Research of technological possibilities of heat pumps’ application in district heating of residential buildings
Abstract
The main users of district heating (DH) systems are multi-apartment buildings – 53% of these buildings in Lithuania are supplied with heat from DH systems. Heating systems in buildings are the largest final consumer of energy, accounting for almost half of total energy consumption in many European countries. One of the measures planned for the Lithuanian energy policy in the heat sector of renewable energy sources (RES) until 2030 is the installation of heat pumps (HP) in the DH networks. The purpose of the study is to evaluate the technological possibilities of integrating HP into existing buildings to evaluate the low temperature heat supply. To evaluate the potential temperature lowering of the building heating system, a graph of the lowest possible building heating system temperatures is set, according to which the heat pump for the heating substation is selected, which would raise the temperature of the heat carrier supplied from DH networks to the required temperature for the heating and hot water systems of the building. Applying thermodynamic analysis, a mathematical model is developed that evaluates the ability of the HP to raise the temperature of the supplied heat carrier at the heat substation and determines the energy efficiency of such a solution. During the simulation, two alternatives of constant (regardless of outdoor air temperature) heat carrier temperatures supplied from DH networks were considered: 60 °C (alternative A) and 55 °C (alternative B). To adapt the most appropriate option for the integration of HP, it would be appropriate to combine both alternatives, i. y. to supply 60 °C from the DH network in the cold period of the year and 55 °C in the warm period of the year.
Article in Lithuanian.
Šilumos siurblių taikymo centralizuotai aprūpinant daugiabučius pastatus šiluma technologinių galimybių tyrimas
Santrauka
Pagrindiniai centralizuoto šilumos tiekimo (CŠT) sistemų vartotojai yra daugiabučiai pastatai – 53 procentai šių pastatų Lietuvoje aprūpinama šiluma iš CŠT sistemų. Pastatų šildymo sistemos yra didžiausias galutinis energijos vartotojas, kuris sudaro beveik pusę viso energijos suvartojimo daugelyje Europos šalių. Viena iš planuojamų Lietuvos energetinės politikos priemonių atsinaujinančių energijos išteklių (AEI) šilumos sektoriuje iki 2030 m. yra šilumos siurblių (ŠS) diegimas CŠT tinkluose. Tyrimo tikslas yra įvertinti technologines galimybes esamuose pastatuose integruoti ŠS, siekiant taikyti žemos temperatūros šilumos tiekimą. Siekiant įvertinti pastato šildymo sistemos temperatūrų žeminimo potencialą, nustatomas žemiausių galimų pastato šildymo sistemos temperatūrų grafikas, pagal kurį pastato šilumos punktui parenkamas ŠS, kuris pažemintą iš CŠT sistemų tiekiamą šilumnešio temperatūrą pakeltų iki reikiamos pastato šildymo ir karšto vandens sistemoms temperatūros. Taikant termodinaminę analizę sukurtas matematinis modelis, įvertinantis ŠS galimybes pakelti tiekiamo šilumnešio temperatūrą šilumos punkte ir nustatantis tokio sprendimo energinį efektyvumą. Modeliavimo metu nagrinėtos dvi tiekiamo iš CŠT tinklų pastovių (nepriklausomai nuo lauko oro temperatūros) šilumnešio temperatūrų alternatyvos – 60 °C (alternatyva A) ir 55 °C (alternatyva B). Siekiant pritaikyti tinkamiausią ŠS integravimo variantą, būtų tikslinga derinti abi alternatyvas, t. y. šaltuoju metų laikotarpiu iš CŠT tinklo tiekti 60 °C, o šiltuoju metų laikotarpiu – 55 °C šilumnešį.
Reikšminiai žodžiai: centralizuotas šilumos tiekimas, daugiabutis namas, šilumos siurblys, žemos temperatūros šilumos tiekimas, šilumos nuostoliai tinkle.
Keyword : district heating, apartment building, heat pump, low temperature heat supply, heat loss in the network
This work is licensed under a Creative Commons Attribution 4.0 International License.
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