CONVEYOR BROILER FOR FOODSERVICE APPLICATIONS

Transcription

1 Design & Engineering Services CONVEYOR BROILER FOR FOODSERVICE APPLICATIONS Report Prepared by: Design & Engineering Services Customer Service Business Unit December 2012

2 s Design & Engineering Services (DES) group is responsible for this project. It was developed as part of s Emerging Technologies Program under internal project number. DES Project Manager Brian James conducted this technology evaluation with overall guidance and management from Emerging Technologies Assessment Program Manager Paul Delaney. For more information on this project, contact brian.james@sce.com. Disclaimer This report was prepared by (SCE) and funded by California utility customers under the auspices of the California Public Utilities Commission. Reproduction or distribution of the whole or any part of the contents of this document without the express written permission of SCE is prohibited. This work was performed with reasonable care and in accordance with professional standards. However, neither SCE nor any entity performing the work pursuant to SCE s authority make any warranty or representation, expressed or implied, with regard to this report, the merchantability or fitness for a particular purpose of the results of the work, or any analyses, or conclusions contained in this report. The results reflected in the work are generally representative of operating conditions; however, the results in any other situation may vary depending upon particular operating conditions. Page i

3 ABBREVIATIONS AND ACRONYMS Btu Btu/h DES FSTC FTC hr kw kwh lbs SCE yr British Thermal Unit British Thermal Units Per Hour Design and Engineering Services Food Service Technology Center Foodservice Technology Center Hour Kilowatt Kilowatt-hour pounds Year Page ii

4 FIGURES Figure 1. Conveyor Broiler Loading Side (Left) and Delivery Side (Right)... 3 TABLES Table 1. Summary of Results and Cost Effectiveness... 5 EQUATIONS Equation 1. Daily Energy Consumption... 3 Page iii

5 CONTENTS INTRODUCTION 2 ASSESSMENT OBJECTIVES 2 PRODUCT ASSESSED 2 TEST METHODOLOGY 3 RESULTS 4 Energy Input Rate... 4 Preheat and Idle Tests... 4 Cooking Test... 5 Cost Effectiveness Model... 5 CONCLUSION 7 RECOMMENDATION 7 REFERENCES 7 Page iv

6 INTRODUCTION The Food Service Technology Center (FSTC), also known as Fisher-Nickel, Inc., administered by Pacific Gas and Electric, tested three different conveyor broiler designs for use in Carl s Jr. Restaurant. In collaboration with FSTC, s (SCE) Design and Engineering Services (DES) organization and Foodservice Technology Center (FTC) evaluated the findings from FSTC s report, Carl s Jr. Conveyor Broiler Testing & Evaluation 1. ASSESSMENT OBJECTIVES This project evaluates the operation and performance of the Nieco conveyor broilers under the conditions of ASTM Standard Test Method for performance of Conveyor Broilers (F ). The testing seeks to evaluate the idle, cooking energy consumption, and production capacity of the three different conveyor broiler designs for us in Carl s Jr. Restaurants. The testing examines the: Energy Input Rate: The peak rate at which a conveyor broiler consumes energy, in kw. Preheat Energy Consumption: The amount of energy consumed, kilowatt-hours (kwh), by the conveyor broiler while preheating its cook zone from the ambient temperature until the primary heating elements cycle off. Idle Energy Rate: The conveyor broiler s required rate of energy consumption (kilowatts (kw)) necessary to maintain its cook zone temperature at a specified thermostat setpoint. Cooking Energy Efficiency: The quantity of energy imparted to a specific food product; expressed as a percentage of energy consumed by the conveyor broiler during the cooking event. Cooking Energy Rate: The average rate of energy consumption (kw) during the heavy load-cooking test. Production Capacity: The rate pounds (lbs)/hour (hr) at which a conveyor broiler brings the specified food product to a specified cooked condition. This does not necessarily refer to the maximum rate, and the production rate varies based on the amount of food cooked. PRODUCT ASSESSED The Nieco1424 gas conveyor broiler is the existing standard cooking platform in Carl s Jr. Restaurants. The broiler is a standard pass-through design with a single chain conveyor running through the cooking chamber that accommodates three cooking lanes for product, three rows deep. A catch tray at the end of the conveyor collects the cooked product. The conveyor runs continuously throughout the day, with the heat source constantly energized. The broiler uses infrared gas broilers to heat the broiling chamber and electric motors to drive the conveyor through the chamber. A secondary chain runs beneath the main cooking chamber with electrically-heated platens for toasting buns. The 1424 comes with or without a catalyst. In recent years, Air Quality Management Districts in California began requiring Page 2

7 conveyor broilers to have an added catalyst to reduce the particulate emissions from cooking meats. Nieco developed a new JF143 concept conveyor broiler that recycles waste heat from the radiant heat source and uses that to enhance cooking. A pressure box captures heat from the cooking chamber and a blower forces the hot air back down onto the food product. The convective heat transfer maximizes the heat to the food product and allows the burner size to be reduced substantially over traditional radiant-only designs. The recycled heat also warms a toasting platen and eliminates the need for additional resistance heat for the bun toasting platens. Figure 1 displays the new JF143 system. FIGURE 1. CONVEYOR BROILER LOADING SIDE (LEFT) AND DELIVERY SIDE (RIGHT) The incremental installed cost of the new system is estimated to be $14,000. TEST METHODOLOGY Laboratory testing of the conveyor broilers was performed according to ASTM F test method for the performance of conveyor broilers. The testing provides information to determine: Energy Input Rate Preheat Energy Consumption Idle Energy Rate Cooking Energy Efficiency Cooking Energy Rate Production Capacity The daily energy consumption was calculated by equation 1 below. EQUATION 1. DAILY ENERGY CONSUMPTION Where: EDAY = LBFOOD = Daily Energy Consumption (Btu/day) Pounds of Food Cooked per Day 60 Page 3

8 COOK RATE = IDLE RATE = TON = PC = NP = TP = EP = Heavy Load Cooking Energy Rate (Btu/h) Idle Energy Rate (Btu/h) Operating Hours/Day Production Capacity (lbs/hr) Number of Preheats/Day Preheat Time (min) Preheat Energy (kwh/day) RESULTS The following is a summary of the tests conducted by the FSTC to compare the energy consumption of the existing conveyor broiler platform (with and without the optional catalyst) and the proposed JF143 broiler. ENERGY INPUT RATE Prior to testing, the maximum energy input rate was measured and compared with the manufacturer s nameplate value. This procedure ensured that the appliances were operating within specified parameters. The measured maximum energy input rate for the 1424 conveyor broiler was 100,700 Btu/h and 3.07 kw, for the gas and electric sources, respectively. The measured maximum energy input rate for the JF143 broiler was 55,167 Btu/h and 2.36 kw, for the gas and electric sources, respectively. PREHEAT AND IDLE TESTS These tests show how the appliances use energy when not cooking or holding food. The preheat time allows an operator to know precisely how long it takes the appliance to be ready to operate. The idle energy rate represents the energy required to maintain stabilized operating conditions, or the appliance s stand-by losses. The preheat test was conducted after the appliance had stabilized at room temperature (75±5 F) overnight. After each broiler had preheated, it was allowed to stabilize at operating temperature for one hour. Time and energy consumption were monitored for an additional two hours while the broiler maintained a ready-to-cook state. The preheat test results for the 124 broiler with and without the optional catalyst were similar, while the JF143 broiler required a slightly longer preheat period. The 1424 preheated in 8.4 minutes, while consuming 14,130 Btu of gas and 0.45 kwh of electricity. The JF143 required 46.2 minutes to preheat, while consuming 14,210 Btu of gas and 0.62 kwh of electricity. Without the catalyst, the 1424 broiler had a gas idle rate of 81,970 Btu/h and an electric rate of 1.55 kw. With the catalyst the 1424 broiler exhibited a slightly lower gas energy rate, but the electric consumption was essentially unchanged. The gas and electric energy rates for the 1424 broiler with the catalyst were 81,970 Btu/h and of 1.55 kw, respectively during the idle tests. The JF143 broiler had a gas rate of 47,960 Btu/h and an electric rate of 0.37 kw during the idle tests. Page 4

9 COOKING TEST The cooking tests were designed to reflect the appliance s maximum performance under load. The cooking tests were conducted with frozen, quarter-pound, 20% fat hamburger patties. Each broiler was tested using five complete cavity loads of burgers, the first and last loads were considered stabilization loads. After cooking, the patties were collected from the discharge pans and places on a wire rack for two minutes before being weighed. During these heavy-load cooking tests, the 142 broiler without catalyst had a gas cooking energy rate of 78,560 Btu/h and an electric rate of 1.35 kw, while producing burgers at a rate of 47.6 lb/hr. With the catalyst, the 1424 had a gas cooking energy rate of 79,240 Btu/h and an electric rate of 1.35 kw, while producing burgers at a rate of 41.7 lb/h. The heavy-load cooking tests on the JF143 broiler showed a gas cooking energy rate of 50,940 Btu/h and an electric rate of 0.33 kw, while producing burgers at a rate of 41.7 lb/hr. COST EFFECTIVENESS MODEL Measure data for cost effectiveness modeling are based on equipment use characteristics for Carl s Jr. conveyor broilers in a typical store. The operating assumptions (hours per day, pounds of food cooked per day) were supplied by Carl s Jr. A simple cost model was developed to calculate the relationship between various cost components (e.g. preheat, idle and cooking costs) and annual operating cost, using laboratory test data. For this model, the production line was operated over an 18 hour day, 364 days per year. The idle time was calculated as the difference between the total operating hours and the time cooking and preheating for each appliance. Unitized cost effectiveness determinants are summarized in Table 1. Annual energy use was calculated based on preheat, idle, and cooking energy cost. Annual energy use in this example is based on the broiler operating for 18 hours a day, 364 days per year, with one preheat daily and cooking 355 pounds of product per day. The assumed energy cost is $1.00/therm for natural gas and $0.13/kWh for electricity. From the data provided in Table 1, the new conveyor broiler provides an annual electricity energy savings of 7,131 kilowatt hours per year (kwh/yr), and a demand reduction of 1.09 kw due to the improved design to recycle waste heat and eliminate electric heating elements. TABLE 1. SUMMARY OF RESULTS AND COST EFFECTIVENESS 1424 BROILER WITHOUT 1424 BROILER WITH CATALYST JF143 BROILER WITH CATALYST CATALYST Preheat Time (min) Gas Preheat Energy (Btu) 14,130 14,130 14,210 Electric Preheat Energy (kwh) Gas Idle Energy Rate (Btu/h) Electric Idle Energy Rate (kw) ,970 78,120 47, Page 5

10 Gas Cooking-Energy Rate (Btu/h) Electric Cooking-Energy Rate (kw) 78,560 78,240 50, Production Capacity (lb/hr) Operating Hours/Day a Operating Hours/Year a Pounds of Food Cooked per Day a Gas Cost ($/therm) Daily Gas Energy Consumption (Btu) 1,452,655 1,410, ,870 Annual Gas Energy Consumption (therms) b 5,289 5,132 3,240 Estimated Gas Savings (therms/yr) c - - 1,892 Electricity Cost ($/kwh) Daily Electricity Energy Consumption (kwh) Average Demand (kw) Estimated Demand Reduction (kw) Annual Electric Energy Consumption (kwh) ,697 9,621 2,490 Estimated Electricity Savings (kwh/yr) c - - 7,131 Total Annual Operating Energy Cost ($) 6,550 6,383 3,563 Estimated Operating Cost Savings ($/yr) c - - 2,820 Incremental Measure Cost d ,000 Estimated Useful Life (year) 12 e Broiler 12 e Catalyst 5 f Broiler 12 e Catalyst - 5 f a Operating estimates based on the procedure for calculating daily energy consumption of a conveyor broiler, adapted from the procedure for calculating daily energy consumption of conveyor broiler based on reported test results, Appendix X2 in ASTM F2239. b 1 therm = 100,000 Btu c Energy and cost savings for the JF143 broiler were based on the 1424 broiler with catalyst as the baseline. d Total installed cost per manufacturer estimates. e Estimated useful life is based on 2008 DEER estimates for food service equipment. f Estimated useful life of the catalyst is based on manufacturer s estimates and is consistent with California Air Resource Board estimates for catalyst useful life. Page 6

11 CONCLUSION Based on applying the ASTM test method, the prototype JF143 effectively replaces the standard 1424 conveyor broiler, while cutting the energy consumption in half during both idle and cooking. The results can be used to estimate the annual energy consumption for the broilers in a typical Carl s Jr. store. Using a simple cost model the energy consumption under various operating modes, the energy savings potential of the prototype JF143 broiler can be assessed. Based on the energy consumption model, the Nieco 1424 conveyor broiler would consume a total of 5,132 therms and 9,621 kwh per year. The JF143 broiler would consume 3,240 therms and 2,490 kwh per year based on the model. Using $1.00/therm and $0.13/kWh, the 1424 broiler will have an estimated operating cost of $6,383/yr and the JF143 broiler will have an estimated operating cost of $3,563/yr, for an annual energy savings of $2,820. RECOMMENDATION Based upon energy savings and demand reduction test results, the recommendation is that Carl s Jr. installs the new JF143 conveyor broiler in their restaurants. The technology should be adopted into SCE s Energy Efficiency portfolio. REFERENCES 1. Carls Jr. Conveyor Broiler Testing & Evaluation. Food Service Technology Center, Fisher-Nickel, inc. July 2011 Page 7