Gas compressor and gas compression system

A gas compression system comprising:

• a gas compressor including a low pressure stage compressor body that compresses gas, an intercooler that cools compressed gas delivered from the low pressure stage compressor body, a high pressure stage compressor body that further compresses the compressed gas cooled by the intercooler, an aftercooler that cools the compressed gas delivered from the high pressure stage compressor body, a low pressure gas path that introduces the compressed gas delivered from the low pressure stage compressor body into the high pressure stage compressor body through the intercooler, and a high pressure gas path that introduces the compressed gas delivered from the high pressure stage compressor body to a demand destination through the aftercooler, the gas compressor comprising:
• a first low pressure branch path that is branched from the low pressure gas path;
• a first low pressure gas release valve that is disposed on the first low pressure branch path and releases the compressed gas delivered from the low pressure stage compressor body;
• a first high pressure branch path that is branched from the high pressure gas path;
• a first high pressure gas release valve that is disposed on the first high pressure branch path and releases the compressed gas delivered from the high pressure stage compressor body;
• and
• a control device that controls the first low pressure gas release valve and the first high pressure gas release valve,
• the first low pressure branch path being branched from the low pressure gas path on an upstream side of the intercooler and on a downstream side of a heat exchanger for low pressure stage exhaust heat recovery that effects heat exchange between the compressed gas delivered from the low pressure stage compressor body and a fluid for exhaust heat recovery,
• the first high pressure branch path being branched from the high pressure gas path on an upstream side of the aftercooler and on a downstream side of a heat exchanger for high pressure stage exhaust heat recovery that effects heat exchange between the compressed gas delivered from the high pressure stage compressor body and the fluid for exhaust heat recovery,
• the control device effecting heat exchange between the compressed gas and the exhaust heat recovery fluid that pass through the heat exchanger for low pressure stage exhaust heat recovery and the heat exchanger for high pressure stage exhaust heat recovery, while releasing the compressed gas from the first low pressure gas release valve and the first high pressure gas release valve during no-load operation, by opening the first low pressure gas release valve and the first high pressure gas release valve at a time of switching from load operation to the no-load operation of the low pressure stage compressor body and the high pressure stage compressor body;
• a second low pressure branch path branched from the low pressure gas path on an upstream side of the heat exchanger for low pressure stage exhaust heat recovery;
• a second low pressure gas release valve disposed on the second low pressure branch path;
• a second high pressure branch path branched from the high pressure gas path on an upstream side of the heat exchanger for high pressure stage exhaust heat recovery;
• and
• a second high pressure gas release valve disposed on the second high pressure branch path,
• the control device being configured to
• determine whether or not a disabling condition for disabling an exhaust heat recovery function during the no-load operation is satisfied,
• when the disabling condition is not satisfied, open the first low pressure gas release valve and the first high pressure gas release valve and close the second low pressure gas release valve and the second high pressure gas release valve at the time of switching from the load operation to the no-load operation of the low pressure stage compressor body and the high pressure stage compressor body, and
• when the disabling condition is satisfied, open at least the second low pressure gas release valve and the second high pressure gas release valve at the time of switching from the load operation to the no-load operation of the low pressure stage compressor body and the high pressure stage compressor body.