Two-Stage Heating for Large Flow Applications

The HTRJ-RT preheating heat exchanger package solves a common challenge in large-scale hot water systems. How can you maintain a stable temperature with high and variable flow rates? Our solution uses two heating stages. A plate heat exchanger provides preheating, while a vertical half-storage floating coil heat exchanger provides final heating. Cold water first passes through the plate heat exchanger for an initial temperature rise. It then enters the half-storage heat exchanger for final heating to the set temperature. This two-stage approach keeps the outlet temperature stable even when water demand changes significantly. This product provides consistent performance for demanding applications.

Efficient Temperature Lift Across Two Stages

Consider the logic behind this design. If cold water enters the half-storage heat exchanger directly, the temperature difference is very large. This reduces heat exchange efficiency and increases steam consumption. The preheating stage uses a low-temperature heating source, such as waste heat from cooling water or solar-heated water, to raise the incoming cold water temperature from 10°C to 30–40°C. The final stage then uses steam to heat the water to 60°C. Each stage operates within its suitable efficiency range. This approach provides better overall energy efficiency than single-stage heating. The plate heat exchanger comes from Alfa Laval or Tranter and uses S30408 or S31603 stainless steel. The preheating unit uses a vertical half-storage floating coil design.

Applications and Support

This package suits projects that require large and steady hot water flows. Examples include large stadiums, convention centers, and district heating stations. The hot water storage tank material options include carbon steel lined with copper, carbon steel lined with SUS444, S30408, or S31603 stainless steel. Circulation pumps come from Grundfos, Xylem, Wilo, or Nanfang Pump Industry. We support custom manufacturing according to your drawings. There is no minimum order quantity. Standard lead time is about 50 days. The 12-month warranty covers the complete system. This Preheating Heat Exchanger Package provides a practical solution for complex hot water systems.

Technical Specifications

Parameter	Value
Package Type	Preheating heat exchanger package
Main Equipment	Plate heat exchanger + vertical half-storage floating coil heat exchanger
Plate Heat Exchanger Brands	Alfa Laval / Tranter
Circulation Pump Brands	Grundfos / Xylem / Wilo / Nanfang Pump Industry
Control Component Brands	Schneider / ABB / Siemens / Chint
Tank Material	Carbon steel lined with copper / carbon steel lined with SUS444 / S30408 / S31603
Piping Material	Thin-wall S30408 / S31603 stainless steel