Two-stage flash evaporation and two-stage compression heat pump device with double heat sources and operating method

Abstract

The invention discloses a two-stage flash evaporation and two-stage compression heat pump device with double heat sources and an operating method. The device comprises a heat collection system, a primary flash evaporation system, a secondary flash evaporation system and a steam compression system. The method comprises the following steps: producing hot water introduced into a hot water tank according to different low-grade heat sources through three operation methods of a single heat source including solar heat, double heat sources including solar heat and waste heat and a single heat source including waste heat, and recycling low-grade heat such as solar heat and waste heat through manners of two-stage flash evaporation and two-stage compression. Compared with the organic heat pump working medium, the evaporation latent heat value of the water is high; a large amount of low-grade heat is recycled; the coefficient of performance of the heat pump device is greater than 10; the low-pressure steam is compressed for two times through a low-pressure steam compressor and a high-pressure steam compressor; the quality of the steam can be effectively improved; the temperature of the steam reaches 120 DEG C or higher; the high-temperature heating requirement can be met; the problem of haze pollution caused when the fire coal is used for heating in the northern regions of China in winter is fundamentally solved.

Description

technical field [0001] The invention relates to a heat pump device, more specifically to a two-stage flashing two-stage compression heat pump device with dual heat sources, belonging to the technical field of energy and heat pumps. Background technique [0002] In the era of rapid economic development, environmental issues have become the primary issue, posing severe challenges to the long-term survival and development of human beings. Especially in North China in winter, when coal-fired heating is used for heating, serious smog pollution is caused. Under the policy of "coal-to-electricity", the use of heat pump devices for heating and heating has become a mainstream, but the condensing temperature of existing heat pump devices Most of them are between 45 and 55°C, which cannot solve the problem of high-temperature heating and heating well. Therefore, it is imperative to develop a new type of high-temperature heat pump device for high-temperature steam generation and high-te...

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Problems solved by technology

As a heat pump working fluid with excellent performance, water is usually used to recover low-grade (below 100°C) heat by means of low-pressure flash evaporation. The low-pressure steam is compressed by a steam compressor to increase the temperature and then used for heat treatment. : "A method of recovering heat from condensate water with double flashing and boosting pressure" adopts the method of "two-stage flashing + pressurization" to recover the heat of 190°C high-temperature condensate. It should be clear that 190°C high-temperature condensate belongs to high Quality heat, the method not only cannot solve the problem of low-grade (below 100°C) heat recovery and conversion into high-grade (above 100°C) heat, but also leads to a decline in the quality of heat (obtained steam temperature is much lower than 190°C condensation water temperature) , is meaningless; another example is the patent: "A Cascaded Recovery System and Method for Waste Heat from Industrial Wastewater", which makes good use of the "low pressure flash evaporation + vapor compression" technology to recover industrial waste heat. Analyzing its principle will reveal the invention There is still the problem that the low-grade heat recovery rate is not efficient enough. Improving the low-grade heat recovery rate is still the key to the technology, and the problem of low condensation temperature of the existing heat pump technology has not been solved well. We still need to do a lot to solve these problems work

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