Technology of Heat and Moisture Regeneration for Ventilation Systems

2021 ◽  
pp. 174-222
Keyword(s):  
Silica Gel ◽  
Air Temperature ◽  
Sodium Acetate ◽  
Temperature Drop ◽  
Sodium Sulphate ◽  
Efficiency Factor ◽  
Cold Air ◽  
Temperature Efficiency ◽  
Heat And Moisture ◽  
Ventilation Systems

The chapter is focused on technology of heat and moisture regeneration for ventilation systems. In the first sub-division recent progress in adsorptive technologies for air dehumidification, heating and conditioning is analyzed. In the next sub-divisions results of original researches of authors on adsorptive heat and moisture regeneration are given. The design of adsorptive heat-moisture regenerator for ventilation systems is shown. Its operation and the results of field tests are described. The technology of regeneration of low-potential heat and moisture by composite sorbent ‘silica gel – sodium sulphate' is suggested. Experimental plots of temperature, absolute and relative humidity at the inlet and the outlet of the apparatus and between cassettes with the composite are given. Correlation of flows switch-over time, airflow rate and temperature drop is stated. The relationships temperature efficiency factor vs. dimensionless temperature drop and moisture efficiency factor vs. absolute humidity dimensionless drop are derived with fair accuracy for engineering calculation. Ability of purposeful modification of the above-mentioned characteristics within broad ranges by changing the half-cycle time, the size of the granules of the adsorbent and its amount is revealed. The mathematical model and algorithm for determining the basic parameters of adsorptive regenerator operating processes are developed. The proposed algorithm involves calculating the volume of air passed through the layer of adsorptive heat-storage material, the concentration of water in the airflow at the outlet of the regenerator, the adsorption, the heat of adsorption, the final temperature of the cold air, the air temperature after mixing the cold air from the street and the warm air in the room at the warm end of the regenerator during inflow, calculation of the final concentration of water in the flow at the cold end of the regenerator, the volume of air passing through the layer of heat-accumulating material, adsorption and heat of adsorption, the final temperature of the air at the cold end of the regenerator, the air temperature after mixing of the cold air from the street and the warm air from the room at the cold end of regenerator during outflow, determining the temperature efficiency coefficient, summarized adsorption and maximal adsorption time. The correlation of air temperatures near the warm and cold end of the regenerator, as well as the temperature efficiency factors calculated according to the proposed algorithm and obtained by experimental way is confirmed. The mathematical modeling of the processes of operation of adsorption regenerators based on composites ‘silica gel – sodium sulphate' and ‘sodium acetate' in the conditions of the typical ventilation system of residential premises is carried out. The dependences of the temperature efficiency factor vs. the time of switching air flows and the velocity of air flow, as well as the temperatures of external and internal air under stationary conditions are shown. An optimal composition of composite adsorbents is stated to be 20% of silica gel and 80% of salt, that is, sodium sulphate or sodium acetate. Due to higher value of maximal adsorption composite ‘silica gel – Na2SO4' is shown to be required in half as much as compared with ‘silica gel – CH3COONa'. The results of the research can be used in the development of energy-efficient ventilation systems and devices for residential and warehouse premises.

scholarly journals Choice Criteria of Adsorbents for Heat Energy Converters in Ventilation Systems

2019 ◽  
Vol 83 (1) ◽  
pp. 4-9 ◽  
Author(s):  
Elena Belyanovskaya ◽  
R. Lytovchenko ◽  
Konstanthyn Sukhyy ◽  
O. Prokopenko ◽  
O. Yeromin ◽  
...  
Keyword(s):  
Silica Gel ◽  
Air Temperature ◽  
Sodium Sulphate ◽  
Efficiency Factor ◽  
Heat Of Adsorption ◽  
Heat Energy ◽  
Cold Air ◽  
Temperature Efficiency ◽  
Heat And Moisture ◽  
Ventilation Systems

The criteria of adsorbent selection for adsorption transformers of thermal energy in ventilation systems are considered. The main characteristics of adsorbents that affected the structural parameters of the adsorption module are revealed. The method of determining the mass of the adsorbent and the volume of the adsorption unit in ventilation systems has been developed. The main factor affecting the volume of adsorbent is confirmed to be maximal adsorption. The advantages of ‘salt in the porous silica gel matrix’ composites are compared with traditional silica gels. On the example of an adsorption regenerator of low-potential heat and moisture, the greater effectiveness of the composites "silica gel-sodium sulphate" is shown in comparison with the composite 'silica gel - sodium acetate'. According to the experimental data on the operation of the adsorption regenerator of heat and moisture on the basis of the composite 'silica gel – CH3COONa', the adequacy of the proposed algorithm for determining the temperature efficiency factor has been confirmed. Suggested algorithm includes the calculation of the air volume passed through the layer of heat-storage material, water concentration in the air at the exit from the heat accumulator, adsorption, heat of adsorption, the final cold air temperature, air temperature after mixing cold air from the street and the warm air in the room at the inlet, the calculation of the concentration of water in the flow at the exit from the heat regenerator, the adsorption and heat of adsorption, the final temperature of the warm air, the air temperature after mixing the cold air from the street and the warm air from the room during the discharge, determination of the temperature efficiency factor, total adsorption and time to achieve the maximal adsorption. The efficiency of the processes of operating adsorption regenerators based on composites 'silica gel - sodium sulphate' and 'silica gel-sodium acetate' in the conditions of the typical ventilation system of housing premises was compared. The parameters that correspond to the maximum value of the temperature efficiency factors: the humid air velocity is about 0.22 - 0.32 m/s and the time of switching of the flows up to 5 minutes. The influence of meteorological conditions on the efficiency of the adsorption regenerator has been confirmed. The higher efficiency of adsorption regenerators based on 'silica gel - sodium sulphate' composites is explained, which is explained by higher values of maximal adsorption, which results in increasing the heat of adsorption. The results of the research can be used for the selection of adsorbents for energy-efficient heat energy converters in ventilation systems for residential and warehouse premises.

scholarly journals PERFORMANCE CHARACTERISTICS OF ADSORPTIVE REGENERATOR OF LOW-POTENTIAL HEAT AND MOISTURE BASED ON COMPOSITE ADSORBENTS ‘SILICA GEL – SODIUM SULPHATE’ SYNTHESIZED BY SOL – GEL METHOD

2018 ◽  
Vol 82 (1) ◽  
Author(s):  
Олена Анатолівна Бєляновська ◽  
Роман Дмитрович Литовченко ◽  
Костянтин Михайлович Сухий ◽  
Михайло Порфирович Сухий ◽  
Михайло Володимирович Губинський
Keyword(s):  
Silica Gel ◽  
Air Temperature ◽  
Sodium Sulfate ◽  
Sol Gel ◽  
Efficiency Coefficient ◽  
Final Temperature ◽  
Cold Air ◽  
Gel Method ◽  
Temperature Efficiency ◽  
Heat And Moisture

Досліджені експлуатаційні характеристики адсорбційного регенератора низько-потенційного тепла та вологи на основі композитних сорбентів «силікагель – натрій сульфат», синтезованих золь – гель методом. Розроблені математична модель та алгоритм визначення базових параметрів процесів експлуатації адсорбційного регенератора в умовах сектора житлово-комунального господарства.  Запропонований алгоритм включає розрахунок об’єму повітря, який пройшов через шар теплоакумулюючого матеріалу, концентрації води в повiтрi на виході з теплового акумулятора, адсорбції, теплоти адсорбції, кінцевої  температури холодного повітря, температури повітря після змішування холодного повітря з вулиці та теплого повітря в приміщенні при подачi, розрахунок концентрації води в повiтрi на виході з теплового акумулятора, об’єму повітря, який пройшов через шар теплоакумулюючого матеріалу, адсорбції та теплоти адсорбції, кінцевої температури теплого повітря, температури повітря після змішування холодного повітря з вулиці та теплого повітря з приміщення при викиді, визначення температурного коефіцієнта корисної дії, сумарної адсорбції та часу досягнення максимальної адсорбції. Підтверджена кореляція температур повітря біля теплого та холодного кінці регенератора, а також теплових коефіцієнтів корисної дії, встановлених за результатами розрахунків згідно запропонованого алгоритму та дослідним шляхом. Проведено математичне моделювання процесів експлуатації адсорбційних регенераторів на основі композитів «силікагель – натрій сульфат» в умовах типової системи вентиляції житлових приміщень. Показана залежність теплового коефіцієнта корисної дії від часу перемикання потоків повітря, швидкості руху потоків повітря, а також температур зовнішнього та внутрішнього повітря в стаціонарних умовах. Максимальні значення теплових коефіцієнтів корисної дії встановлені при швидкості вологого повітря близько 0,22 –  0,32 м/с та часу перемикання потоків 5 – 10 хв.. Виявлено вплив швидкості руху потоків вологого повітря на час досягнення максимальної адсорбції. Результати проведеного дослідження можуть бути використані при розробці енергоефективних вентиляційних систем та пристроїв для житлових та складських приміщень. The performance characteristics of the adsorptive  regenerator of the low-potential heat and moisture on basis of the composite sorbents ‘silica gel - sodium sulfate’ synthesized by sol-gel method are studied. The mathematical model and algorithm for determining the basic parameters of adsorptive regenerator exploitive processes in the housing and communal services sector are developed. The proposed algorithm includes calculating the volume of air passed through the layer of heat-accumulating material, the concentration of water in the flow at the exit from the regenerator, the adsorption, the heat of adsorption, the final temperature of the cold air, the air temperature after mixing the cold air from the street and the warm air in the room at the warm end of the regenerator during inflow, calculation of the final concentration of water in the flow at the cold end of the regenerator, the volume of air passing through the layer of heat-accumulating material, adsorption and heat of adsorption, the final temperature of the air at the cold end of the regenerator, the air temperature after mixing of  the cold air from the street and the warm air from the room at the cold end of regenerator during outflow, determining the temperature efficiency coefficient, summarized adsorption and maximal adsorption time. The correlation of air temperatures near the warm and cold end of the regenerator, as well as the thermal efficiency coefficients stated by the results of calculations according to the proposed algorithm and experimental way is confirmed. The mathematical modeling of the processes of operation of adsorption regenerators on the basis of ‘silica gel - sodium sulfate’ composites in the conditions of the typical ventilation system of residential premises is carried out. The dependences of the temperature efficiency coefficient vs. the time of switching air flows and the velocity of air flow, as well as the temperatures of external and internal air under stationary conditions are shown. The results of the research can be used in the development of energy-efficient ventilation systems and devices for residential and warehouse premises

scholarly journals Performance of an Adsorptive Heat-Moisture Regenerator Based on Silica Gel–Sodium Sulphate

2020 ◽  
Vol 12 (14) ◽  
pp. 5611
Author(s):  
Elena Belyanovskaya ◽  
Miroslav Rimár ◽  
Roman D. Lytovchenko ◽  
Miroslav Variny ◽  
Kostyantyn M. Sukhyy ◽  
...  
Keyword(s):  
Power Consumption ◽  
Silica Gel ◽  
Pressure Loss ◽  
Air Conditioning ◽  
Structural Characteristics ◽  
Sodium Sulphate ◽  
Efficiency Factor ◽  
Air Pressure ◽  
Temperature Efficiency ◽  
Efficiency Factors

The performance of an adsorptive heat-moisture regenerator based on a silica gel–sodium sulphate composite adsorbent was studied. The correlation between the adsorbent composition and structural characteristics of the laboratory-scale device was investigated. An algorithm for the calculation of the efficiency factors of the adsorptive regenerator was further developed. The suggested algorithm calculates the operational parameters, including the temperatures, humidities and volumetric flows of internal and external air, and estimates the regenerator’s performance via temperature and moisture efficiency factors, total adsorption and time needed to achieve maximum adsorption, air pressure loss and fan power input. The validity of the calculation results obtained using the proposed algorithm was confirmed experimentally. Temperature efficiency factor, air pressure loss and fan power consumption are crucial parameters for the estimation of the optimal operating regime of an adsorptive heat-moisture regenerator. The correlation between meteorological conditions and efficiency factors was assessed and applied in a simulation of residential house-scale air conditioning unit operation. Maximal values of temperature efficiency factor were found at internal and external air temperatures of 15 to 20 °C and −5 to 0 °C, respectively. Moisture efficiency factors were observed to reach their maximum at the absolute humidities of external and internal air of 4.0 to 5.0 g/m3 and 2.75 to 3.0 g/m3, respectively. The fan power consumption of the adsorptive heat-moisture regenerator was found to be comparable to or even lower than that of commercial air conditioning units used in comparably voluminous interiors.

Design and Performance of Adsorptive Heat Pumps

2021 ◽  
pp. 223-250
Keyword(s):  
Heat Pump ◽  
Silica Gel ◽  
Heat Supply ◽  
Sodium Acetate ◽  
Energy Performance ◽  
Heat Pumps ◽  
Sodium Sulphate ◽  
Heat Supply Systems ◽  
And Performance ◽  
Supply Systems

The chapter is devoted to design and performance of adsorptive heat pumps. In the first sub-division, state-of-the-art of the adsorptive heat pumping is analyzed. It involves analysing operating principle of adsorptive heat pumps, comparing of the properties of adsorbents used, bed specifications, and operating conditions. Original construction of the adsorptive heat pump is designed by authors for independent heat supply systems or hot water supply of buildings and other structures for various purposes. The composites ‘silica gel – sodium sulphate' or ‘silica gel – sodium acetate' were used as adsorbents. Discharging was performed in a daytime, when heat pump supplied heating system with water warmed to 45 – 35°C. The regeneration mode proceeded at night from 0.00 to 8.00 a.m. Efficiency of suggested adsorptive heat pump is estimated by two methods: as ratio of adsorption heat to sum of desorption heat and external heat supplied to sorbent during its heating up to regeneration temperature (coefficient of performance of cycle) and as ratio of heat of adsorption to heat supplied by solar collector (net coefficient of performance). Suggested heat pump coefficients of energy performance of cycle are stated to be 2.084 when composite ‘silica gel – sodium sulphate' used and 2.021 when ‘silica gel – sodium acetate' used. Seasonal dependence of net coefficient energy performance for suggested adsorptive heat pump based on composites ‘silica gel – sodium sulphate' and ‘silica gel – sodium acetate' is revealed. Correlation of coefficients of energy performance of adsorptive heat pump and composite sorbents properties (sorption capacity and regeneration temperature) is stated. Insignificant decreasing of coefficients of energy performance when ‘silica gel – sodium acetate' used is explained by lower sorptive capacity as compared to ‘silica gel – sodium sulphate'. Suggested heat pump application perspectives are shown for heat supply systems to result from traditional energy sources independence and environmental advantages. Adsorptive heat pumps development challenges, major limitations for commercialization of adsorptive heat pumping, and requirements to ongoing innovations are analysed. The present chapter can be useful for energy efficient decentralized heat supply systems based on adsorptive heat pump unit.

scholarly journals Effects of vernal equinox solar eclipse on temperatures and wind directions in Switzerland

2017 ◽  
Author(s):  
Werner Eugster ◽  
Carmen Emmel ◽  
Sebastian Wolf ◽  
Nina Buchmann ◽  
Joseph P. McFadden ◽  
...  
Keyword(s):  
Air Temperature ◽  
Solar Eclipse ◽  
Wind Direction ◽  
Temperature Drop ◽  
Swiss Alps ◽  
Maximum Temperature ◽  
Small Scale ◽  
Near Surface ◽  
Vernal Equinox ◽  
Cold Air

Abstract. The vernal equinox total solar eclipse of 20 March 2015 produced a maximum occultation of 65.8 to 70.1 % over Switzerland during the morning hours (09:22 to 11:48 CET). Skies were generally clear over the Swiss Alps due to a persistent high-pressure band between the UK and Russia associated with a rather weak pressure gradient over the continent. To assess the effects of penumbral shading on near-surface meteorology across Switzerland, air temperature data measured at 10-minute intervals at 184 MeteoSwiss weather stations that reported air temperature at 10-minute intervals were used. Wind speed and direction data were available from 165 of these stations. Additionally, six Swiss FluxNet eddy covariance flux (ECF) sites provided turbulent measurements at 20 Hz resolution. During maximum occultation the temperature drop was up to 5.8 K at a mountain site where cold air can pool in the topographic depression of the weather station. The bootstrapped average of the maximum temperature drops of all 184 MeteoSwiss sites during the solar eclipse was 1.51 ± 0.02 K (mean ± SE). A detailed comparison with literature values since 1834 showed a temperature decrease by 2.6 ± 1.7 K (average of all reports) with extreme values up to 11 K. On fair weather days under weak larger scale pressure gradients, local thermo-topographic wind systems develop that are driven by small-scale pressure and temperature gradients. At one ECF site, the penumbral shading delayed the morning transition from down-valley to up-valley wind conditions, and at another site, it prevented this transition from occurring at all. Data from the 165 MeteoSwiss sites measuring wind direction did not show a consistent pattern of wind direction response to the passing of the penumbral shadow. These results suggest that the local topographic setting had an important influence on the temperature drop and the wind flow patterns during the eclipse. Still, results tend to lend support to a recent theory that the anticyclonic cold-air outflow from the center of the eclipse only extends ≈ 1600 km outwards, with cyclonic flow beyond that distance. This contrasts with an earlier theory that the anticyclonic outflow should reach as far as ≈ 2400 km from the center of the eclipse, which would have included all of Switzerland during the 2015 eclipse. Nevertheless, a significant cyclonic effect of the passing penumbral shadow was found in the elevation range ≈ 1700–2700 m a.s.l., but not at lower elevations of the Swiss Plateau. Thus, measurable effects of penumbral shading on the local wind system could be even found at ≈ 2000 km from the path of the eclipse (that is, Switzerland during the 2015 eclipse).

scholarly journals Performance of adsorptive heat-moisture regenerator

2020 ◽  
Vol 84 (1) ◽  
pp. 98-103
Author(s):  
Elena Belyanovskaya ◽  
Roman Lytovchenko ◽  
Kostyantyn Sukhyy ◽  
Mikhaylo Sukhyy ◽  
Mykhailo Gubynskyi ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Silica Gel ◽  
Air Temperature ◽  
Ventilation System ◽  
Absolute Humidity ◽  
Sodium Sulphate ◽  
Adsorbent Layer ◽  
Services Sector ◽  
Calculation Results ◽  
The Mathematical Model

The performance of the adsorptive heat-moisture regenerators based on the composite materials ‘silica gel - sodium acetate’ and ‘silica gel – sodium sulphate’ have been studied. The mathematical model and algorithm for determining the basic operating parameters of adsorptive regenerator in the housing and communal services sector have been further developed. The proposed algorithm which involves calculating the air volume passed through the adsorbent layer, the final absolute humidity of air near the outlet from the regenerator, the adsorption and the heat of adsorption  during inflow and outflow, the final temperature of the external cold air, the air temperature after mixing the cold external air and the internal warm air in the room near the warm end of the regenerator during inflow, the air temperature after mixing of the cold external air and the warm exhaust air from the premise near the cold end of regenerator during outflow, determining the temperature and moisture efficiency factors has been completed by computing the Reynolds criterion of the adsorbent layer, the coefficient of the hydraulic resistance, the pressure loss, the consumed power of ventilator, summarized adsorption and time to achieve maximal adsorption . The adequacy of suggested mathematical model is confirmed by sufficient correlation of experimental data and calculation results with the proposed algorithm. The performance of adsorptive regenerators based on the adsorbents ‘silica gel – CH3COONa’ and ‘silica gel – Na2SO4’ has been simulated in the conditions of the conventional ventilation system of living quarters. The efficiency of adsorptive regenerators has been compared when ‘silica gel – CH3COONa’ and ‘silica gel – Na2SO4’ used. The correlation of design and efficiency of adsorptive regenerators is shown.

scholarly journals Performance adsorption regenerator of heat and moisture based on composite ‘silica gel – sodium acetate’

2019 ◽  
pp. 74-81
Author(s):  
Elena A. Belyanovskaya ◽  
Roman D. Lytovchenko ◽  
Kostyantyn M. Sukhyy ◽  
Olga O. Ovchinnikova ◽  
Mykhailo V. Gubynskyi
Keyword(s):  
Silica Gel ◽  
Sodium Acetate ◽  
Heat And Moisture

Design of Adsorptive Heat Storage Devices

2021 ◽  
pp. 89-123
Keyword(s):  
Silica Gel ◽  
Heat Supply ◽  
Sodium Acetate ◽  
Heat Storage ◽  
Sodium Sulphate ◽  
Silica Gels ◽  
Storage Devices ◽  
Composite Adsorbents ◽  
Supply Systems

The chapter is devoted to prospects of application of adsorptive heat storage devices, principles of operating the adsorptive heat storage systems, design of adsorptive storage devices and main factors determining the design of adsorptive heat storage unit. Perspectives of application of adsorptive heat storage devices in heat supply systems were analyzed. Basic principles of operating of heat storage devices were considered. Adsorptive heat storage units operating in close and open modes were compared. Constructions of adsorptive heat storage units operating in open and close mode were described. An efficient algorithm for calculating the volume of the adsorptive thermal energy storage device for a decentralised heat supply system of a private house is suggested by authors. The following procedure of computation is proposed to involve: calculation of thermal load for heating including the determination of thermal losses through external fences, thermal losses due to infiltration and internal heat dissipation, the evaluation of maximal adsorption, adsorption heat, and determination of adsorbent mass and adsorbent volume. The maximal adsorption value is suggested to be calculated by the characteristics of the adsorbent, that is, its maximal adsorption or in the absence of data for a composite adsorbent, as a linear superposition for a mechanical mixture. The adsorbent mass is suggested to calculate as a ratio of a thermal load for heating and heat of adsorption. The adsorbent volume is calculated as ratio of mass and density of adsorbent. An evaluative calculation of the heat load for a private house was carried out with the proposed algorithm. Mass and volumes of conventional silica gels were compared with composite adsorbents ‘silica gel – sodium sulphate' and ‘silica gel – sodium acetate' obtained by sol gel method developed by authors. Mass and volume of silica gels occur to surpass the suggested composite at least by 1.5 – 5 times. This is shown to result from higher maximal adsorption and heat of adsorption of suggested composite adsorbents. The optimal composition of the composite adsorbents ‘silica gel – sodium sulphate' and ‘silica gel – sodium acetate' was determined according to the minimal volume of the layer of heat storage material. Both the lowest volume values and the highest efficiency of a composite adsorbents with a mass ratio of silica gel and Na2SO4 or CH3COONa 20: 80 are explained by the maximum value of adsorption heat. Suggested composite adsorbent ‘silica gel – sodium sulphate' and ‘silica gel – sodium acetate' are shown to be promising for heat supply systems.

Construction and Operating Parameters of Adsorptive Chillers

2021 ◽  
pp. 251-289
Keyword(s):  
Silica Gel ◽  
Density Ratio ◽  
Energy Performance ◽  
Sodium Sulphate ◽  
Efficiency Factor ◽  
Radiant Flux ◽  
Coefficient Of Performance ◽  
Solar Collectors ◽  
Optical Efficiency ◽  
And Performance

The chapter is devoted to the design and performance of adsorptive chillers. Basic types of design and operating principle of adsorptive chillers were analyzed. Advantages and disadvantages performance of one-, two-, three-, and four-bed solar power adsorptive chillers are compared. Performance of adsorptive refrigerators based on composite adsorbents was studied. The correlation between the adsorbent composition and the coefficient of energy performance of the adsorptive chiler was revealed. An optimal composition of adsorbent 'silica gel – sodium sulphate' is stated to be of 20% silica gel and 80% sodium sulphate. The maximal values of the coefficient of performance of cycle of studied solar adsorptive chiller about of 1.14 are stated for composites containing about 20 wt. % silica gel and 80 wt% sodium sulphate. As a consequence of decreasing of adsorbent mass, the coefficient of performance is shown to increase when sodium sulphate content in the composite increased. Regeneration process parameters of the composite were shown to strongly affect on the coefficient of performance of the adsorptive chiller. The growth of the coefficient of performance is stated to result from decreasing the difference between adsorbent temperature and regeneration temperature from 85 to 55°C. The basic factors affecting the net coefficient of energy performance of the adsorptive solar refrigerator were stated daily solar radiant flux alongside with composition of the adsorbent and difference between adsorbent temperature and temperature regeneration. Net coefficients of performance of solar adsorptive refrigerator based on composite ‘silica gel – sodium sulphate' were stated to change from 0.25 to 0.34 during operating period. Utilization of the adsorption heat is suggested to warm the heat carrier which applied to heat adsorbent during regeneration. The ways to improve the design and performance of adsorptive solar chillers are suggested. The first one involves the introduction of solar collectors made of cellular polycarbonate plastics in the design of adsorptive solar chiller. Instantaneous efficiency coefficient were calculated as special thermal performance-solar radiant flux surface density ratio, optical efficiency factor is determined as special thermal performance-solar radiant flux surface density ratio at the equal temperatures of heat transfer medium and environment, reduced heat loss factor being calculated as the product of solar collector efficiency factor and net heat loss coefficient. The environmental test of developed collectors PSK-AV2-3, PSK-AV1-2, PSK-AV2-1, PSK-VS1-2, PSK-VS2-2, PSK-VS2-3, PSK-ST10-PW were conducted. The correlation of their results with laboratory tests when the thermohydraulic stand applied is shown. Relative accuracy of laboratory and environment tests was shown to be not exceeding 5 – 7%. The optical efficiency factor and the coefficient of thermal losses of polymeric solar collectors were determined. On the basis of the dependencies of the efficiency of the solar collectors vs. the reduced temperature, optimal designs of the polymeric solar collectors for the adsorption chilling solar systems are determined to be depended on the temperature of the regeneration temperature of the sorbents. As the temperatures of the regeneration of composite adsorbent ranged from 50ºС to 60ºС, appliance of the collectors PSK-AV2-1, PSK-CT10-PW occur to be expedient, and PSK-AB2-3, PSK-VS2-3, PSK-AB1-2, PSK-VS2-2, and PSK-VS1-2 are revealed to be more efficient when regeneration temperatures increased over 80 ºС. Thermotechnical characteristics of designed polymeric solar collectors are shown to surpass conventional metal and vacuum collectors. The perspectives of polymeric solar collectors in the design of adsorptive chilling solar plants were shown. Another way to improve the performance of adsorptive solar chillers concerns with equipping it with a photosensitive element and an electric drive, which will allow changing the angle of slope of the adsorber to the horizon depending on the intensity of the solar radiation. The chapter can be useful for design the efficient adsorptive chilling plants.

Sign in / Sign up

Export Citation Format

Share Document