Combination of air-source heat pumps with liquid desiccant dehumidification of air

Zhang, Li; Hihara, Eiji; Saikawa, Masatoshi

doi:10.1016/j.enconman.2011.12.023

Cited by 74 publications

(21 citation statements)

References 17 publications

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“…Three subsystems in the above two FFASHP heating system contain the following components: evaporator, condenser, expansion valve, compressor, four-way valve, solution pump, sprinkler, solution tank or dehumidifier and regenerator. It should be noted that Figure 13 only gives simple schematic diagrams of the systems and their detailed structures can be referred to the relevant references [79,84,87]. (2) Main parameters For the FFASHP heating system based on method 1, the parameters of the test room and main components are listed in Table 4.…”

Section: Characteristics Of Different Frost-free Technologiesmentioning

confidence: 99%

“…For the FFASHP heating system based on method 2, the solution, the main components, the indoor and outdoor environment parameters in different studies are listed in Tables 6 and 7. Table 6 shows the parameters of numerical calculation of Zhang et al [84]. Table 7 summarizes the analysis calculation and design parameters when Su et al [73,87] and Yongcun et al [53] analyzed the performance of this FFASHP heating system.…”

Section: No Parameter Valuementioning

confidence: 99%

“…Therefore, it is necessary to study the heat transfer enhancement technology of the gas-liquid-solid multiphase heat transfer process on the surface of the air-side fin-tube heat exchanger under the solution spray working condition. For another FFASHP heating system based on an air pre-dehumidification subsystem [84,87] shown in Figure 13, when the ambient air temperature and RH were in the frosting region, the air pre-dehumidification subsystem was opened, the outdoor air (OA) firstly passed through a dehumidifier to reduce the moisture content of the outdoor air and decreased the dew point of the For another FFASHP heating system based on an air pre-dehumidification subsystem [84,87] shown in Figure 13, when the ambient air temperature and RH were in the frosting region, the air pre-dehumidification subsystem was opened, the outdoor air (OA) firstly passed through a dehumidifier to reduce the moisture content of the outdoor air and decreased the dew point of the air.…”

Section: Nomentioning

confidence: 99%

“…Afterwards, the dry air (DA) flowed into the air heat exchanger to heat and evaporate the refrigerant in tube, and there was no frost on the air heat exchanger surface [84].…”

Section: Nomentioning

confidence: 99%

See 3 more Smart Citations

Frosting Phenomenon and Frost-Free Technology of Outdoor Air Heat Exchanger for an Air-Source Heat Pump System in China: An Analysis and Review

Zhang

Zhang³

et al. 2018

Energies

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Frost layer on the outdoor air heat exchanger surface in an air-source heat pump (ASHP) can decrease the system coefficient of performance (COP). Although the common defrosting and anti-frosting methods can improve the COP, the periodic defrosting not only reduces the system energy efficiency but also deteriorates the indoor environment. To solve these problems, it is necessary to clearly understand the frosting phenomenon and to achieve the system frost-free operation. This paper focused firstly on the analyses of frosting pathways and frosting maps. Followed by summarizing the characteristics of frost-free technologies. And then the performances of two types of frost-free ASHP (FFASHP) systems were reviewed, and the exergy and economic analysis of a FFASHP heating system were carried out. Finally, the existing problems related to the FFASHP technologies were proposed. Results show that the existing frosting maps need to be further improved. The FFASHP systems can not only achieve continuous frost-free operation but reduce operating cost. And the total COP of the FFASHP heating system is approximately 30–64% higher than that of the conventional ASHP system under the same frosting conditions. However, the investment cost of the FFASHP system increases, and its reliability also needs further field test in a wider frosting environment. In the future, combined with a new frosting map, the control strategy for the FFASHP system should be optimized.

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Section: Characteristics Of Different Frost-free Technologiesmentioning

confidence: 99%

Section: No Parameter Valuementioning

confidence: 99%

Section: Nomentioning

confidence: 99%

“…Afterwards, the dry air (DA) flowed into the air heat exchanger to heat and evaporate the refrigerant in tube, and there was no frost on the air heat exchanger surface [84].…”

Section: Nomentioning

confidence: 99%

See 2 more Smart Citations

Frosting Phenomenon and Frost-Free Technology of Outdoor Air Heat Exchanger for an Air-Source Heat Pump System in China: An Analysis and Review

Zhang

Zhang³

et al. 2018

Energies

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“…Simulation results showed that the proposed system consumed 51% less cooling energy compared to the conventional VAV (Variable Air Volume) system. A new type of frost-free air-source heat pump system with integrated liquid desiccant dehumidification was proposed [10], and the comparison results showed that COP of the frost-free air-source heat pump system was 30%e40% higher than that of heat pump heating integrated with an electric heater humidifying system. The effect of variable fresh air ratios on the performance of a liquid desiccant air conditioning was studied by Niu et al [11].…”

Section: Introductionmentioning

confidence: 99%

Suggested solution concentration for an energy-efficient refrigeration system combined with condensation heat-driven liquid desiccant cycle

2015

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a b s t r a c tThis paper presents a hybrid energy-efficient refrigeration system enhanced by liquid desiccant evaporative cooling technology for subcooling the refrigerant, where the liquid desiccant cycle is driven by the exhausted heat from the condenser and three commonly used liquid desiccants: LiCl, LiBr and CaCl 2 aqueous solutions are considered here. The solution concentration for the proposed hybrid energyefficient refrigeration system should be determined and optimized carefully for better performance. Sensitive study of solution concentration involved in the hybrid system is conducted at different condensation temperature. The results indicates that under standard working condition (i.e., condensing temperature is 50 C), the optimum solution concentration is 0.31 for LiCl aqueous solution, 0.45 for LiBr aqueous solution and 0.42 for CaCl 2 aqueous solution, while the maximum COPs are nearly same. When the condensing temperature is 45 C, the optimum solution concentration should be set at 0.27 for LiCl aqueous solution, and 0.41 for LiBr aqueous solution and 0.37 for CaCl 2 aqueous solution, while condensing temperature is 55 C, it is 0.35 for LiCl aqueous solution, 0.49 for LiBr aqueous solution and 0.45 for CaCl 2 aqueous solution. The simple fitting formulas are obtained, and performance improvement potential is discussed.

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The Basic Idea of the THIC Air-Conditioning System

Liu

Jiang

Zhang

2013

Temperature and Humidity Independent Control (THIC) of Air-Conditioning System

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Combination of air-source heat pumps with liquid desiccant dehumidification of air

Cited by 74 publications

References 17 publications

Frosting Phenomenon and Frost-Free Technology of Outdoor Air Heat Exchanger for an Air-Source Heat Pump System in China: An Analysis and Review

Frosting Phenomenon and Frost-Free Technology of Outdoor Air Heat Exchanger for an Air-Source Heat Pump System in China: An Analysis and Review

Suggested solution concentration for an energy-efficient refrigeration system combined with condensation heat-driven liquid desiccant cycle

The Basic Idea of the THIC Air-Conditioning System

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