Heat Meter Research Articles

Effect of an asymmetric flow disturber on an ultrasonic flowmeter

AbstractAn ultrasonic flowmeter used in custody-transfer heat metering applications is subject to several test applications for approval. A flow disturbance test with an asymmetric swirl generator upstream of the device is performed to evaluate its accuracy with and without the swirl generator. This standard asymmetric swirl generator is designed to reproduce the behaviour of applications in the field, such as an out of plane 90° double bend. To assess the compliance of the already approved device (Endress+Hauser Prosonic Flow E Heat) for heat metering applications with the standard asymmetric swirl generator, extensive Computational Fluid Dynamics (CFD) simulations are performed. The steady and transient CFD simulations are carried out on a High-Performance Computer (HPC) for several volume flows. With the developed automated simulation method, a virtual calibration of the device takes place. The calibration curves for the cases of a straight pipe, and an asymmetric flow disturber mounted upstream of the flowmeter are attained from experiments and simulations. The agreement of experiments and simulations is discussed and physical insight for the behaviour of the flow disturber and the flowmeter is gained.

Numerical simulation of ultrasonic heat meter by multiphysics coupling finite-element simulation software

Objective: To increase heat calculation accuracy, the numerical simulation of the ultrasonic heat meter is explored by multiphysics coupling. Methods: The COMSOL, a multiphysics coupling finite-element simulation software, is used to build the coupling model of the sound field, structure field, and electric field. The propagation of ultrasonic waves in heat meters is simulated, and its sound field distribution in pure water is analyzed. According to the operating conditions of ultrasonic heat meters, the influence of impurities with different concentrations on ultrasonic propagation is analyzed. The end-face sound pressure levels of the incident transducer and the receiving transducer are compared to obtain the attenuation laws of ultrasonic waves in the liquid-solid two-phase flow. Results: The main lobe and multiple side lobes exist during the propagation of ultrasonic waves. The energy of the main lobe is higher than that of the side lobes. Bubbles resonate under the action of the sound field. Also, bubbles of different diameters correspond to different resonance frequencies, which have larger sound pressure than that of the incident sound field. Most of the sound waves are reflected at the liquid-solid interface, while some of them continue to propagate through the media, affecting the sound pressure distribution on the end-face of the receiving transducer, thereby affecting the measurement accuracy of the ultrasonic heat meter. Conclusion: The reliability and detection efficiency of the heat meter is improved, which is significant and theoretically valuable.

Computer Vision-based Reader for analogue Energy/Water Meters in low-cost embedded System: a Case Study in an Office Building in Scotland

Implementation of cost-effective energy conservation measures (ECMs) is expected to generate up to 18% of carbon emissions reductions in office buildings. In order to determine adequate ECMs for a specific building, operational data is required. However, buildings generally lack operational data in the form of time series that can limit a breath of analysis required for determining adequate ECMs. Energy time-series data is commonly lacking in the UK due to uneven availability of smart meters (heat, gas, water), security restrictions in Energy Information Systems (EIS) and building management systems (BMS), restrictions and costs associated for automated reporting from utility companies, etc. This work presents a non-intrusive computer vision-based reader to generate energy readings at 10-minute resolution using a Raspberry-Pi, a traditional webcam and an LED light. OpenCV, an open source computer vision library, is used to detect and interpret numeric values from a heat meter, which are in turn uploaded to a cloud-based energy platform to create a complete operational data set enabling detailed analytics, fault detection and diagnostics (FDD) and model calibration. A case study of an office building in Scotland is presented. The building has a heat meter with no remote access capabilities. The accuracy of the method, i.e. the ability of the script to accurately derive the rate of change between readings, resulted on a 92% percent during a test done for 100 samples. Recommendations for accuracy improvements are included in the conclusions.

Research on computer centralized management system based on thermal energy data acquisition and display

The thesis discusses the thermal energy related theories and designs a thermal energy measurement and control system based on the AT89S52 microcontroller. Through the DS18B20 temperature sensor and DN20 flow sensor, the temperature and flow data are directly transmitted to the microcontroller. Calculate the value of heat energy consumed according to the formula, and display related information such as consumption, balance, temperature, time through the LCD display, and the system is provided with a voice warning prompt. The output signal of the one-chip computer passes the D/A, V/I circuit, and transmits the output signal to the electric regulating valve to control the opening degree of the valve to adjust the indoor temperature. Through CAN bus and non-contact IC card module to realize remote meter reading and user?s prepayment function. System data is stored in the storage chip AT24C04A to prevent data loss. The prepaid heat meter cannot only solve the problem of heat consumption measurement in the heating system, but also greatly improve the accuracy and timeliness of heating billing, eliminate errors, omissions, and other issues, and provide a scientific, timely, accurate, and reasonable civilian heating system. Thermal energy billing, charging, and control provide effective tools.

Data driven process for the energy assessment of building envelope retrofits

In the last decades, a growing industry has been created in relation to building envelope retrofits. Linked to the lack of financial capacity of many building owners, innovative instruments such as energy performance contracts have been promoted by public bodies. This kind of instruments require of detailed energy assessment processes in order to define the expected heat load reduction and the associated economic flows between building owners and Energy Services Companies. When dealing with building envelopes, existing methods for building envelope heat loss characterization require of substantial efforts in terms of equipment and time, which makes them difficult to apply in real practice. In this paper, a novel method is proposed based on whole-building heat load assessment by means of heat meters, and analytical calculations of building envelope transmission heat load coefficients. This method, which requires minimal or no additional equipment, can be used over historical data from District Heating systems. It assigns a specific load fraction to building envelope heat transfer and allows to assess the expected reduction due to the building envelope retrofit. Numerical and experimental data is presented based on an educational building in the city of Burgos, Spain.

For creating layered composite materials based on monocrystalline silicone for gradient heat measurement based by diffusion welding method

ABSTRACT A distinctive feature of laminated composite materials (LCM) is that they are always functional materials – materials with a special set of properties, which are created to solve a specific problem. The creation of layered structures is associated with the choice of the technological process of its manufacture; pairs of materials, geometric characteristics of layers; layer layouts, which together provide the desired set of properties. The development of approaches to creating LCM based on monocrystalline silicon by diffusion welding for gradient heat metering are discussed in this article.

Operating the hot water supply system problems during transfering the hostel to the apartment house status

The energy infrastructure modernization is a complex social and technical problem requiring an integrated approach. After analyzing the hot water system operation in a residential apartment building, being previously a hostel, the reason for the temperature regime violation was determined. In connection with the building status change, the residents number has significantly decreased, the service block, which led to a change in water consumption conditions has been eliminated. In addition, the requirements for minimum water temperature in centralized hot water systems have changed. The question of using a dead-end hot water supply system possibility, provided by the project or its reconstruction into the circulation network, was considered. The studies were conducted in accordance with the methodology described in MIC 4.3.2900-11 “The centralized hot water supply systems hot water temperature measurement”. There was a discrepancy in the temperature coolant standard indicators at the dismantling points on different floors of the building. The difference in temperature at the input (the heat meter and thermometer readings) and at the end user is associated with additional water cooling in the supply pipes of the domestic hot water heating system. When transferring the public buildings to housing stock, it is necessary to revise not only water consumption rates, but also the hot water supply scheme in general. The lack of circulation leads to waste of hot water and increases the cost to the consumer. To ensure the required temperature standards for a full day in a dead-end hot water supply system, which is provided for by the project, continuous dismantling of the water is required, which is difficult to achieve with a changed building status. The resolution of the problem is possible only when the domestic hot water heating system is switched to the circulation mode with the circulation piping and the circulation pump installation.

Problems of operating the hot water supply system during transfering the hostel to the apartment house status

The energy infrastructure modernization is a complex social and technical problem that requires an integrated approach. After analyzing the hot water system operation in a residential apartment building, previously a hostel, the reason for the temperature regime violation was determined. In connection with the building status change the number of residents has significantly decreased, the service block has been eliminated, which led to the changes in water consumption conditions. In addition, the requirements for minimum water temperature in the centralized hot water systems have changed. The using a dead-end hot water supply system possibility question, provided for by the project or its reconstruction into the circulation network, was considered.The studies were conducted in accordance with the methodology described in MUK4.3.2900-11 “The centralized hot water supply systems hot water temperature measurement”. There was a discrepancy in the standard indicators of the coolant temperature at the points of dismantling on different floors of the building. The difference in temperature at the input (data of the heat meter and thermometer) and at the end user is associated with additional water cooling in the supply pipes of the HWS system. When transferring public buildings to housing stock, it is necessary to revise not only water consumption volumes, but also the hot water supply scheme in general. The lack of circulation leads to hot water waste and increases the cost to the consumer.To ensure the required temperature standards for a full day in a dead-end hot water supply system, which is provided by the project, continuous dismantling of the water is required, which is difficult to achieve with a changed building status. The resolution of the problem is possible only when the hot water supply system is switched to the circulation mode with the installation of circulation piping and the circulation pump.

Similarity of the asymmetric swirl generator and a double bend in the near-field range

An asymmetric swirl generator (ASG) is considered to replace the current swirl generator in the upcoming 2020 revision of the standard for heat meters EN 1434. While recent studies have shown its superiority with respect to a reproducible representation of the double bend out-of-plane (DB) flow disturbance in the far field, there are still open questions regarding the similarity in the near-field range and the determination of an optimum testing distance. In this paper, we examine the performance of an ASG in the potential testing range and investigate an increase of the segmental orifice plate. Laser Doppler anemometry (LDA) measurements downstream of the ASGs and a DB carried out at Reynolds numbers (Re) of 5×104 and 5×105 are evaluated based on a comparison of the flow patterns and a quantitative analysis by means of performance indicators. The results indicate, that the original version of the ASG does not reach the level of asymmetry and swirl provided by the DB in the near-field range. An increase of the orifice height yields higher swirl and asymmetry, hence, a better similarity of the flow characteristics. A maximum degree of resemblance with the crescent-shaped velocity patterns of the DB is found seven diameters downstream of the modified ASG. In contrast, a testing distance of two diameters or less does not represent the DB, as the early flow development bears the traces of the disturber's geometry. The results may be considered for the implementation of the test procedure in EN 1434 and the next revision of the standards for water meters.

Using Different ML Algorithms and Hyperparameter Optimization to Predict Heat Meters’ Failures

The need to increase the energy efficiency of buildings, as well as the use of local renewable heat sources has caused heat meters to be used not only to calculate the consumed energy, but also for the active management of central heating systems. Increasing the reading frequency and the use of measurement data to control the heating system expands the requirements for the reliability of heat meters. The aim of the research is to analyze a large set of meters in the real network and predict their faults to avoid inaccurate readings, incorrect billing, heating system disruption, and unnecessary maintenance. The reliability analysis of heat meters, based on historical data collected over several years, shows some regularities, which cannot be easily described by physics-based models. The failure rate is almost constant and does depend on the past, but is a non-linear combination of state variables. To predict meters’ failures in the next billing period, three independent machine learning models are implemented and compared with selected metrics, because even the high performance of a single model (87% true positive for neural network) may be insufficient to make a maintenance decision. Additionally, performing hyperparameter optimization boosts the models’ performance by a few percent. Finally, three improved models are used to build an ensemble classifier, which outperforms the individual models. The proposed procedure ensures the high efficiency of fault detection (>95%), while maintaining overfitting at the minimum level. The methodology is universal and can be utilized to study the reliability and predict faults of other types of meters and different objects with the constant failure rate.

Quantitative study on adjacent room heat transfer: Heating load and influencing factors

Household heat metering plays a significant role in building energy efficiency and has become an inevitable trend in northern China. Precise supplying aims to ensure indoor thermal comfort while realizing energy saving with occupants’ behavior. Due to the different indoor temperature, interior envelope material and occupancy rate of each room, the Adjacent Room Heat Transfer (ARHT) will greatly affect the fair heating charging under household heating metering. This study takes an office building in Beijing as the object to measure the indoor and outdoor temperature in winter. EnergyPlus is adopted to establish a building model and calculate the heating load. The time-dependent temperature of the simulated room is compared with the hourly measured temperature to validate model accuracy. The validated model is further adopted to calculate the ratio of ARHT under three different conditions. The result indicates all these three factors have important impacts on ARHT. The ratio of ARHT to the real total heating load could stay around 40% and even reach up to 70%. The result shows an unexpected influence of ARHT, while it provides a case study for fair allocation of heat charges, which is vital to the implementation of household heat metering in China.

Large eddy simulation study on flow characteristics of ultrasonic heat meter at low Reynolds number

Ultrasonic heat meter is widely used in heat metering, and its measurement accuracy depends on the flow characteristics of the reflected channel. In this paper, LES (Large Eddy Simulation) method is used to calculate the flow field of the ultrasonic heat meter at low Reynolds number. Through the analysis of the flow field, it is shown that the velocity gradient near the cylindrical reflector is larger, especially at the tail of the first cylindrical reflector; the eddy formed by the flow can scour the reflecting surface and prevent scaling; the average linear velocity over time of the reflecting channel is obtained by the calculation results. The range of velocity variation is 0.609%.

Study on the influence of reflecting channel position on flow velocity characteristics of ultrasonic heat meter

In this paper, LES (Large eddy simulation) method is used to study the influence of different channel positions on the flow velocity of the ultrasonic heat meter, and the variation of the average linear velocity of different channel with time is researched. Through the calculation results, the velocity characteristics of 11 channels of the U-shaped reflecting device ultrasonic heat meter are analysed. The results show that the vortex behind the reflecting cylinder affects the velocity distribution in the channel. Statistical analysis shows that the linear average velocity in different positions of the channel fluctuates with time, but the fluctuation amplitude is basically the same. The average linear velocity asymmetry of reflecting channel far from the vortex zone is smaller, and the deviation of the average velocity is less than that of the average velocity, therefore, the distribution of the velocity is more reasonable.

수열원 열펌프시스템용 적산열량계의 냉방, 난방 성능특성에 관한 연구

In this study, the cooling and heating amount, temperature, flow rate of turbine type heat meter for water source heat-pump system were experimentally investigated at the standard operating conditions. The obtained cooling and heating capacity from the heat meter were deviated within 5.0%, 3.8% comparing with the precise values calculated from an accredited test facility. Even though the accumulated cooling and heating amount values of the heat meter had a small difference comparing with the precise values, the temperatures of heat meter showed greatly different values comparing with the precise temperature. Therefore, it is highly recommended to develop the heat meter which is appropriate for the water source heat pump systems.

COMPARABLE ANALYSIS OF THE INSTRUMENT PARK OF COMMERCIAL ACCOUNTING OF THERMAL ENERGY IN THE URBAN DISTRICT SAMARA

A comparative metrological analysis of the instrument fl eet of commercial accounting of heat energy and coolant was carried out based on the results of periodic calibration of measuring instruments in 2004 - 2005 and 2016 - 2017. Methods reviewed for assessing the suitability of coolants and their components (fl ow, temperature, pressure transducers) and measuring sets based on them. From the metrological point of view, the obtained results of the analysis make it more reasonable to form a list of recommended metering devices, and they will also be useful in predicting the costs of metrological and routine maintenance of existing heat metering systems.

Impact of fermentation temperature on required heat dissipation, growth and viability of yeast, on sensory characteristics and on the formation of volatiles in Riesling

Background and Aims Temperature control during fermentation significantly impacts the energy demand of wineries. We determined the heat required to be dissipated from wine tanks under three different temperature programs (14, 16–11–17 and 19°C) during 1200 L Riesling fermentations and investigated the influence of temperature on yeast growth and viability, the formation of yeast derived volatiles and wine sensory properties. Methods and Results Heat dissipated by the coolant was determined using heat meters. At 19°C, ~70% less heat had to be dissipated compared to that at 14°C, whereas ~30% less heat had to be dissipated for the 16–11–17°C temperature program. The duration of fermentation was 15, 13 and 9 days for the 14, 16–11–17 and 19°C programs, respectively. Characteristic profiles of heat dissipated per day and reduction in specific gravity were observed. The formation of most esters was more pronounced in the second half of fermentation at higher temperature. Hexyl acetate, however, was formed early and no temperature influence was observed. The final concentration of ethyl decanoate, ethyl octanoate and ethyl hexanoate was greater for fermentations at 19°C, while that of ethyl butanoate was highest at 14°C. No difference was found in the final concentration of acetate esters or acetic acid. Acetaldehyde concentration was 35% lower for fermentations at 19°C, compared with those at 14°C. Descriptive analysis, at 5 and 11 months after bottling, revealed no significant difference in wine sensory profiles. Flow cytometry showed faster yeast growth, greater population size and rapid viability decline at the higher fermentation temperature. Conclusions Energy savings can be achieved by reducing the required dissipated heat through temperature management of fermentations, without compromising wine composition. Ambient temperature should be considered when deciding on temperature management and related saving potentials. Significance of the Study Potential energy savings were demonstrated that may facilitate innovation in fermentation cooling systems.

Design and application of heating metering and monitoring system based on cloud platform

With the scale of equipment needed to be managed in heat metering monitoring system becoming larger, how to realize simple management and ensure scalability is a problem that needs to be studied. Based on the comprehensive application of information and communication technology, this paper studies and expounds the intelligent management of heat metering based on cloud platform, and analyses and plans the intelligent management platform of heat metering. It is convenient for heating companies to monitor the status of the site, find problems in time and deal with them. It realizes user addition and management and facilitates business expansion. By promoting rational consumption of heat energy, the intelligent management platform of heat metering can realize energy saving, environmental protection, fair trade and make the best use of everything.

Experimental analysis of radiators’ thermal output for heat accounting

Radiators represent the most spread heating body (installed since late 1800s) and in the last decades different radiators typologies have been proposed on the market, characterized by different materials, sizes, shapes, etc. Recent EU Directive on energy efficiency has set the obligation to install individual meters for space heating in building served by a central heating source. To this aim, when direct heat meters are not technically feasible, indirect systems like heat cost allocators are applied on each radiator in a dwelling and the knowledge of single radiators’ thermal output is essential for an accurate and fair heat cost sharing. The EN 442:2014 describes a method for radiators’ thermal output measurement whose expanded uncertainty is lower than 1% in reference laboratory conditions. However, radiators’ thermal output is strongly dependent on installation and boundary conditions. Thus, to get radiators’ thermal output at operating conditions “characteristic equations” are available but, unfortunately, they do not include any possible actual operating condition among which: installation position with respect to the wall and the floor, presence of grid/shelf/niche or an obstruction (e. g. caused by curtains), thermo-fluid-dynamic condition variations (inlet flow rate and temperature), and hydraulic connections. In this paper, the experimental results of thermal output measurement of different radiators typologies (cast iron, aluminum) at different installation conditions are presented, together with an analysis of the associate technical-economic effects on space heating cost sharing. Reductions of radiators’ thermal output up to 15% due to hydraulic connections and between 10% and 20% due to flow-rate variations have been found. Furthermore, different installation conditions showed deviations between operating and standard radiators’ thermal output between 5% and 15%.

Simulation and optimization of water-wall tube panels design for power boilers

The article presents a water-wall tube panels simulation technique that uses finite element method as well as the power boiler water-wall structure design optimization method. Results of the proposed method verification and its application to the design of boilers of different capacities are discussed. The technique is to replace water-wall tube panels with equivalent plates. Replacement plates’ parameters calculation is reported, panels one-way heating metering is described. Optimization of the water-wall structure design is carried out in two stages: at the first stage, water-wall tube panels are replaced with orthotropic plates; at the second stage, sub-simulation with solid models is used to identify problem areas of the design. Solid-state models of the problem areas get connected to the orthotropic plates at calculated boundary conditions. The described approach improves accuracy of the simulation results and significantly reduces the models complexity and its computation time. The proposed simulation and optimization method has been tested and successfully applied to design power steam boilers with steam generating capacity of 500, 1030 and 1900 tons of steam per hour. As a result, while maintaining the specified reliability and durability, significant reduction of metal content in boiler structure is achieved.

Development of a Mathematical Model for Precise Temperature Measurement in Geoinformation Systems for Monitoring Individual Heat Consumption In Apartment Buildings

One of the main energy saving objectives is to find methods for metering individual heat consumption in each apartment of an apartment building. Achievements in the area of microprocessor devices made it possible to create a new type of measurement and control systems for monitoring and metering energy resources. Newly developed heat meters are the ground for fundamental changes in energy saving and energy efficiency. Apartment buildings are heated by various hot water distribution systems, for which it is not always possible to use conventional heat meters. The ambiguity related to the parameters of heat meters can adversely affect the estimation of heat consumption by each apartment in an apartment building. This paper is aimed at analyzing a new contact temperature measurement method and means used to create a system for heat monitoring and metering in an apartment building. The developed system can be used to meter energy resources of facilities distributed in a specific area, with geographic referencing to each facility. This makes it possible to remotely monitor heat energy consumption, which makes the energy consumption control system much more transparent and ensures public control. The system gathers data from a large number of users, processes data in real time and promptly responds to users’ requests based on recent developments in information technology. An important advantage of the developed system is that it can be used to anticipate emergency situations taking into account various factors, such as weather conditions and the age of buildings. Due to all of the above, the system can be used in the future not only in Russia but also abroad.