlation reflectometers. The charge separation is primarily caused by the redistribution and loss of beam ions due to magnetic gradient and curvature drift as well as collision effects, and it is maintained through continuous beamlet injection. The electric field is calculated using Poisson’s equation, taking into account both classical and neoclassical polarization effects. The results demonstrate that despite the high losses and low heating efficiency associated with localized beamlets, they are capable of generating a significant radial electric field characterized by a steep gradient. This presents opportunities for external control of the electric field, potentially enhancing plasma confinement.

Numerical investigation on pool boiling heat transfer with trapezoidal/inverted trapezoidal micro-pillars using LBM

Pool boiling with high-efficient heat transfer process is crucial to chemical engineering, nuclear engineering, electronic cooling, and other energy conversion applications. Surface modification technology has attracted more attention in recent years as a simple and reliable boiling enhancement technique. Most of the studies using surface modification technology have focused on the enhancement effect of rectangular micro-structures, only a few researchers have adequately investigated the enhancement effects on pool boiling heat transfer and mechanisms of other complex micro-structures (like circle, trapezoid, or inverted trapezoid). In the present study, the pool boiling processes on surfaces with trapezoidal/inverted trapezoidal micro-pillars were numerically investigated using lattice Boltzmann method (LBM). The bubble dynamics and heat transfer characteristics during the pool boiling processes on surfaces with different pillar bottom angles (30° ≤ θ ≤ 135°) were compared under different wall-superheat conditions. The orthogonal tests were adopted on micro-pillars to optimize the geometric parameters, including the bottom angle of the micro-pillar, the bottom width of the micro-pillar, the number of the micro-pillar, and the height of the micro-pillar. A new CHF correlation on the mixed wettability surface with trapezoidal/inverted trapezoidal micro-pillars was proposed. It can be found that the main mechanism of nucleate boiling heat transfer on the micro-pillars is the evaporation of the microlayer, and the pillar bottom angle reveals a remarkable effect on the pool boiling performance on the mixed wettability surfaces. The surface of θ = 135° has the minimum wall-superheat at the onset of nucleate boiling (ONB). Within a wide range of wall-superheat conditions, the heat transfer efficiency of pool boiling firstly increases with the increasing of the bottom angle of the micro-pillar and subsequently decreases. The surface of θ = 60° has the highest critical heat flux (CHF). The surface of θ = 90° has the highest heat transfer efficiency in the film boiling process. The results of orthogonal tests suggested that the bottom angle of the micro-pillar is the most significant influential factor, and the optimal geometrical combinations were proposed. The new CHF correlation has acceptable accuracy in predicting the CHF on surfaces with trapezoidal/inverted trapezoidal pillars, which provides guidance for the design and optimization of micro-structured surface modification in various pool boiling applications.

Thermomechanical properties of confined magnetic nanoparticles in electrospun polyacrylonitrile nanofiber matrix exposed to a magnetic environment: structure, morphology, and stabilization (cyclization).

Electrospun metal oxide-polymer nanofiber composites hold promise for revolutionizing biomedical applications due to their unique combination of electronic and material properties and tailorable functionalities. An investigation into the incorporation of Fe-based nanofillers for optimizing the polyacrylonitrile matrix was conducted, where the systematic and organized arrangement of inorganic components was achieved through non-covalent bonding. These carefully dispersed nanomaterials exhibit the intrinsic electronic characteristics of the polymers and concurrently respond to external magnetic fields. Electrospinning was utilized to fabricate polyacrylonitrile nanofibers blended with Fe2O3 and MnZn ferrite nanoparticles, which were thermomechanically, morphologically, and spectroscopically characterized in detail. With the application of an external magnetic field in the course of dynamic mechanical measurements under tension, the storage modulus of the glass transition T g of PAN/Fe2O3 rises at the expense of the loss modulus, and a new peak emerges at ∼350 K. For the PAN/MnZn ferrite nanofibers a relatively larger shift in T g (from ∼367 K to ∼377 K) is observed, emphasizing that in comparison to Fe2O3, Mn2+ ions in particular enhance the material's magnetic response in MnZn Ferrite. The magnetic oxide particles are homogenously dispersed in polyacrylonitrile, corroborated by high-resolution scanning electron microscopy. Both nanopowder additions lead to a slight shift of the peak towards larger angles, related to the shrinkage of the polymer. Produced nanofibers with high mechanical and heating efficiency can optimize the influence of the intracellular environment, magnetic refrigeration systems and sensors/actuators by their magnetic behavior and heat generation.

Power disassembly equipment for high efficiency heat transfer plate heat exchangers

Plate heat exchangers are realized by means of a heat transfer mechanism, in which heat is naturally transferred from the hot substance to the object with a lower temperature according to the laws of thermodynamics. Two liquids of different temperatures flow on the wall, heat transfer on the wall and convection of the liquid on the wall, thus promoting heat transfer between the two liquids. Under the same flow rate and power consumption conditions, its heat transfer coefficient is three times that of shell and tube heat exchangers, which is a key and efficient new equipment for effectively using effective resources and saving and developing new energy. However the heat supply plate heat exchanger has a tiny circulation surface and is easily obstructed. Regular maintenance and cleaning, troubleshooting, and plate replacement all necessitate frequent heat exchanger disassembly and installation. The requirements and challenges in dismantling and assembling the heat exchanger are very high, and manual disassembly is wasteful, making consistent force difficult to achieve. The current methods of disassembly and assembly are inefficient and incorrect. The intelligent mechanization of disassembly and assembly equipment is realized in this paper by driving, clamping, automatic control, distance measurement, sensing, and other systems. The problems of uneven force, low efficiency, and precision in plate heat exchanger disassembly and assembly are solved. Our power disassembly equipment for high efficiency heat transfer plate heat exchangers not only enhances disassembly efficiency and precision, but it also ensures the safe operation of the plate heat exchanger heating system, and the heat transfer efficiency and heat exchange efficiency are improved. Furthermore, it has a wide range of applications in the petroleum, chemical, and other industries.

Performance comparison of U-tube and coaxial borehole heat exchangers with numerical simulations

It is well known that geothermal heat is a virtually unlimited energy source beneath the ground, which is formed by the radioactive decay of naturally unstable elements. However geothermal energy has been utilized since the ancient ages, it is still a mission for humanity – even in the times of energy crisis with high prices – to find sustainable solutions for high-efficiency heat energy production. Apart from the conventional hydrothermal wells and production/injection systems, an increasing attention is drawn into deep coaxial heat exchangers and heat pumps, utilized in a single wellbore. Optimization of these systems need to be done with an increased care, however it is possible with results obtained from a set of numerical simulations. The present paper investigates hypothetical, single deep “U”, “double-U” and coaxial arrangements under different flow rates, where the main target was to analyze efficiency of each model, with short time thermal response simulations.

Feasibility study of a defrosting method at thin frost moment based on temperature difference recognition

In the frosting-defrosting cycle of an air-source heat pump, it is crucial to determine the defrosting start time reasonably to enhance efficient operation. A straightforward defrosting control strategy for thin frost moments, based on temperature difference recognition proposed. This method was implemented while ensuring that the reduction in the heat transfer rate remained within a certain ratio, thereby avoiding a rapid decline in heat transfer efficiency. For the experiments, bare aluminum, hydrophilic, and superhydrophobic heat exchangers were set up, and the defrosting effect was explored by varying the thin frost moment point and melting temperature. The experimental results indicate that the method effectively improves the rate of heat acquisition (ROHA) of a single cycle compared with defrosting under complete frost blockage, irrespective of the surface properties. Superhydrophobic heat exchangers prove to be the most suitable choice. When the heat transfer rate decayed by 25%, the defrosting energy consumption of the superhydrophobic heat exchangers was lower by 37.2% and 29.9%, and the ROHA was higher by 11.3% and 11.7%, respectively, compared to those of the hydrophilic and bare aluminum heat exchangers. Throughout cyclic operation, the superhydrophobic surfaces demonstrated stable performance. However, the high-efficiency heat transfer times of the hydrophilic and bare aluminum heat exchangers were only 73.8% and 54.4%, respectively, of the superhydrophobic heat exchangers, due to the influence of water stagnation. Under the control of this defrosting strategy, the superhydrophobic heat exchanger can achieve low-temperature defrosting and reduce the energy consumption of defrosting medium preparation while ensuring a certain ROHA. This defrosting method holds potential for engineering applications.

High-efficiency heating and cooling technology with embedded pipes in buildings and underground structures: A review

The thermally activated system utilizes heat exchange pipes embedded in buildings and underground structures to efficiently and stably regulate thermal and humidity environment of building and underground spaces by fully utilizing low-grade energy and heat storage characteristics of the embedded pipe structure. In this review, a comprehensive summary and analysis of the research on embedded pipe heat exchange system are provided, including TABS classification, influencing factors, enhancement strategies, system integration and optimization, application potential, and development trends. The three forms of embedded pipe structures in building enclosures, namely floors, walls, and ceilings, are thoroughly explored. Specifically, to address the demand for environmental regulation in underground spaces, embedding pipes within underground infrastructures is proposed to cater to heating needs in cold region tunnels, cooling requirements in urban tunnels, and deicing/snow melting on road pavements. Various enhancement methods for TABS are suggested to improve operational effectiveness, including utilizing phase change materials, implementing reasonable and effective intermittent operation schemes and control strategies, and integrating with auxiliary air conditioning and dehumidification systems. Future research directions are identified, such as strengthening the prefabrication of embedded pipe thermal activation systems, introducing machine learning algorithms to enhance system intelligence, and combining new technologies to improve system integration as well as integrating the thermo-active system into the fifth-generation district heating and cooling networks. This review work of thermal activation systems with embedded heat transfer pipes will be of some significance in guiding future research and application of embedded pipes heating and cooling of buildings and underground spaces.

Heat Transfer Performance of a 3D-Printed Aluminum Flat-Plate Oscillating Heat Pipe Finned Radiator.

As electronic components progressively downsize and their power intensifies, thermal management has emerged as a paramount challenge. This study presents a novel, high-efficiency finned heat exchanger, termed Flat-Plate Oscillating Heat Pipe Finned Radiator (FOHPFR), which employs arrayed flat-plate oscillating heat pipes (OHP) as heat dissipation fins. Three-dimensional (3D)-printed techniques allow the internal microchannels of the FOHPFR to become rougher, providing excellent surface wettability and capillary forces, which in turn significantly improves the device's ability to dissipate heat. In this study, the 3D-printed FOHPFR is compared with traditional solid finned radiators made of identical materials and designs. The impacts of filling ratio, inclination angle, and cold-end conditions on the heat transfer performance of the 3D-printed FOHPFR are investigated. It is demonstrated by the results that compared to solid finned radiators, the FOHPFR exhibits superior transient heat absorption and steady-state heat transfer capabilities. When the heating power is set at 140 W, a decrease in thermal resistance from 0.32 °C/W in the solid type to 0.11 °C/W is observed in the FOHPFR, marking a reduction of 65.6%. Similarly, a drop in the average temperature of the heat source from 160 °C in the solid version to 125 °C, a decrease of 21.8%, is noted. An optimal filling ratio of 50% was identified for the vertical 3D-printed FOHPFR, with the minimal thermal resistance achieving 0.11 °C/W. Moreover, the thermal resistance of the 3D-printed FOHPFR is effectively reduced compared to that of the solid finned radiator at all inclination angles. This indicates that the FOHPFR possessed notable adaptability to various working angles.

Optimization of microchannel heat sink based on multi-objective particle swarm optimization algorithm for integrated circuit chips cooling

The microchannel heat sink is an effective way to solve the heat dissipation problem in integrated circuit chips. In order to obtain the high efficiency and low resistance microchannel heat sink, the three variables (△h, f, g) were selected as the design variables, and the thermal resistance and pumping power were selected as objective functions. Then, the RSM, multi-objective particle swarm optimization algorithm and K-means clustering method were comprehensively applied to the multi-objective optimization of the microchannel heat sink with turbulence to obtain the five representative solutions (Case A–Case E), and the results were verified by CFD. The research shows that the maximum relative errors between Pareto optimization values and numerical simulation values of thermal resistance and pumping power of the five groups representative solutions are 0.637% and 1.187%, respectively. The Pareto optimization values are in good agreement with the numerical simulation values, and there is an effective tradeoff point between the five representative solutions of the Pareto optimal solution to make both the pumping power and thermal resistance within the optimal range. Compared with before optimization and the research results of Han Wang et al. [Appl. Therm. Eng. 2022;215:118849], the comprehensive heat transfer performance of the optimized microchannel heat sink has been improved, where the comprehensive heat transfer performance of the Case B ( Δ h = 0.0400 mm, f = 0.0979 mm, g = 0.5000 mm) is the best. The maximum temperature and pressure drop of the optimized microchannel heat sink can be reduced by 3.045% and 7.659%, respectively. Compared with the research results of Han Wang et al. [Appl. Therm. Eng. 2022;215:118849], the temperature distribution more uniform and the pressure drop of the microchannel heat sink after optimization (Case B) decreased by 7.058%. This optimization method can provide a reference for the optimization design of the microchannel heat sink structure parameters for integrated circuit chips cooling.

EFEK PEREKAT GETAH DAMAR TERHADAP KARAKTERISTIK PERPINDAHAN PANAS DALAM PROSES PEMBAKARAN BRIKET SARANG LEBAH AMPAS SAGU

This research aims to evaluate the ignition quality of briquettes made from sago waste and coconut shells and determine the heat transfer rate in the combustion process of briquettes using damar resin as a binder through conduction and convection. The research method employed laboratory experiments, utilizing two testing models: honeycomb briquettes with 14 holes made from sago waste, coconut shells with damar resin as a binder, and a similar honeycomb briquette model using tapioca flour as a comparative adhesive. The tools used included an infrared thermometer, a moisture meter for measuring water content, an anemometer for measuring air velocity, a stopwatch, a scale, and a briquette stove.
 The research findings indicate that honeycomb briquettes with 14 holes made from sago waste and coconut shells with damar resin as a binder exhibit faster combustion with a content level of approximately 10-12%. The conduction heat transfer in these briquettes is approximately 26,376 watts/m2, while the convective heat transfer reaches 40,801 watts. In comparison, the testing with tapioca flour as a binder shows a conduction value of 42,206 watts/m2 and convection of 43,208 watts. From these research results, briquettes made from sago waste and coconut shells with damar resin as a binder can be an effective alternative to replace kerosene fuel. The high combustion speed and efficient heat transfer make these briquettes attractive for alternative energy use

Study on the performance of oil fume heat recovery heat exchanger based on micro heat pipe array

In China, the utilization of high-temperature flue gas waste heat recovery has been widely studied and developed, while the large number of low-temperature flue gas waste heat recovery has not been fully developed. Therefore, research has been conducted on the heat transfer characteristics of plate heat exchangers for low-temperature oil fume. The heat exchanger were 28–44 ℃ at the hot end and − 10 to 5 ℃ at the cold end. The outlet temperature, wind speed, etcetera were measured and recorded by changing indoor and outdoor temperature, variable flow rate and variable fin size. The impact of different working conditions on heat transfer and heat transfer efficiency of the heat exchanger was analyzed. The result showed that within the range of effective experimental test temperature, the variation trend of Nu and h was the same for heat exchangers with different finned fins and heat pipes with a different liquid-filled working medium The Nu value increased linearly with the increase of the Reynolds coefficient (Re), and the heat transfer coefficient presented a quadratic curve and increased with the increase of Re. Smaller fins had a higher efficiency and higher heat transfer. The heat exchange efficiency was stable between 0.75 and 0.97, which was higher than the value required by the national standard. At the same time, the heat exchanger also met the demand for high-efficiency heat recovery at low outdoor temperature, which has a wide application prospect.

Transfer learning model to predict flow boiling heat transfer coefficient in mini channels with micro pin fins

Flow boiling in mini channels with micro pin fins is a promising heat sink technique to achieve high-efficient aircraft thermal management. The accurate prediction of its heat transfer coefficient is critical for the practical design of two-phase heat exchanger based on mini channels with micro pin fins. Previous investigation shows that heat transfer coefficient prediction accuracy of the machine learning method is generally better than that of conventional empirical correlations. However, the machine learning method cannot guarantee its prediction accuracy among different data domains. To extend the application region of the conventional machine learning method, a transfer learning framework was proposed in present study. First of all, an experimental system was built to acquire test data from different sample domains (i.e., the diamond pin fins with different geometries). Then a conventional machine learning model was developed based on the deep learning method. Furthermore, the developed deep learning model was adjusted with transfer learning process, and the performance of these two kinds of models (i.e., conventional machine learning model and transfer learning model) was comprehensively evaluated. Results showed that the conventional machine learning model had a good prediction accuracy with an overall deviation of 4.11 % but was only confined in the same data domain as training data. Differently, the transfer learning model with 70 % data set from the new domain can achieve appropriate prediction in the new domains with deviation of 4.28 %. The results of this paper demonstrated that the conventional machine learning model can extend into different domains with reasonable prediction accuracy through transfer learning frameworks. It will benefit the practical design of high-efficiency heat exchangers for aircraft thermal management.

On the Innovation, Design, Construction, and Experiments of OMEGA-Based SSPS Prototype: The Sun-Chasing Project

This study systematically introduces the development of the world’s first full-link and full-system ground demonstration and verification system for the OMEGA space solar power satellite (SSPS). First, the OMEGA 2.0 innovation design was proposed. Second, field-coupling theoretical models of sunlight concentration, photoelectric conversion, and transmitting antennas were established, and a systematic optimization design method was proposed. Third, a beam waveform optimization methodology considering both a high beam collection efficiency and a circular stepped beam shape was proposed. Fourth, a control strategy was developed to control the condenser pointing toward the sun while maintaining the transmitting antenna toward the rectenna. Fifth, a high-efficiency heat radiator design method based on bionics and topology optimization was proposed. Sixth, a method for improving the rectenna array’s reception, rectification, and direct current (DC) power synthesis efficiencies is presented. Seventh, high-precision measurement technology for high-accuracy beam-pointing control was developed. Eighth, a smart mechanical structure was designed and developed. Finally, the developed SSPS ground demonstration and verification system has the capacity for sun tracking, a high concentration ratio, photoelectric conversion, microwave conversion and emission, microwave reception, and rectification, and thus satisfactory results were obtained.

A numerical investigation of subcooled flow boiling heat transfer in twisted elliptical tubes

Twisted elliptical tubes possess superior heat transfer performance due to their unique geometry. It is necessary to further explore their potential applications in high-efficiency heat transfer devices. This study conducted a numerical simulation investigation to analyze the flow boiling heat transfer characteristics of subcooled water inside twisted elliptical tubes. The results show that the spiral flow inside twisted elliptical tube causes the fluid with relatively small vapor volume fraction to tend to distribute near the wall, while also increases turbulence intensity and promotes interactions among bubbles. Moreover, increasing the aspect ratio of the twisted elliptical tube can effectively improve the heat transfer coefficient and has a relatively small impact on the pressure drop of the fluid in the tube. Simulation data show that when the aspect ratio increases from 1.41 to 1.80, the heat transfer coefficient of the pipe increases by 15.21 %, while the pressure drop increases by 3.34 %.

Squid-Inspired Powerful Untethered Soft Pumps via Magnetically Induced Phase Transitions.

Soft robots possess unique deformability and hence result in great adaptability to various unconstructive environments; meanwhile, untethered soft actuation techniques are critical in fully exploiting their potential for practical applications. However, restricted by the material's softness and structural compliance, most untethered actuation systems were incapable of achieving fully soft construction with a powerful output. While in Nature, with a fully soft body, a squid can burst high-pressure jet flow from a cavity that drives the squid to swim swiftly. Here, inspired by such a unique actuation strategy of squids, an entirely soft pump capable of high-pressure output, fast jetting, and untethered control is presented, and it helps a bionic soft robotic squid to achieve a high-efficient untethered motion in water. The soft pump is designed by a reversible liquid-gas phase transition of an inductive heating magnetic liquid metal composite that acts as an adjustable power source with high heat efficiency. In particular, being purely soft, the pump can yet lift ∼20 times its weight and achieve ∼3 times the specific pressure of the previous record. It may promote the application of soft robots with independent actuation, high output power, and embodied energy supply.

A frequency domain dynamic simulation method for heat exchangers and thermal systems

Dynamic simulation of thermal systems is crucial for their optimal control but facing the challenge of balancing calculation accuracy and efficiency, where numerically high-efficient and accurate heat exchanger (HX) modeling is a key. Herein, we propose a frequency domain model for HXs' dynamic simulation in the to meet this challenge. The governing equations of HXs are first converted to frequency domain through Fourier transform, and the analytical solution of the converted equations yields the frequency domain HX model in the form of transfer matrix that connects the inlet temperature variations and outlet temperature responses. Furthermore, integrating transfer matrices of HXs into the system's transfer matrix enables a high-efficiency thermal system simulation. Numerical cases of a single HX, a HX network, a district heating network, and a thermodynamic cycle are used to validate the developed method and demonstrate its efficacy by comparing it against finite difference/volume method. Results show that the proposed method could reduce the calculation time by 2–3 orders of magnitude, and the maximum deviation of node temperature is around 1 K. The proposed method can be a powerful tool for the analysis of thermal systems and potentially integrated energy systems.