Wastewater desalination system utilizing a low-temperature heat pump

2017 ◽  
Vol 42 (3) ◽  
pp. 1132-1138 ◽  
Author(s):  
Junling Yang ◽  
Chong Zhang ◽  
Xuejun Lin ◽  
Zhentao Zhang ◽  
Luwei Yang
Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1853 ◽  
Author(s):  
Pavel Neuberger ◽  
Radomír Adamovský

The efficiency of a heat pump energy system is significantly influenced by its low-temperature heat source. This paper presents the results of operational monitoring, analysis and comparison of heat transfer fluid temperatures, outputs and extracted energies at the most widely used low temperature heat sources within 218 days of a heating period. The monitoring involved horizontal ground heat exchangers (HGHEs) of linear and Slinky type, vertical ground heat exchangers (VGHEs) with single and double U-tube exchanger as well as the ambient air. The results of the verification indicated that it was not possible to specify clearly the most advantageous low-temperature heat source that meets the requirements of the efficiency of the heat pump operation. The highest average heat transfer fluid temperatures were achieved at linear HGHE (8.13 ± 4.50 °C) and double U-tube VGHE (8.13 ± 3.12 °C). The highest average specific heat output 59.97 ± 41.80 W/m2 and specific energy extracted from the ground mass 2723.40 ± 1785.58 kJ/m2·day were recorded at single U-tube VGHE. The lowest thermal resistance value of 0.07 K·m2/W, specifying the efficiency of the heat transfer process between the ground mass and the heat transfer fluid, was monitored at linear HGHE. The use of ambient air as a low-temperature heat pump source was considered to be the least advantageous in terms of its temperature parameters.


Author(s):  
Shuichi Umezawa ◽  
Haruo Amari ◽  
Hiroyuki Shimada ◽  
Takashi Matsuhisa ◽  
Ryo Fukushima ◽  
...  

This paper reports application study of newly developed turbo heat pump for 130 degrees Celsius (°C) water for an industrial process in an actual factory. The heat pump is characterized by high efficiency and large heat output, by using a state-of-the-art turbo compressor. The heat pump requires a low temperature heat source in order to achieve high efficiency. The heat demand is for several drying furnaces in the factory, which requires producing hot air of 120 °C. The heat exchanger was designed to produce the hot air. Experiments were conducted to confirm the performance of the heat exchanger under a reduced size of the heat exchanger. Low temperature heat sources are from both exhaust gas of the drying furnaces and that of an annealing furnace. The heat exchangers were also designed to recover heat of the exhaust gas from the two types of furnace. A thermal storage tank was prepared for the low temperature heat source, and for adjusting the time difference between the heat demand and the low temperature heat source. The size of the tank was determined by considering the schedule of furnaces operations. As a result of the present study, it was confirmed that the heat pump was able to satisfy the present heat demand while retaining high efficiency. Primary energy consumption and CO2 emission of the heat pump were calculated on the basis of the present results in order to compare them with those of the boilers.


2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Maarten G. Sourbron ◽  
Nesrin Ozalp

With reducing energy demand and required installed mechanical system power of modern residences, alternate heat pump system configurations with a possible increased economic viability emerge. Against this background, this paper presents a numerically examined energy feasibility study of a solar driven heat pump system for a low energy residence in a moderate climate, where a covered flat plate solar collector served as the sole low temperature heat source. A parametric study on the ambient-to-solarfluid heat transfer coefficient was conducted to determine the required solar collector heat transfer characteristics in this system setup. Moreover, solar collector area and storage tank volume were varied to investigate their impact on the system performance. A new performance indicator “availability” was defined to assess the contribution of the solar collector as low temperature energy source of the heat pump. Results showed that the use of a solar collector as low temperature heat source was feasible if its heat transfer rate (UA-value) was 200 W/K or higher. Achieving this value with a realistic solar collector area (A-value) required an increase of the overall ambient-to-solarfluid heat transfer coefficient (U-value) with a factor 6–8 compared to the base case with heat exchange between covered solar collector and ambient.


2012 ◽  
Vol 170-173 ◽  
pp. 2550-2553 ◽  
Author(s):  
Guang Hui Zhou ◽  
Shi Wei Feng ◽  
Si Qi Cui ◽  
Yin Liu

A heat pump is a kind of energy saving equipment. It can effectively improve the grade of low temperature renewable and waste energy. Because of the increasing demands for higher temperature energy in many industrial processes and other fields, the development and research of high temperature heat pumps have been becoming more and more pressing and significant. This paper briefly summarizes the development status in two aspects: the development of working fluids and system features and characteristics of different cycle types.


2014 ◽  
Vol 535 ◽  
pp. 37-41
Author(s):  
Yang Li ◽  
Xiu Juan Liang

In the cold and severe cold regions of our country, the average temperature in winter outdoor usually below -20°C. Air conditioning units was limited and damaged when it running under such conditions. In order to solve the the problems pointed out previously, the paper put forward solutions of the fresh air handling units in combination with heat pump unit of heat recovery fresh air and heat pipe heat pump low temperature heat recovery unit. Comparison energy-saving and recovery period of the two method through experimental research.


2021 ◽  
Vol 7 ◽  
pp. 266-278
Author(s):  
Shuaiqi Li ◽  
Shihui He ◽  
Wenji Song ◽  
Zipping Feng

2021 ◽  
Vol 327 ◽  
pp. 01015
Author(s):  
Hristov Hristo ◽  
Aleksandrov Svetoslav ◽  
Petrova Todorka ◽  
Ruskova Milena ◽  
Gotcheva Velitchka ◽  
...  

The possibilities for low-temperature heat pump and conventional drying of blueberries during preliminary osmotic dehydration was studied. A full factor experiment of type 22+3 was performed. The kinetics of the process during variation of the main mode parameters: inlet temperature and thickness of the drying layer (load on the scaffolding) was studied. The curves of the drying process U = f (τ) and the curves of the drying speed dU / dτ = f (U) were constructed. The influence of the regime parameters on the drying time was established. Regression models of the drying coefficient during the second period of drying were presented.


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