An external cooling system with cold storage for DC converter valve and its operation method

Abstract

The invention provides an external cooling system with cold storage for DC converter valves and its operation method. The system includes an air cooler, a plate heat exchanger, a water chiller, a fixed-frequency cold pump, a buffer tank, and an inclined temperature layer type cold storage tank. , frequency conversion cold pump and cooling water pump. The plate heat exchanger is divided into hot side and cold side. The improvement is that the hot side of the plate heat exchanger is connected in series with the air cooler, plate heat exchanger and cooling water pump. Circulation circuit; the cold side of the plate heat exchanger, the inclined temperature layer cold storage tank, and the frequency conversion cold pump are connected in series to form the cooling branch of the cold storage tank; The cooling branch of the cold tank and the cooling branch of the chiller are connected in parallel and then connected in series with the plate heat exchanger to form a cold side circulating cooling circuit. Compared with the prior art, the external cooling system with cold storage for DC converter valves provided by the present invention and its operation method have a large temperature range of cold storage, can withstand high temperatures in summer, and have antifreeze ability through heat storage in winter.

Description

technical field [0001] The invention relates to an external cooling system, in particular to an external cooling system with cold storage for a DC converter valve and an operating method thereof. Background technique [0002] As my country's high-voltage direct current transmission technology becomes increasingly mature, the construction of direct current transmission projects is in a golden period of development. In the high-voltage direct current transmission system, the cooling system is an important component of the heat dissipation system of the converter valve, and its operation directly affects the power transmission capacity of the entire direct current system. Therefore, it is particularly important to ensure the stable, reliable and efficient operation of the cooling system. [0003] The closed circulating water cooling system of modern high-power power electronic devices usually uses air coolers as external cooling equipment in high cold and water-scarce areas. T...

AI Technical Summary

Problems solved by technology

Due to the periodic change of ambient temperature, when the difference between the inlet water temperature of the air cooler and the ambient temperature is small, the efficiency of the air cooler will be very low and the air cooler will occupy a very large area

Due to the large number of air coolers, the pressure ratio and space layout of pipelines often become a difficult problem for technicians; on the other hand, many converter stations reach the limit temperature and the annual cumulative time within 5°C near the limit is very short , causing the air cooler bank to be idle for much of the year

Finally, the current water-cooling systems all use devices without cold storage, the system has small heat capacity, small thermal inertia, and is highly sensitive to climate

When the temperature of the system rises too fast, the transition time from alarm to trip is very short, and false alarm signals such as tripping will be generated, which will affect the normal operation of the converter valve; design a large number of heaters

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