scholarly journals Perspective Performance Evaluation Technique for a Cascade Heat Pump Plant Functions at Low Temperature Heat Source

2017 ◽  
Vol 2 (2) ◽  
pp. 13 ◽  
Author(s):  
Ali H. Tarrad
Keyword(s):  
Performance Evaluation ◽  
Low Temperature ◽  
Heat Source ◽  
Heat Pump ◽  
Evaluation Technique ◽  
Temperature Heat ◽  
Pump Plant

scholarly journals Analysis and Comparison of Some Low-Temperature Heat Sources for Heat Pumps

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1853 ◽  
Author(s):  
Pavel Neuberger ◽  
Radomír Adamovský
Keyword(s):  
Heat Transfer ◽  
Low Temperature ◽  
Heat Source ◽  
Heat Pump ◽  
Heat Exchangers ◽  
Ambient Air ◽  
Heat Transfer Fluid ◽  
Heat Sources ◽  
Ground Heat Exchangers ◽  
Temperature Heat

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.

Application Study of Newly Developed Turbo Heat Pump for 130 Degrees Celsius Water for an Industrial Process

2011 ◽  
Author(s):  
Shuichi Umezawa ◽  
Haruo Amari ◽  
Hiroyuki Shimada ◽  
Takashi Matsuhisa ◽  
Ryo Fukushima ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Low Temperature ◽  
Heat Source ◽  
Heat Pump ◽  
High Efficiency ◽  
Industrial Process ◽  
Application Study ◽  
Hot Air ◽  
Heat Demand ◽  
Temperature Heat

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.

Determination of Heat Transfer Characteristics of Solar Thermal Collectors as Heat Source for a Residential Heat Pump

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Maarten G. Sourbron ◽  
Nesrin Ozalp
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Low Temperature ◽  
Heat Source ◽  
Heat Pump ◽  
Solar Collector ◽  
Heat Transfer Characteristics ◽  
Pump System ◽  
Heat Pump System ◽  
Temperature Heat

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.

scholarly journals Thermodynamic analysis of the heat pump steam system with medium-low temperature heat source

2021 ◽  
Vol 7 ◽  
pp. 266-278
Author(s):  
Shuaiqi Li ◽  
Shihui He ◽  
Wenji Song ◽  
Zipping Feng
Keyword(s):  
Low Temperature ◽  
Heat Source ◽  
Heat Pump ◽  
Thermodynamic Analysis ◽  
Temperature Heat ◽  
Steam System

The Optimal Peak-Adjusting Parameters of Low-Temperature Heat Source Heating

Solar Energy ◽  
2005 ◽  
Author(s):  
Ronghua Wu ◽  
Chenghu Zhang ◽  
Dexing Sun
Keyword(s):  
Low Temperature ◽  
Heat Source ◽  
Heat Pump ◽  
Water System ◽  
Weather Conditions ◽  
Integrated System ◽  
Hot Water ◽  
Cold Weather ◽  
Design Parameters ◽  
Temperature Heat

The integrated low and high temperature heating water system consists of heat pump heat source and boiler heat source. The heat pump heat source abstract heat from low temperature heat source and produce hot water up to 65°C. During mild weather, the 65°C hot water is sufficient for building heating. During cold weather conditions, the boiler heat source will have to be used to produce hot water at 90°C or higher to satisfy the building comfort. To improve the system economy, the integrated system has to maximize the use of the low temperature heat source since it is free. This paper presents a theoretical models and analysis to optimize the system design parameters.

Determination of Heat Transfer Characteristics of Solar Thermal Collectors as Heat Source for a Residential Heat Pump

2015 ◽  
Author(s):  
Maarten G. Sourbron ◽  
Nesrin Ozalp
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Low Temperature ◽  
Heat Source ◽  
Transfer Coefficient ◽  
Heat Pump ◽  
Solar Collector ◽  
Solar Thermal ◽  
Heat Transfer Characteristics ◽  
Temperature Heat

One of the best ways of making efficient use of energy in residential units is to use heat pump. Heat pump performance can be further enhanced by integrating a solar thermal unit to provide hot water and subsidize space heating. This paper presents numerically examined energy feasibility study of a solar driven heat pump system for a low energy residence, where a flat plate solar collector served as the sole low temperature heat source. A parametric study on the ambient-to-solar fluid heat transfer coefficient has been conducted to determine the required solar collector heat transfer characteristics in this system. 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. Achievement of this value with a realistic solar collector area (A-value) required an increase of the overall ambient-to-solar fluid heat transfer coefficient (U-value) with a factor of 6 to 8 compared to the base case with only natural convection heat exchange between solar collector cover and ambient.

Performance evaluation of secondary loop low-temperature heat pump system for frost prevention in electric vehicles

2021 ◽  
Vol 182 ◽  
pp. 115615
Author(s):  
Wanyong Li ◽  
Yusheng Liu ◽  
Rui Liu ◽  
Dandong Wang ◽  
Junye Shi ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Low Temperature ◽  
Heat Pump ◽  
Electric Vehicles ◽  
Pump System ◽  
Heat Pump System ◽  
Temperature Heat ◽  
Secondary Loop

scholarly journals Influence of the Thermal Energy Storage Strategy on the Performance of a Booster Heat Pump for Domestic Hot Water Production System Based on the Use of Low Temperature Heat Source

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6576
Author(s):  
Ximo Masip ◽  
Emilio Navarro-Peris ◽  
José M. Corberán
Keyword(s):  
Low Temperature ◽  
Heat Source ◽  
Heat Pump ◽  
Energy Recovery ◽  
Hot Water ◽  
Water Volume ◽  
Water Production ◽  
Domestic Hot Water ◽  
Temperature Heat ◽  
Variable Water

Energy recovery from a low temperature heat source using heat pump technology is becoming a popular application. The domestic hot water demand has the characteristic of being very irregular along the day, with periods in which the demand is very intensive and long periods in which it is quite small. In order to use heat pumps for this kind of applications efficiently, the proper sizing and design of the water storage tank is critical. In this work, the optimal sizing of the two possible tank alternatives, closed stratified tank and variable-water-volume tank, is presented, and their respective performance compared, for domestic hot water production based on low temperature energy recovery in two potential applications (grey water and ultra-low temperature district heating). The results show that the efficiency of these kind of systems is very high and that variable-water-volume tanks allow a better use of the energy source, with an 8% higher exergy efficiency and around 3% better seasonal performance factor (SPF), being able to provide similar comfort levels with a smaller system size.

Heat Pump Efficiency in fifth Generation Ultra-Low Temperature District Heating Networks using a Wastewater Heat Source

Energy ◽  
2021 ◽  
pp. 121318
Author(s):  
Tobias Reiners ◽  
Michel Gross ◽  
Lisa Altieri ◽  
Hermann-Josef Wagner ◽  
Valentin Bertsch
Keyword(s):  
Low Temperature ◽  
Heat Source ◽  
Heat Pump ◽  
District Heating ◽  
Pump Efficiency ◽  
Fifth Generation ◽  
Heating Networks
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