Boiler

A boiler for heating fluid by using heat generated by a heat generation body, the boiler including

• the heat generation body and
• a container having the heat generation body inside and configured such that an inside of the container is filled with gas with higher specific heat than that of air, comprising:
• a controller configured to control a heat generation amount of the heat generation body under a situation where the gas has been supplied into the container;
• and
• a heat transfer pipe configured such that the fluid flows inside, wherein the heat transfer pipe is arranged to surround the heat generation body, wherein the heat transfer pipe spirally extends and is arranged to surround the heat generation body.

A boiler for heating fluid by using heat generated by a heat generation body, the boiler including

• the heat generation body and
• a container having the heat generation body inside and configured such that an inside of the container is filled with gas with higher specific heat than that of air, comprising:
• a controller configured to control a heat generation amount of the heat generation body under a situation where the gas has been supplied into the container;
• and
• a heat transfer pipe configured such that the fluid flows inside, wherein the heat transfer pipe is arranged to surround the heat generation body, wherein the heat transfer pipe includes multiple water pipes extending in a vertical direction, and the water pipes are arranged to surround the heat generation body.

A boiler for heating fluid by using heat generated by a heat generation body, the boiler including

• the heat generation body and
• a container having the heat generation body inside and configured such that an inside of the container is filled with gas with higher specific heat than that of air, comprising:
• a controller configured to control a heat generation amount of the heat generation body under a situation where the gas has been supplied into the container;
• and
• a heat transfer pipe configured such that the fluid flows inside, wherein the heat transfer pipe is arranged to surround the heat generation body, wherein the heat transfer pipe is heated by conduction, convection, and radiation of heat generated by the heat generation body.