Top PDF Feasibility study of Maisotsenko indirect evaporative air cooling cycle in Iran

Feasibility study of Maisotsenko indirect evaporative air cooling cycle in Iran

Feasibility study of Maisotsenko indirect evaporative air cooling cycle in Iran

This paper presents energy and exergy analysis of air cooling cycle based on novel Maisotsenko indirect evaporative cooling cycle. Maisotsenko cycle (M-cycle) provides desired cooling condition above the dew point and below the wet bulb temperature. In this study, based on average annual temperature, The Iran area is segmented into eleven climates. In energy analysis, wet-bulb and dew point effectiveness, cooling capacity rate and in exergy analysis, exergy input rate, exergy destruction rate, exergy loss, exergy efficiency, exergetic COP and entropy generation rate for Iran's weather conditions in the indicated climates are calculated. Moreover, a feasibility study based on water evaporation rate and Maisotsenko cycle was presented. Energy and exergy analysis results show that the fifth, sixth, seventh and eighth climates are quite compatible and Rasht, Sari, Ramsar and Ardabile cities are irreconcilable with the Maisotsenko cycle.
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The energy and exergy analysis on the performance of counter-flow heat and mass exchanger for M-Cycle indirect evaporative cooling

The energy and exergy analysis on the performance of counter-flow heat and mass exchanger for M-Cycle indirect evaporative cooling

A new type of heat and mass exchanger (HMX) taking advantage of the Maisotsenko cycle (M- Cycle) [1] has attracted great attention in recent years for providing the air below the wet bulb temperature of inlet air without moisture content increase. Usually, the heat and mass transfer characteristics and performance of the HMX are investigated through numerical simulations [2-6], experiments [7-8] and analytic methods [9-11]. However, the most of the previous studies made use of the mathematical models that were sourced from the first law of thermodynamics and neglected the existence of the energy quality and irreversibility of the thermodynamic process. Nevertheless, the exergy analysis, known as the second law method, can characterize the irreversibility of the heat and mass transfer processes within the HMX and fulfill of the incompleteness of the energy analysis alone. In conjunction with exergy analysis, the energy applied can be utilized better and HMX design can be oriented towards a possible state of thermodynamic perfection.
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A Review on Potential of Indirect Evaporative Cooling System

A Review on Potential of Indirect Evaporative Cooling System

One of the world’s most energy consuming sector is heating, ventilation and air conditioning. A lot of energy is consumed by traditional cooling systems based on the conventional vapour compression refrigeration cycle. The VCR system which contains refrigerants in circuits produced a harmful effect on environment and also dangerous to human life if leakages occur. These factors were mainly responsible for the development of evaporative coolers. In direct evaporative cooling system, it will give adequate temperature drop of air with increase in humidity which is not desirable for human health. So for overcoming these difficulties, indirect evaporative cooling system will be used for air coolers in which heat mass exchanger is used. To get higher temperature drop and wet bulb effectiveness above 100%, Scientist Valeriy Maisotsenko developed Maisotsenko cycle. The aim of our study is to find the best alternative of existing conventional cooling systems.
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Experimental Verification of Indirect Evaporative Cooling-Assisted Internally Cooled Liquid Desiccant Dehumidifier

Experimental Verification of Indirect Evaporative Cooling-Assisted Internally Cooled Liquid Desiccant Dehumidifier

The main objective of this study is to estimate the system performance of an evaporative cooling assisted internally cooled liquid desiccant dehumidifier (ICLD). The feasibility of an evaporative cooling assisted ICLD is analyzed using an environmental climate chamber test for a variation in the working airflow on the evaporative cooling channel. In the process air channel of the ICLD, the air stream was maintained at a constant mass flow rate when the working air steam was changed to modulate the increase in airflow ratio from 0.25 to 1.0. The ICLD performance was measured under a constant temperature and humidity to simulate hot and humid outdoor air conditions. To evaluate its performance, the cooling capacity, wet-bulb effectiveness, coefficient of performance, and volumetric mass transfer coefficient of the ICLD were evaluated based on the measured data. As the results indicate, the 0.5 ratio of airflow between the working and process air stream showed a higher performance in terms of dehumidification and sensible cooling than a different airflow ratio.
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Fresh Air Pre-cooling and Energy Recovery by Using Indirect Evaporative Cooling in Hot and Humid Region – A Case Study in Hong Kong

Fresh Air Pre-cooling and Energy Recovery by Using Indirect Evaporative Cooling in Hot and Humid Region – A Case Study in Hong Kong

in hot and humid regions because of its relatively low cooling capacity [1] . Many researchers suggest that EC can be used as an effective way for fresh air pre-cooling combined with mechanical cooling, especially when huge amount of fresh air is needed, but the application cases are very limited [2~3] . This paper reports a case study for applying a hybrid Regenerative Indirect Evaporative Cooling System (RIECS) with mechanical cooling to an all-fresh-air A/C system of a wet market in Hong Kong. The original proposed Rotating Heat Recovery Wheel (RHRW) is substituted by the RIECS. The feasibility study has been carried out to analyse the energy saving and economic efficiency of the RIECS, and compare its performance with a wheel heat recovery system and a system without any heat recovery device. The results provide references for EC fresh air pre-cooling applications in hot and humid regions.
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Extracting Radiant Cooling From Building Exhaust Air Using the Maisotsenko Cycle Principle

Extracting Radiant Cooling From Building Exhaust Air Using the Maisotsenko Cycle Principle

* Corresponding email: eteitelb@princeton.edu ABSTRACT Indirect evaporative cooling has exciting implications for air based thermal comfort. With recent advances in the research and commercialization of Maisotsenko Cycle (M-Cycle), or dew-point, evaporative cooling, thermodynamics can be fully leveraged to provide effectively free air cooling. However, few studies seek to generate cool surfaces by evaporation for radiant cooling. As a method to reduce building energy consumption, such an evapo-radiative system would maintain occupant thermal comfort at higher ventilation air temperatures and provide cooling at low cost. This study explores an analytical model for an M-Cycle evapo-radiative cooling system that derives a 1-D temperature profile throughout an experimental module and compares the outputs to experimental data to begin the model validation process.
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Solar assisted desiccant evaporative cooling system for office buildings in Iran: a yearly simulation model

Solar assisted desiccant evaporative cooling system for office buildings in Iran: a yearly simulation model

Abstract. In this research, the feasibility of solar assisted desiccant evaporative cooling system for oce buildings was studied. An oce building located in Chabahar, Iran, as a high cooling load demanding region, was considered as the case study. Dierent congurations as desiccant-based cooling systems were examined to determine the most appropriate conguration in terms of established indoor air conditions and required cooling energy. The congurations were simulated hourly, and the monthly mean values were determined. TRNSYS software was used for this purpose. The results indicated that the desiccant-based cooling system operating in the recirculation cycle with pre- cooling Cong. E has the potential to keep the indoor air conditions within the standard recommendations. In addition, it was shown that Cong. E is the superior conguration in terms of the energy performance and can meet the cooling energy requirements of the space. The potential for providing the desiccant regeneration heat by the solar energy was also investigated. Three standard solar thermal panels were explored to propose the most proper array plant. The study showed that an array of solar panels, consisting of two rows of four unglazed solar thermal collectors, could meet the heat energy requirement by the regenerating process.
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Performance Analysis of Indirect Evaporative Cooling System using M Cycle

Performance Analysis of Indirect Evaporative Cooling System using M Cycle

The experimental results of the evaporative air cooler prototype were compared against the previous experimental study (Riangvilaikul and Kumar 2010). The comparison was made on the basis of the different operating conditions, structural and geometrical sizes of heat/ mass exchanger. In Fig. 21 and Fig. 22, the rates of decreases in wet bulb and dew point effectiveness with increasing air velocity were similar between the previous experimental study and recent experiment. In previous experimentally study inlet dry bulb temperature and humidity ratio maintained as a 34°C and 19 g/kg respectively.
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A Review of Evaporative Cooling Technologies

A Review of Evaporative Cooling Technologies

Several research studies conducted to develop and modify the thermal process of the M-cycle IEC to overcome the above mentioned drawbacks and to enhance the efficiency and increase the thermal performance. Zhao et al. [31] introduced a new counter-flow heat and mass exchanger based on M-cycle of a dew-point evaporative cooling system. In this structure, unlike the cross-flow Maisotsenko-cycle heat exchanger, holes are located at end of flow channels as presented in Fig. 8. The product air flows through and along the dry channels losing sensible heat to wet channels and at the end of dry channels part of cooled product air is delivered to the conditioned space and the remaining air is diverted to the adjacent wet channels as cold working air transferring heat latently with the water and sensibly with the product air in the dry channel. It was found that the wet bulb effectiveness achieve up to 130% and dew-point effectiveness of up to 90%. Furthermore, a comparative study between cross-flow and counter-flow M-cycle base IEC system showed that the counter-flow arrangement achieved around 20% higher cooling capacity and 15–23% higher dew-point and wet-bulb effectiveness respectively under the same geometrical sizes and operational conditions. Contradictory, the cross-flow exchanger has 10% higher performance which is due to an increase in power consumption of counter-flow heat exchanger [32].
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Using Evaporative Cooling Methods for Improving Performance of an Air cooled Condenser

Using Evaporative Cooling Methods for Improving Performance of an Air cooled Condenser

A water pump is used to raise the water pressure and causes the water vapor to exist from the nozzles. The volume flow rate of the water that used in these three modifications processes is fixed and measured continuously, and the water evaporation for these systems is also estimated. The (VN) modification process makes the condenser air flow to contain an evaporated water droplet for increasing the heat transfer. The (VN) produce very small droplets (below 25μm in size) which injected in a counter flow to the air stream direction for an optimal evaporation result. For (SW) modification, the initial experimental investigations show that the optimum condenser cooling performance would be achieved when the nozzle is located about (4.5 cm) above the top surface of condenser coil.
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Low energy, wind catcher assisted indirect-evaporative cooling system for building applications

Low energy, wind catcher assisted indirect-evaporative cooling system for building applications

Figure 5.4 Incorporation of the modified wind catcher with the PEC and fans The PEC used in this system (Figure 5.5) has a diamond shape which allows a cross flow arrangement; the PEC media is manufactured from a special cellulose paper (pads) that absorb and hold moisture and these are separated by thin plastic sheets to give structural strength and prevent moisture exchange. As presented earlier in section 4.1.the cross fluted design of the PEC media results in two important effects. First, it optimizes the amount of surface area available to hold the water which the air flows over, and secondly the way it is aligned causes the air to change direction in a way that ensures all of the air to be contacted with the wetted media surface before leaving the pad. A carefully designed flute angle directs water towards both the air inlet and outlet side; the water then intrinsically flushes away dust, algae, and mineral build up on the evaporation surfaces.
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The Industrial Choice. SPRAY TYPE AIR COOLER. Air Cleaning Humidification Air Conditioning Dehumidification Evaporative Cooling

The Industrial Choice. SPRAY TYPE AIR COOLER. Air Cleaning Humidification Air Conditioning Dehumidification Evaporative Cooling

This single device is capable of performing several func- tions depending upon how the thermodynamic condition of the water is controlled. If we recirculate water and pass out- side air through the air cooler we have an evaporative cooler. The recirculated water will stabilize at near the wet bulb tem- perature, and the temperature difference between the entering and leaving air will approach the wet bulb depression. The evaporative cooler may be used effectively in almost all areas of the United States for spot cooling of personnel working in high-heat producing operations, for general cooling of whole areas of hot operation where large air volumes can be used. This same cooler can work as a highly efficient heat absorber when provided with chilled water from a mechani- cally refrigerated chiller or from a well (well water temperature 55°F or lower).
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EVAPORATIVE COOLING AND HUMIDIFICATION ADIATEC EVAPORATIVE COOLING AND HUMIDIFICATION. High-Pressure System

EVAPORATIVE COOLING AND HUMIDIFICATION ADIATEC EVAPORATIVE COOLING AND HUMIDIFICATION. High-Pressure System

• Pulls air from above the system rather than below, using the warmest air and minimizing the chance for condensation forming from fog return. • Utilizes flexible tubing to increase installation speed. • The hub style system allows for easier access to

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Evaporative Cooling and Humidification

Evaporative Cooling and Humidification

b. What parameters would be affected? The parameters that will be affected will be mass flow rates, temperature and enthalpy. 5. Conclusion The group learned how to use the heat exchanger and the cooling tower. For the entering air, the relative humidity reached its highest value on Trial 4 and remained constant until Trial 6. For the exiting air, the range of the relative humidity is close to each other but did not become constant averaging to 68%. Its highest relative humidity happened in Trial 4 with 70.2%.

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Thermal Effectiveness Characteristics of Low Approach Indirect Evaporative Cooling Systems in Buildings

Thermal Effectiveness Characteristics of Low Approach Indirect Evaporative Cooling Systems in Buildings

The thermal effectiveness of such systems (as a measure of the degree to which the system has succeeded in exploiting the cooling potential of the ambient air) is a key parameter. This paper presents the results of experimental research into the thermal effectiveness of a water-side, open, indirect evaporative cooling test rig, designed to achieve low (1–4 K) approach conditions in the temperate maritime climate of northern Europe. The sensitivity of the thermal effectiveness to a series of key operating variables is investigated. High thermal effectiveness of up to 0.76 was found with both cooling tower air-flow rate and secondary water-flow rate having a strong impact. Primary water-flow rate however, has a weak impact on thermal effectiveness but a major impact on energy performance—indicating scope for a considerable improvement in energy performance at the expense of a minor reduction in thermal effectiveness. A proposed energy efficient control strategy for this form of cooling water generation is proposed and supported by an analysis of the measured results.
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Air Conditioning System with Modified Condenser Ducts and Evaporative Cooling

Air Conditioning System with Modified Condenser Ducts and Evaporative Cooling

Air movement over the surface of condenser tubes is by natural convection. As air comes in contact with the warm- condenser tubes, it absorbs heat from the refrigerant and thus the temperature of the air increases. Warmer air being lighter rises up and cooler air replaces it from below to take away the heat from the condenser. This cycle goes on. Since air moves very slowly by natural convection, the rate of flow of heat from the refrigerant to air will be small. Thus a natural convection condenser is not capable of rejecting heat rapidly. Therefore a relatively large surface area of the condenser is required.
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Performance Improvement of a Regenerative Gas Turbine Cycle Through Integrated Inlet Air Evaporative Cooling and Steam Injection

Performance Improvement of a Regenerative Gas Turbine Cycle Through Integrated Inlet Air Evaporative Cooling and Steam Injection

Nishida et al. 1 have analyzed the performance characteristics of two configuration of regenerative steam-injection gas turbine (RSTIG) systems. They concluded that the thermal efficiencies of the RSTIG systems are higher than those of regenerative, water injected and STIG systems. . Hawaj & Mutairi 2 studied a cogeneration system comprising a combined cycle power plant (CCPP) with an absorption chiller used for space cooling. They have also studied the relative advantage of using CCPP with absorption cooling over thermally equivalent mechanical vapor compression (MVC).They found that a cogeneration CCPP with absorption cooling yields significantly less power penalty than a CCPP with a MVC cooling. Pelster et al. 3 studied the combined cycle with advanced options viz. compressor air inter-cooling, water injection and reheating. They studied environmental and economic analysis simultaneously. They have optimized the system for economic and other better operations. Bhargava & Homji 4 have studied parametric analysis of existing gas turbines with inlet evaporative and overspray fogging. Chaker et al. 5 have presented fog droplet sizing analysis, nozzle types, measurement, and testing. The result of extensive experimental and theoretical studies conducted over several years includes coupled with practical aspects learned in the implementation of nearly 500 inlet fogging systems on gas turbines ranging in power from 5 to 250 MW. This study describes the different measurement techniques available, covers design aspects of nozzles, provides experimental data on different nozzles, and provides recommendations for a standardized nozzle testing method for gas turbine inlet air fogging. Bansode 6 have studied the effect of fog cooling system for inlet air cooling. They concluded that performance parameters indicative of inlet fogging effects have a definite correlation with the climate condition (humidity and temperature) and showed improvement in turbine power and heat rate. Alexis 7 has studied the performance parameters for the design of a combined refrigeration and electrical power cogeneration system. A steam power cycle (Rankine) produces electrical power 2 MW and steam is bleeded off from the turbine at 7bar to warm a factor or units of buildings during winter or to supply a steam ejector refrigeration cycle to air-conditioning the same area during the summer. Kumar et al. 8 have been developed design methodology for parametric study and thermodynamic performance evaluation of a gas turbine cogeneration system (CGTS).
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Energy Saving in Split Air Conditioner using Evaporative Cooling Pad at the ODU

Energy Saving in Split Air Conditioner using Evaporative Cooling Pad at the ODU

E nergy is a very significant factor in driving durable economic growth and development of any country. The decrease of energy consumption through efficient energy use or by reducing the consumption of energy sources is a goal in all engineering fields. Air conditioning systems are nowadays commonly used in buildings due to the improvement of both qualities of life and comfort levels in the society. Lombard et al. [1] presented review on building energy consumption and according to that HVAC system consumes about 10% of total energy consumption in developed countries. Since huge numbers of air conditioners are in use, any considerable improvement in the performance of the same will have a huge effect on the power consumption. In summer when the temperature is so high, the power consumption of air conditioners increases abruptly and as a consequence, their performance decreases. This problem arises as the compressor has to produce a higher pressure ratio than its design condition.
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EVAPORATIVE COOLING DESIGN GUIDELINES MANUAL

EVAPORATIVE COOLING DESIGN GUIDELINES MANUAL

One historical name for some types of EAC's is an "air washer". Although some older versions of air washers were not very efficient at cleaning tiny particulate from the air stream, they would catch and wash down some dust and larger particulates. Newer evaporative pads with denser media are better at washing the air, but still are not as efficient as typical air filter media. The tradeoff for high filtration efficiency is the pressure drop across the filtering media that the supply fan has to overcome, thus using more fan energy. The newer 12 to 18" thick (in the direction of air flow) rigid media is much more efficient at filtration because it has two methods of air filtration. First is the fluted bend inside the cardboard media that makes the air change direction slightly. When the air molecules change direction, the heavier dust particles can't turn as fast, and impact on the media wall (known as an inertial mass separator). The second stage to the filtration is the wet surface where the dust particle impacted. Through surface tension, it holds on to the dust, and eventually is washed into the sump (known as a viscous impingement filter, like your nose). While evaporative media is not designed to operate as a filter, the 12" rigid media when wet will capture over 90% of particles 5-10 microns or larger, according to test information from Munters Corp., a manufacturer of rigid media. “Fungus spores are usually from 10 to 30 micron, while pollen grains are from 10 to 100 micron, with many common varieties in the 20 to 40 micron range… Particles larger than 8 to 10 micron in diameter are separated and retained by the upper respiratory tract”. 33 See Figure 20 for the for the particle size efficiency graph.
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A critical review on evaporative desiccant cooling

A critical review on evaporative desiccant cooling

A simulation study on desiccant wheel shows the achievable working range of DAC system [16]. It is found that the DAC system can achieve versatile range of humidity and temperature but its performance and economic feasibility (PEF) depends on some static constraints which include: (i) Ambient conditions (temperature, humidity, SHR), (ii) Demand conditions (temperature, humidity, flow rate or ventilation), (iii) Type of regeneration heat source (electricity, gas, solar or waste heat). A solar thermal and electric driven desiccant cooling system was experimentally evaluated [16]. During nighttime the system stored thermal energy for daytime initial operation which makes the system cost effective by using relatively lower price of electricity hence was preventing total reliance on solar energy. The system was preliminarily tested in winter season and was concluded that it can be operated in day and night time economically. The study was expanded by same authors with the aim to develop a novel desiccant HVAC system. The outdoor air conditions were set to the standard summer condition i.e. 30 1C and 60% RH with flow rate of 200 m 3 /h. The return air was kept at standard
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