Seeking new materials for gas water heater heat exchangers

I. Background:

At present, there are two kinds of materials for heat exchangers in the gas water heater industry: copper or stainless steel. We hope to find new materials or solutions to solve the corrosion problems of existing copper tube heat exchangers.

II. Parameters:

Target:Machinability (welding, bending, etc.); corrosion resistance (medium salt spray test is not less than 3,000 hours); weight and cost do not float too high; thermal conductivity is moderate, close to stainless steel.

Environment temperature:within 1200°C

Water temperature:0-100°C

1、The overall structure of the heat exchanger is illustrated (take the 16L heat exchanger as an example):

2、Figure 1, Figure 2, Figure 3 and Figure 4 are photos of the frontal structure of the heat exchanger at different positions (see pictures on this post). The internal key specifications are shown in Table 1.

Heat exchanger specifications (Table 1):

Inlet pipe 12.7 +/- 0.05*0.6

Box tube (shell around tube) 14 +/- 0.05*0.6

Small U 14 +/- 0.05*0.8

Large U1 (center distance 36 +/- 0.1) 16 +/- 0.05*0.8

Large U2 (center distance 34 +/- 0.1) 16 +/- 0.05*0.8

Outlet pipe connection 14 +/- 0.05*0.6

Outlet pipe 12.07 +/- 0.05*0.6

Bypass 5 +/- 0.05*1

Discarted solutions

• Stainless steel

Possible solution areas

• New material instead of cooper tube
• Add new material copper alloy