Hot Water Module

🔹 1. What is a Hot Water Module?

A Hot Water Module (also called a Hot Water Skid or Hot Water Generation System) is a compact pre-assembled system that heats water using an external energy source — such as a boiler, steam, flue gases, or electric heaters — and circulates it for use in process heating, HVAC systems, industrial washing, or domestic hot water networks.

It typically contains:

Heat exchanger (plate or shell-and-tube)

Circulation pump

Control valves

Temperature sensors and safety controls

Expansion tank

Control panel

Piping and insulation

🔹 2. Working Principle

Here’s how a Hot Water Module works step-by-step:

Heat Source Input

The module receives heat energy from a source such as:

Steam from a boiler

Flue gases from a generator or furnace (via heat exchanger)

Thermal oil circuit

Electric heating elements

Heat Transfer

The heat exchanger transfers heat from the primary side (steam/flue gas) to the secondary side (water).

Water Circulation

The circulating pump moves the heated water through the distribution system to supply points (process lines, coils, or storage tanks).

Temperature Control

A temperature controller adjusts the control valve to maintain the set outlet water temperature.

Return and Reheat

The return water comes back to the module to be reheated, forming a closed-loop circuit.

🔧 Simplified Flow Diagram

Copy code

Steam / Flue Gas / Heat Source

                  │

                  ▼

           ┌─────────────┐

           │ Heat Exchanger │

           └─────────────┘

                  │

        ┌─────────┴─────────┐

        │                   │

   Hot Water Out       Return Water

        │                   │

        ▼                   ▲

     Process / Use     Circulation Pump

        │                   │

        └──────Control Panel───────→ Temperature Sensors

🔹 3. Design & Drawing Overview

A Hot Water Module drawing (P&ID or schematic) includes:

Component

Symbol

Function

Heat Exchanger

HX

Transfers heat

Pump

P

Circulates water

Control Valve

CV

Regulates flow/temperature

Temperature Sensor

TT

Measures temperature

Pressure Gauge

PG

Monitors pressure

Expansion Tank

ET

Absorbs thermal expansion

Control Panel

CP

Automates control

🔹 4. Benefits

✅ Energy Efficient – Reuses waste heat (e.g., flue gas or jacket water).

✅ Compact Design – Skid-mounted, easy to install and maintain.

✅ Automatic Control – Maintains consistent outlet temperature.

✅ High Reliability – Built-in safety and redundancy options.

✅ Versatile – Used in food, textile, chemical, and HVAC systems.

✅ Eco-Friendly – Reduces fuel consumption and CO₂ emissions.

🔹 5. Profitability & Economic Advantage

Item

Description

Impact

Fuel Savings

Uses waste heat from generators or boilers

↓ Operating cost by 20–40%

Lower Maintenance

Fewer moving parts compared to boilers

↓ O&M cost

Quick Payback

Depending on system size, typically

6–18 months

Continuous Hot Water Supply

Improves process efficiency

↑ Productivity

Reduced Water Heating Cost

Especially when using EGB or flue gas

↑ ROI

💡 Example:

If a 1 MW generator produces ~450 °C exhaust gas, an EGB + Hot Water Module can recover 100–150 kW of thermal energy — enough to produce 2–3 tons/hour of 90 °C hot water.

🔹 6. Applications

Generator Exhaust Heat Recovery

Central Heating Systems (Hotels, Hospitals)

Industrial Process Heating (Textile, Dairy, Chemical)

District Heating Networks

Preheating Boiler Feedwater

Would you like me to draw the full schematic (P&ID style) of a Hot Water Module connected to a flue gas heat recovery system (EGB)?

It will clearly show the exhaust → heat exchanger → hot water loop → return line, with labels for all components.