Method of detection of district heating pipe network leakage using data monitoring of heat energy consumers

Currently, information systems to get data of metering devices are introduced to calculate the consumed thermal energy. The metering devices are installed at the thermal station of the consumers. However, the processing of these data is usually limited to the monthly data collection to calculate the payments and to monitor the output of the observed parameters beyond the established boundaries. The urgent issue is the possibility to use these data for the in-depth study of the processes, and, in particular, to detect district heating pipe network leakage. The authors have used both the methods and tools to model and analyze the operating modes of district heating pipe networks, methods to collect and monitor data of heat supply metering devices, methods to model district heating pipe networks in the geoinformation systems environment. The authors have proposed the method to detect the sections of the heat network where a heat medium leak has occurred. The difference of the method is the use only of the readings of the metering devices installed at consumers. The limitations of the application of the method and its implementation in geoinformation system environment are considered. An example is given to illustrate the possibility to detect the location of leakage based on the analysis of real data of the house heat metering devices collected during leakage and leakage elimination. Practical application of the developed method is discussed by the example of a real situation of leakage at the section of the heat network of the ISPU boiler house. The results obtained have confirmed the possibility to detect localization of leakage in heating networks based on the analysis of meter readings installed at consumers. The developed method can be applied in information systems to monitor the operating modes of district heating networks to search the places of accidents.

Thermal Optimization Potentials for NRU MPEI Facilities

A set of activities on surveying the energy performance of eight large facilities of the National Research University Moscow Power Engineering Institute (NRU MPEI) was accomplished. In view of quite significant amounts of electricity and heat consumed by the NRU MPEI, a number of objectives were set forth on evaluating the NRU MPEI facilities’ general energy efficiency, analyzing the climatic characteristics of the facilities location places, revealing inefficient use of energy resources, and determining the priority areas for achieving a more efficient use of them. The current situation existing at each facility was examined, the thermal performance characteristics of the buildings were analyzed in general, the thermal parameters of enclosing structures were calculated, and energy balances were drawn up. With the aid of infrared imaging, losses were evaluated, and the places of maximum heat leaks in the cold season of a year were identified. The analytical survey was supplemented with field measurements of the necessary parameters of the buildings and heat carriers. An important feature of the study was that it involved evaluating the climatic characteristics of the facilities location places. Thus, a change in the design temperature and a considerable variation in humidity influence the condition of the structure. The number of temperature transitions through the zero degree point tends to grow. The alterations of frost to rain has an adverse effect on the condition of facilities. The analysis results have shown that the climatic characteristics that existed at the time the major part of the MPEI buildings were constructed have changed significantly over time. In the course of the study, a number of measures were developed and suggested that take into account the differences and characteristics of each building, as well as the state of their engineering systems. Since the engineering equipment items of the structures are in a different state, the energy saving measures for each of them are also different. Application of the comprehensive approach helps match the obtained data with the readings of water and heat metering instruments, and with the infrared images of enclosing structures. The selected technical measures are necessarily complemented by a set of measures to economically and morally stimulate the saving of all types of energy resources.

Forecasting the Heat Load of Residential Buildings with Heat Metering Based on CEEMDAN-SVR

The energy demand of the district heating system (DHS) occupies an important part in urban energy consumption, which has a great impact on the energy security and environmental protection of a city. With the gradual improvement of people’s economic conditions, different groups of people now have different demands for thermal energy for their comfort. Hence, heat metering has emerged as an imperative for billing purposes and sustainable management of energy consumption. Therefore, forecasting the heat load of buildings with heat metering on the demand side is an important management strategy for DHSs to meet end-users’ needs and maintain energy-saving regulations and safe operation. However, the non-linear and non-stationary characteristics of buildings’ heat load make it difficult to predict consumption patterns accurately, thereby limiting the capacity of the DHS to deliver on its statutory functions satisfactorily. A novel ensemble prediction model is proposed to resolve this problem, which integrates the advantages of Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN) and support vector regression (SVR), called CEEMDAN-SVR in this paper. The proposed CEEMDAN-SVR algorithm is designed to automatically decompose the intrinsic mode according to the characteristics of heat load data to ensure an accurate representation of heat load patterns on multiple time scales. It will also be useful for developing an accurate prediction model for the buildings’ heat load. In formulating the CEEMDAN-SVR model, the heat load data of three different buildings in Xingtai City were acquired during the heating season of 2019–2020 and employed to conduct detailed comparative analysis with modern algorithms, such as extreme tree regression (ETR), forest tree regression (FTR), gradient boosting regression (GBR), support vector regression (SVR, with linear, poly, radial basis function (RBF) kernel), multi-layer perception (MLP) and EMD-SVR. Experimental results reveal that the performance of the proposed CEEMDAN-SVR model is better than the existing modern algorithms and it is, therefore, more suitable for modeling heat load forecasting.

PORTABLE HEAT METERING SYSTEM DESIGN

In modern construction practice, more than half of buildings in operation require modernization of thermal insulation. However, in order to select an effective insulation system, it is necessary to know the actual thermal and technical characteristics of structures and parameters of the building internal environment. The paper analyzes methods and equipment for evaluation of the thermal performance of outdoor enclosures. The advantages and disadvantages of the main devices recommended by the regulatory documents for field research are shown. According to the data obtained, a heat engineering complex is developed for conducting field studies of heat and humidity of wall structures and microclimate of building premises. Software improvement together with Arduino reader device allow monitoring both at stationary and non-stationary thermal conditions of external enclosures and indoor climate parameters in field conditions.

Effect of an asymmetric flow disturber on an ultrasonic flowmeter

An 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.