Plate-type Heat Exchanger Research Articles

해양복합온도차발전용 복수기 증기 취출 유동 해석

The concept of C-OTEC (Combined-Ocean Thermal Energy Conversion) was proposed to run a heat engine using the temperature difference between the steam exhausted into the condenser of an existing power plant and the deep sea water. To vaporize a working fluid of the heat engine, saturated steam in the condenser needs to be extracted to the evaporator of C-OTEC. Installation of steam guide vanes inside the condenser is considered to effectively extract steam from the condenser to the C-OTEC evaporator. In the present study, three-dimensional computational fluid dynamics analysis of flow inside the condenser with various sizes of steam guide vanes is conducted. Influences of the steam guide vane size upon flow and pressure distributions in the condenser are analyzed using the conventional CFD method while fluid flow and pressure drops inside small complicated channels of plate-type heat exchanger units in the C-OTEC evaporator is equivalently simulated using the porous medium approach. It is found from the analysis results that as the steam guide vane diameter increases, the steam extraction rate as a figure of merit linearly increases while the condenser pressure rise as a penalty exponentially increases. As a result, an optimal size of the steam guide vane for the condenser analyzed in the present study is proposed.

Consecutive charging and discharging of a PCM-based plate heat exchanger with zigzag configuration

Due to the remarkable energy savings, isothermal nature of the operation and low costs, energy storage with phase-change materials (PCMs) is a reliable technology for filling the gap between energy supply and demand. In this paper, an attempt has been made to modify the storage functionality of PCM in a plate type heat exchanger with zigzag configuration. A two-dimensional, time-dependent simulation model for the PCM phase transition during the charging and discharging modes has been developed and validated via earlier related findings. The effects of zigzag angle orientation, inlet flowrate and mean temperature of the heat transfer fluid (HTF) are thoroughly studied and revealed. Results show that increasing the angle of zigzag orientation has no noticeable impact on the development of phase transition during the early stages of operation. However, this effect becomes more noticeable and almost leads to faster storage/retrieval rates as time further elapses. It is found that the system with the zigzag angle of 60° augments the storage rate by 32.6% compared with the system of 30° zigzag angle. Also, higher HTF temperature and/or higher Reynold number result in faster phase-transition rates during both parts of the energy charging-discharging cycle.

Pipe sizing of district cooling distribution network including in energy transfer station

A district cooling system (DCS) distributes chilled water to different buildings connected to the main plant. The benefits of a DCS include greatly increasing energy efficiency and decreasing life cycle operation costs. The installation, maintenance, and design of a DCS can be expensive, however. Therefore, means of decreasing costs without cutting quality is necessary. Given this, a hypothetical DCS is presented with a constant temperature difference set-point of 9°C. The DCS was set to have a system diversity of about 80%. Hydraulic calculation will be used in the study in order to determine the smallest possible pipe sizes that would permit normal operation below allowable limits. The network is divided into 3 parts; namely the main line (ML), the plot take-off (PTO), and the plate-type heat exchangers (PHEs). The DCS will have a piping network connected to 12 energy transfer stations, each with 3 sets of PHEs. Initial guess values of pipe dimensions and friction factors will first be calculated using continuity and the Von Karman equation. A single-variable Newton-Raphson method is then used on the implicit Colebrook-White equation to estimate the actual friction factor for each pipe. Then, the calibrated pipe sizes will be determined by cross-referencing theoretical values with industry-standard sizes as specified in ASHRAE. In calculating the friction factor, it was found that the values increase as the given tonnage decreases, thus implying a decrease in pipe size as the chilled water flows toward the last building. The entire study was conducted on MATLAB. It must be noted that the study is only limited to the selection and design of a simple DCS.

Performansi Pipa Bersirip Alat Penukar Kalor Udara-Tanah Menggunakan Siklus Terbuka

In heat exchanger analysis using the Earth Air Heat Exchanger method, the overall heat transfer coefficient is known. This tool uses tubes in its design. The weakness of tube and plate type heat exchangers is the relatively low heat transfer coefficient, which can only reach a maximum of 60%. Therefore, a method to improve the heat transfer efficiency is using a fin. The purpose of this study is to calculate and compare the effectiveness (ε) value of experimental and theoretical of the Earth Air Heat Exchanger, as well as to find out the value of the coefficient of performance. The result showed that the average COP value of the experimental result is 0.63 at a speed of 1 m / s, 0.54 at the speed of 2 m / s, and 0.75 at the speed of 3 m / s, while theoretically is 0 , 73 at 1 m / s, 0.57 at 2 m / s, and 0.80 at 3m / s. For the value of the average effectiveness of the experimental results obtained 0.85 at the speed of 1 m / s, 0.93 at the speed of 2 m / s, and 0.89 at the speed of 3 m / s, while the theoretical result is 0.995 at the speed of 1 m / s, 0.997 at 2 m / s, and 0.998 at 3 m / s.

Energy cost and efficiency analysis of greenhouse heating system enhancement using phase change material: An experimental study

The growing production of greenhouse gases and fossil fuels price obligated decision-makers in communications to implement energy sources more efficiently. The greenhouses have been developed through the years for the safe production of food sources. Thermal energy devotes a large portion of energy need in greenhouses. In developing countries, the rate of fuel consumption in the greenhouse is high, and there is an urgent need for improving heating systems. Here the possibility of reusing and storing the waste heat by phase change material (PCM) in a sample greenhouse studied experimentally. The PCM heat recovery system (PCM HRS) is a20cm×50cm×140cm plate type heat exchanger where the plates are replaced with PCM plate containers. The charge and discharge of the system are performed in two separate sections. The discharge stage organized in two separate schemes: delivering the stored heat directly inside the greenhouse space and using stored heat to preheat the combustion air of the burner. The heating system analyzed from the viewpoint of energy and the results show that the effect of preheating the heater air gives rise to a 23.7% reduction of gas consumption and the effect is much more pronounced compared to the direct using of the stored heat. Also, the resulted energy saving obtained by using the PCM HRS returns the initial investment within four months.

Condition Monitoring and Predictive Maintenance of Process Equipments

Industry 4.0 the proclaimed fourth industrial revolution is unfolding at the moment. It is characterized by interconnectedness and vast amounts of available information. Industrial production has evolved enormously over the last centuries due to modern instruments. Hence issue of the instrument failure is very paramount in any industry. Even if one machine fails it halts the whole production. Overall, it may cost us with more man-hours, project delay, process latency and all this sums up as a huge loss. The life of the instruments should be taken care by continuously monitoring its health. Any faulty or unnatural disturbance in usage of the instrument may lead to its failure. Every instrument needs proper maintenance, even with the slight negligence towards the anomaly it may lead to instrument failure. In, predictive maintenance historic data is utilized and analyzed with the help of advance analytics and modelling techniques using Machine learning, moreover we can predict failures and can schedule the maintenance beforehand and predict failure in advance. With the help of relevant sensor dataset, we can estimate the remaining runtime of the instruments. This maintenance approach helps to lower the costs which are incurred due to system shut downs. It also ease the scheduling and maintenance activities.In this work, three different industrial case studies are considered like shell and tube type heat exchanger, plate type heat exchanger, and semiconductor manufacturing process.Here the predictive maintenance is carried out for heat exchanger by utilizing the concept of multi linear regression and time series analysis. For the semiconductor manufacturing dataset, support vector machine algorithm is implemented to find out the good and bad quality of semiconductor production slots.

Batch Scheduling Algorithm with Approximation of Job Completion Times and Case Studies

Many small and medium-sized manufacturing companies process various product types to respond different customer orders in a single production line. To improve their productivity, they often apply batch processing while considering various product types, constraints on batch sizes and setups, and due date of each order. This study introduces a batch scheduling heuristic for a production line with multiple product types and different due dates of each order. As the process times vary due to the different batch sizes and product types, a recursive equation is developed based on a flow line model to obtain the upper bound on the completion times with less computational complexity than full computation. The batch scheduling algorithm combines and schedules the orders with same product types into a batch to improve productivity, but within the constraints to match the due dates of the orders. The algorithm incorporates simple and intuitive principles for the purpose of being applied to small and medium companies. To test the algorithm, two case studies are introduced; a high pressure coolant (HPC) manufacturing line and a press process at a plate-type heat exchanger manufacturer. From the case studies, the developed algorithm provides significant improvements in setup frequency and thus convenience of workers and productivity, without violating due dates of each order.

Nano fluids effect on crossflow heat exchanger characteristics – Review

Abstract The main objective of moderation in the heat transfer equipment is to utilize the vitality and capital cost. The Cooling system's thermal performance is mainly based on the Performance of the heat exchanger. The cross-flow heat exchanger works more efficiently with a high rate of heat transfer when compared with shell and tube heat exchanger, spiral heat exchanger, and plate type heat exchanger. One method of enhancement of heat transfer rate in different types of heat exchangers is possible with the use of nano fluids instead of plain fluids. In extent, the study focuses on the specialist's improvement in experimental and analysis of cross-flow heat exchanger which incorporates structure, experimental outcomes with different fluids like air, water, Nano fluids and further more numerical analysis (CFD, COMSOL and ANN). Various investigations have revealed enhancements in heat transfer by a heat exchanger by means of the utilization of nanofluids acquired by suspending X2O3 type oxides, for example, Al2O3, TiO2 and SiO2 in water. Cross flow heat exchanger mostly used for hygienic standards at large canteens, hospitals, food industries and they will not exchange humidity like a rotary heat exchanger.

고온수 온도에 따른 축열식 판형 열교환기의 축/방열 특성

Heat pump systems for high-temperature steam generation using waste heat generated in industrial sites are attracting attention. However, the disadvantage of waste heat is that it fluctuates quantitatively and qualitatively during the acquisition process. This study proposes the combination of the heat exchanger and thermal storage tank in a high-temperature heat source system to enhance the use of industrial waste heat as an energy source. The developed thermal storage type heat exchanger has a plate type heat exchange structure and allows mutual heat transfer between three mediums, including a phase change material (PCM). Named a thermal storage type plate heat exchanger (TSPHE), it comprises 16 kg of a PCM, with a phase change temperature of 68.8℃ to provide heat storage function. The heat storage and release characteristics of the PCM according to the temperature of hot water and cold water were verified through a heat transfer experiment using the TSPHE. Also, because of the structural characteristics of the TSPHE, the phenomenon of the three-medium heat exchange was verified during the experimental process. The heat storage and heat dissipation characteristics according to the supply temperature conditions of the heat medium used in the TSPHE were analyzed. The results of this study will be used as basic data for applying a thermal storage type evaporator to a high-temperature heat pump that generates steam using industrial waste heat.

Design and Performance Test of 2 kW Class Reverse Brayton Cryogenic System

With the increased commercialization of high-temperature superconducting (HTS) power cables cooled using liquid nitrogen and the use of liquefied natural gas as fuel, the need for large-capacity reverse Brayton cryogenic systems is gradually increasing. In this paper, the thermodynamic design of a reverse Brayton cryogenic system with a cooling capacity of the 2 kW class at 77 K using neon as a refrigerant is described. Unlike conventional reverse Brayton systems, the proposed system uses a cryogenic turbo-expander, scroll compressor, and plate-type heat exchanger. The performance test conducted on the fabricated system is also described. The isentropic efficiency of the cryogenic turbo-expander was measured to be 86%, which is higher than the design specification. The effectiveness of the heat exchanger and the flow rate and operating pressure of the refrigerant were found to be lower than the design specifications. Consequently, the refrigeration capacity of the fabricated reverse Brayton cryogenic system was measured to be 1.23 kW at 77 K. In the future, we expect to achieve the targeted refrigeration capacity through further improvements. In addition, the faster commercialization of HTS power cables and more efficient storage of liquefied natural gas will be realized.

A comparative study on utilizing hybrid-type nanofluid in plate heat exchangers with different number of plates

Different methods have been utilized to enhance the thermal efficiency of the heat exchangers (HEs). A widely used method to upgrade the thermal efficiency of HEs is upgrading the thermal properties of working fluid by utilizing nanoparticles. In this study, Al2O3 and CuO have been utilized to prepare Al2O3–CuO/water hybrid nanofluid. Accordingly, Al2O3 and CuO nanoparticles have been mixed into the water with 1% (50:50) weight concentration. The main objective of this work is testing the prepared hybrid nanofluid in plate-type HEs (PHEs) with 8, 12 and 16 plates to determine the influence of number of plates on heat transfer improvement by hybrid nanofluid. Experimental findings of the present study demonstrated that utilizing Al2O3–CuO/water hybrid-type nanofluid in the PHE enhanced thermal efficiency notably in comparison with single-type nanofluids. Using this hybrid nanofluid increased the thermal performance in all PHEs with different number of plates. However, it is observed that increasing number of plates led to more increment in thermal performance by utilizing hybrid nanofluid. The highest increment in overall heat transfer coefficient was obtained as 12%, 19% and 20% in PHEs with eight, 12 and 16 plates, respectively. In addition, the highest enhancement in effectiveness was achieved as 10%, 11.7% and 16% in PHEs with eight, 12 and 16 plates, respectively.

RETRACTED ARTICLE: Study on various control strategies of plate type heat exchanger for non-Newtonian fluids

Heat exchangers are expedients used to transfer of heat energy from one medium to other while preventing the two from mixing. Heat exchangers are hired in a selection of domestic, commercial, and industrial applications, such as air conditioning, power production, refrigeration, process industry, and manufacturing industry. A larger variation in the temperature affects property of non-Newtonian fluids, thus affects the uniform heat transfer process. This paper is primarily to deal the response analysis of different controllers that is regulating the outlet temperature of fluid inside the PHE is proposed. The cold fluid flow is highly influenced on the hot water temperature, the research work mainly focuses on controlling cold fluid flow. In order to attain the precise model of the system, a mathematical model by first principle methods and process history based methods were used. A PI, PID and Model Predictive Controller (MPC) are known for its better control action of the system. The controller’s performance analysed such as PI, PID and MPC controller to adjust the temperature of hot fluid outlet to a required setpoint. Performance criteria analysis value for various controllers are PI, PID and MPC. It is understood that MPC controller results lower value of performance measures compared to other controllers, this implies that it could track the setpoint by rejecting the external disturbances with less settling time and moderate oscillation. The transient performance and the error criteria of the controllers are investigated and the best controller to regulate the temperature is found out. It is found out that the MPC controller outperforms PI and PID controller from the results of simulation.

Experimental study of the thermal performance of a novel plate type heat exchanger with phase change material

The paper presents an experimental investigation of a novel latent heat thermal energy storage system. The new energy storage unit is a pillow plate type heat exchanger with multi flowing channels, while the phase change material (PCM) - sodium acetate trihydrate (SAT) works as the energy storage medium. Water as the working fluid, flows in the distributed channels inside the plates to charge or discharge the system. The thermal performance of the latent heat thermal energy storage system was evaluated, including the outlet temperature of water, thermal power and energy, effectiveness and heat transfer coefficient. Results from the experimental analysis showed that the released energy of system can reach up to 6.3 MJ with the average power 4 kW. The overall heat transfer coefficient and heat transfer area ranges from about 25 to 70 W/k from 100 to 500 L/h flow rate. The pillow plate type heat exchanger showed good thermal performance, offering high heat transfer rate under the compact structure. Also, the novel multi flowing channels designed heat exchanger provides more flexibility and adaptability for real application, it has a wide application prospect in the fields of solar water energy storage, heat pump water heater system and waste heat recovery system.

Experimental heat transfer studies on copper nanofluids in a plate heat exchanger

The objective of the present work is to study the influence of copper nanoparticle concentration on heat transfer performance of a mixed base fluid. In the present study, the performance of copper nanoparticles in ethylene glycol (eg) + propylene glycol (pg) + water (W) base fluid was analyzed in the chevron- type plate heat exchanger. The sol-gel method was used to prepare copper nanoparticles (100 nm), dispersed in two different mixed base fluids of volume fractions 5%EG + 5%PG + 90%W and 15%EG + 5%PG + 80%W. Experiments were performed by varying the nanoparticle concentration from 0.2 to 1.0 vol.%. Three different hot fluid inlet temperatures were used (55, 65 and 75 ?C). It is revealed from the study that the rate of heat transfer increased significantly with the mixed base fluid. Result shows that at 75 ?C, 9 and 14.9% enhancement in the Nusselt number is obtained for 5%EG + 5%PG + 90%W and 15%EG + 5%PG + 80%W base fluid, respectively, for the nanoparticle concentration of 1%.

Thermal performance evaluation for solidification process of latent heat thermal energy storage in a corrugated plate heat exchanger

This study used latent heat thermal energy storage (LHTES) within a commercial plate-type heat exchanger (PHE) to numerically investigate the solidification process of phase change material (PCM). PCM fills the space between corrugated steel plates, and water at a certain temperature passes from top to bottom between two neighboring plates as heat transfer fluid (HTF). To determine the optimum geometry and operating conditions for the solidification process, the phase change process was investigated with three different plate geometries, different heat transfer fluid input temperatures (12 °C, 17 °C, and 22 °C), different steel plate thicknesses (0.4 mm, 0.6 mm, and 0.8 mm) and different Phase Change Materials (RT-35 and n-octadecane). Numerical analyses were simplified to two dimensions based on the finite volume method. The study results show that using the same phase change material, boundary conditions, and geometric features, the time for full solidification of phase change material decreased by a maximum of 63% in the plate heat exchanger-latent heat thermal energy storage system designed with geometry-A as phase change material layer compared to a cylindrical latent heat thermal energy storage system with the same volume of phase change material.

EFFECT OF NON-NEWTONIAN FLUIDS ON THE PERFORMANCE OF PLATE TYPE HEAT EXCHANGER

A plate heat exchanger constitutes a series of parallel plates, placed one on top of the other so as to permit the forming of a series of channels for fluids to flow between them.The objective of this analysis is to study the performance of the plate type heat exchanger (PHE) with the non-Newtonian fluid (sodium alginate). The experiment were conducted on Plate type Heat Exchanger for parallel and counter current flow patterns with different concentration (0.1%,0.5% and 1%) of cold fluid. A comparison among collateral flow and counter current flow heat exchanger was done. The obtained result shows that counter current flow heat exchanger proved to be more effective than parallel type heat exchanger.

Sınırlı Deneysel Verilerle Yapay Sinir Ağı Kullanılarak Chevron Tipi Isı Değiştirici için Termal Modelleme ve Performans Analizi

The problem of heat exchange between two or more fluids at different temperatures is one of the most important and most common problems of engineering applications. In order to solve this problem efficiently, the transfer of energy between two liquids at different temperatures is carried out by heat exchangers. Heat exchangers increase the energy efficiency as they can transfer the energy contained in the system to another part of the process instead of just pumping and wasting. A plate heat exchanger, a variant of heat exchanger, use a series of thin plates to transfer heat between two liquids. Thermal modelling of the heat exchanger is important due to determination of the outlet temperature of fluids depending on the system parameters. In this paper, an artificial neural network (ANN) model is used to simulate the thermal performance of a chevron type plate heat exchanger using water as working fluid. The ANN algorithms have a widely usage in thermal analysis studies of heat exchangers such as modelling of heat exchangers, estimation of heat exchanger parameters, estimation of phase change characteristics in heat exchangers and control of heat exchangers. The outer temperatures of the water are estimated depending on the cold water mass flow rate, inlet hot water temperature and inlet cold water temperature by using limited experimental data. Then the experimental results and the estimated results are compared for testing the accuracy and reliability of the developed algorithm. The results show that the experimental and estimated results have a good agreement. The developed network structure estimates the outlet temperatures with 2.58 % and 1.80 % for hot and cold water, respectively. In addition, the predicted performance of the network developed by applying untested input parameters was examined. Estimation accuracy was compared with theoretically calculated output temperatures by thermal analysis using the same inputs. According to the obtained results, it is seen that the theoretical results and prediction results are compatible with each other in determining the output for new inputs and the reliability of the developed network is proved in different inputs according to this result. After that, experimentally not obtained variations of the heat transfer rate, overall heat transfer coefficient and energy efficiency are determined depending on the inlet temperatures and mass flow rate of cold water.

Thermo-hydraulic performance analysis of multi-pass chevron type plate heat exchanger

Thermo-hydraulic performance of PHE in Z-type flow arrangement under the steady state in four different pass arrangements 1–1, 2–2, 3–3 and 4–4 for both isothermal as well as non-isothermal conditions is experimentally investigated. This work is reported for Reynolds number, Re = 330–2850 and Prandtl number, Pr = 4.5–5.0. The present experimental investigation is carried out for mass flow rate, ṁ=0.63-1.35kg/s, volume flow rate same for both hot and cold fluid, V̇ = 2000–5000 LPH and mixed chevron angle for chevron plates (30° and 60° plates alternatively). Multi-pass arrangements are made for the equal number of pass for both hot and cold fluids with counter flow arrangements. The present study brings about the effect of an increasing number of pass on the thermo-hydraulic behaviour of PHE. The results show that with a high number of the pass, increase in velocity may be counterproductive in terms of effectiveness and Nusselt number enhancement at the same mass flow rate condition. However, for the same NTU condition higher number of pass brings to decrement in the effectiveness of PHEs. On the basis of experimental data, correlations have been proposed for Nusselt number, effectiveness and friction factor individually for each 1–1, 2–2, 3–3 and 4–4 pass arrangements of PHE.

Exergy analysis of plate heat exchanger with graphene alumina hybrid nanofluid: experimentation

The water-based hybrid nanofluid is proposed as a cooling agent in a corrugated counter-flow type plate heat exchanger aimed at sub-ambient temperature applications. For this purpose, an experimental investigation has been done with different working fluids. Fluids considered as a coolant are DI water, alumina nanofluid, and alumina-graphene hybrid nanofluid in 80:20 nanoparticle ratio by volume with a total volume concentration of 0.01% dispersed in DI water. Various exergy related performance factors like coolant outlet temperature, coolant exergy rate, irreversibility rate, non-dimensional exergy, and second law efficiency have been considered. The influence of coolant inlet temperature and flow rate on different parameters has been investigated. Coolant outlet temperature, coolant exergy rate, irreversibility rate and non-dimensional exergy augments by 2.5%, 4.8%, 7.5% and 3.5%, respectively. While the second law efficiency degrades using nanoparticles and increasing flow rate and decreases with the coolant inlet temperature.

Exergy analysis of plate heat exchanger with graphene alumina hybrid nanofluid: experimentation

The water-based hybrid nanofluid is proposed as a cooling agent in a corrugated counter-flow type plate heat exchanger aimed at sub-ambient temperature applications. For this purpose, an experimental investigation has been done with different working fluids. Fluids considered as a coolant are DI water, alumina nanofluid, and alumina-graphene hybrid nanofluid in 80:20 nanoparticle ratio by volume with a total volume concentration of 0.01% dispersed in DI water. Various exergy related performance factors like coolant outlet temperature, coolant exergy rate, irreversibility rate, non-dimensional exergy, and second law efficiency have been considered. The influence of coolant inlet temperature and flow rate on different parameters has been investigated. Coolant outlet temperature, coolant exergy rate, irreversibility rate and non-dimensional exergy augments by 2.5%, 4.8%, 7.5% and 3.5%, respectively. While the second law efficiency degrades using nanoparticles and increasing flow rate and decreases with the coolant inlet temperature.