scholarly journals Heat pump technologies of low temperature drying of capillary-porous materials spherical shape

2020 ◽  
pp. 7-12
Author(s):  
Yu.F. Snezhkin ◽  
V.М. Paziuk ◽  
Zh.O. Petrova
Keyword(s):  
Low Temperature ◽  
Porous Materials ◽  
Heat Pump ◽  
Experimental Studies ◽  
Average Energy ◽  
Spherical Shape ◽  
High Energy ◽  
Heat Pumps ◽  
Heat Pump Drying ◽  
Low Temperature Drying

Heat pump technologies have become widely used in space heating and air conditioning systems, and the heat pump can be used for low-temperature drying of capillary-porous materials. Recuperative and condensing heat pumps, which allow both drying and cooling of the material, have become the most widespread. The developed condensing heat pump drying unit with a mine chamber implements a low-temperature drying process of spherical capillary-porous materials at a drying agent temperature of 40-50°C with a decrease in material humidity by 11% to a final humidity of 8%. Experimental studies on a heat pump drying unit for drying capillary-porous materials of spherical shape indicated a significant reduction in average energy costs per process up to 3700 - 4100 kJ/kg of evaporated moisture. The increase in energy consumption increases significantly in the second part of the second period, where heat consumption can reach 5000 - 5350 kJ/kg of evaporated moisture. The use of condensing heat pumps for low-temperature drying of capillary-porous materials has shown high energy efficiency compared to existing drying technologies.

scholarly journals Mathematical processing of results experimental studies of low-temperature modes of drying of capillary-porous materials of spherical shape

2019 ◽  
pp. 20-25
Author(s):  
Yu.F. Snezhkin ◽  
V.М. Paziuk ◽  
Zh.O. Petrova
Keyword(s):  
Mathematical Model ◽  
Low Temperature ◽  
Porous Materials ◽  
Experimental Studies ◽  
Spherical Shape ◽  
Response Surfaces ◽  
Convective Drying ◽  
Regression Equations ◽  
Drying Time ◽  
Mathematical Processing

The mathematical processing of experimental data obtained during the drying of spherical form of capillary-porous materials on a convective drying bench allows us to determine the influence of various factors on the process. The main factors influencing the kinetics of drying of capillary-porous materials of spherical shape are the temperature and velocity of the heat carrier, as well as the initial moisture content of the material. For each factor, the variation levels corresponding to the optimal conditions for conducting experimental studies with low-temperature drying conditions are recommended. For a mathematical description of the duration of drying of capillary-porous materials, we use an orthogonal composite plan of the second order. As a result, the proposed mathematical model of the process obtained regression equations and the response surface of the duration of drying of capillary-porous materials of spherical shape. The obtained regression equations of the drying time give a detailed description of the influence of both individual and joint actions of factors, the significance of these parameters is determined by the corresponding coefficients according to Student's criterion. Also, the adequacy of the mathematical model according to Fisher's criterion, which corresponds to the real object, is checked. The construction of the response surfaces of the drying time of capillary-porous materials indicates the nature of the effect of these factors in the given range of variation.

scholarly journals ENERGY SAVING TECHNOLOGIES FOR DRYING OF HEAT-SENSITIVE MATERIALS

2019 ◽  
Vol 41 (4) ◽  
pp. 5-12
Author(s):  
Yu.F. Sniezhkin ◽  
Xiong Jian ◽  
D.M. Chalaev ◽  
М.М. Ulanov ◽  
N.О. Dabizha
Keyword(s):  
Heat Pump ◽  
Thermal Conditions ◽  
High Energy ◽  
Heat Pumps ◽  
Convective Drying ◽  
Drying Time ◽  
Long Duration ◽  
Heat Pump Drying ◽  
Promising Development

The promising development of convective drying of thermolabile materials is the use of heat pumps. The main advantages of heat pump drying are high energy efficiency, controlled thermal conditions of drying, high quality of the final product, environmental cleanliness of the technological process.The processes of air treatment in convective heat pumps with different schemes of dehydration of the drying agent are considered in the paper. As determined, the main disadvantage of heat pump drying is the long duration of the process due to the drying temperature limitation not exceeding 50-60 °C, and the dried material is not initially heated above the temperature of the wet thermometer, which is 25-30 °C. The possibility of using infrared radiation in combination with a heat pump was studied to intensify the process of low-temperature convective drying. It is shown that the combination of heat pump and infrared drying processes provides a synergistic effect, which leads to a shorter drying time and reduced energy consumption, as well as to obtain better quality dried products.

scholarly journals Investigation of low-temperature drying modes plant capillary-porous materials spherical shape

2018 ◽  
pp. 7-14
Author(s):  
V.М. Pazyuk
Keyword(s):  
Porous Materials ◽  
Heat Carrier ◽  
Experimental Studies ◽  
Spherical Shape ◽  
Convective Drying ◽  
Drying Rate ◽  
Drying Process ◽  
Exchange Processes ◽  
Low Temperature Drying ◽  
Kinetics Of

The results of experimental studies of the drying of capillary-porous materials of spherical shape from the influence of the temperature of the heat carrier are given.Spherical granules with a diameter of 2,2 mm were taken to determine the rational modes of drying of capillary-porous materials. For a better evaluation of the nature of the drying process, experimental design studies were carried out on a convective drying stand in an elementary layer.The program of automatic collection and processing of information allows obtaining data on changes in the mass and temperature of the sample during the removal of moisture, and also performs calculations of kinetics of drying in absolute and relative coordinates. This makes it possible to obtain and compare the kinetic and velocity characteristics of colloid capillary-porous materials drying faster, more accurately and reliably.By the method of Krasnikov V.V. the kinetics of drying of capillary-porous materials of spherical shape with a diameter of 2,2 mm with construction of a generalized drying curve with determination and calculation of drying coefficients is considered.The generalized curve of drying rate is constructed and obtained, which allows us to generalize the process of drying of a capillary-porous spherical material. Also, get the formula and determine the overall length of the drying process through the drying rate for each heat treatment.When comparing the values of the process length obtained by experimental studies and determined by the calculations, the experimental error from the calculation does not exceed 3%.The analysis of heat-mass-exchange processes of drying by means of calculations of temperature coefficient b, Rebinder Rb criterion, heat flow q and coefficient of heat transfer α from the influence of heat carrier temperature has been carried out.

scholarly journals Local Heating Networks with Waste Heat Utilization: Low or Medium Temperature Supply?

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 954 ◽  
Author(s):  
Hanne Kauko ◽  
Daniel Rohde ◽  
Armin Hafner
Keyword(s):  
Low Temperature ◽  
Heat Pump ◽  
Urban Areas ◽  
Waste Heat ◽  
Local Heating ◽  
District Heating ◽  
Heat Pumps ◽  
Hot Water ◽  
Local Network ◽  
Medium Temperature

District heating enables an economical use of energy sources that would otherwise be wasted to cover the heating demands of buildings in urban areas. For efficient utilization of local waste heat and renewable heat sources, low distribution temperatures are of crucial importance. This study evaluates a local heating network being planned for a new building area in Trondheim, Norway, with waste heat available from a nearby ice skating rink. Two alternative supply temperature levels have been evaluated with dynamic simulations: low temperature (40 °C), with direct utilization of waste heat and decentralized domestic hot water (DHW) production using heat pumps; and medium temperature (70 °C), applying a centralized heat pump to lift the temperature of the waste heat. The local network will be connected to the primary district heating network to cover the remaining heat demand. The simulation results show that with a medium temperature supply, the peak power demand is up to three times higher than with a low temperature supply. This results from the fact that the centralized heat pump lifts the temperature for the entire network, including space and DHW heating demands. With a low temperature supply, heat pumps are applied only for DHW production, which enables a low and even electricity demand. On the other hand, with a low temperature supply, the district heating demand is high in the wintertime, in particular if the waste heat temperature is low. The choice of a suitable supply temperature level for a local heating network is hence strongly dependent on the temperature of the available waste heat, but also on the costs and emissions related to the production of district heating and electricity in the different seasons.

Low-Temperature Drying Using a Versatile Heat Pump Dehumidifier

2003 ◽  
Vol 21 (3) ◽  
pp. 539-554 ◽  
Author(s):  
V. Sosle ◽  
G. S. V. Raghavan ◽  
R. Kittler
Keyword(s):  
Low Temperature ◽  
Heat Pump ◽  
Low Temperature Drying

Review Status on High Temperature Heat Pumps

2012 ◽  
Vol 170-173 ◽  
pp. 2550-2553 ◽  
Author(s):  
Guang Hui Zhou ◽  
Shi Wei Feng ◽  
Si Qi Cui ◽  
Yin Liu
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Heat Pump ◽  
Heat Pumps ◽  
Industrial Processes ◽  
Paper Briefly ◽  
Development Status ◽  
Temperature Heat ◽  
Waste Energy ◽  
Higher Temperature

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.

scholarly journals Design of an electromagnetic induction steam generator device based on air source heat pump

2022 ◽  
Vol 355 ◽  
pp. 02059
Author(s):  
Zhimo Li ◽  
Jiachun Li ◽  
Xiangli Dong ◽  
Bo Chen ◽  
Qing Li
Keyword(s):  
Heat Pump ◽  
Steam Generator ◽  
Induction Heating ◽  
Electromagnetic Induction ◽  
High Energy ◽  
Heat Pumps ◽  
Outlet Temperature ◽  
Air Source Heat Pump ◽  
Electromagnetic Induction Heating ◽  
Heating Technology

Aiming at the current problems of coal-fired boilers and electromagnetic induction steam generators for environmental pollution and high energy consumption, this article combines air source heat pumps and electromagnetic induction heating technology, and at the same time carries out the structure of the condensate tank and electromagnetic induction steam generator. Redesign. Through trial production and experimentation of the prototype, the results show that compared with traditional coal-fired boilers and separate electromagnetic induction heating technology to generate steam, this device not only achieves energy saving and environmental protection, but also the stability of the steam outlet temperature and the amount of steam generated. Compared with the use of electromagnetic induction heating alone, it has increased by 20%. It can be seen that the use of air source heat pump’ electromagnetic induction heating technology to generate steam saves energy and increases the amount of steam generated.

scholarly journals Environmental tests of vapor compression heat pump for space applications

2020 ◽  
pp. 240-240
Author(s):  
Xudong Ma ◽  
Rui Ma ◽  
Yilin Ye ◽  
Suying Yan ◽  
Feng Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Heat Pump ◽  
Low Temperatures ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Vapor Compression ◽  
Space Applications ◽  
Suitable Temperature ◽  
High And Low Temperatures

Heat pumps are needed to provide a suitable temperature for both people and equipment in spacecraft. This paper reports on work designed to see if vapor compression heat pumps, in particular, can be expected to function normally in space. A vapor compression heat pump was built and tested under conditions of high temperature (70?C), low temperature (0?C), and near-vacuum (10-4 Pa). It was found that the coefficient of performance of this heat pump was 2.99 at both high and low temperatures, and was 2.1 under near vacuum conditions. The results suggest that vapor compression heat pumps are suitable for use in space.

scholarly journals Research in low-temperature heat pump drying

2019 ◽  
Author(s):  
Natalia Dabizha ◽  
Yurii Sniezhkin ◽  
Djamal Chalaev ◽  
Nataliia Malashchuk
Keyword(s):  
Low Temperature ◽  
Heat Pump ◽  
Temperature Heat ◽  
Heat Pump Drying
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