Test Installation Research Articles

Data-driven soft sensors targeting heat pump systems

The development of smart sensors, low cost communication, and computation technologies enables continuous monitoring and accumulation of tremendous amounts of data for heat pump systems. But the measurements, especially for domestic heat pump, usually suffer from incompleteness given technical and/or economic barriers, which prevents database of measurements from being exploited to its full potential. To this end, this work proposes a data-driven soft sensor approach for compensating multiple missing information. The soft sensors are developed based on an ANN model, an integrated multivariate polynomial regression model and empirical model by considering different constrains like data and information availability during model establishing process. All the three models have been validated against the data from a field test installation, and showed good performance for all the compensated variables. Of the three models, the ANN model shows the best performance for all soft sensors, but it has the highest requirement for additional resources to collect training data. While the integrated multivariate polynomial regression model demonstrates excellent accuracy for the majority of soft sensors with manufacturers’ subcomponent data which needs no extra cost. Even though empirical model is not as accurate as the other two models, it still performs good accuracy with limited information from performance map. The methods developed in the present study paves the way for available measured data in thousands of installations to be fully utilized for innovative services including but not limited to: improved heat pump control strategies, fault detection and diagnosis, and communication with local energy grids.

Зносостійкість титанового сплаву ВТ1-0 з модифікованою поверхнею в умовах абразивного впливу

The cost of rebuilding machine parts as a result of wear is enormous and rising every year. At a US symposium on reducing wear in machinery, the general consensus was that wear management is central to solving national problems such as energy conservation, material reduction, and ensuring the reliability and safety of mechanical systems. Nitriding significantly increases the wear resistance of metals and alloys. The formation of chemical compounds in titanium alloys by introducing nitrogen or increasing its concentration limit changes the rate of chemical reactions and the kinetics of oxide film growth, and increases their adhesion to the substrate. This leads to a decrease in the intensity of adhesive node formation and improves the tribological characteristics of titanium alloys. Therefore, it is necessary to study a titanium alloy with a hardened nitrided layer to obtain experimental results to determine the regularity of the influence of diffusion saturation parameters on wear resistance under abrasive conditions. The universal installation "VIPA-1" was used for vacuum ion nitriding in the pulse mode and the formation of diffusion layers on the surface. Technological parameters of vacuum ion nitriding in the pulse mode: temperature - 550°C, pressure - 25-150 Pa, processing time - 10 hours, ratio of reaction gases - 80% Ag + 20% N2. For experimental studies, samples of VT1-0 titanium alloy with dimensions of 30x30 mm and a thickness of 5 mm were used. The surface hardening of the samples was carried out uniformly around the entire perimeter, which ensures a uniform thickness of the diffusion layer. The analysis of the operating conditions of the friction surfaces of most structural elements made it possible to use the installation for bench tests according to the scheme of wear with a free abrasive (Brinell method). Wear tests were carried out on an experimental setup in accordance with GOST 23.208-79 (Fig. 2). The friction process was modelled in the presence of a free, not rigidly fixed abrasive, which coincides with the American standard ASTM C 6568. The experiment was carried out at a sliding speed of 0.158 m/s, a load of 20 kg (with a shoulder of 272 mm) and a friction path of 50 m. Steel 45, hardened to a hardness of 480-500 HB, was used as a reference. The wear body was a disc made of VT1-0 titanium alloy with a diameter of 100 mm and a thickness of 3.5 mm. On the basis of experimental studies, it has been established that the main mechanisms for increasing the wear resistance of titanium alloys as a result of the process of diffusion saturation of the surface with nitrogen during vacuum ion nitriding in the pulse mode are strengthening of the surface layers; creation of a favourable residual stress pattern; change in the patterns of deformation of the surface layers; change in the chemical and adhesive properties of the surface; transfer of diffusing nitrogen atoms into the depth of the matrix during friction due to the tribodiffusion effect. Conclusions. 1. Maximum wear rate of titanium alloy VT1-0 without hardening. 2. The effect of thermocyclic nitriding increases the wear resistance of VT1-0 alloy: in sand - 3 times; in water + sand - 3.5 times; in salt + sand - 2.5 times. 3. The effect of isothermal nitriding increases the wear resistance of VT1-0 alloy: in sand - 4 times; in water + sand - 3.5 times; in salt + sand - 2.5 times.

Стратегічний аналіз та перспективи розвитку ринку електромонтажних послуг Кіровоградщини

The article is devoted to conducting a strategic analysis of the external environment of the functioning of electrical installation enterprises (EIE), as well as to the development, on this basis, of practical recommendations for the formation of strategies for their development. The reliability of power supply systems and the safety of people's lives depend on the quality of work performed by these enterprises. Taking into account the fact that competition in the field of electrical installation services is mainly regional and local in nature, the relevant market of the Kirovohrad region and the city of Kropyvnytskyi was studied. On the basis of a detailed analysis of the sources of each of the selected key industry factors of the external environment (existing and potential competitors, suppliers, consumers), the following were determined: the leading enterprises of the local electrical installation services market and the key factors of their success; the main barriers to entering the industry of potential competitors; factors of quality performance of services and gaining the trust of consumers; directions of related diversification of the electrical installation enterprise; peculiarities of working with suppliers and requirements for the quality of their products. A list of the main competitive advantages of the market leaders of electrical installation services has been established, which include: work experience in this field; positive image among partners and consumers; expanding the share of the market served by the enterprise; execution of a full range of design, testing and electrical installation works and obtaining the appropriate package of permit documentation for this; availability of a modern and effective material and technical base (including certified electrical laboratories), highly qualified management and personnel; use of only high-quality materials in the works; the ability to offer quality services at the best price. The SWOT analysis method, applied on the example of one of the leading enterprises, made it possible to develop a balance of factors of the external and internal environments of EIE, measures to improve the competitive position of this enterprise on the market, to put forward well-founded recommendations for the implementation of a strategy of concentrated growth and a competitive strategy of optimal costs. The presented strategic analysis of the market of electrical installation services and the planned prospects for the further development of one of its leaders can be applied by the participants of this market - electrical installation enterprises to assess their own competitive position, intensify their strategic activities and choose adequate methods of competitive struggle, which, ultimately, will contribute to the development of data enterprises and the industry as a whole.

Experimental evaluation of the impact of pigment-based colored interlayers on the temperature of BIPV modules

While colored photovoltaics are gaining popularity in the market for building-integrated photovoltaics (BIPV), several specific properties are not accounted for in standard PV performance models. This work shows how relying on the coloration efficiency alone can lead to significant errors regarding module temperatures. By comparing measured temperature data from a test installation featuring BIPV façade elements in multiple colors, little correlation is found between total optical losses (reflection and absorption losses) and module temperature. Instead, better correlation is found with total reflectance. This is attributed to the light absorbed in the pigment-based colored layers contributing to module heating, whereas reflected light does not. This is especially relevant for colors with high lightness, such as gray or beige, for which reflection losses are dominating absorption losses. When modelling colored BIPV products, it is therefore recommended to only consider reflection losses for the irradiance contributing to module heating, while continuing to also include absorption losses for the effective irradiance used in electrical performance modelling.

О практических методах определения порометрических характеристик тонких образцов из комбинированного пористого сетчатого материала

On the example of a porous structure operation in the gas-liquid flow as the phase separator, the paper demonstrates the porometric characteristics effect to assess its performance in the capillary-type intra-tank devices of the space propulsion system fuel tanks. It is shown that for manufacture of a permeable phase separator taking into account the stable capillary structure and the possibility to obtain the hydraulic resistance given value, it is advisable to introduce a combined porous mesh material. For practical determination of one of the porous structure characteristics, i.e. the capillary holding capacity, a method is presented for preparing the permeable structure surface of the phase separator material for testing based on the “bubble” technique, and principles of using such wetting liquids as water, glycerin or ethyl alcohol are discussed. Taking into account small thicknesses of the phase separators made of combined porous materials, types of the circuit solutions of the test installations are provided for determining the capillary holding capacity of porous mesh materials differing from the traditional ones used in orosimetry of soils, rocks and filter materials obtained on the basis of powder metallurgy.

Comparative Analysis of Air Conditioning Performance with 0.5 PK Capacity Using Environmentally Friendly Refrigerants

In accordance with the Montreal Protocol, R22 will be completely banned from its use from January 1, 2030. Research looking for alternative refrigerants replacing R22 has experienced a significant increase. One of the replacement refrigerants that have gradually expanded their use are hydrocarbon refrigerants, few of which are R32, R290, and R410a. However, there are no experiments using the same test equipment for use on R32, R410a and R290 refrigerants. In addition, a more detailed study comparing the respective those refrigerants has not been found. This study aims on knowing the performance of machines that use R32, R290, and R410a refrigerants. This research uses 0.5 PK air conditioner. This research has begun with the preparation of tools and materials. Preparatory steps include assembly and setting up test installations, vacuuming, refrigerant filling and leak tests. The testing and the data retrieval steps are carried out after the system operates for about 30 minutes, i.e. until the system is working normally. Data collection is carried out with the change parameter or replacing the refrigerant. After obtaining data, analysis on Coefficient of Performance (COP), electricity costs, and economical refrigerant needs is carried out. The results have shown that the COP of R32 had the highest value from the 1-hour test, which has been 49.1. The most economical electricity cost is assumed to live for 24 hours in 1 month, namely in R32 refrigerant with a total amount of $12.46. The most economical refrigerant capacity operational cost is R290 refrigerant with a total amount of $9.01.

Ispitivanje otpornosti prema požaru požarno otpornih klapni

Passive fire protection is civil engineering discipline which is very popular for research and development of new construction products and test standards. The primary function of passive fire protection product is to achieve the declared fire resistance. Fire resistance of a construction product is expressed as a time interval (30 min, 60 min, 90 min, 120 min ...) in which certain properties of the tested product are preserved. In the given time intervals, it is necessary for the tested product to maintain the thermal insulation properties (I), integrity (E) and additional properties prescribed by the test standard related to the tested product. The fire damper represents part of HVAC system installed on walls which are fire resistance barriers [2]. Additional properties related to fire-resistant service installations- fire dampers (hereinafter only fire dampers) are the leakage on the fire damper in the cold state and the leakage of fire damper (S) during the fire test. In order to determine the previous properties, a test installation for fire dampers was formed, which consists of: installed damper in the test wall, duct and pipeline system, system for measuring the volume flow, cooler and a fan. All the obtained results are graphically presented in the paper and serve for the purpose of determining the mentioned fire properties of dampers and for the purpose of fire resistance classification of construction products.

Study of water resistance of silica protective coatings based on liquid glass

The water resistance of cotton textile materials impregnated with SiO2 sols obtained on the basis of liquid glass was studied. Experimental coatings on fabrics were prepared by the bath method. After applying each coating layer and removing excess ash, the experimental samples were dried at (60–80) ºС. Fabric samples impregnated with sol SiO2 were immersed in containers with distilled water maintaining the same sample/water ratio. The fire-retardant properties of the coatings were determined after standing in water for 2–72 hours. The degree of destruction of coatings during hydrolysis was studied by determining the optical density of the hydrolyzate above the surface of the samples using the spectrophotometric (KFK-2) method. Fire-resistant properties were determined at a laboratory installation for fire tests. Under the influence of water, partial hydration of the surface of the silica coating occurs, which does not lead to its destruction. The presence of a layer of adsorbed water molecules on the surface of the coating is the reason for an additional increase in the fire-retardant properties of the samples. It is shown that the degree of homogeneity of the SiO2 sol affects the resistance to hydrolysis of the gel coatings. Low-concentration SiO2 sols (8 %), which are characterized by high fluidity and have a long service life, have a predominant effect. The long-term effect of water provides an increase in the fire-retardant properties of impregnated samples in comparison with non-impregnated fabric samples. The concentration and degree of homogeneity of the SiO2 sol have a predominant effect on the flame retardant properties. The surface layer of flame-retardants prevents the final burning and smoldering of the samples after removing the fire source, but does not significantly affect values of flame-retardant properties.

Developing an Installation for Hydraulic Testing of Pipeline Valves

Pipeline networks are an integral element of most modern production facilities. One primary element of the system for ensuring the safe operation of such facilities is pipeline valves for various purposes: isolating, non-return, safety, regulating, separating, disconnecting, and others. In turn, to verify the performance of pipeline valves, comprehensive tests are necessary to confirm the main characteristics, such as tightness. This research develops a hydraulic installation for hydraulic in-plant testing of pipeline valves as part of the technological equipment. It includes the structure, simulation of the stress-strain state of core units, and the testing loop hydraulic calculation of the installation. Keywords — finite-element method, hydraulic testing, mathematical simulation, pipeline system, pipeline valves, strength analysis, stress-strain state, technological hydraulic installation

Developing an Installation for Pneumatic Testing of Pipeline Valves

Pipeline systems are used in almost all industries and are rightfully considered one of the safest and most economical ways of transporting various media. Nevertheless, the consequences of failure and violating the integrity of this class of equipment lead to significant technological disasters. Pipeline valves are integral elements of pipeline systems, including those responsible for operational safety. To confirm the main characteristics, such as strength and tightness, pipeline valves must pass a set of tests. However, the problem of equipping production facilities with test equipment is relevant now because a significant part of the equipment fleet no longer fully complies with current operating conditions. Therefore, this study develops equipment for in-plant pneumatic testing of swing check valves for pipeline systems of hazardous production facilities with ultra-high parameters of the working media. Keywords —finite-element method, mathematical simulation, pipeline system, pipeline valves, pneumatic testing, strength analysis, stress-strain state, swing check valve, technological hydraulic installation

Assessment of road surface state with acoustic vector sensor

A method of determining the road surface state based on the sound intensity analysis is presented. The proposed method is designed for the passive, non-contact assessment of a road surface state, especially in dry/wet conditions. The proposed method is intended for monitoring stations utilizing low-cost hardware. The road surface state is determined from the analysis of sound intensity emitted by road vehicles passing by the sensor and recorded with an acoustic vector sensor (AVS). A frequency domain sound intensity analysis included spatial filtering to reduce the environmental interference using the designed amplitude and phase correction algorithms. A test installation in a real-world scenario, consisting of a small AVS constructed from MEMS microphones and a state-of-art optic-based sensor, was used to evaluate the proposed method. A dataset representing many road vehicles moving at different speeds through the observed road section in varying conditions (dry and wet surface) was collected. Compared with the reference data, an evaluation of the proposed method and its accuracy in determining the road surface state is presented and discussed.The project has been subsidized by the Polish National Centre for Research and Development (NCBR) from the European Regional Development Fund No. POIR.04.01.04/2019 entitled: INFOLIGHT—“Cloud-based lighting system for smart cities.”

Experience of the Ural Federal University in Training Specialists in the Field of Renewable Energy Sources

The article describes the long-standing experience gained at the Ural Federal University (UrFU) with training engineering personnel for research and development of renewable energy sources. Quantitative indicators characterizing the numbers of specialists trained in the period from 1997 to 2021, areas and results of scientific researches carried out at the Department of Nuclear Power Plants and Renewable Energy Sources are presented. Information on the test benches and installations used in the educational process is given. The effectiveness of using experimental research and design work of students in the educational process is shown.

Theoretical comparison of two setups for capillary pressure measurement by centrifuge

There are several approaches for the calculation of capillary pressure curves in porous media including the centrifuge method. In this work, a new installation of centrifuge test is introduced and compared with the traditional setup. In the first setup, which is a standard approach in labs, the core face closest to the rotational axis is open to the non-wetting phase, while the farthest face is open to the wetting phase where strictly co-current flow is generated in rotations; labeled Two-Ends-Open (TEO). In the second setup, which is proposed as a new approach, only the outer radius surface is open and is exposed to the light non-wetting phase; labeled One-End-Open (OEO). This setup strictly induces counter-current flow. The two systems and their corresponding boundary conditions are formulated mathematically and solved by a fully implicit numerical solver. The TEO setup is validated by comparison with commercial software. Experimental data from the literature are used to parameterize the models. It is mathematically, and with examples, demonstrated that the same equilibrium is obtained in both systems with the same rotational speed, and changing the installation does not influence the measured capillary pressure. This equilibrium state is only dependent on the rotational speed, rock capillary pressure properties, and fluid densities, not the installation geometry, relative permeabilities, or fluid viscosities. However, the dynamic transition trend and saturation profiles were found to be dependent on the applied installation. It was observed that the OEO setup takes almost identical equilibration time as the TEO setup for mixed-wet states, although it needed much longer time in water-wet states. The presence of threshold capillary pressure significantly increased the time scale of the OEO setup. Also, it was found that in contradiction to the TEO setup, the dynamic saturation profile in OEO was rarely influenced by viscosity ratio. To conclude, the performed history matching analysis demonstrated that the OEO setup can be applied for the calculation of counter-current relative permeability from the production data with reasonable accuracy.

Study of the Accelerated Degradation of the Insulation of Power Cables under the Action of the Acid Environment

Over operation time, there are a number of internal and external factors that change the characteristics of dielectric materials that are part of the electrical equipment. In areas with high pollution, an important requirement is the acidic chemical compounds in the soil in which the power cables are laid, which penetrate the insulation by infiltration, resulting in changes in the parameters of electrical insulation and causing a decrease in operating time. The paper is focused on the analysis, through a series of experimental determinations, of the effects of stresses to which the power cables laid in acidic environments are subjected, by simulating the operating conditions in the laboratory, obtaining concrete results. It also describes the direct current test installation used in the laboratory and presents the two stages of testing the cable sample inserted in the electrolyte, the first being a stage of accelerating the degradation of the insulation by supplying higher voltages to require insulation, and the second stage being the testing in the absence of the electric field, under the direct action of the chemical compounds from the installation tank. Given that in alternating current, the electric field causes an additional heating of the dielectric due to energy losses by electric polarization, the test is performed in direct current, precisely to be able to monitor the variation of insulation resistance in relation to temperature and losses through conduction currents, as a result of the Joule–Lenz effect and not as a result of the dielectric polarization process. At the same time, the power of the direct current source used is lower compared to that of an alternative current test source and does not contribute to the generation of electrical discharges during testing.

Implementation of the IEC TS 60904-1-2 Measurement Methods for Bifacial Silicon PV Devices

Bifacial crystalline Silicon (Si) photovoltaic (PV) devices are attracting considerable interest from manufacturers and the market since they can enhance the performance in comparison with traditional monofacial PV devices. Technical specification IEC TS 60904-1-2 was published in 2019 and proposes several characterization methods for bifacial PV device testing based on single-side, double-sided and natural sunlight illumination. This article analyses the advantages, disadvantages, the suitability and the feasibility of the different methods and compares the electrical performance obtained by the proposed approaches at the European Solar Test Installation for the testing of bifacial Si devices. Deviations in <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">P</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> below 0.9% for the different testing methods under test was obtained except for the double-source approach with a rear reflector (2.59%) where the measurement of the rear irradaince influence the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <u>P</u> </i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> .

Conformity assessment model for mechanical coupling devices and anchors for reinforcing steel for use in concrete structure

The use of mechanical coupling devices and anchors for reinforcing steel for use in concrete structures can simplify the design and construction of reinforced concrete and reduce the amount of reinforcement required. Technical Approvals of these products by suitably qualified organisations are acceptable under Building Regulations and by major specifiers as the appropriate way of assessing non-standard or new and innovative products. Specifiers, manufacturers, traders, and customers increasingly demand certainty in the quality management of mechanical coupling devices and anchors entering the supply chain. The supply chain is extremely complex. The weak traceability systems and pressure on the supply chain to reduce cost have created the environment where risks increase. This unique and comprehensive model describes the technical and assessment requirements for the conformity of mechanical coupling devices and anchors. It covers all stages in the supply chain from the production, assembly, product performance and evaluation of mechanical properties including tensile strength, ductility, permanent elongation (slip), cyclic loading performance and fatigue performance. The essential elements of the quality management system combined with additional requirements on process control, product testing and robust installation methodology are essential and agreed by all relevant sectors of industry.

Developing an accurate and robust tool for pixel module characterization

For operation at the High Luminosity Large Hadron Collider (LHC), the ATLAS experiment is building a new all-silicon inner tracker (ITk). The production and testing of thousands of silicon pixel and strip modules is required to cover the estimated 180 m2 of the total surface area. A compact, affordable and robust module characterization system is required for in-situ testing prior any test beam campaign or installation. A test bench setup based on an infrared laser was developed at IJCLab, allowing also for the use of micro-metric precision scanning with a radioactive source. A detailed schema of the setup, operating principles and testing methods are described in this paper, together with the first results obtained with a FE-I4 silicon pixel module.

A study on solid oxide electrolyzer stack and system performance based on alternative mapping models

In this study, a solid oxide electrolyzer cell (SOEC) stack model is developed based on an alternative mapping concept. The SOEC stack performance in a commercial hot box is systematically studied under different operating currents, flow rates, and flow directions. The results revealed that the SOEC stack operated in a hot box has thoroughly different temperature distributions, resulting in additional efficiency losses and an increase in thermal neutral voltage. The SOEC stack model computation results are summarized into stack performance diagrams and used in the system design. A 6-Nm 3 /h SOEC system with preheaters and recycling cathode materials is designed, and its performance is studied. The system efficiency is greatly influenced by the steam generator, and an external steam source can help increase the total efficiency of the system to more than 83%. Even the current increase may deteriorate the stack performance. It can increase the SOEC system efficiency by saving energy in the steam generator and preheaters. An increase in the flow rate around anode and cathode can improve the system capacity and efficiency. The system's maximum capacity is limited by the preheater heat balance and the stack output temperature. The feasible maximum system capacity is 33.4 kW electrolysis electric power input and 9.93 Nm 3 /h hydrogen production rate. At a constant system capacity, decreasing the air flow rate can minimize the heat losses in anode off-gas and achieve more than 87% nonsteam system efficiency. • A new SOEC stack modeling method based on the alternative mapping concept. • The differences of the stack performances in lab scale test and commercial installation circumstances are fully discussed. • A 6 m 3 /h SOEC demo system is designed and analyzed to get the best capacity and efficiency.

Modernization of the CM-2500g grinder for the sunflower cake preparation

The article discusses the drawbacks of commercial hammer grinders. Serial hammer grinder of CM-2500g type has been improved by modernizing the cutting unit. Test installation has been developed on the basis of the improved design of the CM-2500g grinder. Test installation design is presented, and, in addition to improved grinder of the CM-2500g type, the unit includes a multimedia device in the form of a camera, which makes it possible to obtain an image of the material (sunflower cake) after its grinding and a personal computer for processing this image. Test results on grinding sunflower cake by a grinder of CM-2500g type are presented. Tests of the improved grinder of CM-2500g type showed the compliance of the obtained material (sunflower cake) with zootechnical requirements in accordance with GOST 80-96.

Implementation of systems for the automated feeding of slag-forming mixtures to the molds of the continuous casting machines of PJSC MMK

The data on the use of installations for the automated feeding of slag-forming mixtures to the molds of the continuous casting machines at PJSC MMK produced by TECHNOAP Engineering Ltd. are presented with an indication of the technical characteristics of the equipment. These installations provide a stable and trouble-free process of continuous casting of steel, high quality of cast billets and finished rolled products. There is a positive conclusion of the scientific and technical center of PJSC Magnitogorsk Iron and Steel Works for testing installations for the automated feeding of slag-forming mixtures. The use of this equipment makes it possible to improve working conditions and ensure the production of high-quality, competitive metal products.