A countercurrent heat exchanger

Abstract

The invention proposes a countercurrent heat exchanger, which is a partition wall heat exchanger without mixing between hot and cold gases, and can be used to realize engine exhaust heat recovery, natural gas precooling in natural gas liquefaction process and other gas- Gas heat exchange process. The heat exchanger includes coaxial inner and outer cylinders and a heat exchanger core arranged in a space between the inner and outer cylinders. The heat exchanger core is formed by a hexagonal heat exchanger core basic unit in a circular array around the heat exchanger axis, and the heat exchange air flow is improved through the annular static pressure chamber and the tapered and expanded annular air passage. The uniformity of static pressure distribution on the inlet and outlet sections of the heat exchanger core makes the flow velocity distribution in the heat exchanger more reasonable, and optimizes the heat exchange efficiency and flow resistance of the heat exchanger. In the design of the heat exchanger, special internal heat insulation, internal cooling, expansion gap and fastening design measures are adopted, which can effectively reduce the temperature and thermal stress of the pressure-bearing parts, and improve the pressure-bearing capacity and service life of the heat exchanger.

Description

technical field [0001] The invention relates to a heat exchanger, in particular to a heat exchanger which adopts a countercurrent method and can withstand high temperature and high pressure. Background technique [0002] Gas-to-gas heat exchange is involved in many engineering fields, through which energy can be recovered, thermal efficiency can be improved, or a specific process can be realized more effectively. [0003] In the process of open or closed Brayton power cycle (gas turbine cycle), the exhaust temperature of the expander can reach as high as 600-700°C. With the advancement of modern centrifugal compressor technology, the Brayton cycle device will further develop towards the direction of multi-stage compression intercooling, large flow and small pressure ratio, so that the discharge temperature of the compressor will be lower and lower (<160°C), and the expander will The exhaust temperature is getting higher and higher. At this time, using the exhaust gas of...

AI Technical Summary

Problems solved by technology

[0005] At present, the gas-gas heat exchangers that can directly exchange heat between gas and gas on the market are mainly used in low-pressure or low-temperature environments, such as heat exchangers for industrial furnace tail gas waste heat recovery and preheating air, and their working pressure is approximately One atmospheric pressure, the working temperature does not exceed 400°C, and the equipment is bulky, which cannot meet the technical requirements of the above application fields

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