The dehumidified air was further conditioned with direct and indirect evaporative cooling to produce supply air. Fuel cell based auxiliary power unit for refrigerated trucks. Phosphoric acid fuel cells are generally large and heavy because they are less powerful when compared to other types of fuel cells. The models used for comparison are based on a 60 kw, 360 cell pem fuel cell system. Phosphoric acid fuel cells are also more expensive since the fuel cells require an expensive platinum catalyst. The efficiency of polymer electrolyte fuel cells is closely linked to effective heat and water management. In summary, evaporative cooling is the process of removing heat from a surface due to the evaporation of water. Types of cooling system there are two types of cooling systems. Air cooling system in this type of cooling system, the heat, which is conducted to the outer parts of the engine, is radiated and conducted away by the stream of air, which is obtained from the atmosphere. Quantitative comparison of evaporative and liquid cooled fuel cell systems. Thermal and water management of evaporatively cooled fuel cell vehicles.
Automotive scale fuel cells are most commonly liquid cooled, evaporative cooling is an alternative cooling method where liquid water is added directly into the fuel cell flow channels. The species conservation on a small element of an anode gas channel gives us. Determination of water evaporation rates in gas diffusion. A comparison of evaporative and liquid cooling methods for fuel cell vehicles article pdf available in international journal of hydrogen energy. Evaporative cooling water cannot be used for subsequent purposes other than rain somewhere, whereas surfaceonly cooling water can be reused. Polymer electrolyte membrane pem fuel cells are clean electrical power generators for applications normally up to 100 kw power requirements. Removal of waste heat from a fuel cell is necessary for continuous operation. Is an environmentallyfriendly technology system that addresses recent environmental mandates. A comparison of evaporative and liquid cooling methods for. Polymer electrolyte fuel cells pefc, although a promising technology for carbon free production of electricity, are penalized by system complexity, partly due to cooling and humidifying systems. This manual is intended to be used as a tool for the design of successful and efficient evaporative cooling systems and will allow engineers to specify and design evaporative cooling systems with confidence.
At the point when considering evaporative cooling, one ought to figure out the wet knob and dry globule temperatures of the region. These systems are necessary to avoid the heating up and drying of the membrane, which stop the electrochemical reaction. When the five fuel cells are used in combination with the generator for distrib. Pemfc, like other types of fuel cells, converts the chemical energy of the. On the other hand, the indirect cooling method allows industrial spaces, restaurants or other businesses to cool their spaces to temperatures that are lower than those offered by portable swamp coolers like cool boss. It takes heat energy to change the water or any liquid from a liquid into a vapor. The main disadvantage of this kind of particular cooling is that it is only applicable in dry atmospheres. It used a ld system to dehumidify outside air using membrane hmxs. Thermal and water management of evaporatively cooled fuel cell. Journal logo controloriented model of a membrane humidifier for. This section is dedicated to presenting the fc basis and the content is mainly adapted from the work in.
Pdf evaporativelycooled pem fuelcell stack and system. Evaporation, can be used to remove the heat produced by the exothermic reaction within the fuel cell. A comparison of evaporative and liquid cooling methods for fuel cell vehicles. However, phosphoric acid fuel cells are less efficient when they are used to generate only electricity. Improving the humidification of polymer electrolyte membrane fuelcells.
Fuel cell evaporative cooling using fuel as a carrier gas. An evaporator is exposed to the blown air, and a conduit. When warm, dry unsaturated air is pulled through a watersoaked pad, water is evaporated and is absorbed as water vapor into the air. Novel concept for evaporative cooling of fuel cells. Evaporative cooling differs from typical air conditioning systems, which use vaporcompression or absorption refrigeration cycles. Aeronautical and automotive engineering, loughborough university, loughborough. Evaporation of water in the gas diffusion layers gdl is an important process influencing water management and can even be used for evaporative cooling. The liquid water evaporates within the flow channel, both cooling and humidifying the cell. Review of passive heatingcooling systems of buildings. An evaporative cooler also swamp cooler, swamp box, desert cooler and wet air cooler is a device that cools air through the evaporation of water. Several patents are available in the open literature regarding evaporative cooling for. Water sprayed into a gaseous fuel stream is evaporated in an evaporative cooler adjacent to the fuel cell.
Part of this research program investigated combinations of dehumidification and evaporative cooling in solardriven hybrid desiccant cooling systems. For steam humidifiers, this energy typically comes from the electricity or gas being used to boil the water. Condensationevaporation and transport of liquid water and vapour. Direct and indirect evaporative cooling strategies. Thus, it is of primary interest to develop a fuel cell cooling system controller and validate the assumption that the fuel cell temperature can be maintained without large excursions when subject to fuel cell output power changes and other disturbances. Above approximately 2 kw in output power, water or some other type of liquid cooling fluid is utilized to cool the fuel cell stack instead of air.
Fuel cell cooling can generally be split into three categories, air. Evaporative cooler types evaporative coolers cool boss. Parameters affecting engine transfer engine heat transfer depends upon many parameters,unless the effect of these parameters is known, the design of a proper cooling system will be difficult. This projects objective is to bring a novel technology called the combined air conditioner and power cacp system to technology readiness level trl 6. In this article, we discuss the types of cooling system in engine. Fuel cell thermal management through conductive cooling.
C engine require a cooling system because combustion of fuel takes place inside the engine itself. Thermal and water management of evaporatively cooled fuel. Thermal storage is used to store energy for heating or cooling until needed and uses tank and cell types of storage. The five types resulted from the knowledge that heat accelerates chemical reaction rates and thus the electrical current. Pdf a comparison of evaporative and liquid cooling. History products and services guide contents page introduction 2 history. Pdf despite having efficiencies higher than internal combustion engines. A cooling tower serves to dissipate the heat into the atmosphere instead and wind and air diffusion spreads the heat over a much larger area than hot water can distribute heat in a body of water. The entrained air from adjacent sources is very likely to be warmer than design or ambient conditions and therefore the performance of the acsc is negatively impacted.
Types of cooling system in engine working and advantages. What are the advantages and disadvantages of evaporative. Cooling tower bureau of energy efficiency 5 syllabus cooling tower. Evaporative cooling design guidelines manual iii evaporative cooling design guidelines manual for new mexico schools and commercial buildings principal investigator. Evaporative cooling is a physical phenomenon in which evaporation of a liquid, typically into surrounding air, cools an object or a liquid in contact with it. The cacp is an integrated fuel cell, with a liquid desiccant airconditioning process. Automotive scale fuel cells are most commonly liquid cooled, evaporative cooling is an. Fuel cells can be divided into five major categories named after the electrolyte used in each. It has the advantage of fast startup due to its low operating temperatures of 60oc to 100oc. There exist two types of humidification systems for pemfc, namely internal. Fc is a device that converts the chemical energy from a fuel hydrogen is the most common fuel into electricity, heat and byproducts generally water through a chemical reaction with oxygen or another oxidizing agent. This work details a full system simulation which is then used to compare a conventional liquid cooled fuel cell system to two types of. To compensate, five of the fuel cells and one gasfired generator whose electric output exceeds the output of two fuel cells are used to meet the buildings peak electricity demand, preventing the grid from becoming overly strained.
However, the low temperature requirement has to be addressed with an efficient thermal management system. A fuel cell can be configured to operate with humidification of. Passive evaporative cooling wall based on various porous layers. A comparison of evaporative and liquid cooling methods for fuel cell vehicles a. An overview of fuel cells currently under development. Course contents evaporative coolers, often called swamp coolers, are cooling systems that use only water and a blower to circulate air. Bazzoa combined capillary cooling system for fuel cells. Novel concept for evaporative cooling of fuel cells dora 4ri. You can duplicate the principle behind direct evaporative cooling by wrapping a wet handkerchief around your neck on a hot day and standing in front of a fan. Since evaporative cooling requires efficient ventilation systems in greenhouses, see fact sheet ae 10 greenhouse ventilation, for details on ventilation.
International journal of engineering research and general. Evaporative cooling, effectiveness, performance, energy saving. A comparison of evaporative and liquid cooling methods for fuel cell. Thermal and coolant flow computational analysis of cooling.
Performance evaluation for indirect evaporative cooling etsce7 southern california edison page i emerging products june 2015 executive summary energy used for air conditioning in buildings necessitates massive investments in electric generation and distribution capacity, draws on a substantial portion of our global fuel. A direct evaporative cooling system is the simplest and most popular evaporative cooling system available. It is not successful in the areas where the dampness is high. Major factors to consider in any maintenance and care program for evaporative cooling are difficult to generalize because several different types of cooling pads are now available. The objective of the work presented here is to develop a lin. This technique can be employed with various types of fuel cells, such as membrane fuel cells, phosphoric acid fuel cells, alkaline fuel cells, solid oxide fuel cells, and molten carbonate fuel cells, and various types of fuels, such as methane, propane, naphtha, and natural gas. Evaporative cooling occurs when air, that is not too humid, passes over a wet. Learn vocabulary, terms, and more with flashcards, games, and other study tools. All evaporative cooler types have one thing in common. The fuel cell model remains identical for both cooling methods with the exception of an additional term for liquid water addition in the evaporatively cooled stack and for heat transfer to coolant in the liquid cooled system. Cooling strategies for pem fc stacks helmutschmidtuniversitat. The following two systems are used for cooling the i. The cooling system includes a heat exchange unit coupled to the coolant inlet and the coolant outlet, a coolant pump, and a blower for blowing air through the unit.
Evaporative cooling uses the fact that water will absorb a relatively large amount of heat in. To evaporate 1kg of water into an atmosphere, 680w of energy is required. The fuelsteam stream can then be utilized in the various other fuel cell system operations. The fuel steam stream can then be utilized in the various other fuel cell system operations. Analysis of advanced solar hybrid desiccant cooling. Keeping your cool isnt easy for batteries or fuel cells.
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