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This paper presents the concept of a Rotary Indirect Evaporative Cooler (RIEC) which the operation principle is based on implementation of evaporative cooling in rotary exchanger to increase its cooling effectiveness. The RIEC unit can operate in two modes: standard and regenerative. The mathematical model of RIEC, based on the ε–NTU method, is presented. The operation of RIEC is compared to the traditional Counter-flow Indirect Evaporative Cooler (CIEC) which also operates in two modes: standard and regenerative. Different performance indicators are introduced i.e. Energy Efficiency Ratio (EER), indicators relating the cooling capacity to cooler's length, cooler's inlet cross-section, and to cooler's overall volume. Additional two indicators are introduced to describe RIEC and CIEC operation principles by relating the cooling capacity to the rate of heat or mass transfer occurring in the wetted part of the cooler. The performance of RIEC and CIEC is compared under different climate conditions following Köppen-Geiger climate classification system. It was found that the values of performance indicators calculated for RIEC are higher than for CIEC under various operational parameters and climatic conditions. It was stated that choosing RIEC instead of CIEC allows increasing EER on average by 63% in standard mode and 88% in regenerative mode. It was concluded that RIEC is a competitive solution for cooling purposes due to its lower electricity demand and smaller dimensions.
Demis Pandelidis; Aleksandra Cichoń; Anna Pacak; Paweł Drąg; Marlena Drąg; Korneliusz Sierpowski; William Worek; Sabri Cetin. Performance analysis of rotary indirect evaporative air coolers. Energy Conversion and Management 2021, 244, 114514 .
AMA StyleDemis Pandelidis, Aleksandra Cichoń, Anna Pacak, Paweł Drąg, Marlena Drąg, Korneliusz Sierpowski, William Worek, Sabri Cetin. Performance analysis of rotary indirect evaporative air coolers. Energy Conversion and Management. 2021; 244 ():114514.
Chicago/Turabian StyleDemis Pandelidis; Aleksandra Cichoń; Anna Pacak; Paweł Drąg; Marlena Drąg; Korneliusz Sierpowski; William Worek; Sabri Cetin. 2021. "Performance analysis of rotary indirect evaporative air coolers." Energy Conversion and Management 244, no. : 114514.
The aim of this study was to determine the suitability of a rainwater harvesting system to cover the water demand for indoor hydroponic lettuce cultivation located in Wrocław (Poland). The analysis was performed on the basis of the recorded rainfall in Wrocław in 2000–2019. The analyzed cultivation is located in a hall with an area of 300 m2, where the lettuce is grown vertically by the hydroponic method. The calculations of the rainwater harvesting (RWH) system were carried out considering the selection of the tank capacity for the collected water. The operation of the water storage is simulated using a yield after spillage (YAS) algorithm. It was evident that the proposed system might be an auxiliary system that relieves the water supply network or supports other water recovery systems (e.g., the water vapor condensation in a cross-flow heat exchanger operating as an element of the air conditioning system, proposed in Part 1 of this study). The harvesting system for the selected vertical farming indoor hall covers an average of 35.9% of water needs and allows a saving of 146,510 L of water annually for the cultivation. An average water demand coverage increases up to 90.4%, which allows a saving of 340,300 L per year when the RWH system is combined with water recovery from exhaust air from the hall.
Anna Jurga; Anna Pacak; Demis Pandelidis; Bartosz Kaźmierczak. A Long-Term Analysis of the Possibility of Water Recovery for Hydroponic Lettuce Irrigation in an Indoor Vertical Farm. Part 2: Rainwater Harvesting. Applied Sciences 2020, 11, 310 .
AMA StyleAnna Jurga, Anna Pacak, Demis Pandelidis, Bartosz Kaźmierczak. A Long-Term Analysis of the Possibility of Water Recovery for Hydroponic Lettuce Irrigation in an Indoor Vertical Farm. Part 2: Rainwater Harvesting. Applied Sciences. 2020; 11 (1):310.
Chicago/Turabian StyleAnna Jurga; Anna Pacak; Demis Pandelidis; Bartosz Kaźmierczak. 2020. "A Long-Term Analysis of the Possibility of Water Recovery for Hydroponic Lettuce Irrigation in an Indoor Vertical Farm. Part 2: Rainwater Harvesting." Applied Sciences 11, no. 1: 310.
This paper presents the characteristics of the operation of the system for recovery of water from exhaust air in moderate climates in the years 2010–2019. The proposed system for water recovery uses the phenomenon of condensation in a cross-flow heat exchanger operating as an element of the air conditioning system. The parameters of exhaust air behind the heat exchanger have been determined using a mathematical model of the so-called black box. The mathematical model considers the risk of the cross-freezing of the heat exchanger. The calculations carried out for variable parameters of external air during the analyzed period confirm that the system allows to cover the demand for water for lettuce irrigation during the cold and transitional period, which is a major part of the year. It has been noted that the effectiveness of the system is very high (av. 67.12% per year) due to the specific parameters of the internal air in which the lettuce must be grown and the need for continuous air exchange in such facilities. This means that air is a stable source of water recovery, where the recovery rate depends on the parameters of external air.
Anna Pacak; Anna Jurga; Paweł Drąg; Demis Pandelidis; Bartosz Kaźmierczak. A Long-Term Analysis of the Possibility of Water Recovery for Hydroponic Lettuce Irrigation in Indoor Vertical Farm. Part 1: Water Recovery from Exhaust Air. Applied Sciences 2020, 10, 8907 .
AMA StyleAnna Pacak, Anna Jurga, Paweł Drąg, Demis Pandelidis, Bartosz Kaźmierczak. A Long-Term Analysis of the Possibility of Water Recovery for Hydroponic Lettuce Irrigation in Indoor Vertical Farm. Part 1: Water Recovery from Exhaust Air. Applied Sciences. 2020; 10 (24):8907.
Chicago/Turabian StyleAnna Pacak; Anna Jurga; Paweł Drąg; Demis Pandelidis; Bartosz Kaźmierczak. 2020. "A Long-Term Analysis of the Possibility of Water Recovery for Hydroponic Lettuce Irrigation in Indoor Vertical Farm. Part 1: Water Recovery from Exhaust Air." Applied Sciences 10, no. 24: 8907.
Following paper presents an experimental study on eight potential plate materials for evaporative air coolers. There are three groups of materials: currently used plate materials (kraft papers), new natural origin plate materials (cotton fibers), and new synthetic plate materials (synthetic fibers). Proposed materials were examined in terms of different properties such as upward and downward distribution height, water capacity, durability and diffusivity. The results were compared with data presented by other authors. It was established that, synthetic materials are characterized by superior water distribution qualities in comparison to the materials of natural origin. Basalt paper-like synthetic fiber allowed to rise water vertically to 40 cm during 120 min tests. The highest water rise obtained in other studies was 18 cm, hence basalt paper-like fiber is visibly superior in comparison with the currently known materials. In terms of downward water distribution, two new synthetic surfactant non-wovens show better performance than the existing materials by quickly and evenly distributing water over the entire length of the sample. The durability of synthetic fibers and non-wovens is higher comparing with the materials of natural origin. The results show that synthetic materials are better suited to the role of plate materials in evaporative air coolers.
Demis Pandelidis; Anna Pacak; Aleksandra Cichoń; Wojciech Gizicki; William Worek; Sabri Cetin. Experimental study of plate materials for evaporative air coolers. International Communications in Heat and Mass Transfer 2020, 120, 105049 .
AMA StyleDemis Pandelidis, Anna Pacak, Aleksandra Cichoń, Wojciech Gizicki, William Worek, Sabri Cetin. Experimental study of plate materials for evaporative air coolers. International Communications in Heat and Mass Transfer. 2020; 120 ():105049.
Chicago/Turabian StyleDemis Pandelidis; Anna Pacak; Aleksandra Cichoń; Wojciech Gizicki; William Worek; Sabri Cetin. 2020. "Experimental study of plate materials for evaporative air coolers." International Communications in Heat and Mass Transfer 120, no. : 105049.
This paper presents a numerical and experimental study of four novel, desiccant air-conditioning systems based on pre-cooling of the ambient air. The purpose of the study is to: 1) establish which configuration is most profitable for the future studies through numerical and experimental methods; 2) verify the concept of pre-cooled system and confirm that it is working in experimental conditions (for this purpose two prototypes of evaporative cooling units were developed and compared for different operation arrangements with desiccant wheel); 3) Analyze practical aspects of the systems, which includes water consumption analysis, economic analysis and establishing operational modes during a cooling season in temperate climate conditions (the proposed solution has a significant advantage during operation in a temperate climate, since it can utilize its first evaporative cooler the only source of cooling energy when the humidity of outdoor air allows to to meet the latent cooling load). Four arrangements of the system with different dew point evaporative air cooler prototypes were selected and developed for comparative analysis. The system was simulated as a whole, also, each component was individually tested on measurement station. develop the optimal arrangement of the system through numerical and experimental analysis. Four different performance indicators were considered: thermal COP (Coefficient Of Performance), the ERR (Energy Efficiency Ratio), coefficient a describing the potential in compensating indoor cooling loads, water consumption ratio. Also costs of the systems were compared through economic analysis. It was established that arrangement which is characterized by best-averaged performance in terms of all considered factors is a unit combined with two different types of evaporative coolers (marked as System B)- this is caused by the favorable arrangement of two units, where one is better suited to the pre-cooler role, while the other is better suited as the post-cooler.
Demis Pandelidis; Anna Pacak; Aleksandra Cichoń; Paweł Drąg; William Worek; Sabri Cetin. Numerical and experimental analysis of precooled desiccant system. Applied Thermal Engineering 2020, 181, 115929 .
AMA StyleDemis Pandelidis, Anna Pacak, Aleksandra Cichoń, Paweł Drąg, William Worek, Sabri Cetin. Numerical and experimental analysis of precooled desiccant system. Applied Thermal Engineering. 2020; 181 ():115929.
Chicago/Turabian StyleDemis Pandelidis; Anna Pacak; Aleksandra Cichoń; Paweł Drąg; William Worek; Sabri Cetin. 2020. "Numerical and experimental analysis of precooled desiccant system." Applied Thermal Engineering 181, no. : 115929.
This paper presents the performance research of a hybrid air conditioning system (System II) equipped with novel dew point evaporative cooler (DPIEC) for a retail building located in temperate climatic conditions. The new cooler has a dedicated, adaptable structure that maximizes its performance in the climate conditions of central Europe. The unit can operate as a typical regenerative air cooler when outdoor air is drier than indoor air, it can operate as a counter-flow heat recovery unit when indoor conditions are more dry than outdoor and it can operate as a combination of both arrangements. The year-round, hourly-stepped building energy simulations were carried-out using a prognostic tool of energy consumption. The novel dew point evaporative cooler application potential was established using the black-box model based on regression equations was established based on experimental tests on a prototype of novel DPIEC. The hybrid system operation was compared to the typical air handling unit equipped with a standard energy wheel for heat recovery (System I). Presented research shows that DPIEC can cover about 95% of total cooling loads while the energy wheel covers only 9% of total cooling load. System II allows us to save 65% of seasonal electricity consumption comparing to System I. It comes from the fact that during most of the cooling season DPIEC is in operation and it covers most of the cooling loads without the need to switch the chilled water system.
Demis Pandelidis; Elżbieta Niemierka; Anna Pacak; Piotr Jadwiszczak; Aleksandra Cichoń; Paweł Drąg; William Worek; Sabri Cetin. Performance study of a novel dew point evaporative cooler in the climate of central Europe using building simulation tools. Building and Environment 2020, 181, 107101 .
AMA StyleDemis Pandelidis, Elżbieta Niemierka, Anna Pacak, Piotr Jadwiszczak, Aleksandra Cichoń, Paweł Drąg, William Worek, Sabri Cetin. Performance study of a novel dew point evaporative cooler in the climate of central Europe using building simulation tools. Building and Environment. 2020; 181 ():107101.
Chicago/Turabian StyleDemis Pandelidis; Elżbieta Niemierka; Anna Pacak; Piotr Jadwiszczak; Aleksandra Cichoń; Paweł Drąg; William Worek; Sabri Cetin. 2020. "Performance study of a novel dew point evaporative cooler in the climate of central Europe using building simulation tools." Building and Environment 181, no. : 107101.
The following paper presents the first numerical comparison of heat and mass transfer processes in a traditional cooling tower and a solution based on the Maisotsenko cycle (M-Cycle). The results of the simulation allowed us to analyze the heat and mass transfer process occurring inside the M-Cycle and the traditional cooling tower and to observe its most important characteristics and features. The analysis was performed for two hypothetical situations: 1) both towers having the same external dimensions: the Number of heat Transfer Units (NTU) of M-Cycle cooling tower was two times smaller, due to its geometry; 2) two towers have the same mass transfer surface (i.e. identical NTU in wet channels). It was confirmed that M-Cycle Cooling Tower (MCT) can cool the water below the wet-bulb temperature (which is not achievable by conventional cooling towers), even in very hot and humid conditions (outdoor air temperature of 40 °C and humidity ratio of 20 g/kg). Also, the influence of the selected parameters (including inlet air temperature and humidity, inlet water temperature, NTU, and heat capacity ratio between water and air) on cooling tower performance are documented. Critical factors which have the highest impact on its effectiveness are established and discussed. The study confirmed high practical potential of using M-Cycle in water cooling applications.
Demis Pandelidis; Marlena Drąg; Paweł Drąg; William Worek; Sabri Cetin. Comparative analysis between traditional and M-Cycle based cooling tower. International Journal of Heat and Mass Transfer 2020, 159, 120124 .
AMA StyleDemis Pandelidis, Marlena Drąg, Paweł Drąg, William Worek, Sabri Cetin. Comparative analysis between traditional and M-Cycle based cooling tower. International Journal of Heat and Mass Transfer. 2020; 159 ():120124.
Chicago/Turabian StyleDemis Pandelidis; Marlena Drąg; Paweł Drąg; William Worek; Sabri Cetin. 2020. "Comparative analysis between traditional and M-Cycle based cooling tower." International Journal of Heat and Mass Transfer 159, no. : 120124.
This paper presents a first study of novel air conditioning system based on quasi isothermal dehumidification combined with dew-point evaporative cooling through the Maisotsenko cycle (M-Cycle). The dehumidification process is realized in desiccant coated heat exchanger with heat rejection system. The key idea behind the solution is to maximize the cooling effectiveness by creating favourable conditions for dehumidification and evaporative cooling process. This is achieved by rejecting the heat of sorption in the desiccant system and providing cold and dry air for M-Cycle air cooler, which allows the system to be powered by using low-grade heat energy at 50 °C. The analysis is performed on the basis of experimentally validated numerical models of each component combined in a unified model of the system. The goal of the study is to determine the performance of the solution under different operational conditions. In addition two types of M-Cycle air coolers (i.e. cross-flow and regenerative unit) are compared to establish which unit is more suitable as the source of cooling energy for the system. It was established that proposed system is able to provide comfortable room parameters (supply air temperature equal 17 °C and humidity ratio equal 0.010 kg/kg-da) for outdoor air temperatures ranging from 28 to 36 °C and outdoor air humidity ranging from 0.010 to 0.018 kg/kg-da. This means that the proposed solution is able to provide comfortable conditions in temperate and humid climates. Results also indicate that the system consisting of the regenerative M-Cycle HMX allows better cooling load management, offers higher thermal Coefficient of Performance (COPth) and uses less water compared to the system with the cross-flow HMX. However, the system with cross-flow heat and mass exchanger (HMX) has a relatively greater electrical Coefficient of Performance (COPel) in most cases.
Mrinal Jagirdar; Demis Pandelidis; Anna Pacak; William Worek; Sabri Cetin. Performance evaluation of an air conditioning system based on quasi isothermal dehumidifcation. Energy Conversion and Management 2020, 217, 113009 .
AMA StyleMrinal Jagirdar, Demis Pandelidis, Anna Pacak, William Worek, Sabri Cetin. Performance evaluation of an air conditioning system based on quasi isothermal dehumidifcation. Energy Conversion and Management. 2020; 217 ():113009.
Chicago/Turabian StyleMrinal Jagirdar; Demis Pandelidis; Anna Pacak; William Worek; Sabri Cetin. 2020. "Performance evaluation of an air conditioning system based on quasi isothermal dehumidifcation." Energy Conversion and Management 217, no. : 113009.
Following paper presents detail investigation of the Maisotsenko cycle (M-Cycle) cooling tower through numerical modeling. For the purpose of this study, ε-NTU model of the M-Cycle cooling tower (MCT) was developed and validated against experimental data. The results of the simulation allowed to analyze the heat and mass transfer process occurring inside the M-Cycle cooling tower and observe its most characteristic and important features. It was confirmed that MCT is able to cool the water below the wet-bulb temperature (which is not achievable by conventional cooling towers), even in very hot and humid conditions (outdoor air temperature of 40 °C and humidity ratio of. 20 g·kg−1). They also allowed to study the influence of the selected parameters (including inlet air temperature and humidity, inlet water temperature, NTU and heat capacity ratio between water and air) on the cooling tower performance. Critical factors which have highest impact on its effectiveness were established and discussed. The study confirmed high practical potential of using M-Cycle in water cooling applications.
Demis Pandelidis. Numerical study and performance evaluation of the Maisotsenko cycle cooling tower. Energy Conversion and Management 2020, 210, 112735 .
AMA StyleDemis Pandelidis. Numerical study and performance evaluation of the Maisotsenko cycle cooling tower. Energy Conversion and Management. 2020; 210 ():112735.
Chicago/Turabian StyleDemis Pandelidis. 2020. "Numerical study and performance evaluation of the Maisotsenko cycle cooling tower." Energy Conversion and Management 210, no. : 112735.
In this study, four arrangements of the desiccant system with different Maisotsenko Cycle (M-Cycle) heat and mass exchangers (counter-flow and cross flow heat and mass exchangers) were selected for a comparative study. The proposed system is able to obtain high thermal COPs (up to 4.9) due to effective pre-cooling of the airflow with a highly effective evaporative heat and mass exchanger. The performance of the systems was analyzed numerically with ε–NTU models developed by the authors for moderate climatic conditions. To compare selected systems, different performance indicators were considered. These are the thermal COP (Coefficient of performance), the ERR (Energy Efficiency Ratio), and the humidity ratio decreases. The results show that the desiccant system with two counter-flow heat and mass exchangers (marked as System A) achieves highest humidity ratio decrease, as well as the highest thermal COP. In terms of the EER, factor for system with counter-flow and cross flow heat and mass exchanger (marked as System B) achieves highest effectiveness. There is a slight difference between COP values obtained by System A and System B. That is why it was concluded that System B is a solution which needs more analysis to be done to maximize this desiccant system potential.
Anna Pacak; Demis Pandelidis; Sergey Anisimov. Precooling in Desiccant Cooling Systems with Application of Different Indirect Evaporative Coolers. Robotics in Education 2019, 16 -25.
AMA StyleAnna Pacak, Demis Pandelidis, Sergey Anisimov. Precooling in Desiccant Cooling Systems with Application of Different Indirect Evaporative Coolers. Robotics in Education. 2019; ():16-25.
Chicago/Turabian StyleAnna Pacak; Demis Pandelidis; Sergey Anisimov. 2019. "Precooling in Desiccant Cooling Systems with Application of Different Indirect Evaporative Coolers." Robotics in Education , no. : 16-25.
In this study, the mathematical model equations for solid desiccant system integrated with indirect evaporative coolers with Maisotsenko - Cycle are presented. The authors chose the modified ε–NTU method to describe heat and mass transfer processes in regenerative indirect evaporative cooler and desiccant wheel. The models based on the ε–NTU method show satisfactory agreement with experimental results. That is why this method allows to analyze and develop the performance of solid desiccant systems. In this study, the models allowed to prove that solid desiccant system with an additional heat exchanger before the desiccant wheel (System 1) obtains higher thermal COP values, higher humidity ratio drop and lower supply airflow temperatures in comparison to system with only one heat exchanger after the desiccant wheel (System 2).
Anna Pacak; Demis Pandelidis; Sergey Anisimov. Mathematical modelling of solid desiccant systems. ITM Web of Conferences 2018, 23, 00029 .
AMA StyleAnna Pacak, Demis Pandelidis, Sergey Anisimov. Mathematical modelling of solid desiccant systems. ITM Web of Conferences. 2018; 23 ():00029.
Chicago/Turabian StyleAnna Pacak; Demis Pandelidis; Sergey Anisimov. 2018. "Mathematical modelling of solid desiccant systems." ITM Web of Conferences 23, no. : 00029.
Following paper presents a comparative study of the indirect evaporative exchangers operating as heat recovery units, arranged in the counter- and cross-flow configuration. Presented analyses are carried out with particular emphasis on the condensation process that occurs in the product air channels of the exchangers. Several aspects related to the water vapor condensation are address. Those aspects include the identification of factors that influence the condensation process and analyzing those factors impact on different IEC exchanger configuration. Another issue is a performance comparison of the counter- and cross-flow exchanger for various inlet parameters and operating conditions. Performed analyses are based on the numerical simulations conducted with mathematical ε–NTU model of the heat and mass transfer. Presented model is validated against experimental data and the measurements taken at the test station. Achieved results showed that the counter-flow configuration has higher sensible and latent cooling potential than the cross-flow unit. Nonetheless, due to the technical limitation of the counter-flow configuration, the cross-flow exchanger achieved higher Energy Efficiency Ratio and is characterized by lower investment cost.
Demis Pandelidis; Aleksandra Cichoń; Anna Pacak; Sergey Anisimov; Paweł Drąg. Performance comparison between counter- and cross-flow indirect evaporative coolers for heat recovery in air conditioning systems in the presence of condensation in the product air channels. International Journal of Heat and Mass Transfer 2018, 130, 757 -777.
AMA StyleDemis Pandelidis, Aleksandra Cichoń, Anna Pacak, Sergey Anisimov, Paweł Drąg. Performance comparison between counter- and cross-flow indirect evaporative coolers for heat recovery in air conditioning systems in the presence of condensation in the product air channels. International Journal of Heat and Mass Transfer. 2018; 130 ():757-777.
Chicago/Turabian StyleDemis Pandelidis; Aleksandra Cichoń; Anna Pacak; Sergey Anisimov; Paweł Drąg. 2018. "Performance comparison between counter- and cross-flow indirect evaporative coolers for heat recovery in air conditioning systems in the presence of condensation in the product air channels." International Journal of Heat and Mass Transfer 130, no. : 757-777.
This paper presents a numerical study of a novel, multi-stage desiccant air conditioning system designed for moderate climates. The proposed system is based on multi-stage cooling process through the Maisotsenko Cycle (M–Cycle), regenerative heat and mass exchangers (pre-cooling and post-cooling) combined with a desiccant wheel. The performance of the system was analysed numerically with original ε–NTU models and it was compared with a typical solution based on a desiccant wheel and the Maisotsenko cycle. It was found that multi-stage system obtains lower supply airflow temperatures and higher moisture content decrease in desiccant wheel as compared to typical M-Cycle desiccant system. Moreover, this solution allows a decrease in the regeneration airflow temperature to 40 °C maintaining the same or lower supply airflow temperature in moderate climatic conditions. Using multi-stage cooling, the proposed system was able to attain a thermal COP (defined as amount of cooling capacity obtained by the unit divided by required heating capacity) of up to 4.0. Due to this performance the proposed system has high application potential in moderate climates.
Demis Pandelidis; Anna Pacak; Aleksandra Cichoń; Sergey Anisimov; Paweł Drąg; Borys Vager; Vladimir Vasilijev. Multi-stage desiccant cooling system for moderate climate. Energy Conversion and Management 2018, 177, 77 -90.
AMA StyleDemis Pandelidis, Anna Pacak, Aleksandra Cichoń, Sergey Anisimov, Paweł Drąg, Borys Vager, Vladimir Vasilijev. Multi-stage desiccant cooling system for moderate climate. Energy Conversion and Management. 2018; 177 ():77-90.
Chicago/Turabian StyleDemis Pandelidis; Anna Pacak; Aleksandra Cichoń; Sergey Anisimov; Paweł Drąg; Borys Vager; Vladimir Vasilijev. 2018. "Multi-stage desiccant cooling system for moderate climate." Energy Conversion and Management 177, no. : 77-90.
Following paper focuses on the application of a counter-flow indirect evaporative cooler as a heat recovery device in air conditioning systems in temperate climate (climate where temperature in summer does not exceed 32 °C and humidity ratio does not exceed 15 g/kg, which is typical for Central and Eastern Europe). The purpose of the study is to show the potential of retrofitting conventionally used recuperator exchangers by changing them into indirect evaporative coolers (IEC). Study was performed with original ε-NTU-model. Proposed analysis discussed the critical operational aspects of the IEC unit operating as a heat recovery device, including detail discussion about the heat and mass transfer process with and without condensation in the product air channel and investigation of the influence of different parameters on the exchanger performance. Achieved results are additionally compared with the conventional recuperation process, which is commonly used in temperate climates, in order to show the energy savings which can be obtained by simple modification of such devices. It was found that the counter-flow indirect evaporative cooler is suitable for these climate conditions and it allows to significantly increase the temperature drop during heat recovery process in compare with the commonly used recuperators. In addition, several important operational aspects where analyzed, including analysis of pressure drops inside IEC unit and potential of water recovery from the condensation inside the unit.
Demis Pandelidis; Aleksandra Cichoń; Anna Pacak; Sergey Anisimov; Paweł Drąg. Counter-flow indirect evaporative cooler for heat recovery in the temperate climate. Energy 2018, 165, 877 -894.
AMA StyleDemis Pandelidis, Aleksandra Cichoń, Anna Pacak, Sergey Anisimov, Paweł Drąg. Counter-flow indirect evaporative cooler for heat recovery in the temperate climate. Energy. 2018; 165 ():877-894.
Chicago/Turabian StyleDemis Pandelidis; Aleksandra Cichoń; Anna Pacak; Sergey Anisimov; Paweł Drąg. 2018. "Counter-flow indirect evaporative cooler for heat recovery in the temperate climate." Energy 165, no. : 877-894.
In this study, two different indirect evaporative coolers operating with a desiccant wheel are compared theoretically: System A with the regenerative Maisotsenko Cycle (M-Cycle) unit and System B with the cross-flow M-cycle unit. Each system component performance was simulated using the original ε-NTU model. The influence of selected operational factors, such as inlet air temperature, humidity and regeneration air temperature for two system configurations was analysed and compared. It was established, that System B obtains higher cooling capacities and is more sensitive on ambient air humidity changes than System A.
Anna Pacak; Aleksandra Cichoń; Demis Pandelidis; Sergey Anisimov. Impact of indirect evaporative air cooler type on the performance of desiccant systems. E3S Web of Conferences 2018, 44, 00134 .
AMA StyleAnna Pacak, Aleksandra Cichoń, Demis Pandelidis, Sergey Anisimov. Impact of indirect evaporative air cooler type on the performance of desiccant systems. E3S Web of Conferences. 2018; 44 ():00134.
Chicago/Turabian StyleAnna Pacak; Aleksandra Cichoń; Demis Pandelidis; Sergey Anisimov. 2018. "Impact of indirect evaporative air cooler type on the performance of desiccant systems." E3S Web of Conferences 44, no. : 00134.
This paper investigates the potential of applying an indirect evaporative cooler for heat recovery in air conditioning systems in moderate climates. The counter-flow indirect evaporative heat and mass exchanger is compared with commonly used recuperation unit in terms of achieved energy. The performance analysis of the indirect evaporative exchanger is carried out with original ε-NTU-model considering condensation from treated air. It was found that the indirect evaporative exchanger employed as a heat recovery device, allows to obtain higher performance than conventional recuperator. Additional energy savings potential is related with utilizing the potential of water evaporation to pre-cool the outdoor air. It is also stated that there is a high potential of reusing condensate that forms in product channels of the indirect evaporative exchanger and in the vapour-compression unit and delivering it to the working part of the indirect evaporative exchanger.
Aleksandra Cichoń; Anna Pacak; Demis Pandelidis; Sergey Anisimov. Reducing energy consumption of air-conditioning systems in moderate climates by applying indirect evaporative cooling. E3S Web of Conferences 2018, 44, 00019 .
AMA StyleAleksandra Cichoń, Anna Pacak, Demis Pandelidis, Sergey Anisimov. Reducing energy consumption of air-conditioning systems in moderate climates by applying indirect evaporative cooling. E3S Web of Conferences. 2018; 44 ():00019.
Chicago/Turabian StyleAleksandra Cichoń; Anna Pacak; Demis Pandelidis; Sergey Anisimov. 2018. "Reducing energy consumption of air-conditioning systems in moderate climates by applying indirect evaporative cooling." E3S Web of Conferences 44, no. : 00019.
Demis Pandelidis; Sergey Anisimov; Paweł Drąg; Marek Sidorczyk; Anna Pacak. Analysis of application of the M-Cycle heat and mass exchanger to the typical air conditioning systems in Poland. Energy and Buildings 2018, 158, 873 -883.
AMA StyleDemis Pandelidis, Sergey Anisimov, Paweł Drąg, Marek Sidorczyk, Anna Pacak. Analysis of application of the M-Cycle heat and mass exchanger to the typical air conditioning systems in Poland. Energy and Buildings. 2018; 158 ():873-883.
Chicago/Turabian StyleDemis Pandelidis; Sergey Anisimov; Paweł Drąg; Marek Sidorczyk; Anna Pacak. 2018. "Analysis of application of the M-Cycle heat and mass exchanger to the typical air conditioning systems in Poland." Energy and Buildings 158, no. : 873-883.
In the article the performance of the advanced indirect evaporative air cooler has been investigated. The application of the heat and mass exchanger in an air conditioning systems have been analyzed according to the typical climatic conditions in Poland. The considered indirect evaporative air cooler is based on the cross-flow heat and mass exchanger model with the Maisotsenko cycle (M-Cycle). The main conclusion is that an application of heat and mass exchanger with the M-Cycle to the typical air conditioning systems to the typical climatic conditions in Poland is characterized by the high cooling efficiency.
Demis Pandelidis; Sergey Anisimov; Pawel Drag; Anna Pacak. Application Potential of the M-Cycle Exchanger to Air Conditioning Systems in Poland. DEStech Transactions on Environment, Energy and Earth Sciences 2017, 1 .
AMA StyleDemis Pandelidis, Sergey Anisimov, Pawel Drag, Anna Pacak. Application Potential of the M-Cycle Exchanger to Air Conditioning Systems in Poland. DEStech Transactions on Environment, Energy and Earth Sciences. 2017; (edep):1.
Chicago/Turabian StyleDemis Pandelidis; Sergey Anisimov; Pawel Drag; Anna Pacak. 2017. "Application Potential of the M-Cycle Exchanger to Air Conditioning Systems in Poland." DEStech Transactions on Environment, Energy and Earth Sciences , no. edep: 1.
In this study theoretical analysis of the heat and mass transfer in counter-flow recuperators used for energy recovery in air handling units (AHU) under sub-zero outdoor air temperature operating conditions is presented. The most probable variants of year-round heat exchanger operation performance, which characterized by existence of three active heat and mass transfer zones (“dry”, “wet”, “frost”), and effect of the latent heat of water vapour condensation on the realization of these variants was determined. It was established, that the frost tends to take place with increasing temperature effectiveness of the heat exchanger. Two main techniques of the frost prevention (preheating and bypassing the outdoor airflow) were described and analysed. The values of critical outdoor temperatures and outdoor-to-return airflow rate ratio were determined on the base of parametric frosting limits analysis conducted under different inlet return airflow conditions. The comparison of the heat recovery efficiency and additional energy consumption for the air treatment in the AHU is presented.
Anna Pacak; Demis Pandelidis; Sergey Anisimov; Andrzej Jedlikowski. Analysis of freeze protection methods for recuperators used in energy recovery from exhaust air. E3S Web of Conferences 2017, 22, 129 .
AMA StyleAnna Pacak, Demis Pandelidis, Sergey Anisimov, Andrzej Jedlikowski. Analysis of freeze protection methods for recuperators used in energy recovery from exhaust air. E3S Web of Conferences. 2017; 22 ():129.
Chicago/Turabian StyleAnna Pacak; Demis Pandelidis; Sergey Anisimov; Andrzej Jedlikowski. 2017. "Analysis of freeze protection methods for recuperators used in energy recovery from exhaust air." E3S Web of Conferences 22, no. : 129.
This paper presents results of mathematical simulation of the heat and mass transfer in the two different Maisotsenko Cycle (M-Cycle) heat and mass exchangers used for the indirect evaporative cooling in different air-conditioning systems. A two-dimensional heat and mass transfer model is developed to perform the thermal calculations of the indirect evaporative cooling process, thus quantifying the overall heat exchangers’ performance. The mathematical model was validated against the experimental data. Numerical simulations reveal many unique features of the considered units, enabling an accurate prediction of their performance. Results of the model allow for comparison of the two types of heat exchangers in different applications for air conditioning systems in order to obtain optimal efficiency.
Demis Pandelidis; Sergey Anisimov; Krzysztof Rajski; Ewa Brychcy. Propositions of improvement of the cross-flow M-Cycle heat exchangers in different air-conditioning applications. E3S Web of Conferences 2017, 22, 131 .
AMA StyleDemis Pandelidis, Sergey Anisimov, Krzysztof Rajski, Ewa Brychcy. Propositions of improvement of the cross-flow M-Cycle heat exchangers in different air-conditioning applications. E3S Web of Conferences. 2017; 22 ():131.
Chicago/Turabian StyleDemis Pandelidis; Sergey Anisimov; Krzysztof Rajski; Ewa Brychcy. 2017. "Propositions of improvement of the cross-flow M-Cycle heat exchangers in different air-conditioning applications." E3S Web of Conferences 22, no. : 131.