Grooved tubes for heat exchangers that use a single-phase fluid

A heat exchanger comprising:

• an arrangement having tubes wherein the tubes have a groove bottom thickness Tf and an outside diameter De, for manufacture of heat exchangers using one of a single-phase refrigerant and a coolant fluid, internally grooved by N helical ribs having an apex angle α, height H, base width LN, and helix angle β, two consecutive ribs being separated by a groove, generally flat-bottomed, having a width LR, and a pitch P equal to LR+LN, wherein:
• a) the value of thickness Tf of the tube is such that Tf/De is equal to 0.023±0.005, wherein the values of Tf and De are expressed in mm, with the value of De ranging between 4 and 14.5 mm;
• b) the ribs have the value of height H such that H/De is equal to 0.028±0.005, wherein the values of H and De are expressed in mm;
• c) a number N of ribs is such that N/De is equal to 2.1±0.4, and the value of the corresponding pitch P is equal to n·Di/N, with Di equal to De−2·Tf, and the value of De being expressed in mm;
• d) the base widths LN and LR are such that LN/LR is between 0.20 and 0.80;
• e) the apex angle α ranges from 10° to 50°;
• and
• f) the helix angle β ranges from 20° to 50°;
• so that a single-phase fluid, including one of water and glycol water, are used as one of a refrigerant or coolant fluid to ensure simultaneously a high heat exchange coefficient during heating and cooling, a low level of head loss and a low weight/meter.

A method of using heat exchanger tubes, comprising:

• passing a single phase fluid containing one of water, aqueous glycol solutioon containing 30% glycol, solutions of one of K formate and k acetate, slush, organic liquids and liquid CO2 wherein the tube has a groove-bottom thickness Tf and an outside diameter De, for manufacture of heat exchangers which use one of a single-phase refrigerant and a coolant fluid, internally grooved by N helical ribs with an apex angle α, height H, base width LN, and helix angle β, two consecutive ribs being separated by a groove, one of flat-bottomed and non-flat bottomed, having a width LR, and a pitch P equal to LR+LN, wherein:
• a) the value of thickness Tf of the tube is such that Tf/De is equal to 0.023±0.005, wherein the values of Tf and De are expressed in mm, with the value of De ranging between 4 and 14.5 mm;
• b) the ribs have the value of height H such that H/De is equal to 0.028±0.005, wherein the values of H and De are expressed in mm;
• c) the number N of ribs is such that N/De is equal to 2.1±0.4, and the value of the corresponding pitch P is equal to π·Di/N, with Di equal to De−2·Tf, and the value of De being expressed in mm;
• d) the base widths LN and LR are such that LN/LR is between 0.20 and 0.80;
• e) the apex angle α ranges from 10° to 50°;
• and
• f) the helix angle β ranges from 20° to 50°;
• so that a single-phase fluid, including one of water and glycol water, are used as one of a refrigerant and coolant fluid to ensure simultaneously a high heat exchange coefficient during heating and cooling, a low level of head loss and a low weight/meter.

A method of using heat exchanger tubes, comprising:

• passing a single phase fluid which as a dynamic viscosity between 0.5 and 30 mPa and a Prandtl number between 5 and 160 through a tube wherein the tube has a groove bottom thickness Tf and an outside diameter De, for manufacture of heat exchangers which use one of a single-phase refrigerant and a coolant fluid, internally grooved by N helical ribs with an apex angle α, height H, base width LN, and helix angle β, two consecutive ribs being separated by a groove, one of flat-bottomed and non-flat bottomed, having a width LR, and a pitch P equal to LR+LN, wherein:
• a) the value of thickness Tf of the tube is such that Tf/De is equal to 0.023±0.005, wherein the values of Tf and De are expressed in mm, with the value of De ranging between 4 and 14.5 mm;
• b) the ribs have the value of height H such that H/De is equal to 0.028±0.005, wherein the values of H and De are expressed in mm;
• c) the number N of ribs is such that N/De is equal to 2.1±0.4, and the value of the corresponding pitch P is equal to π·Di/N, with Di equal to De−2·Tf, and the value of De being expressed in mm;
• d) the base widths LN and LR are such that LN/LR is between 0.20 and 0.80;
• e) the apex angle α ranges from 10° to 50°;
• and
• f) the helix angle β ranges from 20° to 50°;
• so that a single-phase fluid, including one of water and glycol water, are used as one of a refrigerant and coolant fluid to ensure simultaneously a high heat exchange coefficient during heating and cooling, a low level of head loss and a low weight/meter.