Urea pump, and control method and control system for urea pump

A urea pump, comprising:

• an inlet pipeline;
• an instant-heating filtering device, wherein an inlet of the instant-heating filtering device is in communication with a urea tank through the inlet pipeline, and the instant-heating filtering device is configured to filter and heat a urea solution flowing in through the inlet pipeline;
• a pressure build-up pump, arranged in the inlet pipeline and configured to drive the urea solution flowing to the instant-heating filtering device through the inlet pipeline;
• an outlet pipeline, in communication with a first outlet of the instant-heating filtering device and configured to feed the urea solution, which is filtered and heated, to a nozzle;
• and
• a return pipeline, in communication with a second outlet of the instant-heating filtering device and configured to feed the urea solution in the urea pump to the urea tank after shutdown of the urea pump, wherein the return pipeline comprises a main pipeline, and a first branch pipeline and a second branch pipeline which are connected in parallel and connected to the main pipeline;
• and
• wherein the urea pump further comprises:
• a relief valve, arranged in the first branch pipeline;
• a return pump, arranged in the second branch pipeline;
• and
• a pressure sensor, arranged in the outlet pipeline.