MEASURED ENERGY CONSUMPTION ANALYSIS OF A DISTRICT HEATING SYSTEM UNDER DIFFERENT TEMPERATURE CONTROL STRATEGIES

2014 ◽  
Vol 22 (02) ◽  
pp. 1450008 ◽  
Author(s):  
SUNG-HWAN CHO ◽  
SEONG-KI HONG ◽  
SANG-HO CHOI ◽  
M. ZAHEERUDDIN
Keyword(s):  
Energy Consumption ◽  
Energy Savings ◽  
District Heating ◽  
Heating System ◽  
Hot Water ◽  
Control Methods ◽  
Outdoor Temperature ◽  
District Heating System ◽  
Partial Load ◽  
Hot Water Supply

In this study, the secondary side measured energy consumption of a district heating system (DHS) with different hot water supply temperature control methods was compared. Two control methods were evaluated: an outdoor temperature reset control (OTRC) and an outdoor temperature predictive control (OTPC). While the OTRC strategy has been widely used for energy savings in DHS, the results show that the OTPC strategy resulted in higher energy savings. In general, the OTPC strategy maintained lower supply water temperature, and thereby reduced standby losses and increased overall heat transfer rate to the heated spaces due to higher water mass flow rate to the spaces. During the actual energy consumption monitoring, the OTPC strategy saved about 6.6% more energy compared to that of OTRC strategy. Also, it was found that under partial load conditions, such as during the daytime, the fluctuations in hot water supply temperature with OTRC were more severe than OTPC strategy. Overall, the results showed that the OTPC strategy gave better control and was more stable under full load and partial load conditions.

scholarly journals District heating system simulation considering consumer and pump operation features

Vestnik MGSU ◽  
2019 ◽  
pp. 748-755 ◽  
Author(s):  
Saule K. Abildinova ◽  
Stanislav V. Chicherin
Keyword(s):  
Mathematical Model ◽  
Energy Consumption ◽  
District Heating ◽  
Heating System ◽  
Hot Water ◽  
Water Supply Systems ◽  
Problem Solution ◽  
District Heating System ◽  
Pump Station ◽  
Pump Equipment

Introduction. The purpose of this investigation is to show what changes introduced in the mathematical model of a district heating system are capable of considerable improving the convergence of simulation results and actual data. The study evaluates the work of heating supply establishments with their customers as well as analysis of the ways of enhancing pump equipment efficiency that allows saving electric energy or increasing output at the same energy consumption. Materials and methods. Engineering acceptance of newly introduced and reconstructed facilities is conducted, heat loads are corrected, disconnections and recurrent connections of indebted consumers are carried out. Studying data submitted by a local heat supply establishment shows that pump seals made from iron and steel are subject accelerated wear in the course of operation. Results. Three variants of the problem solution are suggested: making seals from bronze or stainless steel, prevention of unjustified increase of seal clearances as well as using labyrinth pump seals. This will allow increasing pump equipment efficiency by 5 to 7 % and save about 2 × 105 kW∙h of electrical energy for every pump or increase of output at the same energy consumption. Taking into account that a pump station is a part of the district heating system and unmachined inner surfaces of the pumps have a significant roughness, grinding of these surfaces can improve their hydraulic characteristics of the pumps. In the scope of the suggested method, the entire district heating system is considered not in the situation when actual load is equal to the sum of all the design loads and the pump equipment has manufacturer’s parameters, but accounting actual loads and characteristics. Conclusions. Mathematical model of district heating system heating and hydraulic mode that takes issues mentioned above into consideration would allow simulating joint operation of the heating and hot water supply systems at transient operation modes with higher accuracy.

A New Type of District Heating System Based on Distributed Absorption Heat Pumps

2009 ◽  
Author(s):  
Lin Fu ◽  
Yan Li
Keyword(s):  
Energy Consumption ◽  
Heat Pump ◽  
District Heating ◽  
Heating System ◽  
Heat Pumps ◽  
Hot Water ◽  
Conventional Heating ◽  
Low Grade ◽  
District Heating System ◽  
New Approach

This paper presents a new approach to utilize geothermal energy with absorption heat pump in district heating system. The heat pump is driven by the temperature-difference between primary and secondary heating loops. In this method, the low-grade thermal energy can be used in district heating system effectively, as a result, the heating capacity and energy efficiency of district heating system can be improved more than 20%. On one hand, it could relieve the existing dilemma (shortage) of central heat source, as well enhance the delivery capacity of heating network dramatically. On the other hand, heating cost may be reduced remarkably, due to the reduction in both coal consumption of central heat and energy consumption of delivery pump. Firstly, this paper introduces the district heating method based on distributed absorption heat pumps through the analysis on the parameter characteristics of low-grade energy, hot water of primary and secondary heating network, as well as the operation parameters of absorption heat pumps. Secondly, an economic and energy consumption analysis was discussed by comparing the new approach with conventional heating system. Finally, this paper presents several system configurations, discusses the operation strategies in various conditions, and proposes the operation modes for heating season.

scholarly journals Energy savings for residential heating in two pairs of buildings achieved by implementation of actually consumed energy measuring

2006 ◽  
Vol 10 (4) ◽  
pp. 79-88
Author(s):  
Branislav Zivkovic ◽  
Maja Todorovic ◽  
Petar Vasiljevic
Keyword(s):  
Energy Consumption ◽  
Energy Savings ◽  
Thermal Characteristics ◽  
District Heating ◽  
Heating System ◽  
Total Energy Consumption ◽  
District Heating System ◽  
Residential Heating ◽  
Heating Energy Consumption ◽  
And Control

The paper presents results of heating energy consumption measurements in two pairs of buildings in community New Belgrade for two heating seasons. Influence of these measurements on energy savings is also presented. The measurements were carried out during heating seasons 2002/03 and 2003/04 in buildings in Block 34 and 63, connected to the district heating system "Beogradske elektrane". The buildings in each pair have similar architectural and thermal characteristics. One of the buildings in a pair was "test" building and the other "control" one. In the "test" building the energy consumption for heating of each apartment was measured, as well as total energy consumption for the whole building in the substation. Occupants were able to regulate the heating system. In the "control" building the energy consumption was measured only for the whole building, and occupants had almost no impact on heating energy consumption. The comparison of energy consumption for heating in the "test" and "control" buildings is given in the paper, as well as analysis of the influence of energy consumption measurements on the achieved energy savings. .

scholarly journals Overview of Solutions for the Low-Temperature Operation of Domestic Hot-Water Systems with a Circulation Loop

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3350
Author(s):  
Theofanis Benakopoulos ◽  
William Vergo ◽  
Michele Tunzi ◽  
Robbe Salenbien ◽  
Svend Svendsen
Keyword(s):  
Low Temperature ◽  
Heat Loss ◽  
District Heating ◽  
Heating System ◽  
Hot Water ◽  
Heating Power ◽  
Circulation Loop ◽  
Space Heating ◽  
District Heating System ◽  
Domestic Hot Water

The operation of typical domestic hot water (DHW) systems with a storage tank and circulation loop, according to the regulations for hygiene and comfort, results in a significant heat demand at high operating temperatures that leads to high return temperatures to the district heating system. This article presents the potential for the low-temperature operation of new DHW solutions based on energy balance calculations and some tests in real buildings. The main results are three recommended solutions depending on combinations of the following three criteria: district heating supply temperature, relative circulation heat loss due to the use of hot water, and the existence of a low-temperature space heating system. The first solution, based on a heating power limitation in DHW tanks, with a safety functionality, may secure the required DHW temperature at all times, resulting in the limited heating power of the tank, extended reheating periods, and a DH return temperature of below 30 °C. The second solution, based on the redirection of the return flow from the DHW system to the low-temperature space heating system, can cool the return temperature to the level of the space heating system return temperature below 35 °C. The third solution, based on the use of a micro-booster heat pump system, can deliver circulation heat loss and result in a low return temperature below 35 °C. These solutions can help in the transition to low-temperature district heating.

scholarly journals Advanced Control of a District Heating System with High Residential Domestic Hot Water Demand

2020 ◽  
Vol 160 ◽  
pp. 01004 ◽  
Author(s):  
Stanislav Chicherin ◽  
Lyazzat Junussova ◽  
Timur Junussov
Keyword(s):  
Energy Demand ◽  
Energy Use ◽  
District Heating ◽  
Heating System ◽  
Primary Energy ◽  
Hot Water ◽  
District Heating System ◽  
Domestic Hot Water ◽  
Extreme Load ◽  
Flow Controller

Proper adjustment of domestic hot water (DHW) load structure can balance energy demand with the supply. Inefficiency in primary energy use prompted Omsk DH company to be a strong proponent of a flow controller at each substation. Here the return temperature is fixed to the lowest possible value and the supply temperature is solved. Thirty-five design scenarios are defined for each load deviation index with equally distributed outdoor temperature ranging from +8 for the start of a heating season towards extreme load at temperature of -26°C. All the calculation results are listed. If a flow controller is installed, the customers might find it suitable to switch to this type of DHW supply. Considering an option with direct hot water extraction as usual and a flow controller installed, the result indicates that the annual heat consumption will be lower once network temperatures during the fall or spring months are higher. The heat load profiles obtained here may be used as input for a simulation of a DH substation, including a heat pump and a tank for thermal energy storage. This design approach offers a quantitative way of sizing temperature levels in each DH system according to the listed methodology and the designer's preference.

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