Cascade thermal storage heating system and method

Abstract

The invention discloses a cascade heat storage heat supply system, which comprises a cascade heat exchange circuit composed of a cascade heat exchange circulation pump, a high temperature heat storage module, and a transitional steady flow heat storage heat exchange module connected sequentially through a cascade heat exchange circulation pipeline and A heat supply circuit composed of a transitional steady flow heat storage heat exchange module and a heat supply circulation pump connected in sequence through the heat supply pipeline, the high temperature heat storage module includes a high temperature heat storage body with a heat exchange pipeline inside, and the heat exchange pipeline Both the inlet and outlet ends are connected to the cascade heat exchange circulation pipeline. The transitional steady flow heat storage heat exchange module includes a medium and low temperature phase change heat storage body with a plurality of heating heat exchange tubes and heat release heat exchange tubes inside. Both the inlet and outlet ends are connected to the cascade heat exchange circulation pipes; the inlet and outlet ends of the exothermic heat exchange pipes are connected to the heat supply pipes; both the cascade heat exchange circulation pipes and the heat supply pipes are equipped with circulating heat transfer materials, and the transition is stable. A heat utilization device is arranged between the heat storage heat exchange module and the heat supply circulation pump. The invention has large heat storage and stable heat supply.

Description

technical field [0001] The invention relates to the technical field of heat storage and heat supply. More specifically, the present invention relates to a cascade thermal storage heating system and method. Background technique [0002] In order to rationally use energy, improve energy utilization efficiency, and adjust the time difference between the energy supply side and the energy demand side, energy storage technology has received strong support and development in recent years. Heat storage technology is mainly divided into three types: thermochemical heat storage, sensible heat heat storage and phase change heat storage. [0003] Sensible heat storage is a method of storing heat through the specific heat capacity and temperature difference of the heat storage body, and storing or releasing heat through the increase or decrease of temperature. High-temperature sensible heat storage is widely used because of its simple operation and high energy storage density. However,...

AI Technical Summary

Problems solved by technology

High-temperature sensible heat storage is widely used due to its simple operation and high energy storage density. However, as the temperature of the heat storage body drops, the output power will fluctuate greatly and the heat transfer will be unstable.

Chinese patents ZL201610318705.7 and ZL 201610323747.X proposed mainly adopting the method of parallel and series pipelines, and by switching the corresponding pipelines in different temperature ranges to increase the heat exchange area, the heat exchange power of the high-temperature heat storage body is achieved. Fluctuations within a certain allowable range, but this scheme cannot completely solve the problem of temperature fluctuations, and can only obtain stable heat supply within a certain fluctuation range

Phase change heat storage has the advantages of large phase change latent heat, narrow phase change temperature range, and can significantly reduce the size of the heat storage device. It is a hot research topic at home and abroad. However, phase change heat storage has poor thermal conductivity, Problems such as low energy storage density and serious corrosion

Chinese patent CN203518746U discloses a multi-stage heat recovery phase change accumulator, which is composed of multiple single-stage phase change accumulators filled with different phase change temperature materials connected in series, which improves the heat absorption rate and heat dissipation rate of phase change materials. Heat rate, but the patent uses a spiral coil heat exchange structure, which is generally limited by the material and is difficult to apply to high temperature environments

This method simplifies the structure of the multi-stage recovery heat accumulator and improves the heat absorption and release rate of the phase change material, but it cannot solve the problem of low energy storage density of the phase change heat accumulator

[0005] The high-temperature heat accumulator with high energy storage density is unstable in heat transfer power, and the control and pipeline layout are relatively complicated. The medium-low temperature phase change heat accumulator has low energy storage density and does not have the ability to stabilize and controllable output.

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