Recovery Device Research Articles

Оптимізація параметрів мікроклімату в навчальних закладах з системами локальної рекуперації повітря

The aim is to develop an automatic local air recovery system to ensure thermal comfort and the normative composition of the air environment in educational institution premises. Improving the efficiency of local air recovery systems while maintaining optimal microclimate parameters is possible through the enhancement of automatic control systems for local recovery devices. An automatic air local recovery control system has been developed, which guarantees optimal microclimate parameters in educational institution premises. Computer simulation modeling has been applied to control the microclimate system based on temperature and CO2 concentration. The advantages of the proposed system have been identified, which reduced the duration of exceeding the maximum allowable level of CO2 concentration by 49.5% and decreased the CO2 concentration by 13.1% within the specified temperature limits.

Comparative Performance Analysis of Exhaust Air Heat Recovery Devices Based on Microchannel heat pipe

In response to the problem of low recovery efficiency of sensible heat recovery devices, this paper designs a microchannel heat pipe heat recovery device (MHPHRD) and compares its heat transfer performance during summer use through experiments and simulation calculations. The experimental results show that the microchannel heat pipe (MHP) has strong temperature uniformity, and the temperatures of the evaporation and condensation sections are basically the same. When the inlet temperature of fresh air changes between 32°C and 40°C, the recovery efficiency of the device varies between 67%-80%, and the linear relationship between the two is obvious. The established calculation model has high accuracy, with a maximum error of 0.7% between measured and simulated values. Simulation calculations show that the cooling capacity recovery efficiency of the MHPHRD is 4%-16% higher than that of the cylindrical heat pipe heat recovery device (CHPHRD), and 24%-30% higher than that of the plate heat recovery device (PHRD). The research in this article can provide reference for the practical application of the device.

Matching the output voltage level of the energy recovery device and the voltage of the on-board network

This article deals with the possibilities of applying magnetic dampers for damping of mechanical vibrations, both of car body and of radio-electronic equipment. An electronic device is proposed to adapt the output voltage of the energy recovery device to the voltage of the car’s onboard network or to the power supply voltage of the radio-electronic equipment. In addition, the developed device can be used in conjunction with an energy recovery system for vehicle braking.

Research on Capture Performance of an Induction Type Microplastics Recovery Device

Research on Capture Performance of an Induction Type Microplastics Recovery Device

Development of Residual Iron Scrap Recovery Device with Hot-Tapping

Development of Residual Iron Scrap Recovery Device with Hot-Tapping

Introductory Analysis of Spark Ignition Engine and Extensively Implemented Electric Alternatives

Energy crises and climate change lead to restricted standards of emission and energy consumption in regular road vehicles. Combustion method, ignition time, and injection time are engine development priorities. Optimal injection and ignition timing at 1600 rpm can save 10% on brake fuel. Perfect injection and ignition timing reduce heat loss and emissions. Various approaches to reducing transportation emissions and energy were implemented. Plug-in electric vehicles and hydrogen fuel cell vehicles (HFCV) were eliminated because of the lack of charging and refilling facilities. Mild hybrid energy recovery devices are considered straightforward and effective. Because of its effectiveness and longevity, Kinetic Energy Recovery System (KERS) is the most popular hybrid system in road automobiles. Future road energy recovery systems may include heat energy recovery methods and solar panels. However, electric vehicles with regenerative technologies own the highest energy efficiency among all the proposed solutions with the advantage of no pollution during the operation.

EVALUATION OF THE VALUE OF EQUIVALENT ENERGY LOSSES DUE TO THE QUALITY OF FREQUENCY SYNTHESIS FUNCTIONING IN DIGITAL COMMUNICATION SYSTEMS WITH QUASI-COHERENT RECEPTION OF SIGNALS WITH QUADRATURE AMPLITUDE KEYPAD

Useful transmitted information when using digital transmission systems with quadrature amplitude shift keying lies in the change in the amplitude and phase of the signal. This circumstance causes significantly higher requirements for the magnitude of destabilizing factors, namely the phase noise of signal packages at the input of the demodulating device of signals with quadrature amplitude keying, which affect the useful signal, resulting in a decrease in the reliability of reception. In this article, we restrict ourselves to considering the requirements for short-term frequency stability of synthesizers of digital transmission lines, which use signals of multi-position quadrature-amplitude keying in conjunction with quasi-coherent reception. The carrier wave is extracted on the receiving side directly with the help of a carrier recovery device from the received QAM signal by demodulating it, followed by narrow-band filtering. The phase-locked loop in this case functions as a narrow-band tunable filter for extracting the carrier wave. An increase in the quality of demodulation and signal filtering processes leads to a decrease in the phase fluctuation of the restored carrier, a decrease in the level of additive noise, and a decrease in the magnitude of energy losses when using quasi-coherent reception compared to the ideal one, which requires the complete absence of a phase error of the selected reference signal. Such an approximation of the noise immunity of real coherent QAM demodulators to the theoretical one limits the phase noise of the signal at the demodulator input, which is associated with the non-ideal operation of frequency synthesizers on the transmitting and receiving sides of digital communication lines. The research methods used in the article are based on the theories of potential noise immunity, demodulator synchronization, and phase locked loop systems. For the carrier recovery device, the noise band value was chosen in the range from to (where T – is the symbol duration), since with the indicated ratios, the distribution law of the phase error can be considered normal. It was assumed in the work that the devices for automatic gain control and clock synchronization in the radio receiving system function ideally, and the frequency response of the channel corresponds to the Nyquist condition.

Analysis of the recovery device control system

Energy recovery of various types is an urgent task in the development of control systems for electromechanical devices. rational and careful use of energy resources. The purpose of this work is to analyze four-quadrant asynchronous electric drives with vector frequency-current control systems and autonomous voltage inverters with sinusoidal pulsewidth modulation based on IGBT modules. The design algorithm is considered and the results of modeling of such energy recovery systems are given. The proposed control system of the recovery device can be used as an integral part of a specialized controlled electric drive for escalator stations of the subway, electric transport and other electromechanical systems in order to save energy consumed.

Heat transfer enhancement by diamond nanofluid in gravity heat pipe for waste heat recovery

Waste heat recovery is significant for improving energy utilization, reducing carbon emissions, and neutrality. The gravity heat pipe (GHP) has excellent thermal performance due to the cyclic phase transformation of the working fluid. As an important thermal management device for waste heat recovery, the heat transport capacity of GHP improves, the efficiency and performance of the waste heat recovery increase, and more wasted heat can be stored more quickly. Nano-diamond has the highest thermal conductivity and can be dispersed in water to form a diamond nanofluid, enhancing the thermal performance of GHP. In contrast, the study on the heat transfer behavior of the diamond nanofluid in GHP is insufficient. Besides, the influences of filling ratio (FR), mass fraction (MF), and heat flux on thermal performance are in demand for further study. In this article, the heat transfer behavior is investigated by studying the flow patterns of diamond nanofluids. The influences of filling ratio and mass fraction on flow patterns are analyzed. An orthogonal experiment is conducted; the heat flux has the most significant effect on the thermal performance, followed by the filling ratio and mass fraction. The thermal performance is the best when the optimal parameters (FR = 20%, MF = 1 w.t.%) are selected under a heat flux of 20 × 104 W/m2. The equivalent heat transfer coefficient reaches 3485 W/(m2·°C). This article can achieve a deeper understanding of the diamond nanofluid heat transfer mechanism in GHP and enhance the thermal performance of GHP for better waste heat recovery.

FLOW ENERGY ANALYSIS OF REVERSE OSMOSIS UNIT IN SEAWATER DESALINATION PLANT WITH ENERGY RECOVERY DEVICE

The demand of water is increasing day by day because of population explosion and rapid urbanisation. In this regard, desalination is one of the prominent technologies for providing potable water from saline aqueous media. Among available methods of desalination, seawater reverse osmosis is commercially viable and practiced in many countries of the world. But high energy use is one of the drawbacks of reverse osmosis process. Hence, this study aimed to analyse flow energy of reverse osmosis unit in seawater desalination plant with energy recovery device. A conventional material and energy balances is applied for the analysis. From the analysis, zero loss is observed in recirculation pump and significant loss of 66.65 kJ/s is estimated in energy recovery device. It could be concluded that energy recovery device is a suitable option to reduce the energy use in reverse osmosis unit.

Update of the PERISCOP system for isobaric sampling of deep-sea fauna

We here present an update of the PERISCOP pressurised recovery device (PRD), which has allowed the recovery of live deep-sea fauna, following active sampling by manned or remotely-operated submersibles. It was designed in 2006, has since been deployed almost a hundred times (93), and its operation has now become almost routine. Various hydrothermal vent megafaunal organisms (shrimp, crabs, annelids, mussels, fish,..) were successfully targeted and recovered, allowing access to samples in excellent physiological condition. Gradually, the system was modified, aiming at improved reliability, depth of operation, and simplicity of use, especially regarding its compensator, i.e. the system that compensates for pressure loss experienced during ascent through the water column. Two types of compensators are presented, called “active” and “passive” (with so-called “water-filled” or “oil-filled” modes regarding the latter). Their respective uses are reported and discussed here, and while the active system proves more efficient (recovering at minimum pressure in the range 93.8–98.2% of in situ pressure, as opposed to 80.9–86.6% for the water-filled passive system, while no compensation leads to a range of 63.5–73.0%), the simplicity of the passive compensator greatly improves reliability and ease of use and maintenance. Finally, the monitoring of pressure and temperature of the PRD and the surrounding water column permits to discuss various technical aspects of pressurised recovery, and to propose further improvements.

Analysis of gas–solid two-phase flow and structure optimization of mobile shot blasting machine recovery device

To address the problem of low efficiency of recycling process waste by gas–solid two-phase flow of the shot blasting machine recycling device, a method and structure by increasing the negative pressure value and optimizing the outlet pipe position are proposed. Computational fluid dynamics (CFD), discrete element method (DEM) and discrete phase model (DPM) were used to study the waste recovery efficiency at different pressure outlet conditions and outlet pipe locations. The validity of the model was verified by velocity tests at the outlet and inlet compared with simulations. The effect of particle size and particle generation rate on solid particle recovery efficiency was further investigated by analyzing the flow field distribution of the recovery unit. The results show that the maximum velocity of the gas phase in the recovery device increases with the increase of the absolute value of the outlet pressure, when the outlet pressure is -6500 Pa, the maximum velocity is 67.59 m/s. When the absolute value of the outlet pressure is greater than 6000 Pa, a small amount of steel shot particles is discharged from the recovery bin under the action of the outlet pressure, resulting in the loss of steel shot particles. After the outlet pipe position optimization, the steel shot particle recovery efficiency increased by 10% and the waste particle recovery efficiency increased by 18.9%.

Performance improvement of the electric water heater by a waste heat recovery method with the thermoelectric effect

In this study, a waste heat recovery method based on the thermoelectric effect was proposed to improve the thermal performance of electric water heaters. The method collected the surplus thermal energy in the high-temperature zone and released heat for reuse in the low-temperature zone through the thermoelectric element. A heat-recovery device using a thermoelectric element was designed and conducted experimentally to verify the method's feasibility and energy conservation effect. The device performance of heat absorption and heat release were investigated under various working thermal states. The experimental results showed that the heating COP of the system could be improved to 1.2–2.3 under different temperature conditions, which means the device can save energy than using electric power directly. The heat flux through the device can be actively controlled for an optimal effect of heat recovery. The source-sink matching effect of the device was investigated, and the results indicated that the device's energy efficiency could be higher than 75%. The thermal performance of an improved electric water heater using the heat recovery device was investigated numerically under a specific working condition. The results verified that the heat recovery device reduced heat dissipation and simultaneously increased the temperature of the water outlet.

Thermodynamic analysis of power recovery of marine diesel engine under high exhaust backpressure by additional electrically driven compressor

Marine diesel engines can be exposed to high backpressure conditions, because various aftertreatment systems and waste heat recovery devices have been applied to reduce emissions and some exhaust outlets are below sea level. The engine performance deteriorates sharply under high backpressure. This paper aims to study power recovery method under high backpressure based on thermodynamic analysis. Firstly, thermodynamic model is established and validated by experimental data. Next, effects of turbocharger efficiency and turbine area on power recovery are studied. The results show that feasible turbine performance are limitations for power recovery. If energy of compressor can be increased without changing turbine area, limitations can be overcome. Thirdly, additional electrically driven compressor as a solution is proposed to recover engine power. A comparative study of different electrically driven compressor schemes is carried out. The most suitable scheme is the series scheme at low-pressure stage because operating points for original compressor and electrically driven compressor are within a reasonable range. Finally, research on power recovery is carried out on optimal electric compressor scheme. The results show that when backpressure is 0.65 bar, engine net power can be increased by 49.4% and exhaust temperature drops by about 77 K, which largely reduces turbine thermal load.

Regulation strategies and thermodynamic analysis of combined cooling, heating, and power system integrated with biomass gasification and solid oxide fuel cell

A solid oxide fuel cell combined cooling, heating, and power system integrating biomass gasification is proposed. The hybrid system consists of the biomass gasifier, solid oxide fuel cell-gas turbine, and waste heat recovery device. The system can be divided into different configurations by adjusting the valve opening to change the waste heat mode. The thermodynamic model is established and validated; the system evaluation indicators and the thermodynamic, economic and environmental performance are researched under design conditions. The influences of several crucial parameters on syngas composition and system performance under the different configurations are investigated. This paper also evaluates the scope of system regulation and energy output to meet the energy demand side. The analysis results indicate that system power efficiency is 58.92% at the preferred configuration, and the system energy and exergy efficiency can attain 86.70% and 50.45%. The system total cost rate and the CO2 emission rate are relatively lower, at 19.6$/h and 0.4722kg/kWh. By implementing different configuration strategies, the system exergy efficiency is between 46.55% and 50.45%. The system heating to power ratio and cooling to power ratio can vary from 0 to 0.58 and 0 to 0.77.

Global sensitivity analysis and optimal design of heat recovery ventilation for zero emission buildings

Energy-efficient building services are necessary to realise zero-emission buildings while maintaining adequate indoor environmental quality. As the share of ventilation heating needs grow in well-insulated and airtight buildings, heat recovery in mechanical ventilation systems is increasingly common. Ventilation heat recovery is one of the most efficient and viable means to reduce ventilation heat losses and save energy. Highly efficient heat exchangers are being developed or applied to maximise the energy-saving potential of heat recovery ventilation. Nevertheless, the effects of practical operating conditions and the constraints of heat recovery – such as variations in ventilation rates, frost protection, and the prevention of an overheated air supply over a long-term period, which may significantly influence realistic recovery rates – have been less considered in efforts to maximise the energy savings. It is unclear which design parameters for heat recovery devices have the greatest effect on the annual energy savings from ventilation.This study proposes annual efficiency and annual net energy saving models for heat recovery ventilation that consider ventilation rate variations, the longitudinal heat conduction effect and operating controls. We use a global sensitivity analysis to quantify the contributions of various design input parameters to the variation in annual recovery efficiency and annual net energy savings. We identify the most influential parameters and their significant interaction effects for the annual energy performance of heat recovery ventilation. More attention should be paid to these most influential parameters during the design process. Furthermore, the optimal designs for rotary heat exchangers (as identified by a pattern-search optimisation algorithm) can improve annual net energy savings in demand-controlled ventilation by 33–48%, depending on the building areas. In combination with the reference year analysis presented in this study, heat recovery and demand-controlled ventilation can help to meet the need for highly efficient ventilation systems and zero-emission buildings.

Study of the trapping mechanism of merging drops moving under thermocapillary migration on a surface with wettability contrast

Trapping of drops due to wettability contrast in porous materials emerges in a variety of subsurface and manufacturing applications. In carbon capture and storage, carbon dioxide must be trapped in order to avoid its release into the atmosphere, while trapped oil must be displaced. Both carbon dioxide and oil can exist as drops in porous media. The migration of a single drop attached to a wall can be hindered if the wall surface has a different wettability. However, the trapping condition becomes more complicated in the presence of two or more drops. In this work, we aim to study the trapping mechanism during thermocapillary migration of a merging drop on a heterogeneous surface. To do so, numerical simulations have been performed using the Front-Tracking/Finite Volume Method, where the Navier-Stokes equations are coupled with the conservation equations. The generalized Navier boundary condition (GNBC) has been used as the slip model to remove the viscous singularity. The combined finite-volume and tracking method is able to deal with different types of discontinuities in compressible or incompressible fluid flows, as e.g., interfaces. The material properties of the drop and the ambient fluid are different, and surface tension depends on the temperature. The results have shown that there exist three regimes characterizing the motion of merging drops, including the passage of the leading drop, the trapping of the merging drop, and the partial trapping, which correspond to the trapping of the leading drop but the passage of the merging drop. We show that there is a critical wettability contrast at which the merging drop gets trapped. The effects of Marangoni number (Ma) and viscosity ratio are investigated. The critical wettability contrast decreases with the increase of Ma number and the regime shift as a function of the viscosity and Marangoni number. These findings have implications for the design of geological carbon dioxide storage, improvement of oil recovery and microfluidic device development.

Optimization of geometric parameters of hydraulic turbine runner in turbine mode based on the orthogonal test method and CFD

The hydraulic turbine in turbine mode (TMHT) with ultra-low specific speed is a new type of energy recovery device for recovering energy stored in the high-pressure fluid. In order to solve the problem of insufficient consideration of runner geometric parameter optimization, this paper proposes an optimization strategy (OT-CFD), which is based on the orthogonal test method and computational fluid dynamics (CFD), to optimize the performance of the TMHT runner. Firstly, the orthogonal test schemes are established with 5 levels of runner inlet diameter, outlet diameter, inlet height, blade inlet angle, and blade number. Then 25 three-dimensional models of two-stage TMHT containing flow passage components such as Francis runner are built. Further, the internal flow characteristics and energy characteristics of TMHT are calculated and then verified by the real machine test. By comparing the numerical simulation results, the design schemes of runner geometry parameters corresponding to the highest head (H) and the highest efficiency (η) are determined, respectively. On this basis, the optimization effect of runner geometry parameters is analyzed by numerical simulation based on CFD. In conclusion, the inlet angle is the most important factor affecting the efficiency, and the runner inlet diameter is the most important factor affecting the water head. Compared with the comparison scheme, the optimal η scheme has a more stable flow pattern, which provides an efficiency increase of 10.9%, a water head increase of 26.75 m, and a power increase of 646.32kW, greatly reduces the energy loss in the process of residual pressure recovery; the optimal H scheme has an efficiency increase of 2.61%, but more stable and regular flow pattern. More importantly, the optimal water head scheme, which has a water head increase of 185.53 m and a power increase of 1518.3kW, greatly increases the capacity of recovering the water head.

Experimental study on influence of high exhaust backpressure on diesel engine performance via energy and exergy analysis

Marine diesel engines can be exposed to high backpressure conditions, because various aftertreatment systems and waste heat recovery devices have been widely applied to reduce the emission level, and the outlet of its exhaust manifold is normally below sea level. This article aims to understand the influence of exhaust backpressure on turbocharged engine performance. Diesel engine tests under high backpressure was conducted and it has been found that engine output power drops sharply. To explore the reasons and further study the recovery method, analysis of energy and exergy was carried out. With the increase of backpressure, turbo expansion ratio reduces sharply. But the energy upstream turbine doesn't decrease necessary due to the increase of exhaust temperature. Simultaneously, the exhaust exergy gradually increases by 10.3% when the backpressure increases from 0 bar to 0.55 bar at 75% load, leading to improved energy grade. The turbine output power reduces 56.7% because of the combination results of reduced expansion ratio and increased exhaust energy grade. The method of power recovery should balance these two factors. The study can enlighten the method of power recovery of diesel engine confronted by high backpressure conditions.

A Drying system for Rhizoma et Radix Baphicacanthis Cusiae Based on multi-source coupling and efficient energy storag

The traditional Chinese Herbal Medicine Rhizoma et Radix Baphicacanthis Cusiae mostly grows in Southwest China. However, due to the lack of technology, the key drying process in the production of Rhizoma et Radix Baphicacanthis Cusiae has the problems of low efficiency, long time and uneven quality. The paper designed a drying system of Rhizoma et Radix Baphicacanthis Cusiae based on multi-source coupling and efficient energy storage by investigating the production of Rhizoma et Radix Baphicacanthis Cusiae in southwest China and studying the natural effects of geographical advantages and light conditions in the region. The main body of the system is composed of a two-position water tank heat circulation system, a hemispherical Fresnel lens array, an air source heat pump, a dehumidification and waste heat recovery device, a temperature and humidity sensor, and a heat exchange tube group. The drying system can better meet the drying needs of Chinese herbal medicine Rhizoma et Radix Baphicacanthis Cusiae. It has the advantages of high efficiency, energy conservation and environmental protection, stable operation, and can independently adjust according to the drying temperature. It has strong practicability. While saving energy, it saves high drying cost for farmers, and meets the special requirements of building intelligent agriculture and enriching rural economic business forms.