Heat Exchanger Options for Dry Air Cooling for the sCO2 Brayton Cycle

2017 ◽  
Author(s):  
Anton Moisseytsev ◽  
Qiuping Lv ◽  
James J. Sienicki
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Cost Effective ◽  
Finned Tube ◽  
Air Cooling ◽  
Brayton Cycle ◽  
Dry Air ◽  
Air Atmosphere ◽  
Air Cooler ◽  
Forced Air

The capability to utilize dry air cooling by which heat is directly rejected to the air atmosphere heat sink is one of the benefits of the supercritical carbon dioxide (sCO2) energy conversion cycle. For the selection and analysis of the heat exchanger options for dry air cooling applications for the sCO2 cycle, two leading forced air flow design approaches have been identified and analyzed for this application; an air cooler consisting of modular finned tube air coolers; and an air cooler consisting of modular compact diffusion-bonded heat exchangers. The commercially available modular finned tube air cooler is found to be more cost effective and is selected as the reference for dry air cooling.

Dry Air Cooling and the sCO2 Brayton Cycle

2017 ◽  
Author(s):  
James J. Sienicki ◽  
Anton Moisseytsev ◽  
Qiuping Lv
Keyword(s):  
Nuclear Power ◽  
High Efficiency ◽  
Electrical Power ◽  
Cost Effective ◽  
Finned Tube ◽  
Inlet Temperature ◽  
Air Cooling ◽  
Brayton Cycle ◽  
Water Cooling ◽  
Dry Air

Commercially available and cost effective finned tube air coolers are an enabling technology that makes practical dry air cooling for the supercritical carbon dioxide (sCO2) Brayton cycle by which heat is directly rejected from CO2 to the air atmospheric heat sink. With dry air cooling, sCO2 Brayton cycle conditions need to be re-optimized to increase the main compressor inlet temperature and pressure (e.g., 35 °C and 8.2 MPa) relative to water cooling to limit the air cooler size to a practical value, and to increase the compressor outlet pressure (e.g., 25 MPa) to maintain a high efficiency. With reoptimization, the plant efficiency for the AFR-100 Sodium-Cooled Fast Reactor Nuclear Power Plant (NPP) is similar to that with once-through water cooling, while the NPP capital cost per unit output electrical power ($/kWe) is roughly estimated to be only 2 % greater. For the AFR-100 application, no unique benefit is identified for the sCO2 Brayton cycle relative to the superheated steam cycle with respect to the capability to use dry air cooling.

Inspection Method of Finned Tube and Finned Heat Exchanger

2021 ◽  
Author(s):  
Ju Ding ◽  
Min Zhang ◽  
Shuhong Liu ◽  
Shenghui Wang ◽  
Jielu Wang
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Eddy Current ◽  
Heat Exchangers ◽  
Finned Tube ◽  
Air Cooling ◽  
Finned Tubes ◽  
Detection Technology ◽  
Pressure Test ◽  
Current Detection

Abstract The finned tube heat exchanger is one of the earliest and most successful discoveries in the process of improving tube heat exchange. This method is still the most widely used of all kinds of tube heat transfer surface enhancement heat transfer methods. It is not only suitable for single-fin tube heat exchangers, which are widely used in power, chemical, petrochemical, air-conditioning engineering and refrigeration engineering. Conventional heat exchanger with smooth tubes can be inspected through the pressure test during the manufacturing process. Finned tubes and finned heat exchangers with inner thread structure have some difficult to pass the water pressure test. The same situation exists in regular inspections. Due to structural reasons, it is difficult to carry out regular surface inspections[1]. For these two situations, two different testing methods are required to ensure quality. This article introduces in detail the methods of inspecting finned tubes and finned heat exchangers. Hierarchical comparison of alternatives in hydrostatic testing project, and the eddy current detection technology of the finned tube under the condition of in-service air cooling. The far-field eddy current method is chosen for inspection. And by comparing the standard sample tube, it is mainly used to adjust the sensitivity of the eddy current detector and ensure the accuracy of the test results[2]. The results show that the eddy current detection technology can be more accurate and reliable. The corrosion of the finned tube under service air cooling is detected, and a reliable basis is provided for judging the use of the finned tube and finned heat exchanger[3].

scholarly journals An experimental investigation on air-side performances of finned tube heat exchangers for indirect air-cooling tower

2014 ◽  
Vol 18 (3) ◽  
pp. 863-874 ◽  
Author(s):  
Xueping Du ◽  
Yantao Yin ◽  
Min Zeng ◽  
Pengqing Yu ◽  
Qiuwang Wang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Cooling Tower ◽  
Finned Tube ◽  
Air Cooling ◽  
Flat Tube ◽  
Tube Heat Exchanger ◽  
Air Inlet ◽  
Oval Tube

A tremendous quantity of water can be saved if the air cooling system is used, comparing with the ordinary water-cooling technology. In this study, two kinds of finned tube heat exchangers in an indirect air-cooling tower are experimentally studied, which are a plain finned oval-tube heat exchanger and a wavy-finned flat-tube heat exchanger in a cross flow of air. Four different air inlet angles (90?, 60 ?, 45?, and 30?) are tested separately to obtain the heat transfer and resistance performance. Then the air-side experimental correlations of the Nusselt number and friction factor are acquired. The comprehensive heat transfer performances for two finned tube heat exchangers under four air inlet angles are compared. For the plain finned oval-tube heat exchanger, the vertical angle (90?) has the worst performance while 45? and 30? has the best performance at small ReDc and at large ReDc, respectively. For the wavy-finned flat-tube heat exchanger, the worst performance occurred at 60?, while the best performance occurred at 45? and 90? at small ReDc and at large ReDc, respectively. From the comparative results, it can be found that the air inlet angle has completely different effects on the comprehensive heat transfer performance for the heat exchangers with different structures.

scholarly journals Perancangan Air Cooler Turbin gas Aeroderivative Lm6000 Jenis Compact Heat Exchanger Untuk Meningkatkan Performa Turbin gas

2020 ◽  
Vol 1 (1) ◽  
pp. 61-70
Author(s):  
Dimas Rianto Utomo ◽  
Belyamin Belyamin ◽  
Sonki Prasetya
Keyword(s):  
Heat Exchanger ◽  
Tube Bundle ◽  
Low Pressure ◽  
Finned Tube ◽  
Air Cooling ◽  
Compact Heat Exchanger ◽  
Turbine Inlet ◽  
Air System ◽  
Air Cooler ◽  
Pressure Compressor

Temperatur udara ambient berpengaruh pada performa turbin gas. Temperatur yang tinggi mengakibatkan masa jenis udara menjadi rendah sehingga pada laju aliran udara masuk kompresor lebih sedikit. Teknologi untuk memitigasi permasalahan ini adalah penggunaan Turbine Inlet Air Cooling (TIAC) pada inlet air system turbin gas. Penelitian ini bertujuan untuk mendesain air cooler dengan tipe staggered continous finned tube compact heat exchanger pada turbin gas Lm6000 milik PT.X di Karawang. Proses perancangan air cooler dilakukan dengan  menggunakan perhitungan Kern. Data yang dibutuhkan dalam penelitian ini adalah data dimensi maksimum air cooler, data temperatur air pendingin, data pengoperasi turbin gas dan data bahan bakar yang diambil sebelum dan sesudah pemasangan TIAC menggunakan beban turbin gas yang sama yaitu 22 MW. Hasil yang didapat dari proses perancangan air cooler adalah desain air cooler dengan 187 tube bundle dan nilai koefisien konveksi keseluruhan sebesar 35,4 W/m²°C. Analisis performa turbin gas menunjukkan bahwa temperatur inlet low pressure compressor mengalami penurunan rata-rata sebesar 3,5°C, sementara efisiensi siklus rata-rata meningkat sebesar 1,65%. Adapun peningkatan daya bersih rata-rata sebesar 0,496 MW karenanya dapat menghasilkan  penghematan biaya bahan bakar sebesar Rp1.554.257.011 per tahun.

Analisis Perbandingan Jenis Material Penukar Kalor Plat Datar Aliran Silang Untuk Proses Pengeringan Kayu

2021 ◽  
Vol 9 (1) ◽  
pp. 60-71
Author(s):  
Abeth Novria Sonjaya ◽  
Marhaenanto Marhaenanto ◽  
Mokhamad Eka Faiq ◽  
La Ode M Firman
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Flat Plate ◽  
Heat Exchangers ◽  
Fluid Dynamic ◽  
Cross Flow ◽  
Plate Heat ◽  
Dry Air ◽  
Copper Material ◽  
Plate Type

The processed wood industry urgently needs a dryer to improve the quality of its production. One of the important components in a dryer is a heat exchanger. To support a durable heat transfer process, a superior material is needed. The aim of the study was to analyze the effectiveness of the application of cross-flow flat plate heat exchangers to be used in wood dryers and compare the materials used and simulate heat transfer on cross-flow flat plate heat exchangers using Computational Fluid Dynamic simulations. The results showed that there was a variation in the temperature out of dry air and gas on the flat plate heat exchanger and copper material had a better heat delivery by reaching the temperature out of dry air and gas on the flat plate type heat exchanger of successive cross flow and.   overall heat transfer coefficient value and the effectiveness value of the heat exchanger of the heat transfer characteristics that occur with the cross-flow flat plate type heat exchanger in copper material of 251.74725 W/K and 0.25.

scholarly journals Dry-Cooled Supercritical CO2 Power for Advanced Nuclear Reactors

2014 ◽  
Author(s):  
T. M. Conboy ◽  
M. D. Carlson ◽  
G. E. Rochau
Keyword(s):  
Power Systems ◽  
Nuclear Energy ◽  
Energy Systems ◽  
Air Cooling ◽  
Brayton Cycle ◽  
Heat Rejection ◽  
Ambient Temperatures ◽  
Power Cycle ◽  
Dry Air ◽  
Compressor Inlet

Currently, waste heat rejection from electrical power systems accounts for the largest fraction of water withdrawals from the US fresh water table. Siting of nuclear power plants is limited to areas with access to a large natural supply of fresh or sea water. Due to a rise in energy needs and increased concern over environmental impact, dry air cooling systems are poised to play a large role in the future energy economy. In practice, the implementation of dry air-cooled condensing systems at steam plants has proven to be capital-intensive and requires the power cycle to take a significant efficiency penalty. These shortcomings are fundamental to dry-air steam condensation, which must occur at a fixed temperature. Closed-cycle gas turbines are an alternative to the conventional steam Rankine plant that allow for much improved dry heat rejection compatibility. Recent research into advanced nuclear energy systems has identified the supercritical CO2 (s-CO2) Brayton cycle in particular as a viable candidate for many proposed reactor types. The s-CO2 Brayton cycle can maintain superior thermal efficiency over a wide range of ambient temperatures, making these power systems ideally suited for dry air cooling, even in warm climates. For an SFR operating at 550°C, thermal efficiency is calculated to be 43% with a 50°C compressor inlet temperature. This is achieved by raising CO2 compressor inlet pressure in response to rising ambient temperatures. Preliminary design studies have shown that s-CO2 power cycle hardware will be compact and therefore well-matched to near-term and advanced integral SMR designs. These advantages also extend to the cooling plant, where it is estimated that dry cooling towers for an SFR-coupled s-CO2 power cycle will be similar in cost and scale to the evaporative cooling tower for an LWR. The projected benefits of the s-CO2 power cycle coupled to dry air heat rejection may enable the long-awaited rise of next-generation nuclear energy systems, while re-drawing the map for siting of small and large nuclear energy systems.

Performance Analysis of Multi-Pass Cross-Flow Heat Exchangers

2018 ◽  
Author(s):  
Kiran Lankalapalli ◽  
Ahmed ElSawy ◽  
Stephen Idem
Keyword(s):  
Heat Exchanger ◽  
Performance Analysis ◽  
Thermal Performance ◽  
Heat Exchangers ◽  
Cross Flow ◽  
Threshold Value ◽  
Finned Tube ◽  
Flow Heat ◽  
Rate Ratios ◽  
Side Flow

A steady state sensible performance analysis of multi-pass cross-flow finned-tube heat exchangers is reported. The investigation considers various flow circuiting, such as counter cross-flow, parallel cross-flow, and cross-flow where the tube-side flow is in parallel. A previously developed matrix approach is used to evaluate the heat exchanger performance in each tube pass. The equations required to model the thermal performance of these configurations are presented, and the thermal performance is compared for each type of flow circuiting. Thereafter a parametric study on cross-flow heat exchanger performance is performed by varying physically significant parameters such as number of transfer units (NTU) and capacity rate ratios, and the graphical results for each type of flow circuiting are presented both for both two-pass and three-pass arrangements. A consistent criterion is proposed for each case, wherein increasing the NTU beyond a certain threshold value does not significantly improve heat exchanger thermal performance.

scholarly journals A Nodes-Based Non-Structural Model Considering a Series Structure for Heat Exchanger Network Synthesis

Processes ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 695
Author(s):  
Yue Xu ◽  
Heri Ambonisye Kayange ◽  
Guomin Cui
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Structural Model ◽  
Cost Effective ◽  
Maximum Energy ◽  
Network Synthesis ◽  
Heat Exchanger Network ◽  
Proposed Model ◽  
Effective Network ◽  
Heat Exchanger Network Synthesis

The aim of heat exchanger network synthesis is to design a cost-effective network configuration with the maximum energy recovery. Therefore, a nodes-based non-structural model considering a series structure (NNM) is proposed. The proposed model utilizes a simple principle based on setting the nodes on streams such that to achieve optimization of a heat exchanger network synthesis (HENS) problem. The proposed model uses several nodes to quantify the possible positions of heat exchangers so that the matching between hot and cold streams is random and free. Besides the stream splits, heat exchangers with series structures are introduced in the proposed model. The heuristic algorithm used to solve NNM model is a random walk algorithm with compulsive evolution. The proposed model is used to solve four scale cases of a HENS problem, the results show that the costs obtained by NNM model can be respectively lower 3226 $/a(Case 1), 11,056 $/a(Case 2), 2463 $/a(Case 3), 527 $/a(Case 4) than the best costs listed in literature.

Liquid-Coupled Indirect-Transfer Exchanger Application to the Diesel Engine

1979 ◽  
Vol 101 (4) ◽  
pp. 516-523 ◽  
Author(s):  
James C. Eastwood
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Cooling System ◽  
Relative Effectiveness ◽  
Ambient Air ◽  
Air Cooling ◽  
Performance Curves ◽  
Air Cooling System ◽  
Cooling Function ◽  
Low Charge

The efficiency of turbocharged diesel engines can be increased by cooling the charge air. This paper presents a design approach for liquid-coupled indirect-transfer heat exchanger systems to perform the air-cooling function. The two advantages most commonly cited for this approach to charge-air cooling are (1) the heat exchangers involved are easily packaged so that their shapes can be controlled by judicious design, and (2) simple gas ducting allows for compact machinery arrangements and relatively low charge-air pressure drop. An analytical approach to the design of liquid-coupled indirect-transfer heat exchanger systems is presented. Performance curves are constructed on the basis of this analysis. Four important design conditions are evident from the observation of these performance curves including (1) the relative capacity rate combination of the three fluids (ambient air, coupling liquid, and engine charge-air) which yields the highest overall effectiveness, (2) an optimum coupling-liquid flow rate, (3) the relative effectiveness distribution for each of the two component heat exchangers (hot and cold components), and (4) a broad design range for the optimum area distribution between the hot and cold exchangers. These performance curves serve as a guide for the design of a liquid-coupled charge-air cooling system.

The Concept Design of Tornado Like Jet Condenser Heat Exchanger

2013 ◽  
Author(s):  
G. I. Kiknadze ◽  
I. A. Gachechiladze ◽  
T. T. Barnaveli
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Continuous Medium ◽  
Cost Effective ◽  
Self Organization ◽  
Concept Design ◽  
Resource Saving ◽  
Heat And Mass Exchange ◽  
Double Curvature ◽  
Functional Efficiency

The concept design and fabrication of cost-effective and resource-saving Tornado Like Jet Condensers Heat Exchangers is described. Tornado Like Jet (TLJ) Technologies are utilizing the features of the streams of the continuous medium over the surfaces with dimples of double curvature inducing the secondary twisted vortexes self organization. (TLJ) Technologies are characterized by high functional efficiency of heat and mass exchange. The project is based on theoretical and experimental results obtained by the authors of the project in past years in development of a (TLJ) Technologies package.

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