After steam, condensate is arguably the next most valuable resource available to the plant. Containing up to a quarter of the total energy of the steam from which it came, steam users should be recovering every last drop.
Spirax Sarco UK, explains the several benefits of condensate recovery and how this relatively simple concept can have huge benefits for organizations relying on steam for their process. The ability to recover condensate to the boiler has the potential to provide an exceptional return on investment.
Resource-Saving measures
This energy-saving process is easily achieved and can be done in more ways than one and, because of this, condensate recovery can sometimes feel like the unsung hero in the boiler house. Not only can it cut energy bills dramatically, it can also see maintenance costs reduced.
Utility bills and fuel costs can affect the profitability of the boiler house in a major way
Utility bills and fuel costs can affect the profitability of the boiler house in a major way. Water and energy are clearly the two key resources used to create steam but the ever-present pressure from fluctuating fuel prices can really impact overall running costs. It is for this reason that condensate recovery is one of the most effective resource-saving measures for most steam sites. A steam system can benefit significantly from the recovery of condensate and, even when recovered in small quantities, it can prove economically worthwhile.
Water-Related expenses
While a good system will recover 80 percent of its condensate and feed it back in to the system, failure to recover condensate will cause the boiler house to suffer losses which can only be made up by a supply of freshwater. The energy then used to heat this water to the optimum temperature will directly impact operating costs.
When recycling condensate, users can achieve valuable savings in both fuel and water-related expenses. Condensate is a valuable resource that contains around 25 percent of the heat energy from the original steam. Feeding the boiler with high-temperature condensate provides steam users with the potential to maximize boiler output as less energy is required to convert make-up water into steam. By effectively recovering and utilizing condensate, fuel costs and water consumption are lowered.
Associated energy savings
In a boiler, condensate recovery is also one of the best ways to reduce the level of oxygen in water
In a boiler, condensate recovery is also one of the best ways to reduce the level of oxygen in water, helping to minimize the risk of system corrosion. As condensate is formed from steam it has few impurities but in contrast to this, cold make-up water needs to be treated before entering the system. Importantly, condensate, unlike make-up water, also contains energy from the steam it’s derived from, so again, the more condensate they bring back to the system, the better.
What has to be remembered is that energy is lost during blowdown, so the ability to reduce this process through recovering condensate will allow steam users to benefit from the associated energy savings. By saving energy, operators of steam plants can experience significant financial gain as well as improved equipment life, all while reducing their impact on the environment. No matter how much condensate a site generates per day it should never be put to waste.
Increasing boiler efficiency
Here are some useful tips to provide a starting point:
- Condensate will always be pushed through the trap by motive steam force. If this is not possible, then it may be necessary to use pumps.
- Automatic pump traps act as conventional steam traps, but when back pressure rises, pump traps automatically switch to pumping mode to remove condensate.
- A deaerator head is important to mix returned condensate, flash steam, and cold make-up water as they are fed into the feedwater tank.
- Flash steam is released from hot condensate when its pressure is lowered. Use it, don’t waste it. Collect in a flash vessel and use for heating, and recover any associated condensate.
- Closed-loop, pressurized flash steam recovery allows most of the energy from both the condensate and its flash steam to be used, reducing steam-raising costs and increasing boiler efficiency.
- Use the boiler water and flash steam from the boiler TDS blowdown to heat the boiler feedtank.
There is no doubt that the payback period of an effective condensate recovery system has the potential to make this investment an attractive proposition. The ability to maximize boiler output, and make the best possible use out of the energy found in condensate, should be considered a huge advantage and never underestimated.