Low-temperature frostless heat pump system for exhaust sensible heat regeneration and method

Abstract

The invention provides a low-temperature frostless heat pump system for exhaust sensible heat regeneration. The low-temperature frostless heat pump system comprises a heat pump circulation system anda solution regeneration system; the heat pump circulation system involves a compressor, a four-way reversing valve, a coupling condensation heat exchanger, a first throttling valve, an economizer, a second throttling valve, a heat exchanger, a heat source tower and a solution pump; and the solution regeneration system involves a dead steam recovery chamber, a degasser, a condenser, a dilute solution pump, a first-effect flash evaporation chamber, an intermediate-effect evaporation chamber, a last-effect evaporation chamber, a first-effect circulating pump, an intermediate-effect circulating pump, a last-effect circulating pump, a concentrated solution pump, a condensate pump and a vacuum pump. The invention further provides a using method of the low-temperature frostless heat pump system for exhaust sensible heat regeneration. According to the low-temperature frostless heat pump system for exhaust sensible heat regeneration and and the method, the external circulation flash evaporationof an anti-freezing solution is adopted for the first effect, the irreversible loss of heat transfer caused by large heating temperature difference is reduced, a heating surface is separated from anevaporation surface, and the problem of scaling of the evaporation surface is avoided.

Description

technical field [0001] The invention belongs to the technical field of heat pumps, and in particular relates to a low-temperature frost-free heat pump system and method for regeneration of exhaust sensible heat. Background technique [0002] The biggest problem currently existing in the air source heat pump system is frosting on the surface of the outdoor heat exchanger in winter conditions. Frosting increases the heat exchanger surface resistance, resulting in reduced heating performance and system operating efficiency. At present, there are two ways to solve the frosting problem of air source heat pumps: one is to adopt defrosting technical measures, and the other is to adopt anti-frost technical measures. Conventional defrosting methods mainly include reverse cycle defrosting and hot gas bypass defrosting. Although reverse cycle defrosting can effectively defrost, it needs to absorb heat from the room during defrosting, resulting in large fluctuations in indoor temperat...

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Problems solved by technology

One is that when the solution is in direct contact with the air, most of the heat directly heats the air instead of evaporating water; secondly, the evaporated water vapor cannot be reused, resulting in energy waste

[0004] The invention patents with application numbers ZL201410465836.3 and ZL201410495879.1 respectively proposed a multi-effect distillation and multi-stage flash evaporation coupled with an air source heat pump system. method, the regeneration efficiency is greatly improved, and the application number is ZL201811629423. The patent has been further improved, and a compressor exhaust heat-driven regeneration process is proposed, which is conducive to increasing the operating pressure of the concentration system and is easy to maintain the vacuum of the system. However, this method needs to treat antifreeze It enters the heat exchanger for heating at one time. Under the same heating amount, it is easy to have the problem of high irreversible loss of heat transfer caused by large heating temperature difference or low regeneration efficiency caused by high cycle rate. In addition, considering the falling film evaporation process The amount of antifreeze sprayed in the medium is relatively small. In this application, the antifreeze is directly sprayed onto the surface of the falling film evaporation tube, which may easily lead to insufficient spray density and dry spots, which will reduce the heat transfer performance of the system.

In addition, the above patents for the frost-free heat pump system based on antifreeze regeneration do not address the gas injection enthalpy low-temperature heat pump cycle, which is very common in the northern region

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