Cooling unit and energy storage system

The utility model discloses a cooling unit and an energy storage system, and belongs to the technical field of batteries, the cooling unit is used for cooling a battery pack of a working device, the cooling unit comprises a compressor, a condenser, a delivery pump, a heater, a first pipeline and a second pipeline, the first pipeline is provided with a unit inlet and a unit outlet, and the compressor and the condenser are arranged on the first pipeline; the unit inlet, the compressor, the condenser and the unit outlet are sequentially connected in series, the second pipeline is connected with the compressor in parallel, the heater is connected with the conveying pump in series, an outlet of the heater is located on the downstream of the condenser, and the conveying pump is connected with at least part of the first pipeline in parallel so that refrigerants of the second pipeline can flow to the heater under the action of the conveying pump. Through the arrangement of the heater and the conveying pump, the cooling unit and the energy storage system can be used for heating and can also be used for refrigerating.