System Design Parameters Research Articles

Design of Active Tyre-Suspension-Seat System Through Multibody Model and Genetic Algorithms

The tyre-suspension-seat dynamic system, driveline and engine vibrations are generally considered in the vibrational field as the main factors that influence the particular feeling of comfort perceived by passengers on a vehicle. Hence, the development of several criteria and models for the optimal estimation of the design parameters of such systems. Among these parameters, the most detrimental impacting on the passenger comfort are undoubtedly acceleration and its variation. The two types of suspension systems (conventional passive suspension system and active suspension system) differ as the first foresees the spring-damper characteristics to be adjusted so that only one of several conflicting objectives (such as passenger comfort, road holding, and suspension deflection) is followed. In active suspension systems, instead, these objectives are balanced by the designer in a more efficient manner thanks to the feedback-controller actuator assembly. However, this approach presents some limitations linked to the extremely wide spectrum of magnitude and frequency of external forces that the tyre-suspension-seat system has to efficiently control and mitigate. It remains that in the existing optimisation models and systems time exposure limits established by unification agencies and road authorities are not generally considered. This paper illustrates the development of an active tyre-suspension-seat system control for passenger cars, using both a non-linear multibody model and Genetic Algorithm (GA) controls. A benefit of the proposed active tyre-suspension-seat system control is also to consider various time exposure limits and an active damping element. The main innovative element introduced by this work consists in having coupled an active control to passive mechanical parameters in order to minimize the seat acceleration. The 3 DoF multibody model, applied to a quarter body for symmetry reasons, treated road roughness as an input variable in the GA control so as to determine the vertical component of acceleration. The numerical and experimental applications of the proposed model to a specific case study allowed to validate the effectiveness of the active system towards the vibrations transmitted to the passenger.

Effect some of hydraulic and design parameters of border drip irrigation system and some soil conditioners on irrigation efficiencies

A field experiment was conducted in Missan governorate in the areas of the Al- Asher Makaon adjacent to the basin of the Tigris River. The experiment was carried out in winter season of 2018-2017. The experimental treatment of three lateral pipes spacing at 30 cm (S1), 45 cm (S2) and 60 cm (S3) with three locations L1, L2 and L3 from border. The treatments were applied by using C.R.D design . the results showed effect on irrigation efficiencies such as addition efficiency, distribution efficiency, and water storage efficiency. The factorial coefficients of the experiment were distributed by applying a factorial experiment using the randomized complete block design R.C.B.D. The results showed that there is a highly significant effect of the factor of the distance between the field pipelines, the addition of soil conditioners and the difference in the level of irrigation water in the values of irrigation efficiencies, as the values of water addition efficiency (AE%) and water distribution efficiency values (%Ed) increase with the decrease in the distance between field pipes and the addition of soil conditioners. Reducing the irrigation level to 75% of the Ep values, while this effect is reflected in the water storage efficiency values (%ES), as it increases by increasing the distance between the field pipes, adding soil conditioners, and increasing the irrigation level to 100% of the Ep values.

Parameter Simulation and Design of an Airborne Hyperspectral Imaging LiDAR System

With continuous technological development, the future development trend of LiDAR in the field of remote sensing and mapping is to obtain the elevation and spectral information of ground targets simultaneously. Airborne hyperspectral imaging LiDAR inherits the advantages of active and passive remote sensing detection. This paper presents a simulation method to determine the design parameters of an airborne hyperspectral imaging LiDAR system. In accordance with the hyperspectral imaging LiDAR equation and optical design principles, the atmospheric transmission model and the reflectance spectrum of specific ground targets are utilized. The design parameters and laser emission spectrum of the hyperspectral LiDAR system are considered, and the signal-to-noise ratio of the system is obtained through simulation. Without considering the effect of detector gain and electronic amplification on the signal-to-noise ratio, three optical fibers are coupled into a detection channel, and the power spectral density emitted by the supercontinuum laser is simulated by assuming that the signal-to-noise ratio is equal to 1. The power spectral density emitted by the laser must not be less than 15 mW/nm in the shortwave direction. During the simulation process, the design parameters of the hyperspectral LiDAR system are preliminarily demonstrated, and the feasibility of the hyperspectral imaging LiDAR system design is theoretically guaranteed in combination with the design requirements of the supercontinuum laser. The spectral resolution of a single optical fiber of the hyperspectral LiDAR system is set to 2.5 nm. In the actual prototype system, multiple optical fibers can be coupled into a detection channel in accordance with application needs to further improve the signal-to-noise ratio of hyperspectral LiDAR system detection.

Motor and Transmission Multiobjective Optimum Design for Tracked Hybrid Electric Vehicles Considering Equivalent Inertia of Track System

In the development of hybrid electric vehicles (HEVs), a series hybrid powertrain is mainly utilized in tracked vehicles to reduce energy consumption. In order to achieve high energy efficiency while maintaining the required driving performance, key design parameters of traction systems, such as transmission ratio and motor torque and power, need to be optimized. With the aim of effectively analyzing a complex track system, this article proposes an equivalent inertia model, which collectively represents the motion of each component of the tracked vehicle. The equivalent inertia model showed that the inertial effect was 34.8% higher than when the total mass of the vehicle was considered exclusively. Based on this inertia model, design objectives, such as energy efficiency and driving performance, were defined as quantified functions. Because of the balanced relationships between the objective functions, this study formulated a multiobjective optimization problem that includes motor stack length and transmission gear ratio as design variables. Based on the multiobjective optimization results, a Pareto front was obtained, which illustrates the balanced relationships between the objective functions. Comparing the initial HEV design, the optimum designs can improve energy efficiency and driving performance as a maximum of 13.0% and 2.9%, respectively.

DETERMINATION OF THE OPTICAL TRANSMITTER MODULATION TRANSMISSION FUNCTION IN THE PRESENCE OF LASERS EMITTER

The most acceptable form of transmission of information over the fiber-optic line is its encoding in the form of rectangular pulses. In most cases, a semiconductor laser diode is used as a radiation source, and a single-mode fiber is used as a light guide. The main cause of energy losses in this node is the mismatch of the apertures of the laser diode and the fiber used to propagate the signal. In fiber-optic information systems, where the signal is modulated by the supply voltage, it is important not only to reduce energy losses, but also to transmit the signal to the fiber with minimal distortion. The most effective means of estimating the effect of the optical system of input of radiation into the optical fiber on the degree of distortion of the transformed signal is the use of Fourier transform of the signal with subsequent analysis of its frequency characteristics. Considering the node of the optical transmitter as one of the links of fiber-optic information systems, we conclude that it is necessary to study its frequency characteristics, namely its modulation transmission function. The modulation transfer function of this node depends on the design parameters of the input system. Errors in basing the radiating plane of the laser diode relative to the cardinal points of the optical system for inputting radiation into the optical fiber also have a significant effect on the modulation transmission function. Such errors include defocusing and angular and transverse decentering. Calculations of aberrations with subsequent determination of the scattering function and the use of fast Fourier transform for the calculation of FPM, as well as the calculation of FPM were performed using the program ZEMAX. The research allowed to obtain results characterizing the frequency properties of a typical optical system of laser diode radiation input into a single-mode optical fiber. It is established that the most stringent requirements (at the level of several microns) should be set before the possible defocusing of the radiating plane. Possible transverse decentering is limited to ten fractions of a millimeter, and ultimately its value is determined by the allowable vignetting of the radiation flux.

Demonstration of Optimal Scheduling for a Building Heat Pump System Using Economic-MPC

It is considered necessary to implement advanced controllers such as model predictive control (MPC) to utilize the technical flexibility of a building polygeneration system to support the rapidly expanding renewable electricity grid. These can handle multiple inputs and outputs, uncertainties in forecast data, and plant constraints, amongst other features. One of the main issues identified in the literature regarding deploying these controllers is the lack of experimental demonstrations using standard components and communication protocols. In this original work, the economic-MPC-based optimal scheduling of a real-world heat pump-based building energy plant is demonstrated, and its performance is evaluated against two conventional controllers. The demonstration includes the steps to integrate an optimization-based supervisory controller into a typical building automation and control system with off-the-shelf HVAC components and usage of state-of-art algorithms to solve a mixed integer quadratic problem. Technological benefits in terms of fewer constraint violations and a hardware-friendly operation with MPC were identified. Additionally, a strong dependency of the economic benefits on the type of load profile, system design and controller parameters was also identified. Future work for the quantification of these benefits, the application of machine learning algorithms, and the study of forecast deviations is also proposed.

Energy-efficient preservation environment control for enclosed exhibition hall of earthen relics

Historical earthen sites are bright stars in historical and cultural heritages. In order to effectively protect and display earthen sites (including cultural relics and soil), the fully-enclosed exhibition halls are established but without any environment control system. This will lead to some diseases of earthen sites, e.g., crystallization, structural cracking, which is due to continuous water/moisture loss of earthen sites. Hence, this work aims to control water and heat transfer between earthen site and ambient environment by proposing an energy-efficient environment control system, based on optimal design of ventilation and air conditioning. Numerical strategy was developed to calculate heat & moisture transfer between air and relics. Further this model was applied to optimize key design parameters (e.g. inlet air parameters) of environment control system through numerical simulations. Compared to fully-enclosed exhibition hall without control measures (moisture loss, −1.65 g/s), the moisture loss issue is solved by environment control system with optimal design (moisture gain, 0.013 g/s). The parameter design of control system is very essential, and different design parameters can lead to deviation of energy consumption up to 71%. This research is of great significance to mitigate the deterioration problems of enclosed exhibition hall of earthen relics, and the proposed numerical strategy can provide a useful tool for the control of other similar physical environments.

Design parameters of a reluctance actuation system for stable operation conditions with applications of high‐precision motions in lithography machines

Recently, the reluctance actuator has attracted great attention to replace the Lorentz actuator in the next generation of wafer scanners in semi-conductor lithography machines. The reluctance actuator has a non-linear position-force characteristic, which may cause high oscillations and unstable operation. This study presents a linearisation technique by optimising the main parameters of the reluctance actuator to operate away from the saturation point. Also, in this study, the critical current is formulated for the stable dynamic behaviour of the reluctance actuator. Optimisation based on the Grey Wolf Optimiser is performed considering the high-precision motion requirements and physical constraints. The high-precision motion requirements include the desired work-space displacement, natural frequency, and maximum force. The electromechanical dynamic model of the reluctance actuator motion system is formulated to characterise the interaction among electrical, magnetic, and mechanical parts. The simulation results show that the optimal design of the reluctance actuator works in the linear region, and for stable dynamic behaviour, the input current is limited by the critical current. Finally, a feedforward controller is designed based on the approximation of the force–current relationship to improve the tracking performances of the reluctance actuator motion system. The simulation results in time and frequency domains show an improvement in tracking performances using the feedforward controller.

Determining Proper Daylighting Design Solution for Visual Comfort and Lighting Energy Efficiency: A Case Study for High-Rise Residential Building

Promoting the daylight performance that allows to provide visual comfort conditions by minimizing lighting energy consumption is possible with making a balance of window size, glazing type and shading strategy, which are the major design parameters of the daylighting system. Particularly, in high-rise buildings, where large openings enabling higher daylight availability and view out are preferred, the daylighting system becomes a crucial design consideration in terms of ensuring occupants’ visual comfort and improving lighting energy efficiency. This study aims to identify a proper daylighting design solution with regard to window area, glazing type and shading strategy for a high-rise residential building located in Istanbul considering visual comfort and lighting energy efficiency. The dynamic simulations are carried out by DIVA for Rhino version 4.1.0.12. The results are evaluated with the Daylight Autonomy (DA) to detect daylight availability in the space and Daylight Glare Probability (DGP) to describe the visual comfort conditions related to glare. Furthermore, the lighting energy consumption of each alternative is also analysed to determine the proper daylighting solution. The results have revealed that a proper daylighting solution providing visual comfort by improving lighting energy-efficiency can be determined by the evaluation of the daylight performance both qualitatively and quantitatively.

Optimal structure design of supercritical CO2 power cycle for gas turbine waste heat recovery: A superstructure method

The supercritical CO2 power cycle is an effective way for gas turbine waste heat recovery due to its compact system structure and high efficiency. The stepwise optimization of operating parameters and system structure in the early research results in a great limitation of the search space on the optimal structure, consequently, there are still huge challenges in determining the optimal structure of the supercritical CO2 power cycle for waste heat recovery. Therefore, this study proposed a new superstructure of supercritical CO2 cycle for waste heat recovery based on the concept of splitting, which could optimization system structure and design parameters simultaneously. Taking the net power output as the objective function, the optimal structure of supercritical CO2 cycle under different boundary conditions and equipment parameters are investigated. The results show that the superstructure method produces new cycle structures which are not reported before, which is mainly embodied in the flow split and compression structure of the cold end. Compared with traditional supercritical CO2 and steam Rankine cycles at the heat source temperature of 400–600 °C, the maximum net power output obtained by the superstructure method are increased by 4.09–6.94% and 11.65–21.23%, respectively.

Parameter optimization design and performance analysis of filter‐integrated switched boost grid‐connected inverter

AbstractThis paper proposes a filter‐integrated switched boost grid‐connected inverter by coupling switched boost network between inverter bridge and power grid, which can effectively solve the inherent resonance peak problem of LCL filter. Meanwhile, the proposed topology can realize boost function at AC side, which can effectively avoid the problem of excessive voltage stress caused by the boost at the DC side. Due to the design of the parameters in the control system will affect the effect of resonance spike damping, it will also affect the harmonic content of the grid‐connected current. Based on the stability margin and steady‐state error of the system, combined with the characteristics of the system regulator, the parameter selection area that meets the system requirements is drawn in this paper, and the optimization of the system parameter design method is realized. Finally, the function of the circuit is verified by building an experimental platform.

A review on the application of nanoporous zeolite for sanitary landfill leachate treatment.

This review deals with low-cost nanoporous zeolites for the treatment of sanitary landfill leachate. Organic contaminants and ammoniacal nitrogen are significant parameters in landfill leachate treatment. Adsorption processes are regarded as promising alternative treatment options in this respect. Zeolites are aluminosilicate materials that are widely used in separation, filtration, adsorption and catalysis. Natural zeolite is a low-cost and readily available form of zeolite and is a promising candidate to be used as an ion-exchange material for ammonia and other inorganic pollutant removal from landfill leachate. In this review, adsorption isotherms and kinetic models in batch systems are evaluated and adsorption design parameters of the fixed-bed system are presented. Studies on ammonia removal from landfill leachate via zeolites have been thoroughly investigated. Leachate treatment systems combined with zeolites are presented. Cost of zeolites are also reported in comparison with other adsorbents. The investigated studies demonstrate that activated zeolite can improve the removal of chemical oxygen demand, NH3-N and colour significantly compared to the case where raw zeolite is used. Moreover, the composite of activated carbon and zeolite is also favorable for ammonia removal according to reported findings, where best adsorptive removal is attained on the composite media (24.39 mg/g).

Optimization design and operating parameters of induction heat-ing system for hardening

The paper deals with the problem of optimizing the design and operating parameters of an induction heating system for surface hardening of a steel stepped shaft. The problem of optimal design of an inductor is formulated based on a nonlinear two-dimensional numerical model of coupled electromagnetic and temperature fields, developed in the ANSYS Mechanical APDL software. Alternance method of parametric optimization of systems with distributed parameters is used to optimize induction hardening system. MATLAB software has been used for developing parametric optimization subroutine, which was incorporated into the numerical ANSYS model to simulate a process of induction heating. Commonly used a multi-turn solenoid-style coil fabricated from rectangular copper tubing has been used as a hardening inductor. Besides that, an application of profiled copper turns has been investigated. Optimization of induction hardening system described above allows one to substantially improve heating uniformity and enhance metallurgical characteristics of as-hardened stepped shaft. Localized temperature surplus at an upper diameter shoulder has been minimized. At the same time, sufficient austenitization in the fillet area near stepped region (diameter transition) has been obtained.

Dynamics and Control of a Magnetic Transducer Array Using Multi-Physics Models and Artificial Neural Networks.

A linear mechanical oscillator is non-linearly coupled with an electromagnet and its driving circuit through a magnetic field. The resulting non-linear dynamics are investigated using magnetic circuit approximations without major loss of accuracy and in the interest of brevity. Different computational approaches to simulate the setup in terms of dynamical system response and design parameters optimization are pursued. A current source operating in baseband without modulation directly feeds the electromagnet, which consists commonly of a solenoid and a horseshoe-shaped core. The electromagnet is then magnetically coupled to a mass made of soft magnetic material and attached to a spring with damping. The non-linear system is described by a linearized steady-space representation while is examined for controllability and observability. A controller using a pole placement approach is built to stabilize the element. Drawing upon the fact that coupling works both ways, enabling estimation of the mass position and velocity (state variables) by processing the induced voltage across the electromagnet, a state observer is constructed. Accurate and fast tracking of the state variables, along with the possibility of driving more than one module from the same source using modulation, proves the applicability of the electro-magneto-mechanical transducer for sensor applications. Next, a three-layer feed-forward artificial neural network (ANN) system equivalent was trained using the non-linear plant-linear controller-linear observer configuration. Simulations to investigate the robustness of the system with respect to different equilibrium points and input currents were carried out. The ANN proved robust with respect to position accuracy.

Thermoeconomic assessment and multiobjective optimization of a CCHP and MED hybrid system based on IR‐SOFC / MGT

A thermoeconomic assessment and multi-objective optimization of a novel CCHP and multi-effect desalination (MED) hybrid system driven by an internal-reforming solid oxide fuel cell (IR-SOFC) and a micro gas turbine (MGT) are presented to comprehensively evaluate the hybrid system performance in this research. Firstly, the sensitivity analysis of system key design parameters such as steam to carbon ratio, compressor pressure ratio, pinch point temperature difference, motive steam pressure of MED and inlet pressure of ORC turbine on energy, exergy, economic, and thermoeconomic performance is investigated. It is indicated from the analysis results that the proposed hybrid system could produce power, cooling, heating and potable water which are 300.0 kW, 7.358 kW, 8.757 kW and 0.1715 kg/s, respectively. The system total cost and total cost per unit exergy are $9.838/h and $14.75/GJ under the design condition. A multi-objective optimization by using NSGA-II method is further implemented to obtain the ideal system design parameters and optimal system exergy efficiency, freshwater production, and total cost per unit exergy by setting four groups of different weights to these three objectives. The three-dimensional and two-dimensional Pareto frontier curves of the optimization results are depicted to reveal the relations between the objectives. It is validated that the system exergy efficiency and the system total cost per unit exergy are conflicted with the freshwater production.

Design of Diamond Bits Water Passage System and Simulation of Bottom Hole Fluid Are Applied to Seafloor Drill

The performance of the diamond bit directly affects the drilling efficiency of the seafloor drill. The drill bits used in land drilling are prone to abnormal wear, low coring efficiency, and large sample disturbance in marine exploration. At first, in this paper, the operation and formation characteristics of a seafloor drill are utilized to design a water passage system for bottom-jetting diamond bits based on the multi-objective optimization theory. Additionally, then, fluid dynamics theory and the effects of bit rotation on the flow field at the hole bottom were used to analyze the impact of structural and drilling parameters of the HQ-size bit on the flow field of the waterway system. The linear regression equation of the influence of drilling parameters on the bottom hole velocity field and pressure field is obtained. Finally, a field drilling test of the drill bit was carried out. Considering the effect of the grinding length ratio of the bit on the lopsided wear of the inner and outer diameters, the water passage system parameter design and maximum projection area of the cutting tooth are effective optimization goals to improve the normal service life of the bit. The flow field of the drilling fluid at the hole bottom becomes more turbulent and the efficiency of the carrying cuttings return decreases as the waterway height of the bit increases. The optimal bit rotation speed is 250–400 rpm. When drilling into conventional formations, the pump displacement should be controlled within the range of 50–80 L/min. When drilling into sediment formations, the pump displacement should be controlled within the range of 50–65 L/min. An on-site drilling test verified the rationality of the bit water passage system. This work may enrich the existing theories and designs of the water passage system.

Development of a novel wind to electrical energy converter of passive ferrofluid levitation through its parameter modelling and optimization

The exclusive properties of passive levitation and ultra-low friction surface formation of ferrofluids have been utilized to design a highly efficient wind energy harvester. A novel design of passive ferrofluid levitation wind energy converter has been proposed and laboratory prototype has been developed. The simulation model has been developed using the ANSYS Workbench Maxwell electromagnetic software and validated by the experimental results. In this paper, different approaches such as response surface method (RSM), central composite design (CCD) and artificial neural network (ANN) modelling have been applied to relate the system output power to the input design parameters of the wind energy harvester system. The sensitivity analysis of design parameters and their interactions have been conducted. The CCD and RSM modelling have been applied for predicting the power output from the design parameters for the energy harvester where the design parameters has been optimized for the maximum power output using the genetic algorithm (GA). Also, the RSM modelling is validated by the analysis of variance. As a result, the optimal design parameter combination to produce the highest power output can be identified. The optimization result will be compared with and verified by the prediction result of the ANN model. It is found that within the range of the design parameters, the maximum power output of the wind energy harvester obtained through the RSM with the GA is close to that predicted by the ANN model. The design optimization method can be extended to develop an upscale model of the wind energy harvester for larger power output. The proposed magnetic levitation technology has many more potential applications in sensors and actuators, cooling and mechanical bearings and in health sectors.

X-ray bi-prism interferometry-A design study of proposed novel hardware.

Advances in X-ray phase-contrast imaging can obtain excellent soft-tissue contrast of phase-shift, attenuation, and small-angle scatter. Here, we present fringe patterns for different design parameters of X-ray bi-prism interferometry imaging systems. Our aim is to develop bi-prism interferometry imaging systems with excellent polychromatic performance that produce high-contrast fringes with spatially incoherent X-ray illumination. We also introduce a novel X-ray tube design that uses temporal multiplexing to provide simultaneous virtual "electronic phase stepping" that replace "mechanical phase stepping" popular with grating-based interferometry setups. In our investigation, we develop expressions for the irradiance distribution pattern of a bi-prism interferometer composed of multiple point sources and multiple bi-prisms. These expressions are used to plot fringe patterns for X-ray design parameters, including size of point source, number of point sources, and point source separation, and bi-prism design parameters including material, angle, number of bi-prisms, period, and bi-prism array to X-ray source and detector distances. Results show that the fringe patterns for a bi-prism interferometry system are not longitudinally periodic as with grating interferometers that produce a Talbot-Lau carpet. It is also shown that at 59keV X-rays the bi-prism material should be something comparable to nickel to obtain reasonable fringe visibility. The irradiance distribution pattern demonstrates that bi-prism interferometry may provide comparable or improved fringe visibility to that of gratings. Special care is given to present our findings within the context of previous advancements. A single-shot image acquisition approach using a temporal multiplexed, high-power X-ray source provides virtual electronic phase stepping without focal spot sweeping. This provides multiple images, each at the same exposure and the same projection view, from different fringe locations that allow one to derive the attenuation, phase, and dark-field images of the sample without mechanical phase stepping of a grating.

Thermal-hydraulic design of natural circulation integrated steam generator using design map

A natural circulation integrated steam generator (NCISG) is a new steam generator concept that prevents the sodium-water reaction, which is a major safety issue in sodium heat transfer systems using the water Rankine cycle. To estimate and enhance the heat transfer performance of NCISG according to the design parameters, a design parameter evaluation method using the design map is suggested for the natural circulation system. The design map evaluates the effect of the temperature distribution of the heat transfer system in advance, allowing a simpler evaluation of the design parameters of a natural circulation system. The design map of NCISG is presented, and the effects of the tube diameter and pitch-to-diameter ratio (P/D) on the heat transfer area and natural circulation flow rate were evaluated. The heat transfer area is mostly affected by the tube diameter and the natural circulation flow rate is mostly affected by the P/D. The tendency of the total heat transfer area to be small in a specific natural circulation mass flow rate, regardless of the tube diameter or P/D, was identified and analyzed as a trend of the total UA value according to the natural circulation flow rate and optimal temperature. Finally, the optimal design of the NCISG under the evaluated design variable conditions is presented.

PHYSICO-MATHEMATICAL MODEL OF VENTILATION SYSTEM FORCING OF CLEAN AIR IN LIVESTOCK PREMISES

The microclimate of livestock facilities is determined by a range of factors, including physical parameters: humidity, atmospheric pressure, light, temperature, speed and direction of air movement. Air quality plays an important role - the concentration of harmful gases and microorganisms, dust. The parameters of the microclimate affect not only the productivity of animals, but also their health. In order not to harm the health of the animal and achieve the desired performance, these parameters must be adjusted with special equipment. The purpose of research is to substantiate the design and technological parameters of the ventilation system for the injection of clean air in livestock premises to ensure uniformity of its distribution. The article presents the results of research to substantiate the design and technological parameters of the ventilation system for the injection of clean air in pig farms to ensure uniformity of its distribution. As a result of analytical studies of the parameters of the slit of the nozzle for air injection from the condition of uniform air distribution, an approximate equation for its width δ'y depending on the y-axis location for different effective diameters of the nozzle d'H. For the system of injection of clean air the condition according to which at opening of all discharge valves it is necessary to provide uniformity of distribution of air by system of injection is set. For this purpose the central air duct for air injection should have a wedge-shaped form of length L' with constant height b', with initial width a'N and final a'1. As a result of theoretical researches dependences of a lateral angle of a wedge θ the central air duct of system of injection of pure air and its width on the end a1' on distance between adjacent sections L'0, width of the central air duct on its beginning aN' and quantity of branch pipes for injection N' are established. As a result of analytical studies of pressure losses of the ventilation system of pure air injection of the pigsty, the dependences of changes in pressure losses Δp2 and power NW2 required for pumping air through it on the width of the central air duct aN, air flow through the system qk, length between system pipes L0 and their number N.