Liquid feeding device and fluid chromatograph

A liquid feeding device comprising:

• a discharge channel;
• a pump part having a plurality of plunger pumps connected in series or in parallel to each other and discharging a mobile phase to the discharge channel, wherein at least one of the plurality of plunger pumps is a closing pump in which communication with the discharge channel is shut off during a non-discharge time during which the closing pump is not executing a discharge process for discharging the mobile phase to the discharge channel;
• a feeding pressure sensor detecting a feeding pressure which is a pressure in the discharge channel;
• a precompression process execution part configured to, based on at least an output of the feeding pressure sensor, execute a precompression process for causing the closing pump during the non-discharge time after completing a suction process for sucking a liquid into a pump chamber of the closing pump to perform a discharge operation so that a pressure in the pump chamber of the closing pump is substantially equal to the feeding pressure;
• a discharge speed calculation part configured to calculate a discharge speed v of the plurality of plunger pumps to obtain a flow rate LPRE of the mobile phase discharged to the discharge channel from the pump part such that a converted value of a flow rate LATM of the mobile phase under an atmospheric pressure becomes a set flow rate LSET based on a volume V of the mobile phase in the pump chamber of the closing pump immediately before the precompression process is started, and a volume ΔV, reduced due to the precompression process, of the mobile phase in the pump chamber of the closing pump;
• and
• a discharge operation controller configured to control a discharge speed of the plurality of plunger pumps during a discharge process to be the discharge speed v obtained by the discharge speed calculation part.