An algorithm for designing a cooling system for photovoltaic panels

Solar Energy ◽  
2019 ◽  
Vol 194 ◽  
pp. 450-460 ◽  
Author(s):  
Roozbeh Yousefnejad ◽  
Nima Atabaki ◽  
Mu Chiao
Hydrogen ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 207-224
Author(s):  
Hugo Lambert ◽  
Robin Roche ◽  
Samir Jemeï ◽  
Pascal Ortega ◽  
Daniel Hissel

Tropical climate is characterized by hot temperatures throughout the year. In areas subject to this climate, air conditioning represents an important share of total energy consumption. In some tropical islands, there is no electric grid; in these cases, electricity is often provided by diesel generators. In this study, in order to decarbonize electricity and cooling production and to improve autonomy in a standalone application, a microgrid producing combined cooling and electrical power was proposed. The presented system was composed of photovoltaic panels, a battery, an electrolyzer, a hydrogen tank, a fuel cell, power converters, a heat pump, electrical loads, and an adsorption cooling system. Electricity production and storage were provided by photovoltaic panels and a hydrogen storage system, respectively, while cooling production and storage were achieved using a heat pump and an adsorption cooling system, respectively. The standalone application presented was a single house located in Tahiti, French Polynesia. In this paper, the system as a whole is presented. Then, the interaction between each element is described, and a model of the system is presented. Thirdly, the energy and power management required in order to meet electrical and thermal needs are presented. Then, the results of the control strategy are presented. The results showed that the adsorption cooling system provided 53% of the cooling demand. The use of the adsorption cooling system reduced the needed photovoltaic panel area, the use of the electrolyzer, and the use of the fuel cell by more than 60%, and reduced energy losses by 7% (compared to a classic heat pump) for air conditioning.


Author(s):  
P.R. Swann ◽  
A.E. Lloyd

Figure 1 shows the design of a specimen stage used for the in situ observation of phase transformations in the temperature range between ambient and −160°C. The design has the following features a high degree of specimen stability during tilting linear tilt actuation about two orthogonal axes for accurate control of tilt angle read-out high angle tilt range for stereo work and habit plane determination simple, robust construction temperature control of better than ±0.5°C minimum thermal drift and transmission of vibration from the cooling system.


Author(s):  
John G. Sheehan

The goal is to examine with high resolution cryo-SEM aqueous particulate suspensions used in coatings for printable paper. A metal-coating chamber for cryo-preparation of such suspensions was described previously. Here, a new conduction-cooling system for the stage and cold-trap in an SEM specimen chamber is described. Its advantages and disadvantages are compared to a convection-cooling system made by Hexland (model CT1000A) and its mechanical stability is demonstrated by examining a sample of styrene-butadiene latex.In recent high resolution cryo-SEM, some stages are cooled by conduction, others by convection. In the latter, heat is convected from the specimen stage by cold nitrogen gas from a liquid-nitrogen cooled evaporative heat exchanger. The advantage is the fast cooling: the Hexland CT1000A cools the stage from ambient temperature to 88 K in about 20 min. However it consumes huge amounts of liquid-nitrogen and nitrogen gas: about 1 ℓ/h of liquid-nitrogen and 400 gm/h of nitrogen gas. Its liquid-nitrogen vessel must be re-filled at least every 40 min.


2019 ◽  
Vol 6 (3) ◽  
pp. 80-85
Author(s):  
Denis Igorevich Smagin ◽  
Konstantin Igorevich Starostin ◽  
Roman Sergeevich Savelyev ◽  
Anatoly Anatolyevich Satin ◽  
Anastasiya Romanovna Neveshkina ◽  
...  

One of the ways to achieve safety and comfort is to improve on-board air conditioning systems.The use of air cooling machine determines the air pressure high level at the point of selection from the aircraft engine compressor. Because of the aircraft operation in different modes and especially in the modes of small gas engines, deliberately high stages of selection have to be used for ensuring proper operation of the refrigeration machine in the modes of the aircraft small gas engines. Into force of this, most modes of aircraft operation have to throttle the pressure of the selected stage of selection, which, together with the low efficiency of the air cycle cooling system, makes the currently used air conditioning systems energy inefficient.A key feature of the architecture without air extraction from the main engines compressors is the use of electric drive compressors as a source of compressed air.A comparative analysis of competing variants of on-board air conditioning system without air extraction from engines for longrange aircraft projects was performed at the Moscow Aviation Institute (National Research University).The article deals with the main approaches to the decision-making process on the appearance of a promising aircraft on-board air conditioning system at the stage of its conceptual design and formulated the basic requirements for the structure of a complex criterion at different life cycle stages.The level of technical and technological risk, together with a larger installation weight, will require significant costs for development, testing, debugging and subsequent implementation, but at the same time on-board air conditioning system scheme without air extraction from the engines will achieve a significant increase in fuel efficiency at the level of the entire aircraft.


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