Feasibility of a heat pump-assisted liquid desiccant system for continuous dehumidification and regeneration in temperate oceanic climatic greenhouses

IF 9.9 1区工程技术 Q1 ENERGY & FUELS

Energy Conversion and Management Pub Date : 2024-11-15 DOI:10.1016/j.enconman.2024.119256

Mrinal Bhowmik , Alessandro Giampieri , James Bean , Anthony Paul Roskilly , Zhiwei Ma

{"title":"Feasibility of a heat pump-assisted liquid desiccant system for continuous dehumidification and regeneration in temperate oceanic climatic greenhouses","authors":"Mrinal Bhowmik , Alessandro Giampieri , James Bean , Anthony Paul Roskilly , Zhiwei Ma","doi":"10.1016/j.enconman.2024.119256","DOIUrl":null,"url":null,"abstract":"<div><div>Effective thermo-hygrometric control is essential for buildings and greenhouses, particularly in green and low-carbon production. There is growing interest in integrating heat pumps with liquid desiccant systems to enhance energy efficiency and reduce system size in air moisture control. The current study investigates a novel liquid desiccant system combined with a heat pump for continuous, energy-efficient dehumidification and regeneration in horticultural crop cultivation in greenhouses. The uniqueness of the developed system lies in its integration, contrasting with previous liquid desiccant systems designed with separate dehumidifier and regenerator. A semi-theoretical model is developed and validated using in-house experimental datasets to simulate novel liquid desiccant system performance. Results demonstrate that the system effectively maintains air humidity levels, with a maximum enthalpy demand for dehumidification of 99.1 kJ/kg at a solution temperature difference of 40 °C during summer. The minimum achieved moisture content with lithium chloride, calcium chloride, and potassium formate is 7.64 g/kg<sub>da</sub>, 8.1 g/kg<sub>da</sub>, and 7.78 g/kg<sub>da</sub>, respectively, while regeneration produces maximum moisture contents of 23.5 g/kg<sub>da</sub>, 23.9 g/kg<sub>da</sub>, and 23.7 g/kg<sub>da</sub>. The system's maximum effectiveness reaches 76 %, 75 %, and 74 % for lithium chloride, calcium chloride, and potassium formate, respectively. When dehumidification demand exceeds 1,500 h annually, the payback period is five years or less, making the system suitable for new installations and retrofits. A case study considering outdoor conditions in the northeastern United Kingdom presents simulation results for two distinct scenarios, demonstrating the system's potential in real-world applications.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"323 ","pages":"Article 119256"},"PeriodicalIF":9.9000,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Energy Conversion and Management","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S019689042401197X","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENERGY & FUELS","Score":null,"Total":0}

引用次数: 0

Abstract

Effective thermo-hygrometric control is essential for buildings and greenhouses, particularly in green and low-carbon production. There is growing interest in integrating heat pumps with liquid desiccant systems to enhance energy efficiency and reduce system size in air moisture control. The current study investigates a novel liquid desiccant system combined with a heat pump for continuous, energy-efficient dehumidification and regeneration in horticultural crop cultivation in greenhouses. The uniqueness of the developed system lies in its integration, contrasting with previous liquid desiccant systems designed with separate dehumidifier and regenerator. A semi-theoretical model is developed and validated using in-house experimental datasets to simulate novel liquid desiccant system performance. Results demonstrate that the system effectively maintains air humidity levels, with a maximum enthalpy demand for dehumidification of 99.1 kJ/kg at a solution temperature difference of 40 °C during summer. The minimum achieved moisture content with lithium chloride, calcium chloride, and potassium formate is 7.64 g/kg_da, 8.1 g/kg_da, and 7.78 g/kg_da, respectively, while regeneration produces maximum moisture contents of 23.5 g/kg_da, 23.9 g/kg_da, and 23.7 g/kg_da. The system's maximum effectiveness reaches 76 %, 75 %, and 74 % for lithium chloride, calcium chloride, and potassium formate, respectively. When dehumidification demand exceeds 1,500 h annually, the payback period is five years or less, making the system suitable for new installations and retrofits. A case study considering outdoor conditions in the northeastern United Kingdom presents simulation results for two distinct scenarios, demonstrating the system's potential in real-world applications.

查看原文本刊更多论文

热泵辅助液体干燥剂系统在温带海洋性气候温室中连续除湿和再生的可行性

有效的温湿度控制对建筑物和温室至关重要，尤其是在绿色和低碳生产中。人们越来越关注将热泵与液体干燥剂系统结合起来，以提高能效并缩小空气湿度控制的系统尺寸。本研究调查了一种新型液体干燥剂系统，该系统与热泵相结合，用于温室园艺作物栽培中的连续、节能除湿和再生。所开发系统的独特之处在于它的集成性，与之前设计的液体干燥剂系统（除湿器和再生器分开）形成鲜明对比。为了模拟新型液体干燥剂系统的性能，我们开发了一个半理论模型，并利用内部试验数据集进行了验证。结果表明，该系统能有效保持空气湿度水平，在夏季溶液温差为 40 °C 时，除湿所需的最大焓值为 99.1 kJ/kg。氯化锂、氯化钙和甲酸钾的最小含水量分别为 7.64 g/kgda、8.1 g/kgda 和 7.78 g/kgda，而再生产生的最大含水量分别为 23.5 g/kgda、23.9 g/kgda 和 23.7 g/kgda。氯化锂、氯化钙和甲酸钾的系统最大效率分别达到 76%、75% 和 74%。当每年除湿需求超过 1 500 小时时，投资回收期为五年或更短，因此该系统适用于新安装和改造。一项考虑到英国东北部室外条件的案例研究展示了两种不同情况下的模拟结果，证明了该系统在实际应用中的潜力。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Energy Conversion and Management 工程技术-力学

CiteScore

19.00

自引率

11.50%

发文量

1304

审稿时长

17 days

期刊介绍： The journal Energy Conversion and Management provides a forum for publishing original contributions and comprehensive technical review articles of interdisciplinary and original research on all important energy topics. The topics considered include energy generation, utilization, conversion, storage, transmission, conservation, management and sustainability. These topics typically involve various types of energy such as mechanical, thermal, nuclear, chemical, electromagnetic, magnetic and electric. These energy types cover all known energy resources, including renewable resources (e.g., solar, bio, hydro, wind, geothermal and ocean energy), fossil fuels and nuclear resources.