Low-temperature Technologies最新文献

Theoretical and Experimental Analysis of a Thermoelectric Air-conditioning System 热电空调系统的理论与实验分析

Low-temperature Technologies Pub Date : 2020-06-10 DOI: 10.5772/intechopen.88664

Adeyanju Anthony Ademola

{"title":"Theoretical and Experimental Analysis of a Thermoelectric Air-conditioning System","authors":"Adeyanju Anthony Ademola","doi":"10.5772/intechopen.88664","DOIUrl":"https://doi.org/10.5772/intechopen.88664","url":null,"abstract":"Thermoelectric devices use the Peltier effect that creates a heat flux between the junctions of two different types of materials. The thermoelectric module also referred to as a heat pump transfers heat from one side to the other when a DC current is applied. This study carried out the theoretical analysis of a thermoelectric air conditioning system. A prototype thermoelectric air conditioner of 286W cooling capacity was built and a testing enclosure made from plywood and Styrofoam was also constructed in order to validate the theoretical result with an experimentation. It was discovered that thermoelectric air conditioning took 4 minutes to reach its desired temperature of 22°C, whereas the standard air conditioning system (refrigeration cycle) took 20 minutes to cool to a room temperature. Economically, it was also discovered that thermoelectric air conditioning system is 50% cheaper than the refrigeration cycle air conditioning systems. The thermoelectric air conditioner has cheaper maintenance and greater estimated life span of 7 years more than the refrigeration air conditioner. This is because the air conditioner that operates on the refrigeration cycle uses a rotating compressor, while the thermoelectric air conditioner uses thermometric module.","PeriodicalId":363646,"journal":{"name":"Low-temperature Technologies","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131981948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

An Experimental Study of Synthetics and Natural Refrigerants Gases 合成和天然制冷剂气体的实验研究

Low-temperature Technologies Pub Date : 2020-06-10 DOI: 10.5772/intechopen.89119

E. Santos, Carlisson Azevedo, Caio Macêdo, Carla Azevedo, Raíssa Araújo, Sílvia Soares Gomes, Lana Baia, Yves Alexandrino

引用次数: 1

Effect of Nanoparticles on Performance Characteristics of Refrigeration Cycle 纳米粒子对制冷循环性能特性的影响

Low-temperature Technologies Pub Date : 2019-11-27 DOI: 10.5772/intechopen.89236

Ravinder Kumar

引用次数: 8

Central Air Conditioning: Systems and Applications 中央空调:系统与应用

Low-temperature Technologies Pub Date : 2019-11-22 DOI: 10.5772/intechopen.89455

M. Elnaggar, M. Alnahhal

{"title":"Central Air Conditioning: Systems and Applications","authors":"M. Elnaggar, M. Alnahhal","doi":"10.5772/intechopen.89455","DOIUrl":"https://doi.org/10.5772/intechopen.89455","url":null,"abstract":"It became evident nowadays that modernization influences domestic and commercial HVAC industry, and thus high technological and energy-efficient central air conditioning systems are demanded. Therefore, the selection of proper type of central air conditioning system is a crucial target in the construction industry as improper selection can maximize initial and/or running costs of the system and decreases the human comfort and indoor air quality levels. In fact, a pre-assessment of the construction type and budget available is required for selecting the proper type of central air conditioning system. Therefore, there is a continuous need for an updated material in the literature that reviews the central air conditioning systems and applications, which is the moti-vation of the present chapter. The present chapter reviews the central air conditioning systems and applications. Specifically, all-air systems, all-water systems, and air-water systems are discussed. In addition, all provided systems are further explored through several developed schematic diagrams enabling the identification of their various components and the understanding of their working principles. It is may be of interest to note that this chapter is suitable for undergraduate level students in the fields of HVAC and R, mechanical, and construction engineering.","PeriodicalId":363646,"journal":{"name":"Low-temperature Technologies","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124850755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Energy and Exergy Analysis of Refrigeration Systems 制冷系统的能量与火用分析

Low-temperature Technologies Pub Date : 2019-11-12 DOI: 10.5772/intechopen.88862

S. Seyam

引用次数: 0

Designing Spiral Plate Heat Exchangers to Extend Its Service and Enhance the Thermal and Hydraulic Performance 设计螺旋板式换热器，延长其使用寿命，提高其热工性能和水力性能

Low-temperature Technologies Pub Date : 2019-11-05 DOI: 10.5772/INTECHOPEN.85345

Lázaro Canizalez Dávalos, Edilberto Murrieta Luna, Mario Alberto Rodríguez Ángeles, Víctor J. Cruz Delgado

引用次数: 3

Solar Pond Driven Air Conditioning Using Seawater Bitterns and MgCl2 as the Desiccant Source 以海水卤水和氯化镁为干燥剂源的太阳能池驱动空调

Low-temperature Technologies Pub Date : 2019-10-21 DOI: 10.5772/intechopen.89632

Esam Elsarrag, Opubo N. Igobo, P. Davies

{"title":"Solar Pond Driven Air Conditioning Using Seawater Bitterns and MgCl2 as the Desiccant Source","authors":"Esam Elsarrag, Opubo N. Igobo, P. Davies","doi":"10.5772/intechopen.89632","DOIUrl":"https://doi.org/10.5772/intechopen.89632","url":null,"abstract":"Solar energy is used for a wide range of applications such as electricity production, desalination, cooling, heating, etc. Solar-based technologies are widely spread and increasingly studied in the industry. This theoretical and experimental study focuses on solar ponds as a desiccant and low-grade energy source. A thermal model has been developed for a salinity gradient solar pond (SGSP) with a non-convective zone split into 10 sub-zones. A solar pond was constructed and used as a case study for the validation of the predictive model capabilities. The dimensional characteristics of the pond, as well as the solar radiation intensity and ambient temperature data obtained from the meteorological data, were used to produce the solar pond ’ s zone thermal behaviour data. With regards to the thermal behaviour measurements obtained from the solar pond, the predicted data were found to be higher. There is a significant difference between the real-world and meteorological data obtained, the difference between the predicted and real-world pond temperature data was also attributed to the fact that the actual absorbed solar radiation was reduced due to wall shading effect, turbidity and insufficient duration of operation of the pond. In the following year, the stored heat from the previous summer would be expected to improve thermal storage values obtained partially.","PeriodicalId":363646,"journal":{"name":"Low-temperature Technologies","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132322792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Investigation of Desiccant and Evaporative Cooling Systems for Animal Air-Conditioning 动物空调用干燥剂和蒸发冷却系统的研究

Low-temperature Technologies Pub Date : 2019-09-03 DOI: 10.5772/intechopen.88945

M. Sultan, Hassan Niaz, T. Miyazaki

{"title":"Investigation of Desiccant and Evaporative Cooling Systems for Animal Air-Conditioning","authors":"M. Sultan, Hassan Niaz, T. Miyazaki","doi":"10.5772/intechopen.88945","DOIUrl":"https://doi.org/10.5772/intechopen.88945","url":null,"abstract":"Productivity of livestock animals particularly sheep, goats, dairy, and beef cattle are usually affected due to high thermal/heat (sensible and latent) stresses, particularly in the developing countries. Different types of heating, ventilation, and air-conditioning (HVAC) systems are used worldwide depending upon the ambient air conditions to achieve the animals ’ thermal comfort. In this chapter, few low-cost options for the air-conditioning system and for farm building designs are discussed. Desiccant-based two air-conditioning systems are considered i.e., standalone desiccant air-conditioning (D-AC) and M-cycle assisted D-AC (M-DAC) system. The feasibility of both systems is thermodynamically checked for climatic conditions of Multan, Pakistan. Daily- basis data of ambient and processed air from both systems are analyzed for the thermal comfort of Holstein Friesian cows. Temperature humidity index (THI) is calculated to investigate the thermal heat stress conditions. Results showed that the D-AC system can be used efficiently in the humid climatic conditions with relatively moderate-to-low temperatures. On the other hand, the M-DAC system can be used in humid climatic conditions with relatively high-temperature conditions. It is important to mention that the typical direct evaporative cooling systems can be obviously low-cost options in case of dry climatic conditions.","PeriodicalId":363646,"journal":{"name":"Low-temperature Technologies","volume":"241 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133319841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

Comparative Evaluation of Cryogenic Air Separation Units from the Exergetic and Economic Points of View 从动力性和经济性的角度对低温空分装置进行比较评价

Low-temperature Technologies Pub Date : 2019-08-06 DOI: 10.5772/INTECHOPEN.85765

S. Tesch, T. Morosuk, G. Tsatsaronis

{"title":"Comparative Evaluation of Cryogenic Air Separation Units from the Exergetic and Economic Points of View","authors":"S. Tesch, T. Morosuk, G. Tsatsaronis","doi":"10.5772/INTECHOPEN.85765","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.85765","url":null,"abstract":"The industrial use of cryogenic air separation units started more than 120 years ago. Cryogenic air separation processes produce pure nitrogen, oxygen, and argon, as well as other noble gases. In cryogenic air separation units, the produced amounts of nitrogen and oxygen vary between 200 and 40,000 Nm 3 / h and 1000 and 150,000 Nm 3 / h , respectively. Different configurations of this process lead to various amounts of gaseous and liquid products. In addition, the purity of the products is affected by the schematic. Oxygen in gaseous or liquid form is typically used in the metallurgical (e.g., steel) industry, in chemical applications (as oxidizer), in power plants (for oxy-fuel combustion processes), as well as in the medical and aerospace sectors. Nitrogen in gaseous or liquid form is used as inert or flushing gas in the chemical industry and as a coolant for different applications. In this chapter, different schematics of air separation units are analyzed. An exergetic analysis is applied in order to identify the thermodynamic inefficiencies and the processes that cause them. Finally, the systems are evaluated from the economic point of view.","PeriodicalId":363646,"journal":{"name":"Low-temperature Technologies","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123982360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 19

Modeling of the Energy for Bound Water Freezing in Logs Subjected to Refrigeration 原木冷冻过程中结合水冻结能量的模拟

Low-temperature Technologies Pub Date : 2019-04-25 DOI: 10.5772/INTECHOPEN.83772

N. Deliiski, N. Tumbarkova

引用次数: 1