Energy-Efficient Air-Conditioning Systems for Nonhuman Applications
In addition to humans’ thermal comfort, air-conditioning (AC) could be required for various nonhuman applications, for example, animals’ AC, greenhouse AC, food storage and transportation, industrial processes, and so on. In this regard, optimum conditions of air temperature and humidity are explored and compared on psychrometric charts. Thermodynamic limitations of existing AC systems are discussed from the subject point of view. Consequently, four kinds of low-cost energy-efficient AC systems, namely: (i) direct evaporative cooling (DEC), (ii) indirect evaporative cooling (IEC), (iii) Maisotsenko cycle (M-Cycle) evaporative cooling (MEC), and (iv) desiccant AC (DAC), are investigated for climatic conditions of two cities, that is, Multan (Pakistan) and Fukuoka (Japan). In addition, systems’ fundamentals and principles are explained by means of schematic diagrams and basic heat/mass transfer relationships. According to the results, performance of all systems is influenced by ambient air conditions; therefore, a particular AC system cannot provide optimum AC for all nonhuman applications. However, one or other AC system can successfully provide desired conditions of temperature and relative humidity. It has been concluded that evaporative cooling systems provide low-cost AC for dry climates, whereas DAC system is found energy efficient and viable for humid climates.
Part of the book: Refrigeration
Investigation of Desiccant and Evaporative Cooling Systems for Animal Air-Conditioning
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.
Part of the book: Low-temperature Technologies
Temperature and Humidity Control for the Next Generation Greenhouses: Overview of Desiccant and Evaporative Cooling Systems
Temperature and humidity control are crucial in next generation greenhouses. Plants require optimum temperature/humidity and vapor pressure deficit conditions inside the greenhouse for optimum yield. In this regard, an air-conditioning system could provide the required conditions in harsh climatic regions. In this study, the authors have summarized their published work on different desiccant and evaporative cooling options for greenhouse air-conditioning. The direct, indirect, and Maisotsenko cycle evaporative cooling systems, and multi-stage evaporative cooling systems have been summarized in this study. Different desiccant materials i.e., silica-gels, activated carbons (powder and fiber), polymer sorbents, and metal organic frameworks have also been summarized in this study along with different desiccant air-conditioning options. However, different high-performance zeolites and molecular sieves are extensively studied in literature. The authors conclude that solar operated desiccant based evaporative cooling systems could be an alternate option for next generation greenhouse air-conditioning.
Part of the book: Next-Generation Greenhouses for Food Security
Adsorption-Based Atmospheric Water Harvesting: Technology Fundamentals and Energy-Efficient Adsorbents
Nowadays, atmospheric water harvesting (AWH) became very essential to provide fresh potable water. This technique is in practice since 1900 (US661944A) by Edger S. Belden. Atmospheric water is a source of freshwater with 13000 trillion liters availability of water at any time and can be utilized in overcoming water shortage, especially in arid and rural areas. It holds up the water molecules in the form of vapors and accounts for adding 10% of all freshwater present on the earth. Mainly, the two most common methods have been used for the extraction of atmospheric water. First, the ambient air is cooled below the dew point temperature, and second in which the moisture in atmospheric air is adsorbed/absorbed using desiccant materials. Conventional vapor compression, thermoelectric cooling, dew, and fog water harvesting based systems/technologies possess some limits in terms of energy requirements, less efficiency, and high cost. However, the adsorption based AWH technology is relatively cheaper, environment friendly, and can be operated by a low-grade thermal energy source. The limited availability of commercial instruments to harvest atmospheric water using adsorbents indicates a lack of fundamental studies. The fundamental research on water adsorption, adsorption kinetics, regeneration conditions, and water collecting surface designs has not gained as much interest as required in the field of atmospheric water harvesting. In this regard, this book chapter discusses and presents the progress in the field of adsorbent materials and system designs along with the future directions to accelerate the commercialization of this technology.
Part of the book: Technology in Agriculture
Advancements of Spraying Technology in Agriculture
Plant protection activities are most important practices during crop production. Application of maximum pesticide products with the sprayer. The application of fungicides, herbicides, and insecticides is one of the most recurrent and significant tasks in agriculture. Conventional agricultural spraying techniques have made the inconsistency between economic growth and environmental protection in agricultural production. Spraying techniques continuously developed in recent decades. For pesticide application, it is not the only sprayer that is essential, but all the parameters like the type and area of the plant canopy, area of a plant leaf, height of the crop, and volume of plants related to plant protection product applications are very important for obtaining better results. From this point of view, the advancement in agriculture sprayer has been started in last few decades. Robotics and automatic spraying technologies like variable rate sprayers, UAV sprayers, and electrostatic sprayers are growing to Increase the utilization rate of pesticides, reduce pesticide residues, real-time, cost-saving, high compatibility of plant protection products application. These technologies are under the “umbrella” of precision agriculture. The mechanized spraying system, usually implemented by highly precise equipment or mobile robots, which, makes possible the selective targeting of pesticide application on desire time and place. These advanced spraying technologies not only reduces the labour cost but also effective in environmental protection. Researchers are conducting experimental studies on the design, development and testing of precision spraying technologies for crops and orchards.
Part of the book: Technology in Agriculture
An Overview of Soil Moisture and Salinity Sensors for Digital Agriculture Applications
Soil salinity and the water crisis are imposing significant challenges to more than 100 countries as dominant factors of agricultural productivity decline. Given the rising trend of climate change and the need to increase agricultural production, it is crucial to execute appropriate management strategies in farmlands to address salinity and water deficiencies. Ground-based soil moisture and salinity sensors, as well as remote sensing technologies in satellites and unmanned aerial vehicles, which can be used for large-scale soil mapping with high accuracy, play a pivotal role in precision agriculture as advantageous soil condition monitoring instruments. Several barriers, such as expensive rates and a lack of systematic networks, may hinder or even adversely impact the progression of agricultural digitalization. As a result, integrating proximal equipment with remote sensing and Internet of things (IoT) capabilities has been shown to be a promising approach to improving soil monitoring reliability and efficiency. This chapter is an attempt to describe the pros and cons of various soil sensors, with the objective of promoting IoT technology in digital agriculture and smart farming.
Part of the book: Digital Agriculture, Methods and Applications
Agrovoltaic and Smart Irrigation: Pakistan Perspective
The present study aims to investigate the prospects and challenges that need to be encountered for the adaptation of the novel agrovoltaic irrigation system (AVIS) in Pakistan. The agro-production scenario in Pakistan is periodically declining and leading toward the high delta crops, which develop severe pressure on the conventional energy and water resources. Groundwater might be a viable water source, but its pumping requires massive energy. In addition, excessive pumping declines the water table at a higher pace as compared to the recharge rate hence leading the country toward the exploitation of the valuable reservoir. The AVIS could be an energy-efficient and reliable irrigation solution in a manner of harvesting solar energy for driving smart irrigation systems capable to pumps the metered groundwater according to field requirements. Lack of local understanding, skilled/technical personnel, dependence on local technology, and major capital expenditures might impede technological adaption. The government should take necessary measures to replenish the groundwater reservoirs and also execute research projects that strengthen ground knowledge of AVIS.
Part of the book: Irrigation and Drainage
Crop Residue Collection and Handing Machinery Performance: A Review View all chapters
Increasing demand of agricultural production for human, animal, and industrial requirements is responsible for the enhancement of agricultural and agro-industrial activities. Each step of such activities produces various types of agricultural waste that include crop residue, on-farm livestock and fisheries waste, forest waste, agro-industrial waste, etc. Currently, handling and managing agricultural waste is a challenging task worldwide, especially in the context of environmental pollution control and sustainable agriculture. Thus, efficient management in terms of reuse, recycling, and reduction of agricultural waste is needed not only for the sustainable agriculture but also for farmers’ profitability. Various type of farm machinery is available and are in use to collect the crop residue from the field or directly incorporate the residue into the soil. The incorporated crop residue not only increases the soil fertility but also decreases the greenhouse gases emission due to burning of the crop residue. The crop residue chopper can be a solution of residue management at farmer field level. This chapter provides a review on the crop residue collection handing and incorporation machinery performance and their advancement.
Part of the book: Agricultural Waste