scholarly journals Local Heating Networks with Waste Heat Utilization: Low or Medium Temperature Supply?

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 954 ◽  
Author(s):  
Hanne Kauko ◽  
Daniel Rohde ◽  
Armin Hafner
Keyword(s):  
Low Temperature ◽  
Heat Pump ◽  
Urban Areas ◽  
Waste Heat ◽  
Local Heating ◽  
District Heating ◽  
Heat Pumps ◽  
Hot Water ◽  
Local Network ◽  
Medium Temperature

District heating enables an economical use of energy sources that would otherwise be wasted to cover the heating demands of buildings in urban areas. For efficient utilization of local waste heat and renewable heat sources, low distribution temperatures are of crucial importance. This study evaluates a local heating network being planned for a new building area in Trondheim, Norway, with waste heat available from a nearby ice skating rink. Two alternative supply temperature levels have been evaluated with dynamic simulations: low temperature (40 °C), with direct utilization of waste heat and decentralized domestic hot water (DHW) production using heat pumps; and medium temperature (70 °C), applying a centralized heat pump to lift the temperature of the waste heat. The local network will be connected to the primary district heating network to cover the remaining heat demand. The simulation results show that with a medium temperature supply, the peak power demand is up to three times higher than with a low temperature supply. This results from the fact that the centralized heat pump lifts the temperature for the entire network, including space and DHW heating demands. With a low temperature supply, heat pumps are applied only for DHW production, which enables a low and even electricity demand. On the other hand, with a low temperature supply, the district heating demand is high in the wintertime, in particular if the waste heat temperature is low. The choice of a suitable supply temperature level for a local heating network is hence strongly dependent on the temperature of the available waste heat, but also on the costs and emissions related to the production of district heating and electricity in the different seasons.

scholarly journals RELaTED Project: New Developments on Ultra-Low Temperature District Heating Networks

Proceedings ◽  
2020 ◽  
Vol 65 (1) ◽  
pp. 25
Author(s):  
Antonio Garrido Marijuan ◽  
Roberto Garay ◽  
Mikel Lumbreras ◽  
Víctor Sánchez ◽  
Olga Macias ◽  
...  
Keyword(s):  
Low Temperature ◽  
High Performance ◽  
Waste Heat ◽  
District Heating ◽  
Hot Water ◽  
Thermal Systems ◽  
Heating Source ◽  
Wide Range ◽  
Thermal Sources ◽  
Heating Networks

District heating networks deliver around 13% of the heating energy in the EU, being considered as a key element of the progressive decarbonization of Europe. The H2020 REnewable Low TEmperature District project (RELaTED) seeks to contribute to the energy decarbonization of these infrastructures through the development and demonstration of the following concepts: reduction in network temperature down to 50 °C, integration of renewable energies and waste heat sources with a novel substation concept, and improvement on building-integrated solar thermal systems. The coupling of renewable thermal sources with ultra-low temperature district heating (DH) allows for a bidirectional energy flow, using the DH as both thermal storage in periods of production surplus and a back-up heating source during consumption peaks. The ultra-low temperature enables the integration of a wide range of energy sources such as waste heat from industry. Furthermore, RELaTED also develops concepts concerning district heating-connected reversible heat pump systems that allow to reach adequate thermal levels for domestic hot water as well as the use of the network for district cooling with high performance. These developments will be demonstrated in four locations: Estonia, Serbia, Denmark, and Spain.

scholarly journals Recovery and Transport of Industrial Waste Heat for Their Use in Urban District Heating and Cooling Networks Using Absorption Systems

2019 ◽  
Vol 10 (1) ◽  
pp. 291 ◽  
Author(s):  
Antonio Atienza-Márquez ◽  
Joan Carles Bruno ◽  
Alberto Coronas
Keyword(s):  
Low Temperature ◽  
Waste Heat ◽  
District Heating ◽  
Distribution Networks ◽  
Energy Performance ◽  
Hot Water ◽  
Absorption System ◽  
Urban District ◽  
Heating And Cooling ◽  
Water Mass Flow Rate

The use of industrial excess heat in district heating networks is very attractive. The main issue is the transport of the heat from the point of generation to the local distribution network, in a way similar to the structure of electricity transport and distribution networks. Absorption systems have been proposed to transport and distribute waste heat using two absorption stations. In one of them (step-up station), industrial heat at a low temperature is pumped to a higher temperature to facilitate its transport and at the same time increase the temperature difference between the supply and return streams, in this way reducing the hot water mass flow rate circulating through the heat transport network. Heat is then used in a second absorption system (step-down station) to provide heat to a low temperature local district network. In this paper, several absorption system configurations are analyzed for both stations. A detailed thermodynamic analysis of each configuration is performed using selected energy performance indicators to calculate its global performance. The implementation of these kind of systems could enable the use of waste heat to produce heating and cooling for smart communities located a few dozens of kilometers away from industrial sites.

scholarly journals Heat Pump Use in Rural District Heating Networks in Estonia

2021 ◽  
Vol 25 (1) ◽  
pp. 786-802
Author(s):  
Kertu Lepiksaar ◽  
Kiur Kalme ◽  
Andres Siirde ◽  
Anna Volkova
Keyword(s):  
Heat Pump ◽  
Renewable Energy Sources ◽  
District Heating ◽  
Ambient Air ◽  
Heat Pumps ◽  
Hot Water ◽  
Rural District ◽  
Low Grade ◽  
The Impact ◽  
Heating Networks

Abstract District heating has proven to be an efficient way of providing space heating and domestic hot water in populated areas. It has also proven to be an excellent way to integrate various renewable energy sources (RES) into the energy system. In Estonia, biomass covers most of the heat demand, but carbon-intensive fuels are still used to cover peaks and lows. Heat pumps can be a good solution for rural areas, as there is usually plenty of land available for heat pump facilities. In addition, heat pumps require low-grade heat sources such as ambient air, groundwater, lakes, rivers, sea, sewage water, and industrial waste heat. One of the downsides of heat pumps is the need for large investments compared to boilers fired by natural gas and biomass, and electric boilers. This study examines the impact of heat pump use on consumer prices for district heating in rural district heating networks in Estonia.

scholarly journals Steady state behavior of a booster heat pump for hot water supply in ultra-low temperature district heating network

Energy ◽  
2021 ◽  
pp. 121528
Author(s):  
Tingting Zhu ◽  
Torben Ommen ◽  
Wiebke Meesenburg ◽  
Jan Eric Thorsen ◽  
Brian Elmegaard
Keyword(s):  
Steady State ◽  
Low Temperature ◽  
Water Supply ◽  
Heat Pump ◽  
District Heating ◽  
Hot Water ◽  
State Behavior ◽  
Hot Water Supply ◽  
Steady State Behavior

scholarly journals Enhancing Heating Performance of Low-Temperature Air Source Heat Pumps Using Compressor Casing Thermal Storage

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3269 ◽  
Author(s):  
Zhongbao Liu ◽  
Fengfei Lou ◽  
Xin Qi ◽  
Yiyao Shen
Keyword(s):  
Low Temperature ◽  
Heat Pump ◽  
Waste Heat ◽  
Thermal Storage ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Pump System ◽  
Heat Pump System ◽  
Discharge Temperature ◽  
Vapor Injection

Air source heat pumps (ASHPs) are widely recognized as energy-saving and environmentally friendly heating and air-conditioning equipment with broad applications. However, when conventional ASHPs are operated at a low ambient temperature, they suffer from problems such as high discharge temperature and low heating efficiency. To address these problems, this study designed a new type of dual evaporator combined with a compressor casing thermal storage heat pump system (DE-CCTS) on the basis of a low-temperature air source heat pump water heater with enhanced vapor injection (EVI). The proposed DE-CCTS used thermal storage phase change material (PCM), which was filled in the secondary evaporator (the thermal storage heat exchanger), to recover the waste heat of the compressor casing. Unlike that in the original system under different ambient temperatures, the suction temperature increased by 0.1–1 °C, the discharge temperature decreased by 0.1–0.5 °C, and the coefficient of performance (COP) of DE-CCTS increased by 0.85–4.72% under the proposed system. These effects were especially evident at low temperatures.

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 An analysis of effectiveness of air heat pump operation dependent on change of external air temperature

2021 ◽  
Vol 37 ◽  
pp. 24-30
Author(s):  
O. Shapoval ◽  
N.   Chepurna ◽  
M. Kirichenko
Keyword(s):  
Low Temperature ◽  
Water Temperature ◽  
Heat Pump ◽  
Air Temperature ◽  
Heat Carrier ◽  
Heat Pumps ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Outdoor Air ◽  
High Coefficient

Currently, air-to-water heat pumps are more widely used, which due to the high coefficient of performance reduce energy consumption and negative impact on the environment. They decrease the dependency on costs of energy resources. The work is devoted to solving the urgent problem of improving the efficiency of air heat pumps at low temperature of outdoor air in winter. One of the main problems of an air heat pump is the reduction of productivity when the outdoor air temperature decreases in winter. In this paper, the effectiveness of LG Therma V air-to-water heat pump to provide apartments with heating and hot water supply was analyzed. The heat pump is reversive, which can cool or heat a heat carrier. A four-way valve swithes the coolant flows between air exchangers. On the basis of the obtained results, plots of effectivness of the heat pump dependent on outdoor air temperature are built. It is shown that the effectiveness of the heat pump significantly depends not only on the outside temperature but also on the water temperature at the outlet of the heat pump. The use of heat pumps with a high coefficient of performance can significantly reduce energy costs. The most effective are low-temperature heating systems, in which the water temperature does not exceed 45 °C. The example is floor heating, which requires very low temperature of the floor surface – up to 30 °C. At outdoor air temperature not less than milnus 7 °C the heat pump is effective at higher temperature off heat carrier at output – up to 55 °C. To provide the uninterrupted heat supply, an additional air heater is included. It covers heat load during defrosting and very low outdoor air temperature. On the basis of the conducted researches, the directions of the further experimental and field researches are planned.

scholarly journals Dynamic Simulation Model of Trans-Critical Carbon Dioxide Heat Pump Application for Boosting Low Temperature Distribution Networks in Dwellings

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 484 ◽  
Author(s):  
Livio de Santoli ◽  
Gianluigi Lo Basso ◽  
Davide Astiaso Garcia ◽  
Giuseppe Piras ◽  
Giulia Spiridigliozzi
Keyword(s):  
Carbon Dioxide ◽  
Temperature Distribution ◽  
Low Temperature ◽  
Dynamic Simulation ◽  
Heat Pump ◽  
Distribution Networks ◽  
Heat Pumps ◽  
Hot Water ◽  
Small Scale ◽  
Critical Carbon Dioxide

This research investigates the role of new hybrid energy system applications for developing a new plant refurbishment strategy to deploy small scale smart energy systems. This work deals with a dynamic simulation of trans-critical carbon dioxide heat pump application for boosting low temperature distribution networks to share heat for dwellings. Heat pumps provide high temperature heat to use the traditional emission systems. The new plant layout consists of an air source heat pump, four trans-critical carbon dioxide heat pumps (CO2-HPs), photovoltaic arrays, and a combined heat and power (CHP) for both domestic hot water production and electricity to partially drive the heat pumps. Furthermore, electric storage devices adoption has been evaluated. That layout has been compared to the traditional one based on separated generation systems using several energy performance indicators. Additionally, a sensitivity analysis on the primary energy saving, primary fossil energy consumptions, renewable energy fraction and renewable heat, with changes in building power to heat ratios, has been carried out. Obtained results highlighted that using the hybrid system with storage device it is possible to get a saving of 50% approximately. Consequently, CO2-HPs and hybrid systems adoption could be a viable option to achieve Near Zero Energy Building (NZEB) qualification.

DETERMINING THE PROFITABILITY OF GREENHOUSE ELECTROTECHNOLOGIES: A MODELING APPROACH

HortScience ◽  
1994 ◽  
Vol 29 (4) ◽  
pp. 249a-249
Author(s):  
Eric A. Lavoie ◽  
Damien de Halleux ◽  
André Gosselin ◽  
Jean-Claude Dufour
Keyword(s):  
Energy Consumption ◽  
Heat Pump ◽  
Water System ◽  
Heat Pumps ◽  
Hot Water ◽  
Pump System ◽  
Heat Pump System ◽  
Artificial Lighting ◽  
Hot Air ◽  
Marketable Fruit

The main objective of this research was to produce a simulated model that permitted the evaluation of operating costs of commercial greenhouse tomato growers with respect to heating methods (hot air, hot water, radiant and heat pumps) and the use of artificial lighting for 1991 and 1992. This research showed that the main factors that negatively influence profitability were energy consumption during cold periods and the price of tomatoes during the summer season. The conventional hot water system consumed less energy than the heat pump system and produced marketable fruit yields similar to those from the heat pump system. The hot water system was generally more profitable in regards to energy consumption and productivity. Moreover, investment costs were less; therefore, this system gives best overall financial savings. As for radiant and hot air systems, their overall financial status falls between that of the hot water system and the heat pump. The radiant system proved to be more energy efficient that the hot air system, but the latter produced a higher marketable fruit yield over the 2-year study.

Sign in / Sign up

Export Citation Format

Share Document