Pipe temperature adjusting system and pipe temperature adjusting method

A pipe temperature adjusting system for adjusting a temperature of a liquid conducting pipe, the pipe temperature adjusting system comprising:

• a heat-insulating cover covering the liquid conducting pipe in such a manner as to define a cylindrical space between the heat-insulating cover and the liquid conducting pipe;
• a heat exchange flow path disposed in the cylindrical space and along the liquid conducting pipe in no contact with the liquid conducting pipe, and allowing a heat exchange medium to flow through the heat exchange flow path;
• a pump configured to supply the heat exchange medium into the heat exchange flow path;
• a temperature sensor configured to detect an internal temperature of the cylindrical space;
• a temperature adjuster configured to adjust a temperature of the heat exchange medium to be supplied into the heat exchange flow path;
• and
• a controller configured to control the temperature adjuster and the pump so that the internal temperature detected by the temperature sensor becomes equal to a predetermined target temperature,
• wherein the controller controls the temperature adjuster to adjust the temperature of the heat exchange medium to be supplied into the heat exchange flow path to a temperature at which heat is transferred between an outer space of the heat-insulating cover and the cylindrical space in an amount smaller than an amount of heat transferred between the heat exchange medium in the heat exchange flow path and the cylindrical space, and
• the controller controls the temperature adjuster to adjust the temperature of the heat exchange medium to satisfy following relationships and a required temperature T2 of the heat exchange medium:
• Q1 is an amount of heat transferred from the outer space to the cylindrical space,
• Q2 amount of heat transferred from the cylindrical space into the heat exchange medium in the heat exchange flow path,
• Q
• 1
• =
• π
• ⁡
• (
• θ
• r
• -
• T
• 1
• )
• 1
• α
• ⁢
• O
• ⁢
• D
• 1
• +
• 1
• 2
• ⁢
• λ
• 1
• ×
• ln
• ⁢
• O
• ⁢
• D
• 1
• I
• ⁢
• D
• 1
• ×
• m
• 1
• where
• θr is the outside air temperature (° C.),
• T1 is the target temperature of the internal temperature of the cylindrical space (° C.),
• α is the heat transfer rate (W/m2·K) at the surface,
• OD1 is the outer diameter (m) of the heat-insulating cover,
• ID1 is the inner diameter (m) of the heat-insulating cover,
• λ1 is the thermal conductivity (W/m·K) of the heat-insulating cover,
• ln indicates the natural logarithm of the value that follows it, and
• m1 is the longitudinal dimension (m) of the heat-insulating cover,
• Q
• 2
• =
• π
• ⁡
• (
• T
• 1
• -
• T
• 2
• )
• 1
• α
• ⁢
• O
• ⁢
• D
• 2
• +
• 1
• 2
• ⁢
• λ
• 2
• ×
• ln
• ⁢
• O
• ⁢
• D
• 2
• I
• ⁢
• D
• 2
• ×
• m
• 2
• where
• T1 is the target temperature of the internal temperature of the cylindrical space (° C.),
• T2 is the required temperature of the heat exchange medium (° C.),
• α is the heat transfer rate (W/m2·K) at the surface,
• OD2 is the outer diameter (m) of the heat exchange flow path,
• ID2 is the inner diameter (m) of the heat exchange flow path,
• λ2 is the thermal conductivity (W/m·K) of the heat exchange flow path,
• ln indicates the natural logarithm of the value that follows it, and
• m2 is the length (m) of the heat exchange flow path,
• wherein the required temperature T2 is such that Q1<Q2.