Water Temperature Heat Research Articles

Experimental study on flow boiling and circumferential non-uniform heat transfer characteristics in helically-coiled tube under coupled heat transfer conditions

Helically-coiled tube steam generator has been widely used in nuclear reactor, energy power, petrochemical and other systems. In the liquid metal reactor, the liquid metal on the primary side of the helically-coiled tube steam generator exchanges heat with the water on the secondary side. Due to the coupled heat transfer between liquid metal and water, the distribution of the wall temperature or heat transfer coefficient of helically-coiled tube are significant different in the circumferential direction of the tube cross-section. An experimental system of helically-coiled tube steam generator was set up in this paper. The non-uniform heat transfer characteristics of secondary side fluid of helically-coiled tube steam generator were studied under the coupled heat transfer conditions between the heat transfer of primary side and secondary sides fluid. It was found that the wall temperature or heat transfer coefficient in the circumferential direction of tube cross-section were significantly different, the maximum and minimum wall temperature appeared on the inside and bottom of the tube cross-section, respectively, the maximum and minimum heat transfer coefficient appeared on the outside and top of the tube cross-section, respectively. The effect of secondary side refrigerant pressure, secondary side refrigerant supercooling degree, mass flux of secondary side refrigerant, primary side heating water temperature and mass flux of primary side heating water on the maximum wall temperature, minimum wall temperature, maximum heat transfer coefficient, minimum heat transfer coefficient were obtained. Beside, The local and overall non-uniformity of the wall temperature and heat transfer coefficient in the circumferential direction of tube cross-section were obtained and the influence of each parameter on the local and overall non-uniformity were revealed, respectively. Finally, it was concluded that the non-uniformity of heat transfer coefficient in the circumferential direction of tube cross-section under coupled heat transfer conditions was more obvious than that under constant heat flux conditions. And the the overall non-uniformity of heat transfer coefficient (δh) obtained in our experimental were larger than the δh of Chang et al. [33], Zheng et al. [38], Kong et al. [34], Yao et al. [36] and Niu et al. [37] by 130.67%, 48.10%, 289.48%, 151.28% and 271.67%, respectively.

Pediatric Burn Unit Admission is Associated with School Holidays and Lower Home Childhood Opportunity Level.

Burn injury can have profound detrimental effects on quality of life and mental health of children. We collected demographics, burn etiology, burn date, and home zip code for pediatric patients admitted to our burn unit from 2016-2023. Age, burn date, and etiology of burn were used to assess temporal and mechanistic patterns of injury for pre-school-age and school-age children. Home zip code was used to determine each child's home Childhood Opportunity Index score, which is composed of sub-domains for Education, Health & Environment, and Social & Economic. We calculated the odds-ratio for odds of pediatric burn admission for each COI sub-domain quintile, using very high opportunity neighborhoods as the reference. Scald was the prevailing burn etiology (64%). In school-age children, July was the month with the most burn injuries (19%), attributable to firework injuries. School-age children were also more likely to be injured in a week without classroom instruction (p<0.001). There was a dose-response relationship between Childhood Opportunity Index and odds of burn admission, with the greatest odds of burn admission observed for children from very low educational opportunity areas (OR 5.21, 95% CI 3.67-7.39). These findings support interventions for burn prevention such as increased education about the dangers of fireworks, addressing inequities in access to childcare and extracurricular activities, and reducing the default water heater temperatures in multi-unit dwellings.

Enhanced solar energy utilization of thermal energy storage tanks with phase change material and baffle incorporating holes

In response to the pressing need for more efficient thermal energy storage solutions, this study investigates the strategic implementation of baffles in phase change material (PCM) tanks to enhance thermal performance. PCM offers a promising solution for efficient thermal energy storage (TES); however, ensuring uniform temperature distribution inside the tanks remains challenging. Horizontal baffles with holes of varying diameters were introduced in Tanks 02, 03, and 04, while an inclined baffle with holes was used in Tank 05. The Tank 06 benefitted from an inclined baffle with holes of different diameters. A comprehensive analysis of all Tanks was evaluated by assessing PCM and water heat flux, PCM and water static enthalpy, Richardson number, velocity vectors, temperature, and liquid fraction contours. The results demonstrated that significant improvements were achieved with the addition of baffles. Tank 01, without a baffle, exhibited a melting time of 2860 s. However, the introduction of baffles resulted in reduced melting times for Tanks 02 to 06: 2360 s (17.48 %), 2350 s (17.83 %), 2400 s (16.08 %), 2320 s (18.88 %), and 2240 s (21.67 %), respectively; which led to enhance TES efficiency, and a quicker energy storage process. The study also includes a comprehensive economic analysis, evaluating the total cost (Ctotal) and performance-economic ratio (Pc). Tank 06 shows superior economic performance, with a Pc value of 0.26 despite a slightly higher cost than Tank 01 by $2 USD. These findings highlight the baffle design’s effectiveness in achieving better heat transfer and uniform temperature distribution within PCM tanks, making them more efficient for TES applications.

Experimental investigation of high-temperature heating in open-loop air cycle heat pump system utilizing compressed gas waste energy recovery

Recycling waste energy from compressed gases has consistently been a focal point in the field of energy conservation. This paper presents a novel open-loop air cycle heat pump system designed to recover waste energy from compressed gases. The system maintains stable operation and provide hot water above 80 °C even under extreme ambient temperatures (below −30 °C), thereby catering to diverse heating needs across a wide temperature spectrum. Experimental results show that, when the ambient temperature varies from 10 °C to −20 °C, the heating capacity and water temperature difference between inlet and outlet only decrease by 4.82% and 4.99% respectively, suggesting negligible impact. However, when water flow rate varies from 4 m3/h to 10 m3/h, the heating capacity marginally increases by 3.35% while the water temperature difference between inlet and outlet significantly decreases by 141.95%. Continuous increase of inlet water temperature Tw, in at 0.40 °C·min−1 results in an initial 10% decrease of heating capacity, following which the system automatically adjusts to another stable operational state of around 50 kW heating capacity. This transition has minimal effect on the water temperature difference between inlet and outlet and temperature rise rate of outlet water temperature. The expansion work recovery efficiency of turbine-compressor coupled module is approximately 90%.

Optimal discharge pressure and performance characteristics of a transcritical CO2 heat pump system with a tri-partite gas cooler for combined space and water heating

The transcritical CO2 heat pump holds promise for achieving carbon neutrality in buildings, primarily due to its high energy efficiency in hot water heating. However, using it for space heating often leads to efficiency losses. A heat pump equipped with a tri-partite gas cooler can address this issue by providing both space heating and hot water while maintaining lower refrigerant temperatures at the gas cooler exit. Nonetheless, there is limited research on the characteristics of a CO2 heat pump system designed for simultaneous space and hot water production. This work fills this gap by analyzing the impacts of operational and system configuration, considering the variation of space heating to hot water production loads. A theoretical model is presented and verified with the experiments. Results show that under the specified conditions, the heat load ratio has minimal influence on the optimal discharge pressure. Increasing the water outlet temperature from 60 °C to 80 °C leads to a nearly 14% decrease in maximum COP, with a corresponding 12.2% increase in the optimal pressure. A 10 K rise in water inlet temperature results in approximately a 21% decline in maximum COP. Evaporation temperature has little impact on the optimal discharge pressure, while maximum COP increases by roughly 63% with a rise in evaporation temperature from -10 °C to 10 °C. Space heating water temperature notably affects the optimal discharge pressure. Integration of an IHX enhances system COP but has marginal impact on the optimal discharge pressure. These findings offer insights for designing and optimizing transcritical CO2 heat pumps for simultaneous space and water heating applications.

Multiscale Finite Element Modeling of the Effect of Macro-Encapsulated Phase-Change Materials on the Thermal Performance of Hydronic Floor Heating Systems

Phase-change materials (PCMs) are commonly employed in building service equipment to regulate indoor temperatures and reduce energy consumption. This study conducted multi-scale finite element modeling to analyze the steady-state and dynamic thermal behavior of a hydronic radiant floor heating system integrated with macro-encapsulated PCMs. It predicted performance values for hydronic floor heating with and without macro-encapsulated PCMs. The study assessed the impact of the PCM volume fraction, heating water temperature, capsule thermal conductivity, and shape on the thermal performance of hydronic floor heating through various finite element models. The predictive capability of the finite element model was validated using experimental data, showing good agreement. Although the inclusion of PCMs lowered the floor temperature, it improved temperature distribution and retained heat when the system was inactive. The PCM volume fraction significantly influenced the performance of the hydronic floor. However, the shape of the macro-encapsulated PCM and thermal conductivity of the shell had minimal effects in the studied case. For instance, increasing the thermal conductivity of the shell of the PCM capsule fifty times from 0.3 to 15 W m−1 K−1 resulted in an increase in surface temperature by 1.2 °C.

CO2/acetone mixture desorption process in a plate heat exchanger for compression/resorption heat pumps

Industrial processes represent one of the activities that consume the most energy, which is related to the use of fossil fuels and growing environmental problems. In this way, the recovery of residual heat energy has been presented as an efficient solution to take advantage of low-quality residual heat, where the compressor-resorption heat pump technology has proven to reach high temperature levels with a considerable Coefficient of Performance. The importance of this work lies in the validation of the ecofriendly CO2/Acetone mixture as a useful working fluid for a compressor-resorption heat pump, initiating the experimental study in the desorption process as a novel application. Even more, the cycle of the bomb has been simulated on previous research regarding a literature comparative and the present work validates it by experimental means. The process of desorption of the CO2/acetone mixture was studied in a heat exchanger of plates with operating conditions for conducts formed by 4 plates/3 channels, for compression/resorption heat pumps. Result ranges have been obtained for solution heat transfer coefficient between 0.10 and 0.50 kW × m−2 × K−1, average vapor flow rate between 0.02 and 0.16, heat flow rate between 1.50 and 5.20 kW × m−2 × K−1 and desorption mass flow rate between 2 and 5 kg × m−2 s−1 × 10−3 in the central channel of the plate heat exchanger. Finally, an empirical correlation is proposed to extend the results of the heat transfer coefficient of the CO2/acetone solution in applications outside the experimentally determined range, from the comparison between experimental data and determined by correlation of enthalpy of the solution, an average minimum, mean and maximum deviation of 0.2, 13.5 and 22.3 %, respectively, was determined. In this way, the results shows that the most influential variables are the test pressure and heating water temperature at the inlet of the desorber, where, with a concentration of CO2 (XCO2) between 22 and 25 %, the heat transfer coefficients obtained have an order of 0.50 kW × m−2 × K−1. On the other hand, viscosity favours heat transfer, thermal conductivity is a determining factor for the desorption process. This contributes to lower heat transfer coefficient and heat flow in the heat exchanger for the CO2/acetone mixture compared to the other mixtures.

Experiment study on dryout characteristics and thermal resistance analysis of two-phase closed thermosiphon

This study aims to explore the dryout characteristics of two-phase closed thermosiphon. It involves the design and experimentation on low-liquid filled heat pipes. We investigated the effects of different fill ratios, heating water temperatures, and cooling water flow rates on the start-up characteristics of two-phase closed thermosiphon. Based on the network model, we proposed an analytical expression for the thermal resistance, R, of two-phase closed thermosiphon, and provided an explanation of the various thermal resistance components. This research expands our understanding of dryout and provides insights for optimizing heat pipe design and addressing heat conduction issues with low fill ratios.

Water Quality Trade-offs for Risk Management Interventions in a Green Building.

Premise plumbing water quality degradation has led to negative health impacts from pathogen outbreaks (e.g., Legionella pneumophila and non-tuberculous mycobacteria), as well as chronic effects from exposure to heavy metals or disinfection by-products (DBP). Common water quality management interventions include flushing, heat shock (thermal disinfection), supplemental disinfection (shock or super chlorination), and water heater temperature setpoint change. In this study, a Legionella pneumophila- colonized Leadership in Energy and Environmental Design (LEED) certified building was monitored to study health-relevant water quality changes before and after three controlled management interventions: (1) flushing at several points throughout the building; (2) changing the water heater set point; and (3) a combination of interventions (1) and (2) by flushing during a period of elevated water heater set point (incompletely performed due to operational issues). Microbial (culturable L. pneumophila, the L. pneumophila mip gene, and cATP) and physico-chemical (pH, temperature, conductivity, disinfectant residual, disinfection by-products (DBPs; total trihalomethanes, TTHM), and heavy metals) water quality were monitored alongside building occupancy as approximated using Wi-Fi logins. Flushing alone resulted in a significant decrease in cATP and L. pneumophila concentrations (p = 0.018 and 0.019, respectively) and a significant increase in chlorine concentrations (p = 0.002) as well as iron and DBP levels (p = 0.002). Copper concentrations increased during the water heater temperature setpoint increase alone to 140°F during December 2022 (p = 0.01). During the flushing and elevated temperature in parts of the building in February 2023, there was a significant increase in chlorine concentrations (p = 0.002) and iron (p = 0.002) but no significant decrease in L. pneumophila concentrations in the drinking water samples (p = 0.27). This study demonstrated the potential impacts of short term or incompletely implemented interventions which in this case were not sufficient to holistically improve water quality. As implementing interventions is logistically- and time-intensive, more effective and holistic approaches are needed for informing preventative and corrective actions that are beneficial for multiple water quality and sustainability goals.

Analysis of the Effect of an Absorbent Plate Coated with Cuo Nanoparticles on Single Slope Solar Distillation

Water is one of the basic needs that must be fulfilled by living things, especially humans, starting from daily activities such as cooking, washing, and so on. It is possible that the water source has been contaminated with other contaminants. Various methods are used to obtain proper water, one of which is the solar distillation method. Solar distillation is a method of purifying water that has not been widely used due to its low productivity. Copper Oxide Nanoparticles (CuO) were chosen as the material to be added to the black paint on the bottom of the distillation basin, this was done to increase its productivity. Experiments were carried out with concentrations of copper oxide (CuO) nanoparticles by weight of 10%, 15%, and 20%. It was found that adding nanoparticles to the paint increased the heat transfer rate and water temperature. The results obtained showed that CuO nanoparticles increased efficiency by 6.66%, 16.91% and 27.93% compared to conventional distillation apparatus at concentrations of heavy fractions of 10%, 15% and 20%, respectively. From this modification of the tool, the highest condensate mass was obtained at the concentration of the heavy fraction of 20% CuO nanoparticles with an average of 806 ml/day, while the other variations obtained an average condensate mass of 512 ml/day and 655 ml/day at the concentration of the heavy fraction respectively. 10% and 15% respectively.

Energy simulation on how to go green buildings in an earth's dry climate

Green buildings, i.e. low-energy and environmentally-friendly buildings, are highly demanded for optimizing the energy consumption and reducing the Green House Gas (GHG) Emissions. In this study, energy consumption of a residential building is analyzed in the hot and dry climate of Kashan, Iran. This is done based on the criteria of green buildings, using the Design Builder software. Several approaches are presented and discussed for the analysis, including the installing a thermal insulation layer, using external shadings and interior curtains, regulating the optimal comfort temperature, using an economizer, regulating the optimal domestic heat water (DHW) temperature, and installing photovoltaic panels. We investigate heating and cooling energies, as well as the total amount of energy saving in different conditions of the building. The results demonstrate that using the presented strategies leads to 67% and 39.3% reductions in electricity and gas consumption, respectively. Also, the carbon dioxide emissions are decreased 50.5% as a result of implementing the proposed methods.

IoT enabled smart solar water heater system using real time ThingSpeak IoT platform

AbstractThis dissertation aims to reuse the cold water which will initially present inside the water heater and reduce its wastage by sending it back to the water tank. The water heater temperature could be customized based on the number of users either manually or in an automated way using Internet of Things (IoT) techniques. The system is designed and operated using open‐source hardware and an IoT platform. The smart solar water heater with IoT capabilities continuously monitors the tank level, temperature, and pH level, and the data collected by the IoT node is uploaded/published to ThingSpeak. The IoT cloud analyses the sensor value and instructs the control unit of the smart solar system. The IoT enabled solar water heating system efficiency is high for smart homes and Industry 4.0. The main advantages of this model include handling multiple users, reducing the wastage of cold water, and purifying the water based on TDS level and this model aims to make it possible to control the proposed system from anywhere and at any time. The highest efficiency of the respective solar water heater could be well utilized.

Laboratory and operational analysis of air to water gas absorption heat pump cycle

Gas absorption heat pumps (GAHP) have significant potential to reduce fossil fuel consumption for space heating and hot water production and reduce CO2 emissions. The paper deals with laboratory and operational verification of GAHPs operating with air as a low-temperature energy source. The laboratory verification was used to specify and analyse the courses of one GAHP cycle in terms of cycle phases, outputs, and operating temperatures at different temperatures of the air supplied to the evaporator and heating water temperatures from GAHP. Comparative operational verification was conducted simultaneously in two identical buildings with the same technology and on two identical GAHPs A. The influence of interventions in GAHP control on the operating parameters and the average time of one cycle was monitored. The decrease in outdoor temperature and the transition from using the GAHP for water heating only to using it for space and water heating significantly affected the performance parameters and the average cycle time. Validation measurements were carried out for one year in twelve boiler rooms with GAHP connected in a cascade with gas-condensing boilers. The results showed that in the seasonal evaluation of GAHP operation for space and water heating, the average operation time of GAHP did not significantly affect the performance parameters. A fixed operation control to a higher required temperature of heating water when applying GAHP for space and water heating significantly negatively affected the performance parameters. Compared to heat production from a gas-condensing boiler (GCB), the monitored GAHP operation had lower emissions by 52 kg of CO2 per 1 MWh of heat produced.

A Critical Review on the Factors that Influence Opportunistic Premise Plumbing Pathogens: From Building Entry to Fixtures in Residences.

Residential buildings provide unique conditions for opportunistic premise plumbing pathogen (OPPP) exposure via aerosolized water droplets produced by showerheads, faucets, and tubs. The objective of this review was to critically evaluate the existing literature that assessed the impact of potentially enhancing conditions to OPPP occurrence associated with residential plumbing and to point out knowledge gaps. Comprehensive studies on the topic were found to be lacking. Major knowledge gaps identified include the assessment of OPPP growth in the residential plumbing, from building entry to fixtures, and evaluation of the extent of the impact of typical residential plumbing design (e.g., trunk and branch and manifold), components (e.g., valves and fixtures), water heater types and temperature setting of operation, and common pipe materials (copper, PEX, and PVC/CPVC). In addition, impacts of the current plumbing code requirements on OPPP responses have not been assessed by any study and a lack of guidelines for OPPP risk management in residences was identified. Finally, the research required to expand knowledge on OPPP amplification in residences was discussed.

Analysis of outlet temperature of parabolic trough collector solar water heater using machine learning techniques

The green sources of energy are ocean, hydro, solar, tidal, wave, wind, biomass, etc. Among all these wind, solar and hydro are mainly used. Particularly, solar energy has various applications such as atmospheric energy balance studies, solar energy collecting systems, analysis of the thermal load on buildings, etc. Parabolic trough collector (PTC) based solar water heater (SWH) gains a significant role in water heating systems. Parabolic trough collector is a concentrating type collector which collects the solar radiation in copper tube placed in the focal point of the parabolic trough. It also generates a high temperature which is suitable for steam generation. The main goal of this paper is to predict the outlet temperature of parabolic trough collector solar water heater with time and temperature for different days using various machine learning techniques.

Research on predictive control of energy saving for central heating based on echo state network

It is very important for energy conservation and environmental protection to realize energy-saving control of central heating system by prediction method. In this paper, the system model of central heating is built according to the general principle of secondary heating network, and an energy-saving control scheme based on the combination of dual networks and the regulation of secondary heating network is developed. In order to achieve better energy-saving control, the echo state network method is used to predict the heating water temperature in the heat exchange station controller. In the configuration process of echo state network, the water supply circuit temperature of the secondary heating network is taken as the output, and the 8 parameters of the primary heating network and the secondary heating network are taken as the input. After the stable echo state network is obtained through iterative training, the prediction is completed by using iterative multi-step method. Through the experimental results of three groups of sample data, it can be seen that the echo state network and prediction method constructed in this paper are superior to other methods, and are suitable for energy-saving prediction of central heating system.

Performance evaluation and model of spacesuit cooling by hydrophobic hollow fiber-membrane based water evaporation through pores

A comprehensive mathematical model is presented that accurately estimates and predicts failure modes through the computations of heat rejection, temperature drop and lumen side pressure drop of the hollow fiber (HF) membrane-based NASA Spacesuit Water Membrane Evaporator (SWME). The model is based on mass and energy balances in terms of the physical properties of water and membrane transport properties. The mass flux of water vapor through the pores is calculated based on Knudsen diffusion with a membrane structure parameter that accounts for effective mean pore diameter, porosity, thickness, and tortuosity. Lumen-side convective heat transfer coefficients are calculated from laminar flow boundary layer theory using the Nusselt correlation. Lumen side pressure drop is estimated using the Hagen-Poiseuille equation. The coupled ordinary differential equations for mass flow rate, water temperature and lumen side pressure are solved simultaneously with the equations for mass flux and convective heat transfer to determine overall heat rejection, water temperature and lumen side pressure drop. A sensitivity analysis is performed to quantify the effect of input variability on SWME response and identify critical failure modes. The analysis includes the potential effect of organic and/or inorganic contaminants and foulants, partial pore entry due to hydrophilization, and other unexpected operational failures such as bursting or fiber damage. The model can be applied to other hollow fiber membrane-based applications such as low temperature separation and concentration of valuable biomolecules from solution.

Influence of temperature of return district water on the performance of a backpressure steam turbine installation

The district heating systems supply heat to a wide range of consumers. In the heat source of such systems, highly efficient technologies are used for the combined production of electrical and thermal energy mainly based on steam turbine installations with backpressure turbines or turbines with adjustable steam extractions. Combined production leads to a reduction in fuel consumption (fuel saving) compared to the separate production of the two energy products. The fuel saving resulting from cogeneration reduces carbon dioxide emissions. Combined production affects the amount of fuel saved, leading to a reduction in emitted emissions, both the size of the heat load realize to consumers and the temperature of the water that enters from the return pipeline of the district heating systems into the heat source. In backpressure steam turbine installations, the district water is heated by the steam that enters the boiler-condenser, and in steam turbine installations with adjustable steam extraction, it is heated in a district heater by steam extracted from the turbine. The purpose of this paper is to study the influence of the temperature of return district heating water on the performance of a backpressure steam turbine installation for cogeneration.

Thermal energy storage thermal data processing for heating systems

In order to solve the problem that the traditional industrial control methods cannot control the heating flow and water temperature in a timely and effective manner due to the high delay and complex coupling characteristics of the urban central heating system, the authors propose deep learning-based data processing and management for thermal heating systems. The author analyzes the non-ideality of district heating system and its influence on the application of deep learning technology, and gives solutions, respectively, finally, a primary side regulation scheme of district heating system based on deep learning and automatic control technology is proposed as a whole. The experimental results show that, by comparing the water supply temperature predicted by the equipment model of the primary side heat station with its actual measured value, the mean square error of the prediction results using the model directly is 1.30%, and the mean square error after model correction is 0.094%. The secondary return water temperature was controlled by adjusting the opening of the primary side electric valve, the expected secondary return water temperature in the scheme was compared with the actual secondary return water temperature, and the mean square error was 0.102%. It is proved that the scheme can achieve good control effect in the actual system, and the data result proves that the scheme is feasible.

ESTIMATES OF SURFACE CHANGES OF HEATING HEAT EXCHANGERS FOR INDIVIDUAL HEAT STATIONS WHEN THE TEMPERATURE CHART OF DISTRIBUTION HEAT NETWORK IS CHANGED

The aspects of the functioning of centralized heating systems of residential urban districts after additional insulation of this district existing buildings were considered. The influence of the heat carrier temperature in the district distribution heating network on the heat transfer surface of the heat exchangers that are installed in the individual heat station schemes with independent connection between buildings heating systems and heat networks was analyzed. Estimates were made for a plate heat exchanger with a counterflow pattern of heat carriers that are widely used in heat supply systems. Formulas have been obtained for calculating the heat exchange surface of the district water heater comparing to the surface of the "basic" design case of the heat exchanger, taking into account the district water temperature excess over the building heating water temperature. When finding the heat transfer coefficients in the channels of heat exchangers, known criterion equations for plate heat exchangers were used. The proposed formulas take into account the influence of the ratio of heat equivalents of the carriers flow rate through the heat exchanger and the decrease in heat consumption for heating as a result of building insulation. Buildings that were designed and built in accordance with the requirements for thermal resistance of enclosing structures that were actual several decades ago, after thermal modernization, should meet modern requirements for the thermal resistance of building structures. All estimates of the reduction in the buildings heating load were made in accordance with this approach. An analysis of the obtained results made it possible to propose some recommendations for the selection of district water calculated temperature differences at which a decrease in the heat transfer surface of the plate heat exchanger of the insulated buildings individual heat station can be expected. The proposed recommendations can be useful in developing a heat supply quality control schedule for a district buildings heating systems in a district when buildings thermal insulation process being completed.