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Пояснювальна записка до дипломного проекту бакалавра за темою «Аміачна теплонасосна установка «вода-вода» тепловою потужністю 250кВт», включає в себе 56 сторінок, 10 пунктів, 2 рисунки, 4 таблиці. Дана робота також містить 3 креслення формату А1. В результаті виконання проекту було розраховано та підібрано камерне обладнання, компресор, випарник, конденсатор, а також допоміжне обладнання. Explanatory note to the bachelor's diploma project on the topic "Water-to-water ammonia heat pump installation with a thermal capacity of 250 kW", includes 56 pages, 10 points, 2 figures, 4 tables. This work also contains 3 drawings of A1 format. As a result of the project, chamber equipment, a compressor, an evaporator, a condenser, and auxiliary equipment were calculated and selected.

Пояснювальна записка до дипломного проекту бакалавра за темою «Аміачна холодильна установка для тривалого зберігання груш в м.Дніпро» включає в себе 89 сторінок, 11 розділів, які містять 21 рисунок, 13 таблиць та 11 посилань. Дана робота також містить 2 креслення формату А1 та 2 креслення формату А2. В даному проекті зроблено розрахунок аміачної холодильної установки для тривалого зберігання 500 тон груш в м. Дніпро. В результаті виконання проекту було розраховано та підібрано камерне обладнання, компресор, випарник, конденсатор, а також допоміжне обладнання. The explanatory to the graduation thesis of bachelor on the theme «Ammonia refrigerator for long term storage of pears in Dnipro» includes 89 pages, 11 parts with 21 drawings, 13 tables and 11 references. Also this work includes 2 drafts of A1 format and 2 drafts of A2 format. In this project made the calculation of ammonia refrigeration unit for long term storage 500 ton pears in Dnipro. As a result of project performance were calculated and picked up the chamber equipment, the compressor, the evaporator, the condenser, and also the additional equipment.

To optimize the fuel economy of parallel hybrid electric vehicles (HEVs), improve the working conditions of the engine, and promote the application of deep reinforcement learning (DRL) in the field of energy management strategies (EMSs), this paper firstly proposed a Deep Reinforcement Learning-based EMS combined with an engine start-stop strategy. In addition, considering both the engine and the transmission are controlled components, this paper developed a novel Double Deep Reinforcement Learning (DDRL)-based EMS, which uses Deep Q-Network (DQN) to learning the gear-shifting strategy and uses Deep Deterministic Policy Gradient (DDPG) to control the engine throttle, and the DDRL-based EMS realizes the multi-objective synchronization control by intelligent algorithms. After offline training, the simulation result of the online test shows that the fuel consumption gaps of the proposed DRL-based and DDRL-based EMS are -0.55% and 2.33% compared to that of the deterministic dynamic programming (DDP)-based EMS by overcoming some inherent flaws of DDP, respectively. Moreover, the computational efficiency is improved significantly, and the average output time per action is 0.91ms. Therefore, the control strategy that combines learning-based and rule-based control and the further multi-objective control strategies can achieve good optimization effects and application efficiency.

Eliminating substantial energy dissipation and achieve precise tracking accuracy are both vital for the hydraulic actuated servo system, especially in the face of the global energy crisis and energy exhaustion. When an asymmetric hydraulic cylinder moves symmetrically back and forth, the pressure and flow in the two chambers differ a lot, resulting in huge energy loss. To reduce the throttle loss and overflow loss of the system simultaneously, a hydraulic servo system structure based on dual hydraulic accumulators is proposed in this paper. On the one hand, two hydraulic accumulators with different pressure levels can switch the supply pressure based on the motion direction of the hydraulic cylinder to reduce the throttle loss. On the other hand, the hydraulic accumulators can absorb the excess flow to reduce the overflow loss. In addition, an output feedback controller based on the desired compensation approach is proposed to guarantee the control performance. First, the pressure and velocity signals are replaced by their desired values to reformulate the state equation. Subsequently, the state variables and lumped disturbance are estimated by the low-pass filter-based observer. Compared with the conventional method, this method has the advantages of low noise interference, fewer control parameters and intuitive form. To validate the feasibility of the proposed strategy, the stability of the controller and the energy efficiency of the system are analyzed. The results indicate that the proposed method can significantly improve the system efficiency and ensure tracking accuracy simultaneously.

Ecuador’s geography is very irregular, each region is at a different altitude, rising from sea level to more than 2800 m above sea level. In this sense, the altitude variable becomes important in the behavior of an internal combustion engine. In this work, the behavior of an internal combustion engine with indirect electronic injection is studied at different heights above sea level to facilitate diagnostic tasks. This behavior is determined through the signals emitted by the absolute pressure sensors of the intake manifold and the throttle position, obtained in 11 places with a difference of approximately 500 m in altitude up to 4500 m above sea level. Analysis of these signals indicates the MAP sensor voltage variations are approximately 0.38 V per 1000 m and the engine vacuum decreases approximately 7.7 kPa per 1000 m of the head. Furthermore, the correction ratio made by the electronic control unit ECU on the pulse width and the ignition advance with the height has been determined. These results generated by this research work are important to understand the behavior of engines at altitude and facilitate automotive diagnosis.

This paper proposes a guidance method for the powered soft landing of a launcher with non-cluster configured engines, for which it is difficult to maintain a low thrust-to-weight ratio (TWR) preferable for rocket recovery. For rockets in service with one or two engines rather than a cluster of engines in the boosters, it is a challenge to deeply throttle the engines to a low level, especially lower than 30%, and if one of the two engines is shut down to reduce the thrust, the attitude control is also difficult due to thrust asymmetry. The theoretical analysis and simulations show that the higher the TWR is, the smaller the feasible region for a soft landing becomes. The analysis also reveals that the bang–bang solutions of fuel-optimal methods are vulnerable to uncertainties and disturbances. A thrust regulation rate constraint is proposed or convexified to reconstruct the landing problem under high TWRs. An initial guess based on mean thrust and relaxing the initial velocity constraint is proposed, making both the adaptive collocation method and the successive convex programming applicable for real-time landing planning. Simulations under TWRs larger than four show that the proposed methods ensure a safe landing and are more adaptive than fuel-optimal solutions when facing disturbances and uncertainties.

It is a key and difficult problem to find the optimal powder-feeding technique in the study of powdered engines. In this paper, the feeding of powder in powder engines at different gas-solid ratios was experimentally investigated. Working characteristics of the classic piston-driven powder feeding system were obtained. A high linear tendency between powder mass flow rate and the minimum throttle channel area is observed from the experiment. The solid-gas mass ratio to maintain a stable powder feeding is approximately valued in range of 34.4–54.6 under different throttle channel areas. The least deviation in the relative powder mass flow rate for the tests is −15% to +8%. Due to the high uncertainty of the gas-solid flow structures at different gas-solid ratios, obvious low-frequency oscillations and high-frequency oscillations exist during the powder feeding process. The frequencies of low-frequency oscillations are mainly 1–3 Hz, while those of high-frequency oscillations are 20–30 Hz and 30–45 Hz in different tests.

This paper proposes a Unified Fault-Tolerant Control System (UFTCS) based on advanced analytical and hardware redundancies for Air-Fuel Ratio (AFR) control of Spark Ignition (SI) Internal Combustion (IC) engines. The advanced analytical redundancy part is termed the Hybrid Fault-Tolerant Control System (HFTCS) which consists of both active and passive types. The Lookup Tables (LTs) have been utilized in the active part and a robust proportional feedback controller of high gain with fuel throttle actuator has been implemented in the passive part. Since the failure of any two sensors at the same time or failure of a single actuator causes engine shutdown, an advanced hardware redundancy protocol Modified Triple Modular Redundancy (MTMR) has been suggested for the sensors, and Dual Redundancy (DR) has been proposed for the actuators to prevent the tripping of the engine. MATLAB/Simulink simulation results indicate that the suggested UFTCS is highly robust to the sensor faults in both normal and noisy conditions. The probabilistic reliability analysis for various hardware redundancy schemes also proves the greater overall reliability of UFTCS. Finally, a comparison with the existing AFR control systems is carried out to demonstrate its superior performance.

This article presents methods to increase the efficiency of liquid methanol production and purification installations. Three solutions were proposed: CO2 compression on the side of the CCS power plant, replacement of the throttle valve with an expander, and replacement of the heat exchanger with an ORC module. The calculation methodology was presented, and each concept was thermodynamically analyzed and compared with the reference variant. The installation for the synthesis of liquid methanol was integrated with a wind farm with a nominal power of 8 MW, a photovoltaic farm with a capacity of 2 MW (based on the measurements of the photovoltaic farm installed on the campus of the Silesian University of Technology in Poland), and a water electrolysis installation. This made it possible to increase the efficiency of the entire system to 52.41%, which corresponds to an increase in efficiency relative to the reference case of 3.57 pp. The synergy effect accompanying the use of CO2 from CCS power plants was also noticed, consisting in a simultaneous increase in the efficiency of both the analyzed installation and the power plant.

Load-sensing steering systems for articulated loaders are prone to large pressure shocks and oscillations during steering operations, affecting the system stability. An optimized structure of the redirector with bypass damping is proposed to improve this phenomenon. In this structure, orifices and throttle grooves are added to the traditional redirector. To control the steering load and working conditions, the steering load of the loader is replaced by a pressure regulating valve. Simulation and experimental results reveal that the redirector with bypass damping has better load-sensing characteristics than the traditional redirector. The peak output pressure shock caused by the load unit step signal decreases from 6.50 to 5.64 MPa, which means the pressure oscillation of the hydraulic system is reduced by 13.4%. The pressure fluctuation time can be reduced from 2.09 to 1.6 s, with a decrease rate of 23.4%. The output pressure oscillation decays swiftly, and the smoothness of the steering operation is improved significantly.

The throttle response of a vehicle determines its dynamic properties and is characterized by an acceleration time from 0 to 100 km/h. An experimental study of the influence of vehicle parameters on its throttle response is associated with significant material and labor costs. At the stage of sketching the design of the vehicle, preliminary determination of design parameters and settings, it is rational to use mathematical models. In the existing models of the vehicles movement dynamics, the engine power, as a rule, is set by empirical dependencies and does not take into account the possibility of changing its parameters and characteristics. The paper proposes a mathematical model that combines models of the engine workflow and the dynamics of vehicle acceleration. The mathematical model of the engine workflow is a quasi-stationary thermodynamic model, in which combustion is described by the Vibe equation, and heat transfer with the walls is described by the Woschni equation. To check its adequacy, an experimental study of the VAZ-2108 engine was carried out to obtain external speed, load and control characteristics. Good agreement between the calculated and experimental data is shown. Vehicle acceleration simulation was carried out according to the method of E.A. Chudakov. The parameters of the VAZ-2108 car and the resistance forces during acceleration from 0 to 100 km / h have been determined. It is shown that the car accelerates from 0 to 100 km / h in 18.3 s, which corresponds to the experimental data and indicates the adequacy of the chosen techniques. The influence of changing the parameters and settings of the engine on the dynamics of vehicle acceleration has been investigated. It is shown that in order to achieve better dynamics of motion, the cylinder diameter and compression ratio must be maximized. The ignition timing, intake valve closing angle and excess air ratio have extremes. The efficiency of using a 16-valve cylinder head instead of an 8-valve one is shown. Based on the results of the studies, it was proposed to apply a set of engine parameters, which made it possible to reduce the acceleration time of the VAZ-2108 from 18.3 s to 13.2 s. Thus, the developed mathematical model makes it possible to quantitatively evaluate the influence of engine parameters on the dynamics of vehicle acceleration, to optimize the parameters and settings of the power plant and the vehicle as a whole.

This paper considers to make a small-scale car composed of low-cost hardware components acquire autonomous driving tasks by using deep learning. The tasks to be acquired are assumed to be used for indoor patrols of mobile robots, and are given as a series of tasks, where the car proceeds along the walls of a narrow corridor and stops in front of the target object. The tasks include a three-point turn as a difficult task. The difficulties in the tasks are that different actions are required even for similar input camera images and that the acceleration value cannot be kept at zero when stopped. To deal with these difficulties, we propose models outputting the state of the car in addition to steering and throttle values, models with throttle value of one step before in addition to an image, and improved long short-term memory (LSTM) models with/without additional input and output. Our experiments demonstrate that the proposed LSTM models with three output and additional input achieve a 100% success rate until just before the goal.

With the development of both cryogenic and motor pump technologies, the cryogenic variable thrust liquid rocket engines that using motor pumps have gained considerable attention. However, the heavy battery limits its performance if engine operates for high thrust. To address this challenge, the electric expander cycle system scheme for variable thrust liquid rocket engines is creatively proposed and designed. Subsequently, the system parameters are calculated based on mass and energy conservation with chamber heat transfer considered. As well, the distribution of this novel system state parameters is investigated. Further, a comparison is conducted between the electric expander cycle system, electric pump, and expander cycle systems. The comparison results demonstrate that this innovative system scheme has advantages of simple structure, low battery mass, convenient throttling, and high reusability. The system state parameters distribution indicates that the feed system can achieve the propellants' pressurization requirements throughout the designed 5:1 throttle range, which suggests the feasibility of this system scheme. Moreover, although the proposed system requires more battery power than does the turbine, the turbine power proportion in the entire system increases with thrust. However, the turbine efficiency drops steeply with a decrease in thrust, whereas the double pump efficiency presents a narrow variation range.

Energy management plays a decisive role in the design of efficient 48V mild hybrid drives owing to the limited amounts of energy and power. In particular, strong nonlinearities of an electrified engine air path and the high interaction between the 48V mild hybrid powertrain and the electrical system pose a major challenge. Current research results show the fundamental potential of optimization-based energy management strategies. However there is a lack of optimization-based solutions that allow online direct control of the electrified air path and the electric motor. In this context, this study presents a nonlinear model predictive control (NMPC) approach for a 48V mild hybrid powertrain with an electric supercharger, which is able to simultaneously improve the response behavior and energy consumption. The control concept is developed on the basis of a detailed system description. The special features of optimization-based control for the degrees of freedom of the powertrain, i.e., the belt starter generator (BSG) and the electrified air path through a throttle, waste gate, and electric supercharger (eC), are addressed. After an analysis and verification of the control properties, the NMPC is evaluated in dynamic driving cycle simulations through a comparison with a state-of-the-art rule-based control strategy. The investigations show that the NMPC is able to control the system well even under transient situations with a high influence of disturbance variables. In addition, the NMPC allows a specific and fuel saving use of the 48V system while improving the driving dynamics at the same time.

This study aims are to observe the performance of a six-stroke combustion motor and to analyze the thermodynamics of a six-stroke combustion engine with a power expansion step to the bottom dead center. The fuel used in this observation is pertalite with a RON 90 value. The method used is a true experimental method, with independent variables, namely 35%, 40%, 45%, and 50% throttle openings with loading on the prony disc brake of 10 kg, 20kg, 30kg, 40kg, and 50kg. In the torque data, each throttle opening shows the highest number of 7.26 (Nm) with a load of 50kg and the lowest value of 2.01 (Nm) with a load of 10kg, for effective power the highest value is 8.47 (kW) at 50% throttle opening with load is 40kg and the lowest value is 2.49 (kW) at 35% throttle opening with a load of 10kg, while for the specific fuel consumption (SFC) the highest value is 4.28 (kg/Hp.h) at 40% throttle opening with a load of 10kg and the lowest value is 0.77 (kg/Hp.h) at 50% throttle openings with a load of 50kg, and for the thermal efficiency of the six-stroke motor, which means an average increase of 14.58% compared to the thermal efficiency of the conventional 4-stroke internal combustion engine.

In this article, a new approach for combustion engine test bed system identification is presented. Modern engine test beds are used to reduce development time by utilizing them for hardware-in-the-loop tests. For highly accurate and close-to-reality tests, model-based controllers are deployed, which rely on precise models of the test bed. Hereby, the main challenge is the unknown, cyclic disturbance of the engine due to compression and combustion of the air-fuel mixture. These disturbances also occur when the throttle is kept at zero and have a big impact on the measurements. Therefore, parameter estimation is strongly impeded. A method for dealing with these disturbances and embed them into the identification procedure in a two-step fashion is presented in this contribution. Further advantages of this new approach are that a physical model is obtained, but prior knowledge of parameters is not necessary. Moreover, disassembling of the test bed to perform separate parameter estimation is not needed and hence, the time consumption of the procedure is kept low. Experimental results on a 4-cylinder diesel engine test bed prove the feasibility and effectiveness of the proposed concepts.

In the course of developing designs for mixing heat exchangers that operate on the principle of throttling the working medium on perforated grids, special attention is paid to ensuring the reliability of structures subject to erosive wear when subjected to dripping moisture and temperature stresses.JSC “NPO CKTI” has years of experience in the development of contact-type heat exchangers and was directly involved in the design of separate power plant equipment for LK-60, including a throttle and dampening device (TDD).It provides a description of the functional purpose of the TDD as part of the LK-60 nuclear power plant, the principle of operation and significant differences of the new design from those previously used. It is noted that while in previous designs the TDD included four columns connected in pairs, on LK-60 there are two columns located on top of the condenser. The TDD for LK-60 is designed to receive 132.5 t / h of steam of higher parameters than the previous generation designs intended to receive about 50 t / h of steam.The main technical solutions in the development of the design of the TDD are presented. The design provides access to the throttling lattices for diagnostics and their replacement if necessary which ensures a high degree of maintainability and reliability of the device. Perforation of the lattices arranged in series in the direction of the steam flow is made in such a way that the openings of the previous lattice, if possible, are not located opposite the openings of the subsequent lattice. The distance between the throttling lattices was taken from the conditions for ensuring the design course of the steam throttling process.Results are given of thermal and hydraulic calculations of the TDD. The calculation consists of two main parts. The first part includes thermal and hydraulic calculations with the determination of the degree of perforation of the lattices, the distribution of temperature and vapor pressure over the cross-sections of the TDD, etc. The second part contains the calculation of the cooling condensate injection nozzles.In the course of design studies, strength calculations were performed for all versions of TDD and individual parts. In addition, the nozzles underwent a full test cycle (determination of flow characteristics, water spray quality) in accordance with the test program.

The issues of studying the operating parameters of the elements of lubrication systems for high-speed internal combustion engines preceded the creation of the stand. The engine lubrication system D-246.4 was chosen as a prototype. With the help of this stand it became possible to study the lubrication system for the following characteristics: change the performance of the engine oil pump D-246.4, change and control the engine oil temperature, control the pressure drop on the oil filter, control the engine oil flow, throttle oil at the inlet to the oil pump and on the conditional supply line to the friction units, measuring the vacuum of the system on the suction of the oil pump and recording the parameters of the pulsation of the oil pressure generated by the oil pump. To build mathematical models of the components in the lubrication systems of marine internal combustion engines there is a need to determine their operating parameters. In real operating conditions, such measurements cannot be obtained due to the lack of the necessary test equipment (TE) and the possibility of its installation. The authors describe in detail all the components of the stand for studying the parameters of the elements of lubrication systems of high-speed internal combustion engines, their technical characteristics, describes the diagnostic complex, which recorded the results of research, the results of measuring engine oil pressure pulsation. The stand is used to study the operating parameters of the oil pump and filter used for water. Signals are registered using the Autoscanner diagnostic system. The diagnostic complex is a 64-channel oscilloscope that is connected to a personal computer. This stand for studying the operating parameters of the elements of the lubrication system provides sufficient opportunities to simulate the operating conditions of the elements of the supply and purification of oil and register them both visually and with digital sensors and diagnostic system Autoscanner, digital oscilloscopes or other measuring instruments capable of recording and storing the received data.

The study of potentially high rated alternative fuel (Methanol) for the IC engines is an exciting topic in the recent research advancement. However, the study of combination of methanol and hydrogen is considered to address both economic and environmental needs. Hydrogen with best combustion characteristics will compensate for the drawbacks of methanol as a fuel. In the present investigation hydrogen enrichment to methanol has shown a significant enhancement in performance and combustion; the overall emission has reduced substantially. The experiments for a different set of trials, including hydrogen enrichment ranging between 5% and 20% with 2.5% increment, the engine is operated with wide-open throttle (WOT) condition for different speeds. The increase in enrichment of hydrogen has shown a rise in BTE, BP, and a reduced BSEC value. The percentage increase in BTE is between 20 and 30%, and an increase in hydrogen beyond 12.5% would affect the volumetric efficiency, and thus performance declines after that. The exhaust emissions have a huge impact on hydrogen enrichment; CO, HC, and CO2 emission are reduced by 30–40%; however, an increase in cylinder temperature due to rapid combustion slightly increases the NOx emission. Thus hydrogen enriched methanol operating at higher compression ratio can improve the overall engine characteristics significantly.

The problem of forming the altitude-speed profile of the flight of civil and military transport aircraft (AC) at the ascent stage and optimization according to the economic criterion is solved using a dynamic model of the motion of the center of mass in a vertical plane. The model takes into account the change in the mass of the AC and the systematic component of the wind speed. The aerodynamic characteristics of the AC and its weight, as well as the altitude and speed characteristics and the throttle characteristics of the engines, are close to those of a modern typical medium-range AC. For the given ascent scenario, the optimal and quasi-optimal control laws are found at the acceleration stage. The influence of the scenario’s parameters on the values of the main optimization criteria is estimated. The dependences of the optimal values of the ascent rate on the cost index are obtained and the range of its variability is found.

An experimental investigation has been conducted on a subscale dual-bell nozzle to study the effect of throttle settings on sneak-transition side loads. The results are from a cold-gas test campaig...

A system consisting of an internal combustion engine (ICE) directly coupled to an electric machine for power generation as in range extenders is considered in this brief. The engine power is mostly controlled by acting on the throttle. A second control loop regulates the air-to-fuel ratio by measuring the exhaust oxygen and acting on the fuel-mass flow, whereas the electric machine is usually considered only for the energy conversion. In this brief, the influence of the throttle and the generator speed on the power control is studied. Moreover, a control strategy is proposed that, by acting on the generator, allows the power control without the need of a throttle actuator. The baseline system was compared with the proposed control strategy. The power control leads to a nonlinear control system that is dealt with via feedback linearization. The control strategy was designed and tested in an experimental prototype. The results validate the proposed control structure that ensures a high fuel conversion efficiency within a wide power range and foregoes the throttle actuator. The highest possible fuel conversion efficiency difference in the operation range is 10%.

Today’s High Performance Computing (HPC) systems contain thousand of nodes which work together to provide performance in the order of petaflops. The performance of these systems depends on various components like processors, memory, and interconnect. Among all, interconnect plays a major role as it glues together all the hardware components in an HPC system. A slow interconnect can impact a scientific application running on multiple processes severely as they rely on fast network messages to communicate and synchronize frequently. Unfortunately, the HPC community lacks a study that explores different interconnect errors, congestion events and applications characteristics on a large-scale HPC system. In our previous work, we process and analyze interconnect data of the Titan supercomputer to develop a thorough understanding of interconnects faults, errors, and congestion events. In this work, we first show how congestion events can impact application performance. We then investigate application characteristics interaction with interconnect errors and network congestion to predict applications encountering congestion with more than 90% accuracy.

Titanium, being a structural material, undergoes drilling process frequently for its engineering applications. The superior mechanical properties of titanium alloys make hole-making a highly unsustainable process. The process is marred by high cutting forces, intense tool damage, high energy consumption, poor hole quality, and high process cost. The work presents an approach for viable and cleaner drilling of the difficult-to-cut material by investigating the effects of micro-lubrication and the following two options of cryogenic cooling: (1) evaporative cooling using liquid nitrogen and (2) throttle cooling using compressed carbon dioxide gas. Additionally, the effects of cutting speed and pecking – a technique actualized by rapidly retracting the twist drill by 2 mm at two levels of depth during thru-cutting of the holes – are also quantified. Pecking is not found to be favorable to any of the evaluated sustainability measures. Of the three cutting fluids testes, throttle cryogenic cooling yielded the most advantageous results. The coolant, because of its effective heat dissipation capability, yielded superior outcomes with respect to all the sustainability measures except surface quality. Micro-lubrication proved to be beneficial, at the low level of cutting speed, to specific cutting energy, surface quality, and process cost. Evaporative cryogenic cooling did not yield promising results. The runs employing evaporative coolant or the high level of cutting speed experienced thicker tool adhesions whereas those utilizing pecking showed signs of intense progressive wear. Moreover, the thrust force data indicated occurrence of thermal softening of the work material as the drills progressed through the hole-cutting process. From the holistic perspective of sustainability, it is recommended to adopt throttle cryogenic cooling, a medium-to-high level of cutting speed, and no-pecking for hole-making in the titanium alloy.