Steam Condensate RecoverySystem

General Overview

The steam condensate recovery system collects condensate from the steam distribution system through steam traps and recovers waste heat. Before returning to the boiler, the condensate typically passes through a deaerator to remove unwanted oxygen. Since condensate is purified water at high temperatures, its reuse helps reduce fuel consumption and lowers water treatment costs for make-up water.

Components

Condensate recovery systems are typically equipped with pumps, pipe networks, and a heat exchanger. Condensate is passed into a receiver tank. The components of a condensate recovery system are shown in Figure 1.

Figure 1. Condensate recovery system diagram.
Figure 1. Condensate recovery system diagram.

Condensate Pumps

Condensate pumps are responsible for moving condensate from the receiver tank(s) back to the boiler system. In some cases, the receiver tank, pump, and float controls are packaged together. An appropriately-sized pump is crucial to avoiding condensate buildup, which could create problems with terminal units. Learn More

Pipe Networks

The pipe network of a condensate recovery system transports flash steam and condensate. Designs should consider differential of pressure between different lines. It is usually covered with insulation material to minimize heat losses into the environment.

Evaluation of Energy Consumption

The primary purpose of the condensate recovery system on the steam plant is to minimize heat losses and manage condensate that could otherwise be damaging to the steam plant. Generally, the energy related to the condensate system is not quantified; instead, the energy consumption of the overall low-pressure steam plant is quantified. For more information, see Steam Plant.

Table 1. Key values, components and measurements to evaluate energy consumption.
Plant Quantification Values to be Quantified Energy Consuming Component
Steam boiler plant fuel consumption (Btu) Average hourly fuel consumption (Btu/h) Boiler
Steam plant electricity consumption (kWh)
  • Average hourly burner fan motor (kWh)
  • Total operating hours of burner fan motor
  • Average hourly condensate pump motor kWh
  • Average hourly feedwater pump motor (kWh)
  • Total operating time for pump motors
  • Burner fan motor
  • Condensate pump motor
  • Feedwater pump motor

Further Reading

  • ASHRAE (2014). “ASHRAE Guideline 14-2014 – Measurement of Energy, Demand, and Water Savings.” Annex A.

  • ASHRAE (2020). “ASHRAE Handbook: HVAC Systems and Equipment,” Chapter 11. STEAM SYSTEMS. I-P Edition.

  • U.S. Department of Energy. (2014). “A Sourcebook for Industry – Energy,” https://www.energy.gov/sites/prod/files/2014/05/f15/steamsourcebook.pdf