Prediction of the Deformation of Aluminum Alloy Drill Pipes in Thermal Assembly Based on a BP Neural Network

The connection between the steel joint and aluminum alloy pipe is the weak part of the aluminum alloy drill pipe. Practically, the interference connection between the aluminum alloy rod and the steel joint is usually realized by thermal assembly. In this paper, the relationship between the cooling water flow rate, initial heating temperature and the thermal deformation of the steel joint in interference thermal assembly was studied and predicted. Firstly, the temperature data of each measuring point of the steel joint were obtained by a thermal assembly experiment. Based on the theory of thermoelasticity, the analytical solution of the thermal deformation of the steel joint was studied. The temperature function was fitted by the least square method, and the calculated value of radial thermal deformation of the section was finally obtained. Based on the BP neural network algorithm, the thermal deformation of steel joint section was predicted. Besides, a prediction model was established, which was about the relationship between cooling water flow rate, initial heating temperature and interference. The magnitude of interference fit of steel joint was predicted. The magnitude of the interference fit of the steel joint was predicted. A polynomial model, exponential model and Gaussian model were adopted to predict the sectional deformation so as to compare and analyze the predictive performance of a BP neural network, among which the polynomial model was used to predict the magnitude of the interference fit. Through a comparative analysis of the fitting residual (RE) and sum of squares of the error (SSE), it can be known that a BP neural network has good prediction accuracy. The predicted results showed that the error of the prediction model increases with the increase of the heating temperature in the prediction model of the steel node interference and related factors. When the cooling water velocity hit 0.038 m/s, the prediction accuracy was the highest. The prediction error increases with the increase or decrease of the velocity. Especially when the velocity increases, the trend of error increasing became more obvious. The analysis shows that this method has better prediction accuracy.

Effects of Different Mold Materials and Coolant Media on the Cooling Performance of Epoxy-Based Injection Molds

Metal additive manufacturing techniques are frequently applied to the manufacturing of injection molds with a conformal cooling channel (CCC) in order to shorten the cooling time in the injection molding process. Reducing the cooling time in the cooling stage is essential to reducing the energy consumption in mass production. However, the distinct disadvantages include higher manufacturing costs and longer processing time in the fabrication of injection mold with CCC. Rapid tooling technology (RTT) is a widely utilized technology to shorten mold development time in the mold industry. In principle, the cooling time of injection molded products is affected by both injection mold material and coolant medium. However, little work has been carried out to investigate the effects of different mold materials and coolant media on the cooling performance of epoxy-based injection molds quantitatively. In this study, the effects of four different coolant media on the cooling performance of ten sets of injection molds fabricated with different mixtures were investigated experimentally. It was found that cooling water with ultrafine bubble is the best cooling medium based on the cooling efficiency of the injection molded parts (since the cooling efficiency is increased further by about 12.4% compared to the conventional cooling water). Mold material has a greater influence on the cooling efficiency than the cooling medium, since cooling time range of different mold materials is 99 s while the cooling time range for different cooling media is 92 s. Based on the total production cost of injection mold and cooling efficiency, the epoxy resin filled with 41 vol.% aluminum powder is the optimal formula for making an injection mold since saving in the total production cost about 24% is obtained compared to injection mold made with commercially available materials.

Computer simulation of the reliability of the heat exchange surface of the steam turbine condenser

The aim of the article is to demonstrate the relationship between the adaptive regulation of the heat exchange surface to specific operating conditions of a steam turbine condenser and the reliability and availability of this surface in a specific period of time. The article exemplifies the relationship between the settings of the condenser heat exchange surface and the resulting changes in the reliability structures of this surface. The method of creating a mathematical model of reliability estimation, which is characterized by the variability of the reliability structures of the heat exchange surface in relation to specific operating conditions in a specific period of time, was indicated. Then, exemplary simulations of the adaptation of reliability structures of specific pipe systems constituting the condenser’s heat exchange surface to specific processes of operation of this condenser are presented. The simulations refer to the time-varying thermal loads of the condenser, the time-varying mean thickness of the sediments, and changes in the temperature of the cooling water at the point of its intake over time. The adaptation of certain reliability structures consists in the adaptation of specific systems of pipes through which the cooling water flows to the currently existing operating conditions of the condenser in order to maintain the desired reliability of the heat exchange surface for a specified time. This is done by enabling or disabling the flow of cooling water through a given number of pipes in specific systems under given operating conditions. On the basis of computer simulations, the reliability functions, and the availability functions of the subsystem under consideration were estimated.

Energy-saving investigation of vacuum reactive distillation for the production of ethyl acetate

Ethyl acetate (EtAc) reactive distillation (RD) configurations often use atmospheric pressure, and this operating pressure can be reduced further to conserve energy based on the condenser cooling water temperature. Using the Aspen Plus simulator, two proposed configurations, RD column with stripper and pressure swing reactive distillation (PSRD), were simulated at lower operating pressure. The impact of RD column operating pressure on total energy usage and total annual cost (TAC) was studied. All design parameters were optimized using sequential iterative optimization procedures and sensitivity analysis to minimize the energy cost while maintaining the required product purity at 99.99%. The simulation results showed that the RD column with a stripper is better than PSRD with a saving of 23.17% in TAC and 31.53% in the specific cost of EtAc per kg. Compared to literature results, the proposed configurations have lower reboiler duty requirements and lower cost per kg of EtAc.

Application of jacket cooling water system recovery for fuel heating on diesel engine to reduce emissions

The existence of a diesel engine is very necessary for life today. In development, the diesel engine is experienced many developments in all systems. In line with the development of the diesel engine can’t be separated from the impact of fuel use. This research was carried out to make a fuel heating system by utilizing jacket cooling water system recovery as a fuel heater and the method used in this research is an experimental method including making installation of a fuel heating system, testing on the diesel engine generator with specifications 4 strokes, 4 cylinders, 1500 rpm, 18 kVA using biodiesel (B20) fuel. The data were collected using a smoke opacity meter. The experiment was carried out by heating treatment of fuel starting from 30°C - 50°C at the interval of 5°C. Data analysis by describing experimental data. The result is showed that heating fuel can reduce the emission of the diesel engine.

Problem of maintaining a normal condensate dissolved oxygen concentration

Study presents the results of the steam surface KCS-200-2 reconstruction. In order to maintain the dissolved oxygen concentration, according to the Code of Operation for Power Plants, the steam sparger was installed in condenser hotwell. Despite the abnormal air leakage level, reducing of dissolved oxygen concentration was reached. The dissolved oxygen concentration reduced, on average, by 2 times. As it was expected, in the cases of low inlet cooling water temperature, the final oxygen concentration did not reach the normal level. In last 3 tests the dissolved oxygen concentration was reduced to 19 mg /l. The results show a possibility of described reconstruction experience.

Study concerning the thermal energy balance in an internal combustion engine

In this scientific report the steps for achieving the energy balance on a test engine Daewoo 1.6 liter in 4 cylinders, with 4 valves per cylinder, its power being77 kW, are presented. The engine was connected to a hydraulic brake during the tests. The energy balance was established, based on measurements applied on the stand test, focusing to determine the lost heat and to conceive a Sankey diagram, accordingly. Two sets of measurements were performed and based on them the heat losses were determined and two Sankey diagrams were depicted. The lost heat through the cooling fluid is determined by measuring the cooling water flow rate and its inlet and outlet temperature. The lost heat through the exhaust gases is determined by the difference between the enthalpy of the exhaust gases and the enthalpy of fresh air. The lost heat due to incomplete chemical combustion is determined by analyzing the composition of the exhaust gases. The measurements are centralized on a graphic user interface, supported by a NI Compact RIO platform.

Study on Temperature Control of Gravity Anchorage without Cooling Water

This paper uses Midas Fea simulation software to analyze the hydration heat of a suspension bridge anchorage mass concrete construction without cooling water. According to specific boundary conditions and convection coefficients, the concrete heating process and cooling process are simulated. Analyze the influence of surface air convection coefficient on the surface tensile stress of the cast layer, and the influence of the pouring interval on the interlayer stress of the anchor block, and the temperature difference between the inside and outside of the concrete when the anchor block is layered. It is found that reducing the surface convection coefficient of the pouring layer can effectively improve the stress condition, and the pouring interval has little effect on the stress.