Energy-saving system for replacing low-temperature circulating water of coking plant in winter

The utility model provides an energy-saving system for replacing low-temperature circulating water of a coking plant in winter, which comprises a normal-temperature circulating water cooling device, a low-temperature water cooling device and an energy-saving cooling device, and the energy-saving cooling device comprises a cooling water supply pipeline and a cooling water return pipeline; the cooling water supply pipeline comprises a cooling pump and a cooling water supply pipe, an inlet pipeline of a circulating water supply pump in the normal-temperature circulating water cooling device and a low-temperature water supply pipeline in the low-temperature water cooling device are provided with a first bypass pipeline and a second bypass pipeline respectively, and the first bypass pipeline is communicated with an inlet of the cooling pump. An outlet of the cooling pump is communicated with one end of a cooling water supply pipe, and the other end of the cooling water supply pipe is communicated with a second byp