High Thermal Capacity Research Articles

Insulated concrete form foundation wall as solar thermal energy storage for Cold-Climate building heating system

Employing green energies for building energy sector decarbonization has captured the world’s attention in the current century. However, the imbalance between energy demand and availability necessitates designing reliable and cost-effective energy storage systems. The present study aims to propose an innovative building-integrated solar thermal storage method using insulated concrete form (ICF) foundation walls for residential buildings in cold climates such as that of Canada. Surplus solar thermal energy is stored inside the ICF wall, which has a high thermal capacity and mass and is integrated into the building envelope. The ICF wall and solar thermal collectors are coupled with a water-to-water heat pump to meet building space heating load and domestic hot water demand. Different configurations integrating the ICF wall are modeled and simulated in TRNSYS software to perform a yearly transient analysis. It is shown that a system with ICF walls has an 11% higher solar fraction (SF) than a similar system with a large water thermal storage tank. By replacing the solar thermal collector with a hybrid photovoltaic/thermal collector, the overall system solar fraction can increase to 20% above that of a similar system with a large water thermal storage tank system. An ICF-based system with a 16 m2 solar collector can completely cover nine months of space heating and domestic hot water load for a single-family house in London, Ontario. A detailed sensitivity analysis shows that the proposed ICF-based systems achieve an optimum solar fraction at high tilt angles (65-70°), unlike a similar design with an extensive water thermal storage tank system. Because of their ability to achieve a high SF at high tilt angles, ICF systems are suitable for vertically mounted solar systems typically required by high-rise buildings due to limited roof area. As part of the building envelope, ICF foundation walls have no additional cost and can be considered a feasible strategy for reducing the residential sector’s carbon footprint..

Experimental study of the thermal behavior of PCM and heavy building envelope structures during summer in a temperate climate

The main objective of the study was to evaluate the effects of PCM and traditional masonry construction on the summer thermal performance of the non-air-conditioned residential building in a temperate climate. The research was conducted in three rooms. In the first case, the lightweight frame construction of the walls and ceiling was covered with gypsum board on the inside, while in the second, a layer of Rubitherm® RT25HC was placed. The third room used masonry walls and a reinforced concrete roof. All rooms had identical flooring. The study was conducted between 13.08 and 18.09.2020. For the night period, various rates of mechanical ventilation were used to maintain the room temperature within the range of optimal PCM melting temperatures. The results of the study indicate significantly higher effectiveness of traditional high thermal capacity building materials than PCMs for lowering high indoor temperatures in summer. This occurs when there is a marked increase in outdoor temperature on at least one day, while at the same time the indoor temperature does not significantly exceed the PCM's melting temperature range specified by the manufacturer. Studies have further shown that the cooling efficiency of PCMs remains at a reasonably high level only for a small number of days in summer. This occurs when there is a marked increase in outdoor temperature on at least one day, while at the same time the indoor temperature does not significantly exceed the PCM's melting temperature range specified by the manufacturer.

Nickel foam/Covalent-Organic Frameworks for composite phase change materials with enhanced solar-thermal energy conversion and storage capacity

Shape-stabled composite phase change materials (CPCMs) with outstanding thermal properties and solar-thermal conversion capabilities are of great importance in the efficient usage of renewable solar energy. In this work, Covalent-Organic Frameworks (i.e., COF TpPa) with excellent solar energy absorption capability were successfully loaded within nickel foam (NF) to form NF/TpPa support by a solvothermal method. Subsequently, polyethylene glycol (PEG2000) was adsorbed into the three-dimensional backbone of NF/TpPa to prepare novel CPCMs. With the introduction of TpPa, the PEG can be stably anchored and prevented from leaking because of the capillary forces and hydrogen bonding. The effects of TpPa content and pore size of NF on the thermal characteristics of CPCMs were explored. The obtained PEG/NF/TpPa composites have high thermal storage capacity (118.26 J·g−1), excellent thermal reliability and 1.9 times thermal conductivity of pure PEG. The pore size of NF has a positive correlation with the thermal conductivity of CPCMs. Remarkably, the solar-thermal conversion and storage capacity of CPCMs are greatly improved by TpPa, with its outstanding capacity for light absorption and high surface areas. The solar-thermal conversion efficiency of CPCMs ranges from 89.58% to 96.80%, which is higher than many of the currently reported solar-responsive CPCMs.

Thermal properties of phase change materials ionic liquid/fatty acids for thermal energy storage applications

Researchers have developed advanced energy storage techniques in response to the depletion of energy resources and the escalation of environmental problems caused by increasing population and technological advancements. One of the most promising methods to overcome such issues is the latent heat thermal energy storage (TES) method, which employs phase change materials (PCMs). TES using PCMs are an important category of novel materials that significantly contribute to the efficient use and conservation of solar energy and wasted heat. This work presents a new family of PCMs based on ionic liquid (IL) tris(2-hydroxyethylammonium) formate and fatty acids for the first time that operate in the temperature range of 50–150 °C and offer a safe and inexpensive capacity. Good chemical and thermal stability, low flammability, and low volatility along with the potential to tune chemical and phase properties provide an inherent “green” property for ILs that is well suited to PCMs. Using PCM3, tris(2-hydroxyethylammonium) formate/stearic acid, we demonstrate effective latent heat 246 J·g−1. The results of differential scanning calorimetry analysis show that the PCM2 tris(2-hydroxyethylammonium) formate/palmitic acid has a higher heat capacity 8.194 J·g−1·K−1 at the melting point than the other two PCMs due to its small alkyl chain. Thermal stability analyses show the maximum stability (98 %) for PCM3. Additionally, based on the structure of these PCMs, this study explores the molecular basis for the high thermal energy storage capacity of these materials and highlights the significance of hydrogen bonds in PCM performance. Using simple, cost-effective materials, this method gets around the complexity and expense of composite PCMs. We present design recommendations for implementing our approach in the management of thermal energy storage applications.

Effects of Visitor Influx on the Indoor Climate of the Milan Cathedral

The indoor climate of non-climatized churches is usually subject to cyclical fluctuations of temperature and relative humidity induced by external climate conditions which might be dampened by the high thermal capacity of their envelope. However, several phenomena affect their indoor climate (e.g., internal gains due to people and artificial lighting, air infiltration, etc.), which lead to environmental variations that might jeopardize the artworks contained within. In particular, one of the most influential parameters that may affect non-climatized churches is the massive and intermittent presence of people who constantly visit their spaces. In such regard, long-term monitoring allows the collection of environmental data with different building operation conditions and visitor fluxes. This paper analyses the indoor climate of the Milan Cathedral (Duomo di Milano) in Italy for three continuous years (including the lockdown period that occurred in 2020 caused by the COVID-19 pandemic), with a focus on visitors’ effects on the indoor environment and the conservation of the main artworks contained within. The results of the analysis have shown that spaces with huge volume are most influenced by the opening of the doors rather than the hygrothermal contribution of the intermittent presence of massive crowds. Moreover, the absence of visitors for a prolonged period correlates with an improvement in the indoor conservation conditions for artworks, especially those made of hygroscopic materials, due to the reduction in short, rapid climate fluctuations.

Energy, exergy and economic (3E) study on waste heat utilization of gas turbine by improved recompression cycle and partial cooling cycle

ABSTRACT As the bottom cycle of gas turbine waste heat utilization, the S-CO2 cycle can enhance the power output capacity of the system. Based on the energy analysis of the recompression cycle and the partial cooling cycle for gas turbine waste heat utilization, the two cycles are improved from the matching of heat exchange flow of regenerator and heater in this paper. Under the same parameters, compared with the cycle before improvement, increase in heat source utilization rate and net power output of improved cycles is 45.69% and 39.31%, 43.54 MW and 35.43 MW, and the power consumption cost is decreased by 0.6106 $/kWh and 0.6289 $/kWh. However, as part of heat recovery inside the system is replaced by the heat of the heat source, the thermal efficiency is decreased by 10.43% and 8.7%, respectively. Variable parameter study is conducted on the two improved cycles to analyze the cycle characteristics from the perspective of energy, exergy, and economy (3E). The results showed that the improved recompression cycle has a high thermal power conversion capacity, higher system thermal efficiency and exergy efficiency and lower power generation cost, while the improved partial cooling cycle has higher waste heat utilization potential. However, the area of heat exchangers in both cycles tends to increase, which is not conducive to the compactness of the system.

Enhanced solar/electric-to-thermal energy conversion capability of double skeleton based shape-stabilized phase change materials

In this work, we developed a type of shape-stabilized phase change materials (SSPCMs) based on carbonized melamine foam/graphene aerogel (CMGA) as a supporting material and polyethylene glycol (PEG) as a phase change material. [email protected] SSPCMs were prepared by fabricating a series of CMGA double skeleton with different carbonization temperatures using freeze-drying and high-temperature carbonization, followed by vacuum impregnation of PEG into the CMGA double skeleton. The morphological structure, thermal storage property, shape stability, thermal conductivity, and solar/electric conversion behavior of the fabricated SSPCMs are investigated. The results showed that [email protected] SSPCMs exhibited excellent shape stability, high latent thermal storage capacity of 181.2 J/g, thermal cycling stability, enhanced thermal conductivity with 387% higher than that of pure PEG, solar-to-thermal energy conversion capability with high efficiency of 91.7% and electric-to-thermal energy conversion capability with high efficiency of 87.3%. The results of this work provide a strategy for the design and development of high performance, multiple energy conversion forms of SSPCMs for promising applications in solar energy utilization, energy-efficient buildings, and heat preservation.

Ceramicization mechanism and thermal insulation/ablative properties of hollow microspheres/boron phenolic composites

Phenolic resins with excellent ablative properties and thermal insulation are required in aerospace technology. However, the composites suffer from pyrolytic carbonaceous residues, resulting in susceptible erosion and peeling. This work provides a novel phenolic resin composite with high thermal insulation capacity by introducing hollow silica microspheres (HSMs) as an insulation layer. The effect of HSMs content on the ablation behavior of the composites was investigated, and the ablation mechanism was elucidated. The results show that the composites with microspheres exhibit high uniformity and improved bending strength. By introducing microspheres, the fiber distribution is uniform, resulting in an increase of the bending strength after static ablation to be 7.4 MPa, which is 87% higher than the matrix. The thermal stability of the composite is improved simultaneously and the ablation residual rate after static ablation increases from 67% to 73%. When oxyacetylene ablation for 20 s at the oxygen and acetylene flow rates of 1145 L/h and 838 L/h, respectively, the microspheres construct an insulating network, and the back surface temperature decreases from 280 °C to 178 °C.

Highly Efficient, Antibacterial, and Salt-Resistant Strategy Based on Carbon Black/Chitosan-Decorated Phase-Change Microcapsules for Solar-Powered Seawater Desalination.

Solar-powered interfacial evaporation has been recognized to be a promising and sustainable technology for seawater desalination, in view of the challenge of freshwater scarcity and fossil energy storage. Nevertheless, current cutting-edge interfacial evaporation systems mostly ignore the issues of intermittent solar irradiation and bacterial contamination. We have hereby developed a novel type of an interfacial evaporator equipped with carbon black (CB)/chitosan (CS)-decorated phase-change microcapsules as a multifunctional photothermal material for solar-powered seawater desalination, based on a highly efficient, antibacterial, and salt-resistant multipurpose strategy. In the developed microcapsules, an n-docosane phase-change material (PCM) core was engulfed in a TiO2 shell, followed by surface decorating a CB/CS nanocomposite layer. A high thermal energy-storage capacity of more than 140 J g-1 was achieved, thanks to tight sealing of n-docosane as a PCM core in the perfect core-shell structured microcapsules. Moreover, a rational combination of CS and CB nanoparticles not only contributes an extremely high solar absorption efficiency of 95.04% and good wettability to the as-synthesized microcapsules, but also imparts outstanding antibacterial and salt-resistant abilities to them. These innovative designs enable the developed evaporator to gain a high evaporation rate of 2.58 kg m-2 h-1, along with an evaporation efficiency higher than 90% for consecutive and stable evaporation of seawater under intermittent solar illumination. Compared to conventional evaporators without a PCM, there is an increase by 1.03 kg m-2 in the total water production of the develop evaporator under natural solar illumination for 8 h on a semicloudy day. The resultant evaporated water presents good vegetation compatibility to meet the requirement of crop growth for agricultural cultivation. This work provides a new pathway for designing and developing the high-performance interfacial evaporators with prominent antibacterial and salt-resistant abilities to produce purified water through solar-powered sustainable seawater desalination.

Effect of a High Thermal Capacitance Core–Shell Structure on Co-Ru/SiO2 Catalyst for Low Temperature Fischer–Tropsch Synthesis

Effect of a High Thermal Capacitance Core–Shell Structure on Co-Ru/SiO2 Catalyst for Low Temperature Fischer–Tropsch Synthesis

Analysis and optimization of transient heat dissipation characteristics of high power resistors with a sensible heat storage method

The load voltage of the resistor will rise sharply when there is a control imbalance or short circuit in the circuit, and the resistance wire will fuse in a matter of seconds, causing the resistor to burn. Designing resistors with superior transient heat dissipation capabilities is therefore crucial. In this work, using sensible heat storage, various sizes of iron rods are developed and inserted into the ceramic to enhance heat transfer by utilizing iron’s high thermal conductivity. In addition, to maximize the material’s high thermal capacity for heat storage, ceramic blocks in the form of dumbbells were also put between the ceramic rods inside the resistor. The results demonstrated that both designs could enhance the resistor’s capability to dissipate heat. When iron rods with a diameter of 7 mm are inserted, the device’s capacity for heat storage is raised by 19.09 %, and its heat storage efficiency increases by 16.24 %. The device’s capacity for heat storage can be raised by 20.5 %, and its heat storage efficiency can be raised by 18.23 % by embedding a ceramic dumbbell with a 9 mm diameter.

Optimum Volume Fraction and Inlet Temperature of an Ideal Nanoparticle for Enhanced Oil Recovery by Nanofluid Flooding in a Porous Medium

Nowadays, oil companies employ nanofluid flooding to increase oil production from oil reservoirs. Herein the present work, a multiphase flow in porous media was used to simulate oil extraction from a three-dimensional porous medium filled with oil. Interestingly, the finite element method was used to solve the nonlinear partial differential equations of continuity, energy, Darcy’s law, and the transport of nanoparticles (NPs). The proposed model used nanofluids (NFs) empirical formulas for density and viscosity on NF and oil relative permeabilities and NP transport equations. The NPs thermophysical properties have been investigated and compared with their oil recovery factor (ORF) to determine the highest ORF. Different NPs (SiO2, CuO, and Al2O3) were used as the first parameter, keeping all parameters constant. The simulation was run three times for the injected fluid using the various NPs to compare the effects on enhanced oil recovery. The second parameter, volume fraction (VF), has been modeled six times (0.5, 1, 2, 3, 4, and 5%), with all other parameters held constant. The third parameter, the injected NF inlet temperature (293.15–403.15 K), was simulated assuming that all other parameters are kept constant. The energy equation was applied to choose the inlet temperature that fits the optimum NP and VF to determine the highest ORF. Findings indicated that SiO2 shows the best ORF compared to the other NPs. Remarkably, SiO2 has the lowest density and highest thermal capacity. The optimum VF of SiO2 was 4%, increasing the ORF but reduced when the VF was higher than 4%. The ORF was improved when the viscosity and density of the oil decreased by increasing the injected inlet temperature. Furthermore, the results indicated that the highest ORF of 37% was obtained at 353.15 K when SiO2 was used at a VF of 4%. At the same time, the lowest recovery is obtained when a volume of 5% was used at 403.15 K.

Unveiling sustainable nano-enabled phase change materials for high thermal stability and energy storage capacity

Thermal energy storage and conversion within phase change materials (PCMs) rely on the addition of supporting materials, such as nanomaterials, to improve leakage resistance and heat transfer properties. However, as the supporting fillers obtained from different sources and synthesis methods, the development of renewable and sustainable phase-change composites has received increasing attention in recent years. Here, we develop a phase change composite and adopt Ashby material selection alongside life-cycle assessment to compare and demonstrate the sustainability of different nano-enabled PCMs. The report considers both the environmental impact, economic feasibility and functional performance, including thermal conductivity and energy storage density. The assessment shows that biochar, a biomass derived carbon at low pyrolysis temperature, supporting paraffin composites shows an encapsulation efficiency of >50 %, high shape stability/leakage-resistance capability, suitable cumulative energy demand (100–1000 MJ/kg), and the lowest price (43.00 $/kg with one volume concentration) and price-performance ratio (0.48 $/kJ) In addition, the phase change composite exhibited high chemical compatibility with paraffin, high leakage-resistance (above the pristine phase change temperature at 50 °C) and lowest thermal conductivity (<0.4 W m−1 K−1) compared with other carbon-based phase change composites, such as graphene and carbon nanotubes supported paraffin, which is desirable and demanding for practical integration in insulation and building thermal energy management applications and can be used as an alternative carbon-negative sustainable phase change composite to reduce dependence on mineral-based construction materials.

A novel strategy of thermal management system for battery energy storage system based on supercritical CO[formula omitted

Supercritical CO2 (sCO2) is examined as a working fluid for the first time in a unique thermal management strategy that aims to control undesirable thermal behavior in battery cooling applications. In the pseudocritical region, sCO2 has a high volumetric thermal capacity with low critical pressure and temperature, which not only reduces system complexity and costs but also eliminates the possibility of two-phase critical heat flux and flow instabilities. A pack of 20×5 Li-ion batteries for battery energy storage system (BESS) applications was designed and employed in a structurally optimized thermal management system. Further, the effects of different dielectric fluid media on the number of flow inlets, flow rates, and discharge rates were numerically investigated. Compared with conventional coolants, sCO2 exhibited superior temperature suppression and temperature differences. The rise in both mass flow rate and the number of flow inlets significantly suppressed the maximum temperature and temperature difference. Besides, the pressure drop was slightly increased with the increased mass flow rate. Moreover, sCO2 controls the thermal behavior of a large battery pack at high discharge rates within an optimal range. The finding offers various attributes for cooling large battery packs, particularly for high-power grid stations and BESS. In the future, the practicality of high working pressures and power requirements for the pump should be carefully studied.

Termička barijera u zavarenim spojevima ugljeničnih čelika

When welding carbon steels, a part of the metal of the heat affected zone directly next to the weld bath undergoes austenitic transformation, which is characterized by a combination of minimal thermal conductivity and high thermal capacity. This zone represents a thermal barrier and prevents heat transfer from the weld bath to the base metal. In addition, this zone is able to accumulate and retain a significant amount of heat for a certain period of time. In the heating phase, this barrier has a positive effect on the formation of welded joints, and in the cooling phase it causes a negative effect - the formation of hot or cold cracks, overheating and brittleness of the metal. The negative influence of the thermal barrier on the metal of welded joints increases with the increase of carbon content and alloying elements in steel, and also with the increase of heat input into the welded joint. Currently, an effective means of reducing the negative impact of the thermal barrier on the metal of welded joints is to reduce the heat input to the welded joints and their periodic cooling. Maximum efficiency is achieved in the case of a combination of these two techniques.

Behavior of Steel-Fiber Reinforced Lightweight Self-Compacting Concrete Containing LECA after the Exposure to Internal Sulfate Attack

For many years, lightweight concretes (LWC) have been utilized successfully in the construction of buildings because of their low specific weight, high thermal insulation capacity, and sound insulation. The development that led to lightweight self-compacting concrete (LWSCC) is a significant step forward in recent years. These concrete chains self-compacting concrete's beneficial properties with lightweight concrete. The purpose of this experimental investigation is to determine how the internal sulfates attack effect fresh and hard properties of lightweight self-compacting concrete (LWSCC) made by using lightweight expanded clay aggregate (LECA) before and after the addition of 0.5 volume fraction (Vf) of steel fibers. In fine aggregate, several concrete mixes were cast in different SO3 percentages (0.34, 2, 4, and 6%). The fresh properties of LWSCC concrete were tested, such as (slump, sieve segregation resistance, and L-box test). The hard properties of LWSCC were (Compressive, splitting tensile strength, flexural strength, oven-dried density, and modules of elasticity). The results showed that the presence of SO3 in fine aggregate affects the properties of LWSCC. A significant decrease in fresh properties of LWSCC mixes with (2, 4, and 6%) of SO3 in fine aggregate. In addition, the mechanical properties (compressive St., splitting tensile St., flexural St., density, and modulus of elasticity) decreased as curing age increased, and SO3% increased. When sulfate percent rose from (0.34% to 2%, 4%, and 6%) in compressive St., the reduction was (16.53, 22.45, and 26.47%) at 120 days. Adding 0.5% Vf of steel fiber enhanced the mechanical properties of LWSCC.

Numerical optimization and experimental study of a novel multi-mode chilled beam

• The novel chilled beam can operate as three modes to meet various thermal needs. • Simulation of airflow and heat transfer in the novel beam validated by experiment. • New beam’s high thermal capacities demonstrated in simulation and lab tests. • Novel chilled beam is able to merge the advantages of two beams in one unit. • Simulation-based optimization proved effective and efficient in design process. Chilled beams have been widely used in many regions of the world due to the high energy efficiency and satisfactory thermal comfort they provide. This paper employed a CFD based optimization strategy to develop a novel multi-mode chilled beam (MCB) that could merge the advantages of both passive chilled beam and active chilled beam units. Depending on the specific thermal requirement of indoor space, the novel chilled beam could operate as three different modes which were fast cooling mode, fast heating mode and gentle cooling mode. With the optimal design parameters achieved through numerical optimization, a prototype was built for model validation and a comprehensive performance evaluation. Results showed that the cooling and heating capacities of the optimized MCB unit could reach 3600 W and 4000 W, respectively. Compared with conventional HVAC systems, MCB system improved the energy efficiency could by 9.2% under gentle cooling mode and by 19.0% under fast cooling mode. The noise level for the new chilled beam could be as low as 19.8 dB, providing a good acoustic performance. The CFD based optimization strategy, followed by experimental validation, proved to be an effective and efficient approach for developing a novel chilled beam unit.

Thermal Performance Assessment for an Active Latent Heat Storage Tank by Using Various Finned-Coil Heat Exchangers

Paraffin-based latent heat storage has a higher thermal capacity than sensible heat storage. Despite that, the actual implementation of paraffin as an active latent heat storage (ALHS) system is limited due to low charging and discharging rate with unequal temperature distribution as the impact of mushy region formation. The present study evaluates the finned-coil heat exchanger for the ALHS tank to overcome the related problems. Three finned-coil configurations are tested experimentally: straight-fin, branched-fin and height-fin. The evaluation uses the ALHS arrangement to assess each configuration's charging/discharging rate. The branched fin provides an equal thermal distribution, promoting a higher final temperature of 112.3°C. It also achieves the highest power rate of 250.5 Watts. The height-fin minimizes the effect of void formation, which maintains a sufficient heat transfer rate during the discharging. However, the average power rate for each model is relatively low. The finding indicates that it is essential to provide adequate heat transfer for the center part of the tank, including adding a branched fin along with coil turn to provide a better heat transfer rate. It boosts the charging/discharging rate, making the system's response time desirable to achieve effective power during the operation.

TiN doped Ni–Co bimetal organic framework based-composite phase change material with enhanced photothermal conversion performance

Shape stability and excellent photothermal conversion performance are critical for composite PCMs in the field of solar energy utilization. This study prepares a nickel and cobalt-based bimetal organic framework (Ni–Co-BTC) which is further employed as the supporting material for 1-octadecanol (OD). The flower-like Ni–Co-BTC with an interconnected network exhibits large specific surface area, pore volume, and appropriate pore size distribution, which is conducive to the encapsulation of OD (up to 70 wt%). In addition, TiN nanoparticles are added to enhance the photothermal conversion performance of composite PCM. Therefore, the obtained OD/Ni–Co-BTC/TiN composite PCM exhibits considerable thermal energy storage capacity (145.8 J/g) and remarkable photothermal energy conversion efficiency (up to 97.75%). Furthermore, the composite PCM has outstanding thermal stability and reliability, and the phase change enthalpy is reduced by only 1.7% after 100 cycles. Accordingly, the composite PCM shows a promising application potential in solar energy harvesting, conversion and storage. • Bimetal organic framework is used as a novel supporting material for PCM. • The incorporation of Co 2+ improves the loading capacity of Ni–Co-BTC for octadecanol. • OD/NCB/TiN displays high thermal energy storage capacity and thermal reliability. • The photothermal conversion efficiency of OD/NCB/TiN is up to 97.75% by dopping TiN.

Towards Predictive Maintenance of a Heavy-Duty Gas Turbine A New Hybrid Intelligent Methodology for Performance Simulation

As the increasing demands of global clean power for the main purpose of lowering environmental pollution, heavy-duty gas turbines are playing an increasingly important role in energy fields because of their low emission, high thermal efficiency and flexible start-up capacity. Accurate modeling and simulation of the turbine performance is extremely needed to precisely design a large-watt industrial heavy-duty gas turbine, which is still very challenging due to the high nonlinearity, system complexity, varying conditions, and strong coupling interaction of high-dimension parameters under the harsh operation environment of the turbine. In order to improve the accuracy and efficiency of the performance simulation model for a heavy-duty gas turbine at various operating conditions, this paper presents a new hybrid intelligent methodology to adeptly integrate system thermodynamic balance mechanism with multivariate data by seamlessly combing advanced signal processing, machine learning and artificial neural network modeling techniques. The thermodynamic model of a complicated single-shaft gas turbine is first created based on the balances of both flow and power in various subsystems including inlet, compressor, turbine, combustor and exhaust. The characteristic curves of compressor and turbine are utilized to accurately represent the physical mechanism and effectively simulate the high nonlinear behaviors of subsystems. Wavelet signal processing and machine learning based feature extraction are employed to preprocess the multivariate raw data of the turbine. Multilayer artificial neural network models are explored to efficiently simulate the start-up transient process of the turbine, thus improve the simulation efficiency and accuracy of the complicated system. Multivariate data collected from a real-world industrial heavy-duty gas turbine is employed to illustrate the effectiveness and feasibility of the proposed methodology.