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Potential of thermal energy accumulation in distric heating systems networks

Derii V.O., PhD (Engin.)
Institute of General Energy of the National Academy of Sciences of Ukraine, 172 Antonovycha St., Kyiv, 03680, Ukraine
Language: English
Source: The Problems of General Energy, 2014, 4(39):29-33
Section: Forecasting, systems analysis, and optimization of the structural development of the energy sector
UDC: 621.643.053
Received: 30.10.2014
Published: 27.11.2014

Abstract:

When using the electrothermal consumers-controllers (ETCC) in distric heating (DH) systems for frequency control, and for active power it is important to know their power during the heating and non-heating seasons and dependency of such power on the ambient temperature. Currently these issues are not studied completely that can be an obstacle to mass adoption of ETCC in DH systems.
Total capacity of standard heat generators and ETCC transferred to the networks is distributed as follows: one part of it is designed to compensate the losses, the second part – to compensate heat load of consumers, and the third part causes the heat energy accumulation, which circulates in the networks.
The conducted studies have shown that during the heating season the value of accumulated heat in the networks is directly proportional to the ambient air temperature. This dependency is expressed by a piecewise linear function. When ambient air temperature is smaller than calculated one, accumulation in heat networks is impossible. This can be explained by the fact that the parameters of the heat carrier reached the maximum permissible values for safety operation of the network, all energy in the network compensates the heat load and losses. When increasing ambient air temperature, the accumulation potential increases reaching a maximum value at the culminating point of the temperature chart.
During non-heating season the only load of DH system is hot water. Heat carrier consumption is 2-3 times smaller than during the heating season. Heat energy accumulation time in the networks coincides with time of minimum hot water distribution. In order to be within the maximum heat carrier temperature in the return pipeline, heat energy can be accumulated at the expanse of increasing the heat carrier consumption at constant temperature in the supply pipeline. The value of accumulated heat energy will be much lower than during the heating season.

Keywords: heating networks, accumulation, heat load, temperature chart, heating power, heat carrier consumption, heat carrier temperature, potential.

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