Medium-Voltage Process Heating for a Sustainable FutureApril 06, 2018
Chromalox DirectConnect™ medium-voltage electric process heating systems are a novel solution that addresses large heating demands in power generation, oil and gas, petrochemical and chemical industries. The on-site, pollution-free equipment capitalizes on all of the advantages of electric process heating while offering significant cost savings over low-voltage, high-amperage designs.
Low-Voltage, High-Amperage Designs
Low-voltage electric heating systems were traditionally viewed as a low-capacity process heating solution, while fossil fuels were favored in applications requiring higher heat capacities. The added benefits of electric process heating have allowed them to gain market share as they:
· Provide unprecedented repeatability and set-point accuracy
· Offer on-site, pollution-free operation
· Eliminate the need for ancillary pollution control devices
In order to support rising demands, complex, multi-megawatt process heating systems have been built and industrial facilities are now faced with escalating installation, maintenance and operating costs. To address these issues, Chromalox introduced DirectConnect medium-voltage electric process heating systems.
Benefits of DirectConnect Medium-Voltage Systems
Chromalox’s DirectConnect process heating solutions minimize operating expenses and installation costs. They deliver unprecedented efficiencies while reducing installation costs, maintenance costs and power losses — an ideal solution for applications greater than approximately 1 MW (approximately 3-4 MMBtu/hr).
Reduced Installation Costs
DirectConnect process heating solutions can tap directly into medium-voltage lines up to 7,200 volts (V). This effectively mitigates the need for large step-down transformers. The lower amperage design also requires fewer circuits, greatly reducing cabling, labor and overall installation costs.
Reduced Maintenance Costs
Unplanned maintenance can give rise to critical downtime. Chromalox’s unique design incorporates individually replaceable heater elements. This effectively saves time and money as the entire heating bundle remains intact while individual elements are replaced. There are also fewer circuits, contactors and solid-state switching devices. The end result is that industrial facilities benefit from reduced downtime and maintenance costs are a fraction of those of a low-voltage, high-amperage design.
Reduced Power Losses
Reduced power losses associated with DirectConnect process heating solutions can help improve efficiency by 3 percent over a low voltage heating system. This is accomplished either by having fewer lower amperage circuits or by an even greater reduction in circuits accompanied by a comparable amperage circuit over thicker gauge wires. In either case, the total impedance of the system is greatly reduced achieving operational efficiencies as great as 99.2 percent.
Second-Generation DirectConnect Technologies
Chromalox’s DirectConnect medium-voltage heating systems can now handle voltages up to and including 7,200 V. They offer the only medium-voltage, single-end, isolated terminal design in the world. They also hold multiple patents and third-party certifications that address the requirements of international markets.
The extended capabilities and unique features of Chromalox’s second-generation DirectConnect medium-voltage heating systems push the limits of efficiency. Their first-generation systems penetrated the North American market where savings were modeled when switching from standard 480 V three-phase, high-amperage circuits to medium-voltage systems operating at 4,160 V. Second-generation systems support capacities up to 7.2 kV with an increased voltage differential that not only yields greater savings, but supports international markets that operate at slightly different voltage ranges centered on 380 V and 6,600 V.
Third-Party Certifications and Patents
DirectConnect electric heaters and control panels have been tested and approved by independent, internationally recognized, third-party laboratories and awarded patents in the U.S., China, Canada, Italy, Spain, Germany, France and the U.K.
Their proprietary technology has received CE, ETL, IEC and UL certifications with a maximum rating up to 7.2 kV, an ATEX/IECEex certification mark for heating assemblies operating in hazardous locations and Patent Cooperation Treaty status globally, bringing the world within reach of Chromalox’s medium-voltage control panels and electric heating systems.
DirectConnect medium-voltage heating technology is unparalleled in the industry. It was the first fully rated, medium-voltage heating element rated for 4,160 V and is now offered with the following unique features:
· The only medium-voltage heating element with third-party certification (ETL File #101361500DAL-001)
· The only medium-voltage SCR control panel with third-party certification (UL 347C)
· The only medium-voltage heating element that can pass an individual 11,360V dielectric withstand test
· Patent-pending SCR panel design with heater soft start algorithm and automatic in-situ dry-out switching capability
To further illustrate the potential savings when switching from a low-voltage, high-amperage system to a medium-voltage heating system, a quote is provided for a 3.23 MW electric process heating system. The medium-voltage system operating at 6,600 V provides for an immediate installation savings of $845,400, with a 20-year return on investment of 427 percent when compared to a low-voltage, high amperage design operating at 380 V.
Potential savings are realized by the elimination of costly step-down transformers (400 kVA NEMA 1: approximately $20,000; 1 MW NEMA 1: approximately $40,000), reduced labor costs for installation (1,270 labor hours compared to 70 labor hours), fewer conduit runs (50 compared to nine) and a drastic reduction in the number of wired circuits (63 separate 380 V circuits compared to three 6,600 V circuits).
The total cost of ownership is also substantially lower. Operational efficiency is effectively boosted to 99.2 percent, maintenance costs are drastically reduced and heater element and circuit replacement costs are significantly less when implementing a 380 V/6,600 V conversion.
As facilities look to reduce their dependency on carbon-emitting heating sources, they need to ensure it is done in a cost-effective manner. Chromalox’s DirectConnect technology enables zero-emissions and near-perfect efficiency for large point-of-use heating systems. Industrial facilities are able to capitalize on potential savings with Chromalox’s multi-megawatt electric heating systems through installation, maintenance and operational cost reductions.