scholarly journals Study fuzzy variable supplied water temperature control for air-to-water heat pumps connected to a residential floor heating system

Author(s):  
Duhui Jiang ◽  
Hongshe Cui ◽  
Rui Sun ◽  
Wei Lin
Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2851 ◽  
Author(s):  
Kenneth Leerbeck ◽  
Peder Bacher ◽  
Rune Grønborg Junker ◽  
Anna Tveit ◽  
Olivier Corradi ◽  
...  

An optimized heat pump control for building heating was developed for minimizing CO 2 emissions from related electrical power generation. The control is using weather and CO 2 emission forecasts as inputs to a Model Predictive Control (MPC)—a multivariate control algorithm using a dynamic process model, constraints and a cost function to be minimized. In a simulation study, the control was applied using weather and power grid conditions during a full-year period in 2017–2018 for the power bidding zone DK2 (East, Denmark). Two scenarios were studied; one with a family house and one with an office building. The buildings were dimensioned based on standards and building codes/regulations. The main results are measured as the CO 2 emission savings relative to a classical thermostatic control. Note that this only measures the gain achieved using the MPC control, that is, the energy flexibility, not the absolute savings. The results show that around 16% of savings could have been achieved during the period in well-insulated new buildings with floor heating. Further, a sensitivity analysis was carried out to evaluate the effect of various building properties, for example, level of insulation and thermal capacity. Danish building codes from 1977 and forward were used as benchmarks for insulation levels. It was shown that both insulation and thermal mass influence the achievable flexibility savings, especially for floor heating. Buildings that comply with building codes later than 1979 could provide flexibility emission savings of around 10%, while buildings that comply with earlier codes provided savings in the range of 0–5% depending on the heating system and thermal mass.


Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1118 ◽  
Author(s):  
Thomas Kemmler ◽  
Bernd Thomas

Heat pumps in combination with a photovoltaic system are a very promising option for the transformation of the energy system. By using such a system for coupling the electricity and heat sectors, buildings can be heated sustainably and with low greenhouse gas emissions. This paper reveals a method for dimensioning a suitable system of heat pump and photovoltaics (PV) for residential buildings in order to achieve a high level of (photovoltaic) PV self-consumption. This is accomplished by utilizing a thermal energy storage (TES) for shifting the operation of the heat pump to times of high PV power production by an intelligent control algorithm, which yields a high portion of PV power directly utilized by the heat pump. In order to cover the existing set of building infrastructure, 4 reference buildings with different years of construction are introduced for both single- and multi-family residential buildings. By this means, older buildings with radiator heating as well as new buildings with floor heating systems are included. The simulations for evaluating the performance of a heat pump/PV system controlled by the novel algorithm for each type of building were carried out in MATLAB-Simulink® 2017a. The results show that 25.3% up to 41.0% of the buildings’ electricity consumption including the heat pump can be covered directly from the PV-installation per year. Evidently, the characteristics of the heating system significantly influence the results: new buildings with floor heating and low supply temperatures yield a higher level of PV self-consumption due to a higher efficiency of the heat pump compared to buildings with radiator heating and higher supply temperatures. In addition, the effect of adding a battery to the system was studied for two building types. It will be shown that the degree of PV self-consumption increases in case a battery is present. However, due to the high investment costs of batteries, they do not pay off within a reasonable period.


2012 ◽  
Vol 77 (673) ◽  
pp. 175-184
Author(s):  
Kozo TAKASE ◽  
Masayuki MAE ◽  
Yoshihiko AKAMINE ◽  
Ryohei KONO ◽  
Makoto SATOH ◽  
...  

Author(s):  
Ružica Todorović ◽  
◽  
Milan Gojak ◽  
Miloš Banjac ◽  
Nedžad Rudonja

The paper presents an exergy analysis of the groundwater heat pump operation for theneeds of building heat-ing. The analysis was conducted on a monthly basis, given the dependence of exergy on the changing state of the envi-ronment. Changes inheating coefficient and exergy efficiencyof thegeothermal heat pumpheating systemdepending onthe influentialparameters wereanalyzed: groundwater temperature fromthe pumping well, changes in the ground-water temperature on the heat pump evaporatorand water temperature inthe heating system.The obtained results provide insight into thermodynamic indicators of heat pump operation depending on the groundwater temperature and the operation mode of the building heating system. The conducted analysis provides guidelines for the design and opti-mization of heat pumps that work with groundwater as a heat source.


2013 ◽  
Vol 353-356 ◽  
pp. 3114-3119
Author(s):  
Jin Yu ◽  
Jiang Fa Feng

The combination of reflecting cavity and cover layer makes it possible for a reflective radiant floor heating system to be characterized by uniform temperature field and low energy consumption. In this paper, the temperature distribution of a reflecting radiant floor heating system in an experimental chamber was tested under different heating conditions by use of copper constantan thermocouple; the temperature distribution of indoor workspace and floor surface was researched when water temperature was at 30°C, 40°C and 50°C and water flow at 0.24m3/h, 0.34m3/h and 0.44m3/h respectively; the temperature distribution on the surface of floors with three different layout patterns was compared. The results prove that a floor equipped with cover layer has a uniform temperature distribution on its surface. When water temperature is at 40°C, and water flow at 0.34m3/h, indoor workspace temperature remains at 20°C, and floor temperature can be controlled between 23°C and 26°C, satisfying peoples daily need for thermal comfort.


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