Globally, the greenhouses' farming area comprises 500 000 ha, and they efficiently produce more than half of the vegetables consumed around the world. Nevertheless, high-yield crops tend to be incredibly energy-intensive. This study proposes designing and building a coupled geothermal heat pump for a 470 m greenhouse in the Andean zone conditions addressing a requirement of 15 °C at night and 30 °C during the day. Firstly, the study determined the energy potential of the solar and geothermal sources employing actual measurements and contrasting the results with theoretical models. Then, it developed an energy balance in the greenhouse to size the geothermal heat pump using the vapor compression cycle. Finally, the comprehensive system was built and evaluated through the Leveled Cost of Heat (LCOH). The operation requires a potential of 29.56 and 65.76 kW for heating and cooling; this is technically feasible when running the system with a heating flow driven by an optimized temperature ramp of 1.64 °C h. Also, the capacity factor (CF) shows that a lifespan between 12 to 14 years is required to reach acceptable LCOH when CF is as low as 0.45. Financially, it is necessary to foster customs exemptions to make it competitive versus more traditional sources such as electricity and LPG since the main components of the heat pump and the geothermal exchanger are not produced locally and represent nearly 70 % of the upfront costs.
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http://dx.doi.org/10.1016/j.heliyon.2021.e08608 | DOI Listing |
J Therm Biol
January 2025
Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu, 610000, China.
Maintaining an optimal indoor thermal environment is crucial for enhancing the welfare and productivity of livestock in intensive breeding farms. This paper investigated the application of a combined geothermal heat pump with a precision air supply (GHP-PAS) system for cooling dairy cows on a dairy farm. The effectiveness of the GHP-PAS system in mitigating heat stress in lactating dairy cattle, along with its energy performance and local cooling efficiency in the free stalls were evaluated.
View Article and Find Full Text PDFHeliyon
January 2025
North China Electric Power University, Department of Power Engineering, China.
In the context of global efforts toward energy transition and carbon neutrality, thermal integrated pumped thermal energy storage (TIPTES) systems, especially those utilizing low-grade heat sources, have garnered significant attention due to their large capacity, flexibility, and environmental advantages. This paper explores a TIPTES system that harnesses industrial waste heat as a heat source. The system's heat pump (HP) subcycle and Organic Rankine Cycle (ORC) subcycle are equipped with regenerators to optimize system configuration and enhance efficiency.
View Article and Find Full Text PDFMicromachines (Basel)
November 2024
School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
The ion drag pump, as one kind of electrohydrodynamic pump, has received considerable attention in fluid applications due to its excellent pumping flow rate and pressure. However, there is a lack of systematic research about the factors that influence pumping performance of the ion drag pump. Here, a photo-induced ion drag pump based on the PLZT ceramic is proposed by combining the photoelectric effect and field emission phenomenon.
View Article and Find Full Text PDFJ Vasc Surg Cases Innov Tech
February 2025
Department of Health and Kinesiology, Purdue University, West Lafayette, IN.
Infect Drug Resist
December 2024
Subdean Office, Anqing First People's Hospital of Anhui Medical University, Anqing City, Anhui Province, People's Republic of China.
Purpose: To evaluate the clinical characteristics, antimicrobial resistance (AMR) phenotypes and genotypes, and homology features of carbapenem-resistant (CRAB) in intensive care unit (ICU) and to provide basis for effectively prevention, control and treatment of nosocomial infections caused by CRAB.
Methods: A total of 39 CRAB strains isolated from hospitalized patients in the ICU and neurosurgical ICU (NICU) between 2020 and 2023 were subjected to antimicrobial susceptibility testing and whole-genome sequencing (WGS). Virulence factor genes (VFGs), antimicrobial resistance genes (ARGs), multilocus sequencing typing (MLST), complete genome multilocus sequencing typing (cgMLST), average nucleotide identity (ANI), and single nucleotide polymorphism (SNP) analyses were performed using WGS.
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