The RACER system was a waste-heat recovery system for the LM2500s (propulsion turbines). Waste heat would generate steam, which would be used in a turbine for greater fuel efficiency, or used in trail-shaft conditions to power the “trailing” shaft.
RACER did not achieve its test objectives during evaluation at the DDG51 Hot Plant, and was removed from the design. In the first three DDGs, there remains a MRG flange where the RACER turbine was to tie in.
Also see DDG51 Contract Design History
Ed notes
– one of the key DDG51 longevity features is the total lack of steam systems, with attendant maintenance complications. Inclusion of the RACER system would have sacrificed long-term maintenance complications and cost for a short term fuel savings. The waste heat systems were a continuing maintenance headache for the Spruance and Ticonderoga classes. (See CAPT Perkinson oral history re: improvements to the Ticonderoga class waste heat design, which improved on the Spruance situation, but did not remove the basic steam challenge)
– this also shows the value of shore-based hot plant testing – the system “failed” in sufficient time that it was removed from the design, leaving only the MRG blind flanges.
Description from GlobalSecurity.org:
RACER (Rankine Cycle Energy Recovery) was the Naval Sea Systems Command [NAVSEA] program to design and develop an advanced, combined gas turbine and steam turbine [COGAS] power plant. The RACER (Rankine Cycle Energy Recovery) system was planned for development and application to US combatant and auxiliary ships. The system will use the exhaust energy from an 18MW gas turbine to produce steam and generate power in excess of 6MW for additional ship propulsion power. The RACER System is expected to provide an overall propulsion fuel reduction upwards of 25%.
The RACER system provides several advantages to a gas turbine powered ship. one of which is improved fuel efficiency for significant annual fuel savings. This saving does not come free, however, since, in general, any additional system installed in the ship will have some maintenance requirements. In keeping with the US Navy’s current emphasis, a key philosophy in the design of the RACER system was to minimize this maintenance burden.
Marine and land based power plants can produce exhaust products in a temperature range of 350-1850.degree. F. In most applications, the exhaust products are released to the environment and the thermal energy is lost. In some instances, however, the thermal energy is further utilized. For example, the thermal energy from the exhaust of an industrial gas turbine engine (IGT) has been used as the energy source to drive a Rankine cycle system.
In the 1970’s and 1980’s the United States Navy investigated a marine application of a Rankine cycle system, referred to as the Rankine Cycle Energy Recovery (RACER) System. Rankine cycle systems can include a turbine coupled to an electrical generator, a condenser, a pump, and a vapor generator. The vapor generator is subjected to a heat source (e.g., geothermal energy source). The energy from the heat source is transferred to a fluid passing through the vapor generator. The energized fluid subsequently powers the turbine. After exiting the turbine, the fluid passes through the condenser and is subsequently pumped back into the vapor generator. In land-based applications, the condenser typically includes a plurality of airflow heat exchangers that transfer the thermal energy from the water to the ambient air.
The DOD Authorization Act, 1985, authorized a lump sum of $9,409,596,000 to be appropriated for Navy research, development, test and evaluation (RDT&E). Pub.l. No. 98-525, sec. 201(a), 98 stat. 2507, october 19, 1984. However, the act provided that, of the amounts authorized in section 201 for Navy RDT&E, “$45,000,000 is available only for continued development of the *** RACER system ***.” Pub.l. No. 98-525, sec. 203(a)(1), 98 stat. 2508. The dod appropriations act, 1985, appropriated a lump sum of $9,172,622,000 for Navy RDT&E, to remain available until September 30, 1986. Pub.l. No. 98-473, 98 stat. 1920, October 12, 1984. That act did not specifically earmark any funds for the racer. By letter dated June 8, 1985, the secretary of the navy advised the senate and house armed services committees (HASC) that the navy planned to obligate $23.427 million for the RACER.
The navy’s compliance with the certification requirements of section 102(h) of the DOD authorization act, 1985. This regard, the Department sought continued funding for the DDG-51 Arleigh Burke class guided missile destroyer in FY 85. Although making funds available for this program, congress has been concerned about the compatibility between the racer system and the DDG 51 class ships.
Section 203(a)(1) of the DOD Authorization Act, 1985, provides that “$45,000,000 is available only for continued development of the *** (RACER) system to ensure compatibility of the RACER system with all ships of the DDG-51 class, including the lead ship.” In commenting on this provision, the house report stated that “the Navy’s present design of the DDG-51 would require a substantial modification to incorporate the RACER system.” H.R. Rep. No. 98-691, 170 (1984). Additionally, section 102(h) of the DOD Authorization Act, 1985, 98 stat. 2501, provides that none of the funds authorized for the DDG-51 program for shipbuilding and conversion ($1,173,900,000) may be obligated or expended until the Secretary of the Navy certifies to the Appropriations and Armed Services committees “that the lead ship in that program is capable of being equipped with the RACERr system without rearrangement of ship spaces and equipment or other major modification to the ship.” By letter dated November 28, 1984, the Secretary of the Navy provided a certification to the oversight committees. In that letter, the Secretary stated that the lead ship of the DDG-51 class could be backfitted with the RACER system and that the retrofit would not “require modification of the length or width of the ship or *** involve relocation of existing watertight boundaries.” In reply, then Chairman Price of the HASC indicated that in his opinion, the certification was inadequate, stressing that the statute anticipates that the lead ship accommodate the racer system “without rearrangement of ship spaces and equipment or other major modifications to the ship.”
On December 21, 1984, in response to Chairman Price’s letter, the secretary certified that “the lead ship, DDG-51, will be capable of being equipped with RACER system without rearrangement of ship spaces and equipment or other major modification to the ship.” Further, the Secretary advised that although the solicitation for the DDG-51 was issued on August 31, 1984, the Navy planned to issue an engineering change proposal to modify the ship’s design to meet the authorization act’s requirements when the shipbuilding contract is awarded.
A review of the legislative history indicates that the Congressional purpose in requiring the certification was to assure “that the lead ship of the DDG-51 program can be readily backfitted with racer system,” and that the first ships in the class be “designed to accommodate an inexpensive retrofit of RACER without extensive modifications.” See H.R. Rep. No. 98-691, 87-88 (1984); and S.Rep. No. 98-500, 74-75, (1984). The congressional concern that the lead ship be capable of accommodating the RACER without extensive design changes to an operational vessel apparently stems from the fact that the RACER and DDG-51 class ship were being developed simultaneously and the lead ship of the class may be on line before development of the RACER is complete.
The authorization act was enacted into law on October 19, 1984, but the solicitation for the DDG-51 had been issued on august 31, 1984. Apparently the solicitation issued at that time did not allow for incorporation of the racer without major modification to the ship because the certification letter of 21 December 1984 indicated the Navy’s plans to issue an ECP to the shipbuilding contract to permit this. Because the solicitation had been issued when the congress imposed the certification requirement, it appears reasonable that the navy should now indicate that the ship “will be capable” of being equipped with the RACER. Additionally, the Navy’s statement that an ECP would be issued to amend the shipbuilding contract once a contractor was selected is concrete evidence that the navy not only understands the requirement but is taking action to comply with the mandate. Bath Iron Works was awarded the shipbuilding contract in April 1985, and in September 1985 the Navy in fact issued an ECP requesting Bath to change the lead ship’s design to comply with the certification requirements. Bath responded to the ECP and the Navy issued a contract modification in June 1986.
During DDG-51 design, space was provided to include the Rankine Cycle Energy Recovery (RACER) system, a steam system under development at the time that recovered gas turbine exhaust heat to provide additional propulsive power. While it promised significant efficiency improvements, this program was cancelled because of major technical development problems.
The RACER system, which utilized high-pressure steam as the working medium, was coupled to the drive system to augment propulsion horsepower. RACER could not be used to power any accessories because it as coupled to the drive system; i.e., if the drive system was not engaged, neither was the RACER system. The RACER system was never fully implemented and the program was cancelled because of problems associated with using high-pressure steam in a marine application.
Retrieved on March 29, 2024 from https://www.globalsecurity.org/military/systems/ship/systems/racer.htm
USS Arleigh Burke Association 