Study on the Pressure Difference Control in Variable Flow Rate Central Heating Systems

2012 ◽  
Vol 193-194 ◽  
pp. 1239-1242 ◽  
Author(s):  
Jia Wen Qiang ◽  
Jian Xiang Guo ◽  
Zhong Wei Sui
Keyword(s):  
Flow Rate ◽  
Pressure Difference ◽  
Evaluation Method ◽  
Heating System ◽  
Pressure Control ◽  
Differential Pressure ◽  
Variable Flow ◽  
Heating Systems ◽  
Central Heating ◽  
Energy Consumption Calculation

Through analyzing the application of pressure difference control system in variable flow rate central heating system, the evaluation method based on maxim energy consumption calculation is presented. The constant and variable differential pressure control is separately studied, a conclusion is come to that the smaller the differential pressure controlled, the more energy saved, and the variable differential pressure control as far as possible to maintain the hydraulic resistance of system is more efficient.

scholarly journals METHODOLOGY OF THE PRIMARY DATA RECONSTRUCTION OF SINGLE PIPE HEATING SYSTEMS/VIENVAMZDŽIŲ ŠILDYMO SISTEMŲ PIRMINIŲ DUOMENŲ NUSTATYMO METODIKA

1999 ◽  
Vol 5 (5) ◽  
pp. 318-322
Author(s):  
Edvardas Tuomas ◽  
Saulius Neverbickas
Keyword(s):  
World War Ii ◽  
District Heating ◽  
Heating System ◽  
Heat Fluxes ◽  
Primary Data ◽  
Complex Coefficient ◽  
Heating Systems ◽  
Pipe System ◽  
Central Heating ◽  
Single Pipe

The majority of dwellings in Lithuania are situated in blocks of flats. The dwellings were built after World War II and they are heated by single pipe central heating systems, connected to district heating. The dwellers are not quite satisfied with such a heating system and try to improve it, but do that in a wrong way, by increasing the surface of radiators. Such means lead to violation of thermal regime and comfort conditions for other dwellers. There exists sometimes the necessity of reconstructing premises and together—the heating system. During the reconstruction the primary heat fluxes from radiators should be known, but very often such data are lost and only the size of radiators (number of sections) are known. To reconstruct the required primary data for single pipe systems is complicated because the temperatures of inlet and outlet water for radiators are unknown. In this article the methodology is proposed how to perform the calculations leading to the required data. The aim of calculations is the establishment of heat fluxes from each radiator connected to the riser. Heat flux from radiator can be calculated according the formula (1) but the complex coefficient is unknown. It could be found from formulae (2) but some magnitudes are unknown. According to the proposed methodology the values of unknown magnitudes are taken approximately and calculations are performed with iterations. In such a way the flow rate of water in riser is established from formula (3), which is the same for each radiator (the property of single pipe system). From formulas (3) and (4) an equation is produced (5), and is used for calculations of unknown temperatures. The equation (6) is used for calculation of heat fluxes from radiators. To carry out the above-mentioned calculations without computer practically is impossible due to many cycles of iteration. The programme was prepared to make easy all these calculations. The scheme of algorithm of programme is given in Fig 1. An example of calculation is given in this article. Calculations were fulfilled by newly created programme. The riser chosen for calculation is shown in Fig 2. The results of calculation are given in Table 1. The table shows that according to the proposed methodology the programme based on it can be used for reconstruction of primary data of single pipe heating systems successfully.

scholarly journals Calculation Of Heat Loss Through The Pipes Of The Interior Central Heating System

2015 ◽  
Vol 5 (2) ◽  
pp. 29-36 ◽  
Author(s):  
I. Giurca
Keyword(s):  
Heat Loss ◽  
Heating System ◽  
Building Energy ◽  
Local Heat ◽  
Heat Losses ◽  
Energy Audit ◽  
Heating Systems ◽  
Central Heating ◽  
Calculation Methodology

Abstract The article presents aspects related to the calculation of heat loss through the pipes of the interior central heating system. The purpose of the article is to detail the local heat losses in case of central heating systems. Based on the conclusions of the article, we propose the modification of the calculation methodology related to the building energy audit.

scholarly journals Hardware-Simulator Development and Implementation for Hydraulic Turbine Generation Systems in a District Heating System

Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 368 ◽  
Author(s):  
Sung-Soo Jeon ◽  
Young Jae Lee ◽  
Yeongsu Bak ◽  
Kyo-Beum Lee
Keyword(s):  
Control Strategies ◽  
District Heating ◽  
Control Valve ◽  
Electrical Energy ◽  
Heating System ◽  
Hydraulic Turbine ◽  
Pressure Control ◽  
Differential Pressure ◽  
District Heating System ◽  
Pressure Control Valve

This paper presents not only a hardware-simulator development for hydraulic turbine generation systems (HTGS) in a district heating system (DHS) but also its control strategies and sequence. Generally, a DHS uses a differential pressure control valve (DPCV) to supply high-pressure–high-temperature fluids for customers depending on distance. However, long-term exposure of the DPCV to fluids increases the probability of cavitation and leads to heat loss in an event of cavitation. Therefore, a HTGS was introduced to solve this problem. It performs differential pressure control of the fluids, replaces the DPCV, and converts excess energy wasted by the DPCV to electrical energy. In this paper, the development of a hardware-simulator for HTGSs with a back-to-back converter, which uses two-level topologies, is proposed; moreover, control strategies and sequence used in this design are presented. The performance and validity of the proposed hardware-simulator and its control strategies are demonstrated by experimental results.

The Matching Research of Soil Source Heat Pump and Central Heating System in Cold Region

2013 ◽  
Vol 805-806 ◽  
pp. 486-491
Author(s):  
Yue Ren Wang ◽  
Yu Feng Jiang ◽  
Min Yu
Keyword(s):  
Heat Pump ◽  
Heat Load ◽  
Working Condition ◽  
Heating System ◽  
Cold Region ◽  
Pump System ◽  
Heat Pump System ◽  
Heating Systems ◽  
Central Heating ◽  
Practical Engineering

Using Dest software simulation benchmark building the dynamic heat load, analyzing its distribution pattern, at the same timewe can also get heat pump units in the COP value is different under different working condition, then the soil source heat pump and central heating complementary heating system, undertake in soil source heat pump system design heat load, under theconditions of different proportion of the whole system operation energy consumption, initial investment analysis, we conclude thatthe soil source heat pump and central heating complementary heating systems of different energy matching optimization features,this provides a reference for practical engineering.

scholarly journals Quantifying the performance of a passive deaerator in a gas-fired closed loop domestic wet central heating system

2016 ◽  
Vol 38 (3) ◽  
pp. 269-286
Author(s):  
David Johnston ◽  
David Glew ◽  
Dominic Miles-Shenton ◽  
Moaad Benjaber ◽  
Richard Fitton
Keyword(s):  
Energy Use ◽  
Closed Loop ◽  
Energy Savings ◽  
Low Cost ◽  
Heating System ◽  
Test Method ◽  
Heat Output ◽  
Heating Systems ◽  
Central Heating ◽  
The Uk

In the UK, approximately 16% of the energy use can be attributed to domestic wet central heating systems. Government financial support and advances in technology have led to boilers becoming more efficient and a range of technologies are now available that claim to be able to improve the efficiency of domestic wet central heating systems. One such low cost technology is a passive deaerator. This article presents the results obtained from installing a passive deaerator on the closed loop of a gas-fired wet central heating system, under controlled conditions in the Salford Energy House. The results indicate that although marginally less heat output was required from the boiler when the passive deaerator was operating, these savings are more or less out weighted by the boiler short cycling more frequently. Consequently, the overall reduction is gas consumption achieved by utilising the passive deaerator device is only of the order of 0.5%; this scale of savings may just be a consequence of measurement noise. The implications are that although a marginal benefit may be attributed to these products, if short cycling takes place, then these savings may become insignificant. Practical application: This article describes a test method that has been used to quantify the energy savings that could be achieved by installing a passive deaerator on the closed loop of a wet central heating system. Although the results indicate that the energy savings associated with using such a device are likely to be marginal, the test method described could be used to test a range of other devices that claim to improve the performance of domestic wet central heating systems, to directly compare before and after performance.

scholarly journals EVALUATION OF HYDRAULIC CONTROL OF THE CIRCUIT OF INDIVIDUAL SYSTEM OF HEATING

2021 ◽  
Vol 6 (3) ◽  
pp. 27-35
Author(s):  
S. Usikov ◽  
T. Starikova
Keyword(s):  
Mutual Influence ◽  
Professional Community ◽  
Heating System ◽  
Differential Pressure ◽  
Point Of View ◽  
Main Task ◽  
Hydraulic Control ◽  
Heating Systems ◽  
Individual System ◽  
Permissible Range

Modern heating systems are a complex set of equipment and elements, the main task of which is to provide comfortable conditions in the serviced premises, regardless of external deflecting factors. Water heating systems with variable hydraulic mode are the most common type of heating in newly constructed residential and public buildings. The installation of differential pressure regulators in individual heating systems is mandatory from the point of view of ensuring noiseless operation and reducing the mutual influence of regulatory areas. However, the location of their installation is controversial in the professional community. This paper covers the range of hydraulic modes of operation of two variants of the design of individual heating system used in this practice of system design: installation of only floor-by-floor collectors, followed by the connection of internal apartment circuits, or with the installation of additional collectors in each apartment. Formulas for estimating changes in the coolant flow rate during operation with high-quality individual control of the system are proposed. The values of the degree of opening of the regulators in the entire permissible range of operation of the system, the hysteresis and the pressure loss created by the differential pressure regulator are obtained. Conclusions are drawn about the rationality of using the proposed designs of the apartment-by-apartment heating system

scholarly journals Mathematical Analysis of Optimal Operating Conditions in Heating Systems

2019 ◽  
Vol 2019 ◽  
pp. 1-16
Author(s):  
Chan Kong ◽  
Yong Sun ◽  
Hongxi Zhang ◽  
Yongjiang Shi
Keyword(s):  
Water Temperature ◽  
Flow Rate ◽  
Heating System ◽  
Optimal Operation ◽  
Operating Conditions ◽  
Experimental Results ◽  
Optimal Operating ◽  
Heating Systems ◽  
Operation Conditions ◽  
Supply Water

With changes in the outdoor air temperature, the heat consumption of buildings also changes. Timely adjustment of the heating systems to ensure optimal operating conditions is extremely significant to save energy. In this study, the operation conditions of a heating system were analyzed numerically, and the existence, uniqueness, and stability of the optimal operation conditions of the heating system were proved. An operation optimization model that could obtain the optimal operation conditions was also established, and the correctness of the model was verified experimentally. Experimental results showed that when the flow rate was 0.606 m3/h, the supply water temperature was 67.13°C, water return temperature was 65.90°C, and the pump consumed the least amount of electricity. The experimental results and model calculation results showed that the operating cost is lower when the system flow rate is low and the supply water temperature is high under the same heat dissipation and indoor temperature.

scholarly journals Design of direct acting differential pressure control valve test bench

2021 ◽  
Vol 327 ◽  
pp. 04002
Author(s):  
Ognyan Bekriev ◽  
Radoslav Asenov
Keyword(s):  
Test Bench ◽  
District Heating ◽  
Control Valve ◽  
Pressure Control ◽  
Differential Pressure ◽  
Heating Systems ◽  
Control Valves ◽  
District Heating Systems ◽  
Pressure Control Valve ◽  
Direct Acting

This article aims to acquaint readers with a designed test bench for direct acting differential pressure control valves. These control valves are used in district heating systems. The conformity of the construction of the test bench with the international standard IEC 60534-2-3:2015 is evaluate and the results of an experimental study of the control valve AVPB DN20 Kvs 6.3 PN16 are present.

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