scholarly journals Feasibility study of a water-to-air heat pipe based heat exchanger for cooling load reduction and energy saving in the office buildings: A simulation study

2017 ◽  
Vol 24 (3) ◽  
pp. 1040-1050 ◽  
Author(s):  
M. Ahmadzadehtalatapeh
2012 ◽  
Vol 38 (1) ◽  
pp. 188-194 ◽  
Author(s):  
Nammont Chotivisarut ◽  
Atipoang Nuntaphan ◽  
Tanongkiat Kiatsiriroat

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 393 ◽  
Author(s):  
Heran Jing ◽  
Zhenhua Quan ◽  
Yaohua Zhao ◽  
Lincheng Wang ◽  
Ruyang Ren ◽  
...  

According to the temperature regulations and high energy consumption of air conditioning (AC) system in data centers (DCs), natural cold energy becomes the focus of energy saving in data center in winter and transition season. A new type of air–water heat exchanger (AWHE) for the indoor side of DCs was designed to use natural cold energy in order to reduce the power consumption of AC. The AWHE applied micro-heat pipe arrays (MHPAs) with serrated fins on its surface to enhance heat transfer. The performance of MHPA-AWHE for different inlet water temperatures, water and air flow rates was investigated, respectively. The results showed that the maximum efficiency of the heat exchanger was 81.4% by using the effectiveness number of transfer units (ε-NTU) method. When the max air flow rate was 3000 m3/h and the water inlet temperature was 5 °C, the maximum heat transfer rate was 9.29 kW. The maximum pressure drop of the air side and water side were 339.8 Pa and 8.86 kPa, respectively. The comprehensive evaluation index j/f1/2 of the MHPA-AWHE increased by 10.8% compared to the plate–fin heat exchanger with louvered fins. The energy saving characteristics of an example DCs in Beijing was analyzed, and when the air flow rate was 2500 m3/h and the number of MHPA-AWHE modules was five, the minimum payback period of the MHPA-AWHE system was 2.3 years, which was the shortest and the most economical recorded. The maximum comprehensive energy efficiency ratio (EER) of the system after the transformation was 21.8, the electric power reduced by 28.3% compared to the system before the transformation, and the control strategy was carried out. The comprehensive performance provides a reference for MHPA-AWHE application in data centers.


2013 ◽  
Vol 446-447 ◽  
pp. 1498-1501 ◽  
Author(s):  
Zhen Dong Liu ◽  
Fang Wang ◽  
Yong Li Chen ◽  
Huo Wu ◽  
Chen Lu ◽  
...  

This paper proposed an energy-saving system which combination solar collectors for heating water system with heat pipe heat exchanger to recover kitchen waste heat. Its working principle is using heat pipe exchangers exhaust heat to warm the cold water from water storage tank, and during the day, take advantage of solar collectors to help heat pipe heat exchanger heating the water. In this design, the heat exchanger tank and the heat storage tank arranged independently, water tank associated control system was provided with automatic temperature regulator to control the opening and stopping of the pump. This system made full use of kitchen waste heat and solar to meet the kitchen cooking and cleaning process hot water supply needs.


2021 ◽  
Vol 11 (12) ◽  
pp. 5636
Author(s):  
Xingbo Yao ◽  
Shuo Han ◽  
Bart Julien Dewancker

China’s rural houses are mostly courtyard-style independent houses. Such houses have certain characteristics, e.g., small mutual influences between houses, strong transformation flexibility, and an easier approach to using the natural environment to develop passive energy-saving characteristics. Therefore, rural houses have large energy-saving potential. In this study, for the first time, the cold alleys between buildings were used as an energy source for passive cooling and ventilation. Traditional houses in Shuhe, China, were used as a case study. The cold alleys in the settlements were used to compensate for the natural conditions in summer, and the cold air in the cold alley was introduced into each room using hot-press ventilation and by employing an accumulation effect from a corresponding patio. The room was ventilated and cooled, and air ducts were used to connect the rooms on both sides of the patio to improve the cooling efficiency. The research variables included the existence or non-existence of wall heat radiation (WHR), and the importance and influence of the WHR on the indoor conditions were verified. The cold air trapped in the new system formed an air partition wall, effectively blocking the direct influence of solar radiation on the room, reducing the heat transfer rate of the residential wall, and consuming part of the heat. In winter, based on using air ducts as supporting members, a glass roof was added to the patio, which improved the heat storage capacity of the patio and turned it into a constant-temperature heater for heating the building interior. Based on calculations, in the new system without WHR, the annual cooling load reduction was 55,417.33 kWh. With WHR, the annual cooling load reduction was 28,537.57 kWh. The annual cooling load of the air insulation wall of the new system was reduced to 1133.7 kWh. In winter, using the glass roof to increase the heat storage capacity of the patio reduced the heating load to 54,537.78 kWh.


2009 ◽  
Vol 33 (12) ◽  
pp. 1089-1098 ◽  
Author(s):  
Nammont Chotivisarut ◽  
Tanongkiat Kiatsiriroat

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