Help Reduce Energy Costs by Recovering Heat From Industrial Refrigeration Systems
|Mike Nielsen | Global Application Team Leader, Vilter
Emerson’s Commercial and Residential Solution’s Business
Heat recovery from industrial refrigeration can be an effective way for facilities to help reduce power consumption and energy costs.
Depending on a system’s setup, the heat produced from a basic screw compressor refrigeration system can be used elsewhere. How it’s recovered and redirected depends on the industry and/or application. Among the most common heat recovery applications is to heat water for purposes unrelated to refrigeration such as wash-down and cleanup in a cold storage processing facility.
Not only can compressor heat recovery help to reduce the amount of energy used to heat water elsewhere in a facility, but it also can contribute to reduced water usage when a system doesn’t have to heat as much water. This is especially relevant in areas where water costs are higher. Every system and installation is different, so it’s important to evaluate whether the potential for reduced energy consumption and costs outweigh the investment in equipment to reuse compressor heat.
Integrating water systems
Under standard operation conditions, industrial refrigeration systems produce condenser heat, super-heated vapor heat, and oil heat. There are multiple ways to integrate these refrigeration systems with a typically separate water system to employ a heat recovery strategy, but some extra equipment may be needed.
The first step is to determine the facility’s hot water requirements and whether refrigeration compressor heat can be utilized in the hot water system. In both new and existing refrigeration systems, the equipment would have to be designed for this expansion.
For instance, some type of water system would be needed, as would a storage tank and a pump to bring in water. Then, the water would need to be pumped out to the heat source and returned to the hot water storage tank.
Consider full energy cost impact
Even though more heat can be generated by elevating the refrigeration system parameters, it’s important to consider how important energy recovery is to your overall operational goals.
Raising the condensing temperature can increase discharge water temperatures. As a result, more energy can go into the compressor, so it’s important to make sure the energy recovered for heating water is worthwhile. In some regions where electricity costs more than natural gas or propane, this approach may not be a good option. In other areas where electricity costs are relatively low and the cost for natural gas or propane is the same or higher than electricity, it might make sense to generate more heat with the compressor.
Many existing systems can be retrofitted to recover refrigeration compressor heat. This can be a bigger undertaking than a new system; re-piping, new equipment or a change in condenser type and heat exchangers can be required. But the investment may be worth the effort if a facility is experiencing high energy costs.
Enabling efficiency and energy savings
Recovering heat from refrigerator compressor systems to heat water for other processes can enable facilities to reduce overall energy costs. Highly efficient equipment such as Vilter™ single-screw compressors are designed to help provide lower lifecycle costs and high reliability. They also can enable facilities to reduce the energy consumed in the refrigeration system while lowering the energy needed to heat the water within those facilities.
To learn more about deploying a heat recovery strategy in your industrial refrigeration system, read our white paper.