New model for onsite heat loss state estimation of general district heating network with hourly measurements

2018 ◽  
Vol 157 ◽  
pp. 71-85 ◽  
Author(s):  
Hai Wang ◽  
Hua Meng ◽  
Tong Zhu
Keyword(s):  
State Estimation ◽  
Heat Loss ◽  
District Heating ◽  
New Model

State estimation models of district heating networks for integrated energy system considering incomplete measurements

2021 ◽  
Vol 282 ◽  
pp. 116105
Author(s):  
Suhan Zhang ◽  
Wei Gu ◽  
Haifeng Qiu ◽  
Shuai Yao ◽  
Guangsheng Pan ◽  
...  
Keyword(s):  
State Estimation ◽  
District Heating ◽  
Energy System ◽  
Integrated Energy System ◽  
Heating Networks ◽  
Estimation Models

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 The influence of heat loss from pipes in an unheated basement on the heating energy consumption of an entire typical apartment building

2020 ◽  
Vol 172 ◽  
pp. 12005
Author(s):  
Anti Hamburg ◽  
Targo Kalamees
Keyword(s):  
Energy Balance ◽  
Heat Loss ◽  
District Heating ◽  
Building Energy ◽  
Energy Performance ◽  
Heat Losses ◽  
Hot Water ◽  
Limited Information ◽  
Apartment Building ◽  
Heating Energy Consumption

The majority of old apartment buildings were designed with an unheated basement. Building service systems such as district heating heat exchangers and pipes for domestic hot water and for space heating are usually located in this unheated basement. In addition, these locations are connected with shafts. All these pipe’s heat losses increase air temperature in the basement. If these losses are included into the building energy balance, then they decrease heat loss through the basement ceiling. The basement’s heat balance is also dependent on heat loss from the basement envelope and outdoor air exchange in the basement. In early stages of design, designers and energy auditors need rough models to make decisions in limited information conditions. Once the effects of heat losses from pipes become apparent, they need to be factored into the buildings energy balance, and their effects on heat loss through the basement ceiling needs to be calculated. In this paper we analyse the effect these heat losses have on the service system’s heat gains and heat loss through an uninsulated basement ceiling at different basement insulation levels and with different thicknesses of pipe insulation. From our study we found that pipe losses in the basement increase the building energy performance value by at least 4 kWh/(m²∙a) and their impact on a renovated apartment building is very important.

scholarly journals Method for Assessing Heat Loss in A District Heating Network with A Focus on the State of Insulation and Actual Demand for Useful Energy

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4505 ◽  
Author(s):  
Stanislav Chicherin ◽  
Vladislav Mašatin ◽  
Andres Siirde ◽  
Anna Volkova
Keyword(s):  
Heat Loss ◽  
Internal Heat ◽  
District Heating ◽  
The State ◽  
Estimation Methods ◽  
Fourth Generation ◽  
Pricing Rules ◽  
Smart Energy Systems ◽  
Data Driven Approach ◽  
The Difference

The goal of this paper was to evaluate heat loss and the demand of district heating (DH) in the context of the fourth generation DH concept using a data-driven approach. The heat loss profile was calculated with GIS Zulu© (software (8.0.0.7539, Politerm, LLC, St.Petersburg, Russia) using eight various states of insulation, detailed information on thermal conductivity, internal heat transfer coefficient, and geometry of the concrete trench. There is a strong correlation between the heat sold and the average annual outdoor temperatures. The outstanding episodes are extremely rare, and the difference in the overall pattern is elusive. The results of the annual heat production and annual heat loss analyses were compared using three different estimation methods. The new method was the only one that showed a positive effect after the complete modernization of thermal insulation. The actual proportion of heat loss is much higher at 16%, while the actual heat delivery is less than anticipated at 85–86% only. The trend of the normative approach is correct but cannot determine changes in network heat loss due to aging. The method focuses on the effects of the state of insulation and actual supply temperature levels. The transition to smart energy systems includes strategic and progressive energy planning, as well as new pricing rules and tariffs. Thus, the method presented is the first step in the transition towards the fourth generation DH networks.

scholarly journals COMPARISON REFURBISHMENT MODELS OF DISTRICT HEATING NETWORKS

2013 ◽  
Vol 20 (1) ◽  
pp. 11-20 ◽  
Author(s):  
Algirdas Kuprys ◽  
Ramūnas Gatautis
Keyword(s):  
Heat Loss ◽  
Residential Buildings ◽  
Functional Dependence ◽  
Harmful Effect ◽  
District Heating ◽  
Residential Building ◽  
Distribution Networks ◽  
Computer Data ◽  
Heat Demand ◽  
The Cost

The renovation of multi-storey residential buildings reduces heat consumption intensity and decreases heat demand, which may have a harmful effect on a district heating supply system. The paper analyses the heat loss change in four district heating distribution networks (DHNs) of Kaunas at the various scenarios of buildings and DHN renovation stages. A bundle of genetic algorithm software package was used to carry out the districts’ distribution network hydraulic calculations in the case of building renovation without changing the hydrodynamic and network routes. The experimental data were used to calculate heat loss for old and new pipes. The computer data of networks used to summarise the cost of DHN then for the renovation of buildings as well as for renovation progress will go evenly with DHN refurbishment. Network optimization results were summarised by functional dependence. The comparison of the projects’ efficiency was analysed in the following cases: the diameters of pipes of DHN were not changed, new diameters of pipes were integrated partly after partial residential buildings renovation and after a complete renovation of residential building and optimisation of pipeline diameters. The efficiency of separate guidelines of the DHN refurbishment project was summarised by performing sensitivity analysis.

A new type of two-supply, one-return, triple pipe-structured heat loss model based on a low temperature district heating system

Energy ◽  
2021 ◽  
Vol 218 ◽  
pp. 119569
Author(s):  
Qian Xu ◽  
Kang Wang ◽  
Zhenwei Zou ◽  
Liqiong Zhong ◽  
Nevzat Akkurt ◽  
...  
Keyword(s):  
Low Temperature ◽  
Heat Loss ◽  
District Heating ◽  
Heating System ◽  
District Heating System ◽  
Loss Model ◽  
Model Based ◽  
New Type

scholarly journals Evaluation Factor for District Heating Network Heat Loss with Respect to Network Geometry

2016 ◽  
Vol 95 ◽  
pp. 279-285 ◽  
Author(s):  
Vladislav Masatin ◽  
Eduard Latõšev ◽  
Anna Volkova
Keyword(s):  
Heat Loss ◽  
District Heating ◽  
Network Geometry

scholarly journals HEAT MODES OF THE HEATING NETWORK IN WARMING BUILDINGS

2020 ◽  
Vol 1 (154) ◽  
pp. 159-164
Author(s):  
A. Aleksahin ◽  
A. Boblovskey ◽  
К. Zhariy ◽  
J. Sidorenko ◽  
М. Skorik
Keyword(s):  
Energy Saving ◽  
Heat Loss ◽  
Heat Supply ◽  
District Heating ◽  
Heating System ◽  
Heat Losses ◽  
Transfer Resistance ◽  
Maximum Heat ◽  
Heating Systems ◽  
Network Water

The results of calculations of heat losses by network pipelines for heating of idealized groups of buildings during insulation of structures are presented in the work. Formulas for estimation of heat loss reduction by heat conduits are proposed depending on the efficiency of energy saving measures for construction and the law of change of network water costs along the length of the heat conduit, which is determined by the network configuration. The purpose of this work is to evaluate the influence of the hydraulic characteristics of the branches of the heating network on the magnitude of heat losses during transportation of the coolant by pipelines of the distribution network to buildings. Idealized groups of buildings with the same number of objects and the same maximum heat consumption for heating of a separate building are considered. For district heating systems, the efficiency of implementing energy-saving measures for buildings is determined not only by the reduction of heating costs, but also by the change in operating costs for the microdistrict heating network, which is caused by the reduction of heat carrier costs and heat losses by heating system pipelines. The magnitude of the heat loss depends on the method of laying the networks, the parameters of the pipeline insulation, the temperature of the coolant, and the environment. In the case of selective insulation of the buildings of the selected group of buildings, the location of the insulated building is significantly influenced by the amount of heat losses by the pipelines. In case of centralized heat supply, a fragment of the construction load decrease due to the insulation of buildings and the reduction of the network water temperature in the space heating devices causes the reduction of heat losses by the pipelines of the distribution thermal networks. The magnitude of the reduction of heat losses by heat pipelines is determined by the degree of efficiency of insulation of buildings, the nature of changes in the cost of the coolant along the length of the branch of the thermal network and practically does not depend on the magnitude of the heating load of buildings. Keywords: centralized heat supply, centralized heating systems, energy saving, heat transfer resistance, enclosing structures, coefficient of efficiency of building insulation, distribution thermal networks, heat loss by pipelines.

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