The Experimental Analysis on the Regularity of Heating Load in Buildings Using Heat Meters with On-Off Time and Area Method in Shijiazhuang Area

2014 ◽  
Vol 694 ◽  
pp. 272-275
Author(s):  
Chao Wang ◽  
Chun Hua Sun ◽  
Cheng Ying Qi ◽  
Feng Yun Jin ◽  
Bo Shao
Keyword(s):  
Load Distribution ◽  
Distribution Curve ◽  
Heating System ◽  
Measuring Method ◽  
Heating Period ◽  
Heating Load ◽  
The Stability ◽  
Heating Loads ◽  
Off Time ◽  
Peak Value

Based on the heating load experiment adopting on-off time and area measuring method of typical heat users located in different places of different buildings in Shijiazhuang, the heating loads of the heat users which are summarized as two typical heat using modes are studied in this paper and the heating loads in the whole winter heating season of the building is estimated. The results shows that with the user’s heat adopting ratio in these two modes increases, the corresponding heating load is lower, the heating load distribution curve gets smoothly in the whole heating period and the peak value of the system heating loads reduces. This regularity of heating load distribution is beneficial for enhancing the stability of heating system and the thermal efficiency of the heat source.

ASSESSMENT OF PINE CROPS GROWTH IN BAIMAK FORESTRY

2020 ◽  
Vol 37 (3) ◽  
pp. 83-90
Author(s):  
T.Z. Mutallapov ◽  
Keyword(s):  
Scots Pine ◽  
Forest Ecosystem ◽  
Distribution Curve ◽  
Comparative Assessment ◽  
Tree Distribution ◽  
Entire Structure ◽  
Structure Changes ◽  
Large Trees ◽  
Different Types ◽  
The Stability

The article presents the results of evaluating the growth of Scots pine in the Baymak forest area. The analysis of forestry and taxation indicators of Scots pine crops on the studied sample areas is carried out, and a comparative assessment of the growth of forest crops growing in different types of forest is given. Increased competition in plantings leads to the natural decline of stunted trees, which is the result of differentiation in the stand. As a result, its structure changes, the number of large trees increases, and, accordingly, the stability of the forest ecosystem increases. In this regard, the appearance of the tree distribution curve by thickness levels also changes. It becomes more "flat", and its competitive load is more evenly distributed over the entire structure of the stand, and competition is weakened.

Predicting Hourly Heating Load in a District Heating System Based on a Hybrid CNN-LSTM Model

2021 ◽  
pp. 110998
Author(s):  
Jiancai Song ◽  
Liyi Zhang ◽  
Guixiang Xue ◽  
YunPeng Ma ◽  
Shan Gao ◽  
...  
Keyword(s):  
District Heating ◽  
Heating System ◽  
District Heating System ◽  
Heating Load

scholarly journals Smart Meter Data Analysis of a Building Cluster for Heating Load Profile Quantification and Peak Load Shifting

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4343
Author(s):  
Yunbo Yang ◽  
Rongling Li ◽  
Tao Huang
Keyword(s):  
Data Analysis ◽  
Peak Load ◽  
Smart Meter ◽  
Load Shifting ◽  
Load Profile ◽  
Transition Season ◽  
Morning Peak ◽  
Heating Load ◽  
Heating Loads

In recent years, many buildings have been fitted with smart meters, from which high-frequency energy data is available. However, extracting useful information efficiently has been imposed as a problem in utilizing these data. In this study, we analyzed district heating smart meter data from 61 buildings in Copenhagen, Denmark, focused on the peak load quantification in a building cluster and a case study on load shifting. The energy consumption data were clustered into three subsets concerning seasonal variation (winter, transition season, and summer), using the agglomerative hierarchical algorithm. The representative load profile obtained from clustering analysis were categorized by their profile features on the peak. The investigation of peak load shifting potentials was then conducted by quantifying peak load concerning their load profile types, which were indicated by the absolute peak power, the peak duration, and the sharpness of the peak. A numerical model was developed for a representative building, to determine peak shaving potentials. The model was calibrated and validated using the time-series measurements of two heating seasons. The heating load profiles of the buildings were classified into five types. The buildings with the hat shape peak type were in the majority during the winter and had the highest load shifting potential in the winter and transition season. The hat shape type’s peak load accounted for 10.7% of the total heating loads in winter, and the morning peak type accounted for 12.6% of total heating loads in the transition season. The case study simulation showed that the morning peak load was reduced by about 70%, by modulating the supply water temperature setpoints based on weather compensation curves. The methods and procedures used in this study can be applied in other cases, for the data analysis of a large number of buildings and the investigation of peak loads.

The Application of the Amorphous Metal Transformers in Heavy Oil Electric Heating System

2014 ◽  
Vol 532 ◽  
pp. 191-195 ◽  
Author(s):  
Bao Jiang Sun ◽  
Lei Su ◽  
Chao Zhang
Keyword(s):  
Electric Heating ◽  
Heating System ◽  
Intermediate Frequency ◽  
Amorphous Metal ◽  
Technical Performance ◽  
Alloy Material ◽  
Working Principle ◽  
The Stability ◽  
And Control ◽  
Fast Rise

In order to solve the problem that the big loss of no-load and the fast rise of temperature when employ the conventional silicon steel metal transformer (SSMT) in the electric heating system, we choose the amorphous metal transformer (AMMT). In this paper, firstly, we give a brief introduction of the amorphous alloy material properties and compare the no-load characteristic of the AMMT with the SSMT. Secondly, the structure of intermediate frequency heating system working principle and control strategy are introduced. Finally, extensive experiments were conducted to validate the ideas. The experiments show that the AMMT not only improve the efficiency of transformer, solve the heating problem of transformer, but also improve the stability, security and other technical performance of the system, so it is worth recommending and promoting.

scholarly journals Influence of Snow Load Distribution on the Stability of Single-layer Reticulated Shells

2020 ◽  
Vol 10 (1) ◽  
pp. 141-147
Author(s):  
Junlin Wang ◽  
Wei Lu ◽  
Chenyang Dun ◽  
Hua Guo ◽  
Jianheng Sun
Keyword(s):  
Load Distribution ◽  
Single Layer ◽  
Snow Load ◽  
The Stability

Numerical Analysis for Bolt Length Based on the Stress Response of Anchorage Surrounding Rock

2012 ◽  
Vol 204-208 ◽  
pp. 4481-4485
Author(s):  
Bin Wang ◽  
Fu Jun Zhao ◽  
Wen Bin Peng
Keyword(s):  
Numerical Simulation ◽  
Stress Response ◽  
Numerical Analysis ◽  
Bearing Capacity ◽  
Distribution Curve ◽  
Surrounding Rock ◽  
Effective Length ◽  
Plastic Failure ◽  
Deep Rock ◽  
Peak Value

The current researches on bolt length are rarely concerned with self-bearing characteristics of anchorage surrounding rock，its stress response is seldom used to analyze the bolt effective length. Tangential stress σθ of surrounding rock is sensitive to mechanical variation of surrounding rock plastic failure fields. When surrounding rock bolted, the distribution curve of σθ presents internal and external peak values from the surface rock to the deep rock, which is verified by numerical simulation. Internal peak value of σθ curve increases with the bolt length, which means the bearing capacity of surrounding rock in plastic failure division is improved, correspondingly, external peak value decreases which shows the supporting behavior of the deep rock is weakened. The results of numerical simulations prove that there exists an effective value of bolt length. If bolt length beyond it, the bearing capacity of anchorage surrounding rock cannot be improved obviously.

Sample stability: a suggested definition and method of determination.

1976 ◽  
Vol 22 (2) ◽  
pp. 176-183 ◽  
Author(s):  
R E Thiers ◽  
G T Wu ◽  
A H Reed ◽  
L K Oliver
Keyword(s):  
Statistical Design ◽  
Measuring Method ◽  
Chemical Constituent ◽  
Sequential Test ◽  
Method Of Determination ◽  
Sample Stability ◽  
Average Change ◽  
Truncated Normal ◽  
Standard Deviations ◽  
The Stability

Abstract We propose defining the stability of any chemical constituent of stored samples in terms that are quantitatively related to the precision of the measurement by which it is determined. We suggest that a constituent may be considered stable, for a stated period and under exactly defined conditions, when the average change in its measured value is less than a chosen number, K, of standard deviations of the data obtained by the measuring method over the concentration range in question. Based on this definition a technique utilizing a graphical truncated normal sequential test is presented as the appropriate experimental and statistical design for measuring stability. The statistical basis for the proposal is presented.

scholarly journals Development of Temperature Process Control Method Using Smith Predictor

2019 ◽  
Vol 111 ◽  
pp. 06016
Author(s):  
Nikolajs Bogdanovs ◽  
Romualds Beļinskis ◽  
Ernests Petersons ◽  
Andris Krūmiņš ◽  
Artūrs Brahmanis
Keyword(s):  
Time Delay ◽  
Control Method ◽  
Distributed Delay ◽  
Heating System ◽  
Smith Predictor ◽  
Hot Water ◽  
Test Bed ◽  
Hot Water Supply ◽  
The Stability ◽  
System With Time Delay

The analysis of a problem of development of control systems for objects with big time delay is carried out in this work. For such objects it is difficult to provide high-quality control, because the control is carried on the last status of object’s output. The main setup methods of PID regulators have been examined. Based on this analysis the technique of complete synthesis of the regulator of higher level is given in order to regulate building’s heating system. This work offers a new method of object’s control with distributed delay. As the test bed for the offered structure of control the valve of hot water supply in a heat-node is used. Using the test bed the stability of the system with time delay have been studied, which is controlled by the PID-regulator assisted by Smith Predictor used to compensate the dead time.

Validation of Hydrodynamic Stability of Supercritical Once-Through Boiler

2008 ◽  
Author(s):  
Bing Wei ◽  
Dong Zhou
Keyword(s):  
Flow Instability ◽  
Hydrodynamic Instability ◽  
Pressure Head ◽  
Operating Conditions ◽  
Hydrodynamic Characteristics ◽  
Boiler Operation ◽  
Calculation Results ◽  
Low Mass ◽  
The Stability ◽  
Heating Loads

Operating safety is one of the most important things to supercritical once-through boilers. To study the hydrodynamic characteristics of fluid in water walls of supercritical once-through boilers and to find out the instable factors will be of great significance to boiler operation. In this paper the mathematical models for hydrodynamic characteristics of fluid in water walls are established. With an example of 600MW boiler, by using the calculation program, the hydrodynamic characteristics curves without and with the throttles at the inlets of the water walls at different operating conditions are presented, the fluid flow instability and the reasons are analyzed. The calculation results show that the boiler operates stably and safely at 100% MCR (Maximum Continuous Rating) condition, the hydrodynamic instability exists at low heating loads of 30% MCR. The method of installing the throttles at the inlets of the water wall pipes will increase the parabola characteristics, help to improve the fluid instability to a certain stable extent, but due to the small curve slopes at low mass flowrates, still need to pay more attention to the low heating loads operation. The existence of gravity pressure head is good to the stability of the vertical upward flow.

scholarly journals The effectiveness of heating of housing unit by renewable energy source

2016 ◽  
Vol 62 (Special Issue) ◽  
pp. S34-S43
Author(s):  
J. Jobbágy ◽  
K. Krištof ◽  
M. Andacký
Keyword(s):  
Heat Loss ◽  
Calorific Value ◽  
Heating System ◽  
Housing Unit ◽  
Heating Season ◽  
Heating Period ◽  
Fuel Wood ◽  
Total Heat Loss ◽  
Infrared Thermometer ◽  
Average Value

The paper is aimed at pointing out possibilities of using of dendromass for heating. The object of interest was heating of housing units with 75.27 m<sup>2</sup> of total area. The average value of dendromass moisture was 17.71%. The inserted fireplace Nordica Focolare 70 with a nominal output of 9 kW was used as a heat source. For temperature measurement, a non-contact infrared thermometer GM 900 was used. The total heat loss transferred through walls of housing unit (heat loss through thermal bridges and ventilation losses) were calculated at the value of 176.26 W/K. Based on the results of samples moisture the net calorific value of one kilogram of burned fuel wood was determined (14.791 MJ kg). The amount of thermal energy which is necessary to supply by the heating system for the whole heating period was 14,199.18 kWh. The weight of raw fuel wood was 5,450.97 kg (at moisture of 30%), dried at 17.71% (4,636.87 kg). Price of raw fuel wood of acacia for the year under evaluation was 64.80 €/m<sup>3</sup> (the required amount of raw fuel wood for heating period was 10 m<sup>3</sup>). Total costs for the heating season was thus 648 €. The price of heat transmitted by the fireplace inset Nordica Focolare 70 inserted into heating system using fuel wood (white acacia) with 17.71% of absolute moisture was 0.045636 €/kWh.

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