Heat Exchanger System Research Articles

Thermochemical modeling and performance evaluation of freeze desalination systems

Freeze desalination (FD) is a method in which saline water is cooled below its freezing point and freshwater is separated from the brine in the form of ice crystals. FD is relatively insensitive to the salinity of the feed solution, making it suitable for desalination of high concentration brines such as the brine rejected from the seawater desalination plants. The design of the FD system and the thermochemical behavior of the brine upon freezing are critical factors in the energy performance of this method. To date, thermochemical properties of the concentrated seawater during cooling, such as the threshold of formation of ice and salt-hydrates and their corresponding cooling load of formation, are not well known. Likewise, the optimal configuration of the FD system to achieve the maximum energy efficiency has not been investigated. This work provides comprehensive data about the cooling load of freezing of concentrated brine rejected from seawater desalination plants along with the threshold of formation of ice and salt-hydrates backed-up by validation. Furthermore, the optimal configuration of the FD system is identified and the effects of the compressor isentropic efficiency and effectiveness of the system's heat exchangers on the work consumption of the FD system were investigated.

Analysis of an earth‐to‐air heat exchanger for enhanced residential thermal comfort

AbstractIt is well known that a massive demand for thermal comfort has resulted in a sharp rise in energy use for residential space heating and cooling. This article presents numerical simulations of a room coupled with an earth‐to‐air heat exchanger system operating at the climatic condition of 21.2497° N, 81.6050° E for both summer and winter seasons. The present study involves an estimate of monthly variations in soil temperature at different depths and a suitable geometrical arrangement of pipe is proposed. The thermal performance of the earth‐to‐air heat exchanger system in terms of the outlet air temperature and effectiveness has been calculated. It is shown that with an effectiveness of 0.77 in summer and 0.78 in winter, the present EAHE system reduces the ambient air temperature from 38 to 28.2°C in the summer and it rises from 13 to 22.9°C in winter, respectively. Finally, an improvement in the thermal comfort condition of the room exposed to the solar radiation has been examined at different time intervals and different heights of the room. During the summer the room temperature dropped by 4.2°C while in winter it rose by 5.2°C. Furthermore, the environmental effects of system have been evaluated, showing energy savings of 3.90 kWh/day during summer and 4.83 kWh/day during winter leading to a decrease in CO2 emissions of 6.13 kg/day in summer and 7.59 kg/day in winter.

Thermal and Viscous Irreversibilities Analysis in a Liquid Metal Phase Change Counter Flow Heat Exchanger

Sodium, a liquid metal, is utilized in a heat exchanger system coupled to a nuclear reactor to produce hydrogen. The subcooled liquid metal enters a counterflow heat exchanger, undergoes a phase change, and exits as superheated vapor. The sodium heating process occurs through heat exchange with superheated helium vapor in three phases: subcooled liquid, saturated vapor, and superheated vapor. This article analyzes the thermal and hydraulic performance of the three stages of the heat exchanger through thermal and viscous irreversibilities using analytical simulation. The solution obtained is based on applying the thermal efficiency method and the second law of thermodynamics. The thermodynamic Bejan number, the relationship between thermal irreversibility and total irreversibility, allows a cost-benefit analysis when determining thermal performance and viscous dissipation. The essential physical quantities used in the analysis are the lengths and internal diameters of the three segments of the heat exchanger. The results are analyzed and compared with previous analytical work published in the literature. Numerical and graphical results are obtained for temperature profiles, thermal effectiveness, heat transfer rate, thermal irreversibilities, pressure drops, viscous irreversibilities, entropy generation rate, and Bejan numbers. It is demonstrated that the cost-benefit is highly advantageous when the diameter used for the internal tubes of the three segments is equal to the diameter of the saturated sodium vapor section, corresponding to ¼ of the speed of sound in the tube.

Parametric Optimization and Efficiency Assessment of Horizontal Earth Water Pipe Heat Exchanger (EWPHE) in the Context of Bangladesh

This study aimed to evaluate the efficiency of the Earth Water Pipe Heat Exchanger (EWPHE) system in Bangladesh through simulation and experimental work carried out at Joypurhat in Bangladesh during the coldest period of the year, January. Additionally, the study sought to establish the method for selecting optimal installation parameters of EWPHE to increase performance and efficiency. A simulation model was made in the TRNSYS (v16.0) platform to determine the optimum values of design parameters. The simulation was run by altering its operating parameters, such as the rate of water flow, length of the pipe, built materials of the pipe, and the diameter of the underground pipeline. According to the findings, pipe burial can be done to a depth of 3.5 meters to achieve optimal output. The results of comparing four distinct materials, namely GI, Steel, PVC, and HDPE, show that these materials' characteristics do not significantly affect how well the systems perform. Additionally, as the water flow rate is increased, it is shown that the EWPHE performance is declining. According to the simulation results, it is concluded that a pipe with a length of 50 meters would be sufficient in the proposed EWPHE system to reach an average temperature decrease from 35 °C to 27 °C. Subsequently, in the field experiment, the EWPHE system had an average efficacy of 55% throughout January, which is quite promising. Journal of Engineering Science 14(2), 2023, 79-88

The Effects of Rotation and Solidity on the Aerodynamic Behavior of Low-Pressure Axial Flow Fans

Abstract Implicit axial flow fan models are commonly used for the numerical analysis of industrial heat exchanger systems. However, these fan models perform poorly within the often complex off-design flow environments characteristic of these systems, as their low-order formulations lose applicability under highly 3D flow conditions. At off-design flow conditions, rotation and blade solidity effects cause physical fan blade behavior to deviate from the anticipated 2D behavior characterized by the implicit models. Physical fan blade behavior at off-design flow conditions, however, remains uncertain and the specific effects of rotation and solidity are not yet widely understood. This study investigates off-design fan blade behavior by presenting explicit 3D computations of two low-pressure axial flow fans. The effects of rotation and blade solidity are then identified through a side-by-side comparison of the computed 3D fan blade data against isolated 2D airfoil data. The rotating fan blade lift characteristics are shown to be distinct from the comparative 2D airfoil trends. At low-flow (off-design) operating conditions, rotation establishes large radial flow movements, and the high blade solidities cause standing vortices to develop within the rotating blade passages. The radial outflow energizes the blades' boundary layers, and the vortices inhibit the flow from separating from the blades' surfaces. Consequently, blade stall is avoided and high lift coefficient values are realized. The presented fan blade lift characteristics are unique relative to literature on other turbomachines of lower blade solidity, highlighting the importance of considering solidity effects in implicit rotor model developments.

Performance of vacuum-insulated central pipes for deep borehole heat exchangers in geothermal systems

Abstract Geothermal energy is considered a promising future energy prospect, with the geothermal well outlet temperature being one of the important parameters affecting possible utilization options. For ground source heat pump applications or direct district heating, using lower temperatures can be acceptable. However, efficient electricity production requires a higher enthalpy gradient, which cannot be achieved without high temperature at the wellhead. The selection of the dry co-axial close-loop deep borehole systems (DBHE) may be, in some cases, very beneficial. The operating performance of co-axial DBHE can be optimized if the undesired heat transfer between the central pipe and annular fluid zones is minimized. Therefore, the operational performance of such a system depends strongly on the high thermal resistance of the central pipe. The most common option would be a low thermal conductivity material, such as high-density polyethylene (HDPE). In addition, vacuum-insulated tubing (VIT) used as the central pipe could be considered. The article presents results from the study aimed at the comparison of the homogeneous central pipe made of HDPE material and the gap-insulated central pipe. In the study, various air pressure levels as well as variations of surface emissivity were examined to reveal the effect on the heat transfer between the fluid channels. The simulation has been performed using a new purposely developed WellTH simulation software. A coaxial heat exchanger system using a VIT outperforms significantly the heat exchanger with an HDPE for deep geothermal wells. However, this advantage diminishes for shallow wells and therefore this tendency should be considered in the design stage.

Consequence of the direction of uniform horizontal magnetic field on nanolubricant flow over a permeable rotating disk

In order to reduce friction between moving elements in automobiles’ heat exchange systems, SAE50 is a vital lubricant. Additionally, by preventing corrosion and abrasion of moving parts, it increases durability, reduces fuel consumption, and improves efficiency. SAE50 has a low thermal conductivity, despite this. The current inquiry is concentrated on how Zinc Oxide-Society of Automotive Engineers 50 nanolubricant flow (ZnO-SAE50 nanolubricant) through a permeable rotating disk is affected by a uniform horizontal magnetic field (UHMF) and thermal radiation. By employing the appropriate transformations, the governing modeled equations are changed into ordinary differential equations (ODEs). Then the ODEs are solved numerically by combining the Runge–Kutta-fourth-and-fifth Fehlberg’s (RKF-45) order and shooting tactic. The findings show that radiation is crucial in enhancing heat transfer for the flow of ZnO-SAE50 nanolubricant over the disk surface. With higher heat source/sink parameter values, it is discovered that the temperature boundary layer produces energy, causing thermal profiles to rise. Further in this scenario, it is found that the increase in magnetic field decreases the fluid flow gradually at rate of 5–10%.

A reinforcement learning-based temperature control of fluidized bed reactor in gas-phase polyethylene process

This study investigates using deep reinforcement learning (DRL) with proportional-integral-derivative (PID) control for temperature cascade control in a fluidized bed reactor within a commercial gas-phase polyethylene process. The heat exchange system's nonlinearity and frequent disturbances pose challenges for PID controllers, particularly under varying conditions. To address this, a PID-DRL cascade control scheme is developed, where a DRL controller is used in the secondary loop. The DRL controller, designed using the actor-critic framework, is trained using the Deep Deterministic Policy Gradient algorithm. The DRL controller is evaluated in three stand-alone secondary loop experiments, as well as three cascade control experiments. Results reveal the DRL controller surpass the traditional PID controller in both scenarios. The DRL controller shows better set point tracking and interference suppression, indicated by lower integral absolute error (IAE) values. The proposed cascade control structure can be used to enhance reactor stability and product quality in gas-phase polyethylene processes.

Thermal performance of medium-deep U-type borehole heat exchanger based on a novel numerical model considering groundwater seepage

The medium and deep U-type borehole heat exchanger (MDUBHE) system is a novel technology to extract deep geothermal energy for building heating. The thermal performance of MDUBHE is influenced by multiple factors, where groundwater seepage is one of the most significant factors. To our best knowledge, the effects of groundwater seepage on MDUBHE are still unclear. In this paper, a novel numerical heat transfer model for MDUBHE considering groundwater seepage is proposed, and validated by CFD simulation and experimental data, with root mean square errors of 0.5 °C and 1.8 °C, respectively. Based on the novel numerical model, the effects of groundwater seepage on thermal performance of MDUBHE and thermal recovery characteristics of rock-soil are investigated. The results show that the computational efficiency of the novel numerical model is improved by two orders of magnitude compared with CFD software in the same case. The heat extraction rate of MDUBHE gradually increases with increase of seepage velocity. The heat extraction rate is improved by 13.63 % when the seepage velocity is 5.0 × 10−7 m/s. Furthermore, groundwater seepage can improve the thermal recovery rate of rock-soil. Compared with no groundwater seepage, the thermal recovery rate is improved by 7.60 % when the seepage velocity is 1.0 × 10−7 m/s. This study is significant for revealing the effect of groundwater seepage on the MDUBHE system.

Influence of liquid layer height on pressure pulsations during evaporation/boiling under reduced pressure conditions

The paper presents experimental data on the influence of the height of the horizontal liquid layer on the amplitude of pressure pulsations obtained during evaporation/boiling under reduced pressure conditions. Also presented are the spectra of pressure pulsation power versus frequency obtained using fast Fourier transform for different heights of the horizontal liquid layer under reduced pressure conditions. It is obtained that the use of a thin film of working fluid during evaporation/boiling under reduced pressure conditions reduces the amplitude of pressure pulsations compared to thicker fluid layers. Analysis of the pressure pulsation spectra for explosive boiling regimes allows us to determine the characteristic frequency corresponding to the periodicity of explosive boiling. Also, this approach allows a quantitative comparison of the power of pressure pulsations obtained in different heat exchange systems and apparatuses.

A study on flow distribution characteristics of heat exchanger module integration scheme for aircraft environmental control system based on CFD

With the rapid development of the civil aviation industry, the performance requirements of the environmental control system for domestic commercial large aircraft are gradually improved, and the ram air inlet heat exchanger system is its main component. Generally speaking, a ram air heat exchanger system mainly includes an air conditioning system heat exchanger, air preparation system heat exchanger, and auxiliary cooling system heat exchanger. The integration mode of the heat exchanger will directly affect the flow and flow distribution characteristics of the ram air heat exchanger system. This paper develops three integration schemes referring to the integration mode of heat exchangers in Boeing 787 and Airbus 350 aircraft. Based on Fluent software, the calculation and simulation of three integrated scheme models under the seven working conditions of taking off, climbing, cruising, descent, hovering, emergency, and landing during flight were carried out, and the flow distribution and flow resistance values of different schemes were obtained, which were compared to meet the heat transfer requirements.

Investigation of various hybrid nanofluids to enhance the performance of a shell and tube heat exchanger

<abstract> <p>In this study, we aim to investigate the heat transfer and flow characteristics of diverse hybrid nanofluids (CuO-ZnO-Water, EG-Water, CuO-EG-Water, SiO<sub>2</sub>-EG-Water, and Al<sub>2</sub>O<sub>3</sub>-EG-Water) as coolants across eight discrete inlet velocities in a shell and tube heat exchanger. Various materials (copper, stainless steel, titanium, and carbon steel) have been employed for the tubing to optimize system performance. The impact of Reynolds number concerning hybrid nanofluids on Nusselt number and friction factor was assessed in this research. The results of the numerical simulations are found to agree well with experimental results within an average deviation of 1.8%. The results indicated the superior heat transfer capabilities of the hybrid nanofluid compared to the base fluid across all conditions. The outcomes revealed the superior heat transfer capabilities of the CuO-ZnO-Water hybrid nanofluid under all tested conditions. When employing CuO-ZnO-Water as a coolant, a substantial increase of over 9% in temperature reduction was observed, as opposed to the approximately 6% attained by other hybrid nanofluids at a lower velocity of 0.5 m/s. Notably, higher Reynolds numbers corresponded to increased Nusselt numbers and decreased friction factors. The decline percentage of the friction factor was 43% at Reynolds number ranging between 10,000 to 40,000. We emphasize the imperative need to optimize nanoparticle types for crafting hybrid nanofluids to enhance the performance of industrial heat exchangers and their coolant efficiency. Ultimately, the utilization of hybrid nanofluids in conjunction with shell and tube heat exchanger systems has yielded a notable enhancement in the overall thermal efficiency of these systems.</p> </abstract>

Digital twin of heat exchange station

The article describes the identification of a heat exchanger system using PLC for measurement, followed by system model identification and reconstruction in Matlab Simulink and SIMIT. The root-mean-square error of the identified system was 2.49 % on training data and 5.33 % in the validation scenario. The system model is suitable for predicting and simulating errors and anomalies; it can be used for the optimisation of control processes or system parameters. Therefore, the model can serve as an educational tool, allowing training of students, operators and other experts. They can experiment without fear of damaging components and without having to wait for the long-time transients of a real system.

Influence of geometric factors on the heat transfer characteristics of two-phase thermosyphons

Thermosyphons are two-phase closed heat exchange systems that contain a certain amount of liquid and utilize the latent heat of vaporization and condensation to transfer heat between the heat source and the heat sink without any external devices. They are a type of heat pipe that lacks a capillary structure, so the return of the condensed coolant from the condensation zone to the heating zone is driven by gravitational forces. Due to the absence of a capillary structure, thermosyphons exhibit lower resistance to the movement of the vapor-liquid mixture from the heating zone to the condensation zone, as well as to the return flow of the condensate. A distinctive feature of such systems is their high equivalent thermal conductivity, which is several orders of magnitude greater than that of natural metals (such as copper or silver). Because of their superior heat transfer characteristics, thermosyphons are widely used in various technical fields, including the chemical and petroleum industries, electronics, telecommunications devices, energy storage systems, and geothermal heating systems, among others. This paper presents experimental data on the heat transfer characteristics of two-phase thermosyphons with an internal diameter of 9 mm and lengths of 500, 700, and 1000 mm, using water as the coolant. The filling ratio (Fr) varied from 0.3 to 1.2. The length of the condensation zone was the same for all thermosyphons. The study was conducted with the thermosyphons oriented vertically at an angle of 90° relative to the horizontal. The influence of the filling ratio and the effective length of the thermosyphons on the minimum thermal resistance, the maximum heat flux, and the equivalent thermal conductivity is analyzed.

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.

Innovative approaches for deep decarbonization of data centers and building space heating networks: Modeling and comparison of novel waste heat recovery systems for liquid cooling systems

The data usage surge drives greater data center demand, amplifying global CO2 emissions. Mitigating climate change necessitates reducing data center CO2 emissions. Reusing waste heat from data centers offers a potential energy efficiency boost and environmental impact reduction. This study utilizes liquid cooling technology to raise waste heat temperature for building space heating and introduces the concept of ‘data furnaces,’ where data centers directly supply waste heat to heat buildings on-site, reducing district heating consumption and lowering CO2 emissions. Efficiently designing a heat recovery heat exchanger system that accounts for both heat rejection and cooling sides of a liquid cooling system is crucial for achieving complete heat recovery without using heat pump, a commonly overlooked aspect in existing literature. To address this issue, we propose two heat exchanger schemes: connecting the building space heating network to the secondary side (Scheme 1) and the primary side (Scheme 2) of the cooling distribution unit. Implementing these innovations leads to the elimination of dependence on a heat pump, substantially cutting energy and CO2 emissions. Using TRNSYS software, we develop, model, and compare waste heat recovery schemes to curb district heating consumption and CO2 emissions. To demonstrate broad implications of the proposed approaches for energy efficiency and sustainability in the data centers and building space heating networks, a showcase study examines constant 25 kW waste heat from a direct-to-chip liquid-cooled rack in an office building with 285.7 MWh annual space heating demand. A novel waste heat recovery rate relationship graph is created to assist system design, uncovering an unexpected result in Scheme 2: waste heat recovery decreases as outdoor temperature falls. In contrast, Scheme 1 maintains a stable waste heat recovery rate around 25 kW, regardless of outdoor temperature fluctuations. As a result, Scheme 1 reuses 155.2 MWh of waste heat annually compared to 138 MWh for Scheme 2. Schemes 1 and 2 yield annual electricity savings of 2290.5 kWh and 905.2 kWh, respectively, for the cooling system. Both schemes achieve profitability within a year through a 25-year life cycle analysis (LCC) and substantially reduce CO2 emissions, with Scheme 1 saving 291,996 kgCO2 and Scheme 2 saving 258,192 kgCO2. The study addresses critical gaps in existing literature by emphasizes LCC. The proposed heat exchanger designs represent pioneering solutions for optimizing waste heat recovery, particularly in challenging climates. New findings offer substantial benefits to both liquid-cooled and air-cooled facilities, making significant contributions to achieve carbon neutrality in data center operations.

Prototype for a shallow geothermal installation for the air conditioning of spaces at a Colombian University

From a literature review, various concepts and methodologies useful for the development of the preliminary stages of planning and design of a ground source heat pump were documented. A prototype of a cooling system for a room in the Universidad EIA was proposed. The heat pump selected to supply the demand has a power of 1-9 kW, and the proposed heat exchanger system corresponds to a closed-loop horizontal slinky-type with an approximate pipe length of 1,301 m, which was calculated through Excel spreadsheets and configured in three or six trenches with a total area required for the installation of 911 and 952 m2, respectively. These results provide the initial conditions for the implementation of an air conditioning project at the site, using shallow geothermal energy. Other alternatives for the heat exchanger systems and considerations for future projects are also presented.

Numerical investigation on the long-term heating performance and sustainability analysis of medium-deep U-type borehole heat exchanger system

Exploiting low-carbon, clean, and stable medium-deep geothermal energy is critical to achieving clean and sustainable heating for buildings in northern China. The medium-deep U-type borehole heat exchanger (MDUBHE) system is a novel technology that has emerged recently for exploiting deep geothermal energy. However, previous studies mainly analyzed the heating characteristics of the MDUBHE system in a single building type (i.e., continuous operational conditions), and the long-term (15-year) heating performance under different operational conditions is still unclear. Moreover, the heating sustainability of the system in different regions has not been clarified. Therefore, to promote the application of the MDUBHE system, this paper conducts numerical simulations to analyze the system's long-term heating performance, thermal recovery characteristics of rock and soil, and the system's energy efficiency under different operational conditions and regions. The results show that the MDUBHE system has high heating sustainability under different working conditions. After 15 years of operation, the maximum decay rate of MDUBHE's outlet water temperature is less than 3.15 % under different operating conditions and less than 3.01 % in different regions. In addition, the maximum decay rate of total system heating capacity is less than 8.86 % under different operating conditions and less than 7.60 % in different regions. Furthermore, the intermittent operation of the system and the higher thermophysical properties of rock and soil can enhance the rock-soil's thermal recovery. The MDUBHE system can efficiently operate over the long term under different working conditions. The maximum decay rates of the system's energy efficiency are less than 1.86 % under different operating conditions and less than 1.60 % in different regions. The study could promote the application of the MDUBHE system in different regions.

Effective thermal-electric control system for hydrogen production based on renewable solar energy

This paper focuses on the design and use of a control system for a renewable energy production plant based on hydrogen. The proposed control system aims at ensuring the stability and smooth functionality of the plant, which consists of a (i) photovoltaic system connected to an electrolyzer through a battery, (ii) a DC/DC step down transformer, and (iii) an electrolyzer heat exchange system. In this study, solar irradiance is the main system input, and hydrogen production the main output. Since the system utilizes solar energy as input, it depends on the random input of solar irradiance, ambient temperature, and wind flow. Furthermore, the electrolyzer's functionality is subject to several operational variables including cell voltage, current, temperature, and pressure. The electrolyzer heat exchange system operates at specified water temperatures and flow rates. The DC/DC output voltage, and therefore the voltage supplied to the electrolyzer, is regulated by changing its duty cycle. To regulate hydrogen production in the renewable energy production plant, an efficient control system is required. Accordingly, in this work, a control system is designed accounting for three different electrolyzer technologies, alkaline, PEM (proton exchange membrane), and E-TAC (electrochemical - thermally activated chemical water splitting). Subsequently, the effectiveness of the control system is analyzed using Matlab and Simulink models. The main results indicate that the battery is a crucial element in the whole system as it supplies the necessary energy to the electrolyzer. By regulating the appropriate components, the proposed control system proved capable of minimizing power fluctuations and increasing system efficiency up to 20% depending on ambient conditions. Additionally, the results indicate E-TAC and PEM efficiencies 13% and 7% higher than alkaline, respectively.

Study on the Effects of Thermal Shaping for 316L Heat Exchange System of Submersible Vehicle on Fatigue Life

In this paper present the effects of 316L steel in the environment of repeated heat load, and the impact of the thermal load on fatigue life. Using thermal fatigue experiments and ABAQUS software, rain flow counting method is used to simplify the strain cycle spectrum of stress load. The Coffin-Manson nonlinear empirical equation was established based on thermal fatigue experiments, and the fatigue life estimation was completed in accordance with the Miner damage accumulation rule and FE-SAFE fatigue software. The test rods were respectively placed at room temperature and heated at 250°C for water cooling for tensile testing. Fatigue tests were performed with 5 strain parameters (0.8%, 0.7%, 0.6%, 0.5% and 0.4%). ABAQUS and FE-SAFE software used to study 316L testing rod fatigue life verification analysis. A composite heat exchange system model made of 316L was designed for the case study. It is found that the fatigue life after heating is reduced by 35% to 12% from the experimental results and numerical simulation calculation. Therefore, when the 316L steel is subjected to thermal fatigue, the fatigue life will be reduced. The research results can provide a reference for the design of heat exchangers using 316 steel in various fields.