scholarly journals Utilization of res using seawater source heat pump with and without energy storage: Comparison of Thermal and Battery Energy Storage

2020 ◽  
Vol 24 (6 Part A) ◽  
pp. 3589-3600
Author(s):  
Anamarija Falkoni ◽  
Vladimir Soldo ◽  
Goran Krajacic ◽  
Matko Bupic ◽  
Iva Bertovic

Heat and cooling stands out with the great potential in decarbonisation since they have a large share in the final energy consumption. Power-to-heat technologies may contribute to the heat sector decarbonisation as well as the integration of renewables if they are sufficiently flexible. They are also shown to have a good effect on the system costs. This work will analyse the potential of seawater heat pump system for the utilization of high share of electricity production from the renewables. The Old City of Dubrovnik is selected as a case study because of its specific situation. A large number of the outdoor units are not well approved by UNESCO since the Old City is under the protection of the UNESCO World Heritage Centre. The results of the study showed that the combination of wind and solar electricity production can cover 67% of load for stand-alone seawater heat pump system based on hourly time step. Utilization of renewable electricity generation, for this case, resulted in 433.71 tCO2/y emission reduction. System based on 10 minutes time step gave poorer results by 6%. System with the additional energy storage gained best results in the case of combined wind and solar electricity generation, as well. It resulted in storage capacity reduction by 78% ac-cording to the case of solar electricity generation and by 60% according to the wind electricity generation. Battery energy storage resulted in 40 times lower volume and 13 times higher investment costs and levelised cost of heat in comparison to the thermal energy storage.

Author(s):  
Haifei Chen ◽  
Guiqiang Li ◽  
Yueyue Ling ◽  
Jie Fu ◽  
Yunjie Wang ◽  
...  

2017 ◽  
Vol 205 ◽  
pp. 4090-4097 ◽  
Author(s):  
Zhang Yin ◽  
Long Enshen ◽  
Zhao Xinhui ◽  
Jin Zhenghao ◽  
Liu Qinjian ◽  
...  

Author(s):  
Pawel Olszewski

The aim of the research was an optimization of long-term heat storage with seasonal regeneration. Energy consumption for central heating during wintertime, transfererred from ground energy storage using a heat exchange device, is the operating principle of such systems. Warmed working fluid is then used in a heat pump system. However, more accurate calculations showed that over time of usage, there is a trend toward cooling at deeper round layers. Such a situation leads to a lowering of ground potential when using heat pump systems. A possible solution to this problem is the application of summer regeneration: during summer months, the working fluid is firstly warmed in solar collectors, and then forced into the same boreholes. The numerical model of a vertical, ground heat exchange device (configured as a "pipe in pipe", known as a Fields' pipe) was specially developed. Temperature distribution of the working fluid along the pipe was one of the boundary conditions, for the co-axial, time-variable, heat conduction task, which described the heat flow in energy storage. The numerical simulation of solar collectors work was based on the Hottel - Whillier - Bliss equation, in which energy flow from the solar collector is calculated, dependant on external parameters such as: insulation or ambience temperature. The combination of three computational parts- the ground heat exchange device, energy storage area and solar collectors battery- allows the target function to be defined for task optimization. The subject of optimization was an energy quantity, which can be taken from energy underground storage, and then utilized by the heat pump system. In the summarized paper, a combination of the input data, which influenced the efficiency of energy storage, was chosen. Hypothetical data were: outside diameter and length of heat exchange device, distance between pipes, fluid flow through the pipe during charge and discharge processes or temperature of inlet working fluid. The influence of individual parameters on the target function, holding all input data constant, was analyzed. A developed evolutionary numerical code known as GENOCOP I (GEnetic algorithm for Numerical Optimization for COnstrained Problems) [3] was used for optimization. After preliminary correction of boundary values of the input data, nine attempts of optimization were taken up. The research results identified optimal values of input parameters for which maximum energy could be taken from ground storage.


2011 ◽  
Vol 354-355 ◽  
pp. 798-801
Author(s):  
Qin Tao Zhou ◽  
Hua Dong ◽  
En Ze Zhou ◽  
Wei Yi

This study presents a simulation approach to assess the viability of solar assisted ground source heat pump system in different regions of China. A short time step model of ground loop exchanger is employed in the simulation with a 30% solar fraction. Weather data files used in the simulation are created based on Chinese Typical Year Weather (CTYW) data. Borehole length is optimized with a safety stop temperature of 0°C. The minimum Entering Fluid Temperature (EFT) decreases 1.3°C after 20-year simulation time and the team effect of ground loop exchangers is weaken as a result of spontaneous recovery of storage temperature. Borehole length replaced by area of solar collector ranges from 3.9m to 2.5m in the six cities. The results show that the annual performance of ground loop exchanger is low in heating-dominated regions and a solar assisted ground source heat pump (SAGSHP) system is needed in order to improve the system performance.


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