scholarly journals Selection and Evaluation of influencing Parameters for Heat Load Forecasting Model

2021 ◽  
Vol 252 ◽  
pp. 03027
Author(s):  
Yuli Wu ◽  
Rui Li
Keyword(s):  
Prediction Model ◽  
Temperature Difference ◽  
Hot Water ◽  
Outdoor Temperature ◽  
Domestic Hot Water ◽  
Model Input ◽  
Average Temperature ◽  
Average Temperature Difference ◽  
Input Parameters ◽  
Heating Load

This paper analyses the factors affecting the heating consumption of a heating substation. The input parameters of neural network prediction model are analysed and selected. The average absolute error, average absolute percentage error, and mean square error are used to evaluate the effect of the prediction model. The results show that when the model input parameters are the maximum outdoor temperature, the average outdoor temperature, the average temperature difference between the primary supply and return of domestic hot water, the heating load in the previous three days, the heating load in the previous two days, the heating load in the previous day and when the model input parameters are the maximum outdoor temperature, the minimum outdoor temperature, the average outdoor temperature, the average temperature difference between the primary supply and return of domestic hot water, the heating load of the previous three days, the heating load of the previous two days, the heating load of the previous day, the effects are better.

Experimental Investigation of Lab-Scale, Heat Exchanger Prototypes Designed to Provide Refugia for Trout

2021 ◽  
Author(s):  
Rajib Uddin Rony ◽  
Adam Gladen ◽  
Sarah LaVallie ◽  
Jeremy Kientz
Keyword(s):  
Heat Exchanger ◽  
Temperature Difference ◽  
Large Scale ◽  
Cold Water ◽  
Cooling System ◽  
Tube Bundle ◽  
Small Scale ◽  
Scaled Model ◽  
Average Temperature ◽  
Average Temperature Difference

Abstract In recent years Spring Creek in South Dakota, a popular fishing location, has been experiencing higher surface water temperatures, which negatively impact cold-water trout species. One potential solution is to provide localized refugia of colder water produced via active cooling. The present work focuses on the design and testing of a small-scale prototype heat exchanger, for such a cooling system. Various prototypes of the heat exchanger were tested in a 1/10th-scaled model of a section of the creek. A staggered, tube-bundle heat exchanger was used. The prototypes consisted of just the heat exchanger placed directly in the scaled-stream model and of the heat exchanger placed inside an enclosure with an aperture. The results show that, without the enclosure, the average temperature difference is 0.64 °C, with a corresponding heat transfer requirement of 1.63 kW/°C of cooling. However, with an enclosure, the average temperature difference is 1.95 °C, which required 0.59 kW/°C of cooling. Modifications to the enclosure decrease the average temperature difference but also decrease the standard deviation of the temperature difference. Thus, the cooling effect is more evenly spread throughout the water in the enclosure. This indicates that the enclosure design can be used to balance the requirements of obtaining a desired temperature difference with a relatively low spatial variation in that temperature difference. These results will be used to guide the design of the large-scale heat exchanger prototype.

A Numerical Simulation Study for the Performance of a Multi-Purpose Large Solar Hot Water System Operated in Taiwan

2016 ◽  
Author(s):  
Ru Yang ◽  
Yu-Ting Yen
Keyword(s):  
Simulation Study ◽  
Air Conditioning ◽  
Storage Capacity ◽  
Water System ◽  
Hot Water ◽  
Climate Data ◽  
Domestic Hot Water ◽  
Computer Simulation Program ◽  
Heating Load ◽  
Evacuated Tube

There is rich solar energy in Taiwan, it also has a great developing potential for solar applications. Solar hot water is able to supply the domestic hot water, the heating load, and the driving energy for absorption cooing. In this paper, a computer simulation program for a multi-purpose solar hot water system providing hot water, winter heating and summer air-conditioning is established by TRNSYS program. Simulation study is done with varying parameters including collector area, storage capacity and type of collector (flat plate and evacuated tube). In order to study the system performance in Taiwan, system simulations are made under the climate data of three representative cities (Taipei in north, Taichung in central, and Kaohsiung in southern) of Taiwan. The results of the present study can provide important reference for the development of the multi-purpose solar hot water system.

scholarly journals Field Study on the Microclimate of Public Spaces in Traditional Residential Areas in a Severe Cold Region of China

2019 ◽  
Vol 16 (16) ◽  
pp. 2986 ◽  
Author(s):  
Yujie Lin ◽  
Yumeng Jin ◽  
Hong Jin
Keyword(s):  
Wind Speed ◽  
Temperature Difference ◽  
Public Spaces ◽  
Average Wind Speed ◽  
Coverage Ratio ◽  
Wind Speeds ◽  
Average Temperature ◽  
Average Temperature Difference ◽  
Average Wind ◽  
The Difference

As residential environment science advances, the environmental quality of outdoor microclimates has aroused increasing attention of scholars majoring in urban climate and built environments. Taking the microclimate of a traditional residential area in a severe cold city as the study object, this study explored the influence of spatial geometry factors on the microclimate of streets and courtyards by field measurements, then compared the differences in microclimate of distinct public spaces. The results are as follows. (1) The temperature of a NE-SW (Northeast-Southwest) oriented street was higher than that of a NW-SE (Northwest-Southeast) oriented street in both summer and winter, with an average temperature difference of 0.7–1.4 °C. The wind speeds in the latter street were slower, and the difference in average wind speed was 0.2 m/s. (2) In the street with a higher green coverage ratio, the temperature was much lower, a difference that was more obvious in summer. The difference in mean temperature was up to 1.2 °C. The difference in wind speed between the two streets was not obvious in winter, whereas the wind speed in summer was significantly lower for the street with a higher green coverage ratio, and the difference in average wind speed was 0.7 m/s. (3) The courtyards with higher SVF (sky view factor) had higher wind speeds in winter and summer, and the courtyards with larger SVF values had higher temperatures in summer, with an average temperature difference of 0.4 °C. (4) When the spaces had the same SVF values and green coverage ratios, the temperature of the street and courtyard were very similar, in both winter and summer. The wind speed of the street was significantly higher than the courtyard in summer, and the wind speed difference was 0.4 m/s.

District Heating

1949 ◽  
Vol 160 (1) ◽  
pp. 1-21 ◽  
Author(s):  
A. Stubbs
Keyword(s):  
Fuel Economy ◽  
District Heating ◽  
Hot Water ◽  
Space Heating ◽  
Low Grade ◽  
High Grade ◽  
Domestic Hot Water ◽  
The Public ◽  
Large Town ◽  
Heating Load

This paper regards district heating as a service intended to satisfy the space heating and domestic hot-water requirements of the public. It sets out a complete scheme for a large town of 250,000 people in such a manner as to show the values of the parts as well as the value of the whole. The build-up of the district heating load is conveniently set out under the headings: ( a) industrial and commercial, ( b) community, and ( c) housing, whilst the engineering and economic features are related to the consumers, the sub- and main-distribution, and generation. District heat is low-grade energy, and its generation is properly associated with the generation of electricity which is high-grade energy. In taking advantage of combined generation of heat and electricity, consideration is given to the already highly organized state of the electricity supply. The conclusion deals with the costs and overall fuel economy and does not deal with improved amenities which, in the opening part of the paper, are taken for granted.

Energy Consumption Analysis of a New Rural Green Building

2012 ◽  
Vol 608-609 ◽  
pp. 1716-1723 ◽  
Author(s):  
Jin Ping Li ◽  
Rong Dan Diao ◽  
Si Cong Ma ◽  
Xiao Chao Leng ◽  
Chun Long Wang
Keyword(s):  
Energy Consumption ◽  
Rural Areas ◽  
Green Building ◽  
Payback Period ◽  
Hot Water ◽  
Outdoor Temperature ◽  
Domestic Hot Water ◽  
Energy Demands ◽  
Energy Consumption Analysis ◽  
Rural Buildings

In order to meet farmers’ energy demands of gas, domestic hot water and winter heating with renewable energy in rural areas, according to farmers’ living habits in winter, a 30m2 insulated rural green building made of brick and concrete, was developed to integrate with thermostatic digester heated by solar energy and low-temperature radiant bed. Energy expenditure and thermal economy of the green building were studied at different winter ambient temperature subsequently. The results show that the consumer’s energy demands of gas, hot water and winter heating can be met in the green building even in winter. When the outdoor temperature is -20°C, the indoor’s is higher than 15°C. Compared with traditional rural buildings made of brick and concrete, the new one saves 2.8 tons of standard coal and RMB￥3275 every year and the payback period of investment of the enforced cost is 3.9 years.

District heating load profiles for domestic hot water preparation with realistic simultaneity using DHWcalc and TRNSYS

Energy ◽  
2020 ◽  
Vol 201 ◽  
pp. 117552 ◽  
Author(s):  
Hagen Braas ◽  
Ulrike Jordan ◽  
Isabelle Best ◽  
Janybek Orozaliev ◽  
Klaus Vajen
Keyword(s):  
District Heating ◽  
Hot Water ◽  
Domestic Hot Water ◽  
Heating Load

scholarly journals A statistical analysis of the relationship between domestic hot water consumption and mean outdoor temperature in Budapest

Időjárás ◽  
2021 ◽  
Vol 125 (1) ◽  
pp. 53-82
Author(s):  
András Horkai
Keyword(s):  
Time Series ◽  
Regression Analysis ◽  
Water Consumption ◽  
Climate Models ◽  
Regional Climate ◽  
Linear Regression Analysis ◽  
Hot Water ◽  
Outdoor Temperature ◽  
Domestic Hot Water ◽  
Time Series Decomposition

This study analyzes how outdoor temperature influences domestic hot water consumption in multiapartment large-panel system buildings in Budapest, Hungary. The analysis is based on data from the validated invoicing system of the district heating provider, and from two weather stations of the Hungarian Meteorological Service. The official monthly hot water consumption data of 72 buildings for 7 consecutive years and the corresponding monthly mean temperatures were used in this study. Linear regression analysis and time series decomposition were carried out. The results prove that the outdoor temperature and the domestic hot water consumption are definitely related. The model based on regression analysis could account for 74% of values. The time series decomposition model is able to estimate hot water consumption per apartment per day for a future month with 94% probability. The study relies on data obtained from a projection of two regional climate models each, namely ALADIN-Climate and RegCM. Based on these data, the model forecasts how the effects of climate change will probably influence domestic hot water consumption in the near future. These results shed light on the factors influencing hot water consumption, and may help authorities and decision makers to form sustainability policies and to plan sustainable resource management.

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