Half-decoupling type graded dehumidifying and cooling dehumidifying heat pump system and method

Abstract

The invention provides a half-decoupling type graded dehumidifying and cooling dehumidifying heat pump system comprising a refrigerant system and an air system. The refrigerant system comprises two compressors and four dehumidification heat exchangers, two four-way reversing valves, an evaporator, two throttling devices and two three-way reversing valves. The air system comprises two draught fans,eight air valves and two air openings. According to the half-decoupling type graded dehumidifying and cooling dehumidifying heat pump system, the dehumidification heat exchangers at different operation pressures are connected in parallel, the evaporation side at the low pressure grade is connected with a dehumidification evaporator and the evaporator in series. A high-pressure dehumidification evaporator adopts a drying agent with a uniform adsorption speed to achieve heat and humidity load pretreatment, condensation of the high-pressure dehumidification evaporator is prevented through a highevaporator temperature, and meanwhile the dew point of air entering the low-pressure dehumidification evaporator is lowered; the low-pressure dehumidification evaporator adopts a drying agent with high adsorption capacity to achieve heat and humidity load efficient treatment, and the switch time of circulations is prolonged. The evaporator connected with the low-pressure side in series can solvethe problem that the heat and humidity load processing capacities of the system are inconsistent.

Description

Technical field [0001] The invention relates to a system in the technical field of solid dehumidification heat pumps, and in particular to a dehumidification heat pump system and method for semi-decoupling type dehumidification and cooling. Background technique [0002] The solid dehumidification air conditioning technology treats the latent heat load in the air based on the adsorption of water vapor by the desiccant, and the sensible heat load is processed by natural cooling sources or traditional compression refrigeration systems. The system realizes the separate treatment of sensible heat load and latent heat load. It overcomes the limitation of the compression type air conditioning technology for centralized processing load. However, the adsorption heat released by the dehumidifying material during the solid dehumidification process will increase the equilibrium adsorption temperature between the desiccant and the treated air, which will not only reduce the moisture absorptio...

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Problems solved by technology

However, the adsorption heat released by the dehumidification material during the solid dehumidification process will lead to an increase in the equilibrium adsorption temperature between the desiccant and the treated air, which will not only reduce the hygroscopic performance of the desiccant, but also increase the regeneration temperature of the desiccant.

The refrigerant-cooled dehumidification heat pump cycle based on the desiccant heat exchanger realizes the optimization of the cooling and dehumidification thermal process through a compact structure, but there are still some limitations in this type of cycle: in order to ensure continuous cooling output, dehumidification and heat exchange The desiccant heat exchanger needs to switch relatively frequently between the evaporation and condensation processes, and the desiccant heat exchanger has a high sensible heat and latent heat load handling capacity during the cold and heat alternating process. The time is inconsistent, and the sensible heat load handling capacity is insufficient.

[0003] After searching the public literature of the prior art, it was found that in order to solve the above problems, Experimental investigation and analysis of composite silica-gel coated fin-tube heat exchangers (2015,51:169-179) published by Y. Jiang et al. on the International Journal of Refrigeration ) proposed to increase the pre-cooling process (refrigerant keeps running in the pipe, and the air outside the pipe is not operated by controlling the fan) at the initial stage of switching to the dehumidification evaporator to delay the high moisture absorption performance of the desiccant, but this increases the complexity of the cycle control At the same time, the continuous cooling process cannot be realized, and the condensation problem can only be prevented by controlling the cycle switching time

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