Energy Saving Analysis on Solar Capillary Radiation Heating System

2013 ◽  
Vol 448-453 ◽  
pp. 2807-2814 ◽  
Author(s):  
Jin Shun Wu ◽  
Song Pan ◽  
Jun Wei ◽  
Hong Wei Liu ◽  
Yi Xuan Wei ◽  
...  

Radiation capillary used as air conditioning terminal lower the demand of heating water temperature. In additional, solar collectors could also supply amount of low grade energy for heating. Meanwhile, solar is a kind of renewable, sustainable and environment friendly energy. It will save a massive of conventional energy if make full use of solar for heating. In this paper, an experimental system made of solar collector, capillary network and pump was built up and tested. According to thermal load of experimental room, both solar collector area and capillary network area are calculated, and circulating water temperature was analyzed in detail. A summary is given about characteristics of heat storage and release of solar collector, indoor air temperature varying and amount of energy saving. The key factors affect efficiency of collector includes water volume, water temperature in tanker and indoor air temperature. The results show that the solar system can well meet the heating demand and the effect of energy saving is very significant compared to common heating system.

2014 ◽  
Vol 672-674 ◽  
pp. 21-25
Author(s):  
Liang Zhang ◽  
Peng Xu ◽  
Jia Chen Mao ◽  
Xu Tang

A seasonal solar soil heat storage (SSSHS) system applied in greenhouse heating has been designed and introduced. The system consists of solar collector subsystem, soil heat storage subsystem, greenhouse heating subsystem, hydronic subsystem and control subsystem. By applying soil heat storage, solar energy stored in the soil under the greenhouse can be transferred and utilized in winter to realize the utilization of cross-seasonal energy. TRNSYS is used to simulate the process and effect in the system of the solar energy collection and soil heat storage in Shanghai, and the simulation is calibrated to improve the precision of the TRNSYS model. When the indoor air temperature of the greenhouse is kept at 12°C throughout the year, the energy saving by using the SSSHS system in Shanghai can be 46.2kWh/(m2∙year).


Fluids ◽  
2021 ◽  
Vol 6 (8) ◽  
pp. 275
Author(s):  
Ahmed J. Hamad

One essential utilization of phase change materials as energy storage materials is energy saving and temperature control in air conditioning and indirect solar air drying systems. This study presents an experimental investigation evaluating the characteristics and energy savings of multiple phase change materials subjected to internal flow in an air heating system during charging and discharging cycles. The experimental tests were conducted using a test rig consisting of two main parts, an air supply duct and a room model equipped with phase change materials (PCMs) placed in rectangular aluminum panels. Analysis of the results was based on three test cases: PCM1 (Paraffin wax) placed in the air duct was used alone in the first case; PCM2 (RT–42) placed in the room model was used alone in the second case; and in the third case, the two PCMs (PCM1 and PCM2) were used at the same time. The results revealed a significant improvement in the energy savings and room model temperature control for the air heating system incorporated with multiple PCMs compared with that of a single PCM. Complete melting during the charging cycle occurred at temperatures in the range of 57–60 °C for PCM1 and 38–43 °C for PCM2, respectively, thereby validating the reported PCMs’ melting–solidification results. Multiple PCMs maintained the room air temperature at the desired range of 35–45.2 °C in the air heating applications by minimizing the air temperature fluctuations. The augmentation in discharging time and improvement in the room model temperature using multiple PCMs were about 28.4% higher than those without the use of PCMs. The total energy saving using two PCMs was higher by about 29.5% and 46.7% compared with the use of PCM1 and PCM2, respectively. It can be concluded that multiple PCMs have revealed higher energy savings and thermal stability for the air heating system considered in the current study.


2019 ◽  
Vol 111 ◽  
pp. 06045
Author(s):  
Mizuki Niimura ◽  
U Yanagi

Subterranean temperature at a depth of 10 m is almost equal to the average outdoor air temperature of the same area. Therefore, if a building cooling trench is used as an outdoor air duct, outdoor air can be cooled in summer and warmed in winter. This energy-saving technique is often used in Japan. However, since the relative humidity in a cooling trench is high, microbe numbers tend to increase in summer. The present study sought to characterize the microbiome status in the cooling trench of such an office building in Japan. Specifically, we performed a metagenomic analysis in which we analyzed DNA directly upon collection from the environment, without intervening cultivation. The results showed the presence of bacteria of the genera Pseudomonas, Lactobacillus, Nesterenkonia, Staphylococcus, Deinococcus, Acinetobacter, Enhydorobacter, and Corynebacterium. Bacteria of the genera Nesterenkonia, Deinococcus, Enhydorobacter, and Corynebacterium predominated on the surface of the trench. Notably, bacteria of the genus Nesterenkonia constituted >50% of the organisms on the surface of the downstream end of the cooling trench. Principal coordinate analysis was used to compare bacterial inhabitants of outdoor air, indoor air from 2nd- and 3rdfloor offices, and the region downstream of the cooling trench. The results suggested that the microbiome of air in this cooling trench influenced indoor air within the building.


Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1863
Author(s):  
Tommy Rosén ◽  
Louise Ödlund

The traditional way of managing the supply and return water temperatures in a district heating system (DHS) is by controlling the supply water temperature. The return water temperature then becomes a passive result that reflects the overall energy efficiency of the DHS. A DHS with many poorly functioning district heating centrals will create a high return water temperature, and the energy efficiency of the DHS will be affected negatively in several ways (e.g., lower efficiency of the flue gas condenser, higher heat losses in pipes, and lower electricity production for a DHS with combined heat and power (CHP)). With a strategic introduction of low-grade heat customers, the return water temperature can be lowered and, to some extent, controlled. With the heat customers connected in parallel, which is the traditional setup, return water temperatures can only be lowered at the same rate as the heat customers are improved. The active management of some customers can lower the return water temperatures faster and, in the long run, lead to better controlled return water temperatures. Active management is defined here as an adjustment of a domestic heating system in order to improve DHS efficiency without affecting the heating service for the individual building. The opposite can be described as passive management, where heat customers are connected to the DHS in a standardized manner, without taking the overall DHS efficiency into consideration. The case study in this article shows possible efficiency gains for the examined DHS at around 7%. Looking at fuel use, there is a large reduction for oil, with 10–30% reduction depending on the case in question, while the reduction is shown to be largest for the case with the lowest return water temperature. The results also show that efficiency gains will increase electricity production by about 1–3%, and that greenhouse gas (GHG) emissions are reduced by 4–20%.


2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Yu Qihui ◽  
Hao Xueqing ◽  
Tan Xin

Using solar energy for space heating is an efficient and simply way to satisfy the energy demands of buildings. In this study, a typical office building is selected as a case model to obtain indoor air temperature characteristics with dual heat storage devices. By analyzing our solar heating system, a mathematical model of the system working process is set up. Using the software matlab/simulink for simulation, the indoor air temperature characteristics in 1 day are obtained. Simulation and experimental results show good consistency. And using the mathematical model, the storage tank size is optimized to search for the minimum size for the fixed building. Based on our analysis, the optimum ratio of storage tank A volume and collector field area is 0.11 m. This research can be a good reference for the design of the solar heating system.


2018 ◽  
Vol 22 (1 Part B) ◽  
pp. 613-621 ◽  
Author(s):  
Jian Sun ◽  
Jing Hua ◽  
Lin Fu ◽  
Shigang Zhang

Decreasing the backwater temperature of the primary pipe in a centralized heating system is one successful way to increase the heating capacity and recover different kinds of industrial low-grade heat from the system. A new system combining an energy storage tank and a heat pump is introduced in this study as the key device in this system, so the temperature difference of this thermal storage tank could be over 25?C. To improve the thermal energy storage tank design, a mathematical model considering disturbance factor is given, an experimental system is built, and good agreement is found when the experimental results are compared with simulation results.


Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 828 ◽  
Author(s):  
Sanghoon Baek ◽  
Sangchul Kim

A phase change material (PCM) is an energy storage mass with high heat storage performance. In buildings, PCMs can be utilized to save energy in radiant floor heating systems. This study aims to analyze the thermal performance and energy saving potential by the PCM radiant floor heating system based on wet construction method and hot water. For such analysis, EnergyPlus program was used. As for the results, it was found that the proposed system almost maintained the set point of indoor air and a floor surface. Moreover, when a 10 mm PCM was applied, it was possible to save 2.4% of heating energy annually compared to existing buildings. In particular, when a 20–50 mm PCM was applied, it was found that 7.3–15.3% of heating energy was reduced annually. If indoor air temperature exceeds the comfort range of the proposed system, this problem can be solved by adjusting the set point of the floor surface or by increasing the temperature of hot water.


2014 ◽  
Vol 564 ◽  
pp. 204-209 ◽  
Author(s):  
Ahmet Ozsoy ◽  
Sabahattin Demirer ◽  
Nor Maria Adam

Domestic hot water preparation systems with flat plate solar collectors are widely used in Turkey. In this collector, the temperature difference between the required water temperature and the ambient air temperature increase causes a decrease in the efficiency of the collector. In this study, the use of double glass in order to increase the efficiency of the collector is studied experimentally.The location is in Isparta South West Turkey. Experimental study is conducted in May 2013 at the Suleyman Demirel University, Isparta. The system components are solar simulator, solar collector, tank, circulation pump, flowmeter, thermocouples, data acquisition device and solar sensor. Solar collector system’s operating temperature is 50oC for winter also summer. The difference between the collector temperature and the ambient air temperature exceeds 25oC in many cases, were found to be more efficient double-glazed collectors. When the temperature difference is 40oC, using double glazing collector is 24% more efficient than using single glazing collector.


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