scholarly journals Operation analysis of primary and secondary networks of distributed solar heating system in Tibet

2021 ◽  
Vol 329 ◽  
pp. 01079
Author(s):  
Chengpeng Liu
Keyword(s):  
Heating System ◽  
Solar Heating ◽  
Temperature Changes ◽  
Operation Analysis ◽  
Primary Network ◽  
Secondary Network ◽  
High Altitude Area ◽  
Distributed Heating ◽  
Secondary Networks ◽  
Operation Characteristics

Tibet is located in a high cold and high altitude area. Heating in winter is an important problem to be solved urgently, and the distributed solar heating system provides a solution for the efficient and clean utilization of energy in this area. Through the test and commissioning of the distributed solar heating system with supplementary combustion in Tibet, the operation characteristics of the heating system are analyzed from the temperature changes of the primary network and the secondary network. The research results can provide technical support for the application and promotion of the solar distributed heating system with supplementary combustion in Tibet.

Problems Arising from Redefinition in Densification Surveys

1974 ◽  
Vol 28 (5) ◽  
pp. 732-738
Author(s):  
Adam Chrzanowski ◽  
Nicholas Canellopoulos
Keyword(s):  
Higher Order ◽  
Relative Accuracy ◽  
Control Network ◽  
Primary Control ◽  
Primary Network ◽  
Secondary Network ◽  
Fitting Method ◽  
Secondary Networks ◽  
Better Than

The redefinition has been considered as a necessary step to improve the primary control network, which at the present does not satisfy the accuracy requirements of all the users. In view of the existing distortions in the primary control and in view of the forthcoming redefinition, the user who is involved in a densification survey faces the following questions: 1) how to perform the adjustment of the secondary networks in order to be independent of the distortion of the primary network, 2) how to take the advantage of those parts of the primary network that satisfy his requirements. If the two questions are answered, one has to solve a problem on how to transform, in the best way, the established secondary network into the redefined coordinates system. The authors try to give an answer to those questions considering the following four cases: 1) the relative accuracy between the higher order points is much better than the relative accuracy of the same points belonging to the densification network; 2) both primary and densification methods have the same accuracy; 3) the relative accuracy of the higher order network is worse than the corresponding of the densification network; 4) the relative accuracy of the points of the higher order network is unknown. The authors advocate that a free adjustment and a fitting method should answer the problem.

scholarly journals Interference Alignment in Multi-Hop Cognitive Radio Networks under Interference Leakage

2018 ◽  
Vol 8 (12) ◽  
pp. 2486 ◽  
Author(s):  
Eylem Erdogan ◽  
Sultan Çolak ◽  
Hakan Alakoca ◽  
Mustafa Namdar ◽  
Arif Basgumus ◽  
...  
Keyword(s):  
Cognitive Radio ◽  
Interference Alignment ◽  
Ergodic Capacity ◽  
Secondary Source ◽  
Primary Network ◽  
Secondary Network ◽  
The Impact ◽  
Secondary Networks ◽  
Diversity Gains ◽  
Multiple Primary Users

In this work, we examine the interference alignment (IA) performance of a multi-input multi-output (MIMO) multi-hop cognitive radio (CR) network in the presence of multiple primary users. In the proposed architecture, it is assumed that linear IA is adopted at the secondary network to alleviate the interference between primary and secondary networks. By doing so, the secondary source can communicate with the secondary destination via multiple relays without causing any interference to the primary network. Even though linear IA can suppress the interference in CR networks considerably, interference leakages may occur due to a fast fading channel. To this end, we focus on the performance of the secondary network for two different cases: (i) the interference is perfectly aligned; (ii) the impact of interference leakages. For both cases, closed-form expressions of outage probability and ergodic capacity are derived. The results, which are validated by Monte Carlo simulations, show that interference leakages can deteriorate both system performance and the diversity gains considerably.

HEAT LOSS ANALYSIS AND OPTIMIZATION OF HOUSEHOLD SOLAR HEATING SYSTEM

2019 ◽  
Vol 50 (7) ◽  
pp. 659-670 ◽  
Author(s):  
Jieyuan Yang ◽  
Jinping Li ◽  
Rong Feng
Keyword(s):  
Heat Loss ◽  
Heating System ◽  
Solar Heating ◽  
Loss Analysis

Effect of CSI Imperfection on Cognitive Underlay Transmission over Nakagami-m Fading Channel

2015 ◽  
Vol 1 ◽  
pp. 59
Author(s):  
Nguyen Hong Giang ◽  
Vo Nguyen Quoc Bao ◽  
Hung Nguyen-Le
Keyword(s):  
Fading Channels ◽  
System Performance ◽  
Performance Metrics ◽  
Maximal Ratio Combining ◽  
Relay Nodes ◽  
Channel State ◽  
Primary Network ◽  
Secondary Network ◽  
System Designs ◽  
Approximate Expressions

This paper analyzes the performance of a cognitive underlay system over Nakagami-m fading channels, where maximal ratio combining (MRC) is employed at secondary destination and relay nodes. Under the condition of imperfect channel state information (CSI) of interfering channels, system performance metrics for the primary network and for the secondary network are formulated into exact and approximate expressions, which can be served as theoretical guidelines for system designs. To verify the performance analysis, several analytical and simulated results of the system performance are provided under various system and channel settings.

scholarly journals Optimization Analysis on Storage Tank Volume in Solar Heating System

2015 ◽  
Vol 121 ◽  
pp. 1356-1364 ◽  
Author(s):  
Tao Li ◽  
Yanfeng Liu ◽  
Dengjia Wang ◽  
Kaifeng Shang ◽  
Jiaping Liu
Keyword(s):  
Storage Tank ◽  
Heating System ◽  
Solar Heating ◽  
Optimization Analysis

Economics of Installation of an Active Solar Heating System

1997 ◽  
Vol 19 (2) ◽  
pp. 163-172
Author(s):  
ARMEN HOVSEPIAN ◽  
MARK KAISER
Keyword(s):  
Heating System ◽  
Solar Heating

Experience With a Solar Heating ATES System for a University Building

1994 ◽  
Vol 116 (2) ◽  
pp. 88-93 ◽  
Author(s):  
E. Hahne ◽  
M. Hornberger
Keyword(s):  
Solar Energy ◽  
Heat Pump ◽  
Waste Heat ◽  
Heating System ◽  
Solar Heating ◽  
Coefficient Of Performance ◽  
Solar Collectors ◽  
Power Station ◽  
Heat Demand ◽  
Heat Store

At Stuttgart University, a solar heating system for an office building with laboratories and lecture rooms was installed in 1985. It consists of 211 m2 of unglazed solar collectors, a 1050 m3 water-flooded pebble bed heat store, and a heat pump. Heat can be supplied to the store from the solar collectors or from a power station (as waste heat). The whole system has worked successfully for five years under varied strategies. In the first two heating periods, the heating strategy was aimed to collect as much solar energy as possible. Thus, about 60 percent of the heat demand could be covered by solar energy; but the yearly heat pump coefficient of performance (COP) was only around 2.76. With an improved heat pump, a monthly COP of 3.6 was obtained. Heat losses from the storage amounted to about 20 percent.

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