Technical Papers. 32nd Annual Meeting. International Institute of Ammonia Refrigeration. March 14 17, 2010

Transcription

1 Technical Papers 32nd Annual Meeting International Institute of Ammonia Refrigeration March 14 17, Industrial Refrigeration Conference & Exhibition Manchester Grand Hyatt San Diego, California

2 ACKNOWLEDGEMENT The success of the 32nd Annual Meeting of the International Institute of Ammonia Refrigeration is due to the quality of the technical papers in this volume and the labor of its authors. IIAR expresses its deep appreciation to the authors, reviewers and editors for their contributions to the ammonia refrigeration industry. Board of Directors, International Institute of Ammonia Refrigeration ABOUT THIS VOLUME IIAR Technical Papers are subjected to rigorous technical peer review. The views expressed in the papers in this volume are those of the authors, not the International Institute of Ammonia Refrigeration. They are not official positions of the Institute and are not officially endorsed International Institute of Ammonia Refrigeration 1001 North Fairfax Street Suite 503 Alexandria, VA (voice) (fax) Industrial Refrigeration Conference & Exhibition Manchester Grand Hyatt San Diego, California

3 Technical Paper #7 How the PSM Mass and Energy Balance Relates to Your Plant s Energy Usage Marcos Braz MRBraz & Associates, PLLC Abstract OSHA and EPA regulations require that a mass and energy balance be performed and documented on systems that exceed a charge of at least 10,000 lbs. of ammonia. These documents are useful for the safety reasons that are intended by the agencies, but they also help personnel and consultants analyze and easily understand complex systems. Use of the MEB can help to determine if there are shortcomings in facility operations or in the refrigeration system itself. The MEB can also be used to help determine the extent of work required for an addition or retrofit of an existing refrigeration system. This paper explains the development of the MEB documents and how they can be used to help save energy and capital improvement costs and improve operations. IIAR

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5 How the PSM Mass and Energy Balance Relates to Your Plant s Energy Usage Introduction When considering a new expansion, retrofit or a greenfield refrigeration project, the decision process to comply with safety standards and optimizing investment generally will be supported by the mass and energy balance document. It is generally the common ground, the reference line on an existing, new or updated refrigeration system. It is well known that formulating and maintaining a mass and energy balance record is a requirement for EPA/OSHA Risk and Process Safety Management and also included in General Duty Clause (EPA) for ammonia refrigeration plants. This safety requirement by EPA/OSHA can be a useful tool for a refrigerated plant to establish equipment installed capacity, optimize energy usage and plan for future expansions. As we all know, energy can neither be created nor destroyed, only modified in its form. We sometimes have difficulty realizing how hard is to trace this energy in a refrigerated facility or process. The energy balance provides useful data we must have before we start to analyze the capital investment for a refrigerated facility or process. Mass and energy in the refrigeration cycle are connected; however they are conceptually different. Energy balance differs from mass balance mainly because the mass balance describes refrigerant flow within a closed refrigeration circuit while the energy balance describes the energy flow between the refrigeration system and the environment. In a refrigerated facility with multiple processes, there are multiple complex interactions with the product, operation logistics, equipment maintenance and building envelope that are quite crucial to reach a mass and energy balance. Technical Paper #7 IIAR

6 2010 IIAR Industrial Refrigeration Conference & Exhibition, San Diego, California In other words, the energy balance is what makes or breaks desired production levels, integrity of the product and safety of the operation. The typical refrigerated facility with holding coolers, freezers, and/or cooling or freezing processes requires large refrigeration systems to be balanced to cope not only with the final production performance and product quality expected, but also with safety issues related to the operation of the system installed. An unbalanced system that does not have the capacity to handle surges in process loading could create serious problems. For example, upset conditions in the pump recirculator vessel could create refrigerant liquid carryover to the compressors or higher head pressure with consequent overstress of the system. The resulting process temperature fluctuation could result in product quality being compromised. Mass and Energy Balance Thermodynamics: The mass and energy balance is generally defined on a new refrigeration project or through reverse engineering when working to balance refrigeration system thermal loads (energy) in an existing refrigerated plant. The difference in temperature between the process fluid and the refrigerant will determine the actual energy that will be transferred and carried by the system. The process fluid media can be air, water, glycol or any fluid that will carry the heat load. The energy balance is based on continuity and the First Law of Thermodynamics of Energy Conservation following a Carnot cycle. The First Law, as applied to a refrigeration system, is described as the change in the internal energy (BTU/ LB) of the refrigerant on a closed thermodynamic system. This change in internal energy varies with the amount of heat/ energy supplied (evaporator) to or removed (condenser) and the work done to it (compressor). 4 IIAR 2010 Technical Paper #7

7 How the PSM Mass and Energy Balance Relates to Your Plant s Energy Usage The mass balance is based on the principle of the conservation of mass. Mass that goes into a system (or sub-system) must come out of it, or else the closed system under consideration must change. The mass flow is based on the energy flow, and can be determined using capacity data, actual data, thermodynamic formulas and arithmetical accounting. Brief Overview of the MEB required by EPA/OSHA The document is a basic flow diagram arranged to illustrate the refrigeration cycle using the components of the refrigeration system. Each piece of equipment should have its rated thermal capacity noted by power, mass flow and physical state (temperature and pressure). Refer to Appendix A for First Law of Thermodynamics formulas and an example of a MEB flow diagram. Equipment Rated Capacity: The capacity of each major refrigeration system component can be found in the data sheets provided by the equipment manufacturer. This capacity is stated at the conditions the equipment was initially designed for. It is important for facility personnel to maintain accurate files of installed equipment. Attention should be given to the existing operating conditions that might differ from the design conditions. This element of change will be addressed later on. Evaporators/Heat Exchangers Datasheets for evaporators and process heat exchangers should be available to identify the design thermal load. Heat exchangers are rated based on mass flow, temperature range and temperature approach. Technical Paper #7 IIAR

8 2010 IIAR Industrial Refrigeration Conference & Exhibition, San Diego, California Most common applications involve air cooling units where the air temperature in the room and the suction temperature in the evaporator yield the actual thermal load absorbed by the refrigeration system. In this case; Room Temperature: (Highest Temperature allowed in the room) is typically defined as the temperature of the air returning to the evaporator. Evaporator Temperature: This is assumed to be the saturated suction temperature (SST) of the refrigerant as measured at the evaporator tubes or the metal temperature in contact with the refrigerant at the evaporator. The Total Heat (thermal) Load absorbed by a given evaporator will then be directly proportional to the Differential Temperature = Air Return Temperature (Ti) Saturated Suction Temperature (Ts) at the Tubes The Ti Ts selected to size the evaporator/heat exchanger will impact the compressor s energy consumption. Higher differential temperature at the evaporator/ heat exchanger (which is typically indicative of relatively smaller coils) requires lower SST, thus higher energy consumption. Refer to Appendix B for typical evaporator rating calculations. Vessels Pressure vessel capacities are rated by free cross sectional area, length and temperature. Their main functions are to hold liquid inventory, separate liquid from vapor and provide a source of refrigerant to feed the evaporators and heat exchangers in the plant. The refrigeration system uses refrigeration vessels as recirculators, liquid separators (suction traps), intercoolers, desuperheaters, economizers, flash vessels, etc, where the thermal load supported by the vessel is determined as described above and in Appendix A and Appendix B. 6 IIAR 2010 Technical Paper #7

9 How the PSM Mass and Energy Balance Relates to Your Plant s Energy Usage Refrigeration pumps are selected to meet the required flow to the evaporators and heat exchangers multiplied by the selected refrigerant recirculation rate. It may be necessary to consider the minimum refrigerant flow required to allow the pump to maintain reliable performance. For hermetic pumps, these requirements will include refrigerant flow to maintain proper motor cooling. Compressors Compressors are rated by their suction/discharge pressure ratio, volumetric capacity, system pressure drop, temperatures at suction and discharge, superheat and oil cooling system. They can be classified as single stage, single stage with economizer, two stage and compound. All the energy of compression including the superheat portion of the discharge gas needs to be considered as it is transported to the next compressor stage or condenser. Attention should be given to the oil cooling system that is being used: a) Thermosyphon Oil Coolers The thermal load removed from the compressor oil by circulating refrigerant to and from the condenser. b) Water Oil Coolers The thermal load removed from the compressor oil by circulating water delivered to the water cooling tower or other heat sink. c) Liquid Injection The thermal load of compression absorbed by high pressure liquid refrigerant injected into the compressor with consequent reduction of capacity. Technical Paper #7 IIAR

10 2010 IIAR Industrial Refrigeration Conference & Exhibition, San Diego, California Condensers Condenser ratings are based on ambient air conditions such as dry and wet bulb using climatic conditions for the site where the equipment is installed. Condensers reject heat using ambient air, evaporative or secondary cooling. Fouling will affect condenser capacity although we don t have a practical method to derate condensers based on fouled surfaces. The thermal load from the thermosyphon oil coolers is added to the condenser load as it is a part of the total heat of compression and refrigeration loads. Using the First Law of thermodynamics and (SUM of Mass In = SUM of Mass Out) one can follow the energy flowing in a refrigeration system as explained above. Many phases of plant operation affect the thermal load utilized including loading, shipping, equipment and room wash down, production sequence, scheduled hours of operation, process equipment utilization, etc). The Disconnect Between System Capacity and the Mass and Energy Balance on a Given Refrigeration System The thermal loads (Energy) imposed on the refrigeration system are driven by these four main components: Conduction Heat transmitted through the building envelope (walls, ceiling, roof, and floor). Infiltration Outside air coming in between open spaces or from doors and other openings. Product Load Includes respiration, chemical reactions and all latent and sensible heat loads of the product being processed. 8 IIAR 2010 Technical Paper #7

11 How the PSM Mass and Energy Balance Relates to Your Plant s Energy Usage Service Load Includes operation equipment, people, battery charging, lighting, washing cycles, cleaning equipment and ancillary thermal loads. These components vary, based on ambient conditions, quantity of product, operating schedule and the traffic of people and products. They relate to our understanding of energy use and the balance of that energy with the installed refrigeration equipment (capacity). Although these components seem quite simple to obtain, the measurements of the heat transfer media temperatures and refrigerant temperature at a typical hour/day/ season is the most important information when discussing a thorough mass and energy balance analysis at a given refrigerated facility. The most effective method to achieve a successful and efficient calculation of thermal loads transferred to the refrigeration system should be by KWh utilization of the compressors, pumps and fans during the hours of operation, day and season. However, there are other electrical loads, such as: lighting, office climate control, water pumps, kitchens and process equipment that are captured at the electrical grid and are in most cases complex to separate. It should be obvious by now that the operation of the plant and refrigeration equipment adjustment have a huge effect in balancing the capacity of the refrigeration equipment installed at the plant. In addition to these factors we have to add another variable the rate of utilization of the system installed. The Diversity Factor and its Effect on the MEB The diversity factor is defined as the percentage of the refrigeration system installed that is necessary to address the normal operation of the plant or refrigerated facility. Technical Paper #7 IIAR

12 2010 IIAR Industrial Refrigeration Conference & Exhibition, San Diego, California Diversity Factor = Capacity to Operate the System / Refrigeration Installed Capacity The plant maximum peak load is defined by the utilization of jacketed vessels, evaporators, or any other heat exchange devices that are meant to work in accordance with the plant operating schedule. The actual thermal load will vary with the utilization time and degree of thermal load imposed on the process line or room. So, the correct calculation method is to understand the usage of the installed plant equipment based on operating parameters and avoid making rough assumptions using a percent of nominal capacity installed. Plant Operation Costs ($) and Refrigeration Capacity Energy balance or optimization of the resources has an added bonus. Refrigeration system optimization results in spending less money. It is important to realize the impact of operation factors (personnel traffic, washing down, pressurization, types of doors, battery room location and cycle of change) on the overall balance and energy cost of the refrigeration system. During the operation of a plant, it is quite common to observe: Product entering and process temperatures that are outside established parameters. The thermal load of the product is significant and directly impacts the performance of evaporators and heat exchangers. Control of product temperatures entering the process or cold storage is crucial to achieving a correct energy balance. Shifting thermal loads to avoid thermal peaks (for example, blast freezing during nighttime) and other strategies can keep the refrigeration system operating under an acceptable diversity factor. 10 IIAR 2010 Technical Paper #7

13 How the PSM Mass and Energy Balance Relates to Your Plant s Energy Usage Doors that are not shut tightly or are not shut at all or are the wrong type of doors contribute to air infiltration. See Figure 1 for an illustration of an open dock door. The thermal loads due to infiltration exchanged between areas separated by doors are very significant and can make a substantial impact on the desired energy balance. Peak traffic through the doors must be known before selecting the right door. Refer to Appendix C for example costs associated with door openings. Cold products and associated equipment passing through a humid environment. Aisles, vestibules or corridors without temperature and humidity control are strong contributors to moisture (latent load) infiltration. Products reaching dew point at their skin temperature also add to moisture infiltration. Moisture infiltration also causes wet floors and, of course, more energy than desired is needed to remove the moisture. Hot products and associated equipment passing through a cold environment. Excessive steaming of hot products produced by extreme temperature differentials will cause excessive load at the evaporator and heat exchanger while producing frosted surfaces with losses of thermal capacity. Losses in insulation (walls and piping) occurring due to compromised vapor barrier. An improper or poorly maintained vapor barrier of a refrigerated facility can add considerable thermal losses that not only impair operation but add to energy usage and costs. See figures 2 and 3 for examples of the application of insulation and vapor barriers. Refer to Appendix D for examples of R value and insulation permeability influence on energy costs. Room and equipment wash-down procedures occur while other process lines in other areas are still ongoing. Freezer Underfloor warming system operating out of parameters. Losses through the freezer floor cannot be neglected and typically they add 1 to 2 Btu/ft2. This Technical Paper #7 IIAR

14 2010 IIAR Industrial Refrigeration Conference & Exhibition, San Diego, California is a small load but it can have variations to add or subtract 10 TR/100,000 FT 2 of freezer floor. Evaporators (cooling units) out of adjustment (liquid feed or suction pressure out of adjustment). Evaporators must be operated at the most efficient compression stage. This will be the highest suction temperature available that is at or below the specified evaporator refrigerant temperature. This directly affects the capacity of the compressor by approximately 4% per degree Fahrenheit of suction temperature change depending on the suction temperature used. The evaporator also needs to have the correct liquid feed and proper distribution to operate efficiently. Condensers fouled or with poor water distribution (evaporative or secondary cooling) Condenser head pressure is a key element that directly impacts the energy balance and consumption at a rate of 1% higher energy usage for each degree Fahrenheit increase on saturated discharge temperature. Fouling on condenser tube surfaces is difficult to estimate. With proper instrumentation, the condenser fouling can be estimated closely enough using air psychometric properties and temperature/pressure measurements of the refrigerant. Compressors with capacity control issues. Several compressors at the same suction level that are not sequenced by a central computer control system can contribute to increased energy consumption and system imbalance. See figure 4 for an illustration of compressor suction piping. Evaporators defrosted in excess, not at all or are not sequenced to maintain a balanced defrost load. See figure 5 for an example of a heavily frosted coil. The configuration of an evaporator with its ratio of surface area and horsepower can have a definite impact on thermal performance, depending on the moisture load of the area where it is working. An evaporator with a small face area and deep 12 IIAR 2010 Technical Paper #7

15 How the PSM Mass and Energy Balance Relates to Your Plant s Energy Usage rows will suffer severe capacity reduction compared to an evaporator configured with a larger face area and fewer tube rows, under the same conditions. Unbalanced Pressurization of production spaces, especially in sanitary environments. During different seasons of the year, conduction and infiltration loads shift and there is a great deal of complexity added to the refrigeration system adjustment. However, a plant with the right equilibrium of controlled pressurization can save a large amount of energy and have a huge impact in the energy balance and operating costs. Refer to Appendix E for examples of pressurization costs and infiltration loads. Unnecessary lighting loads. Lighting fixtures are a great source of power varying from 0.5 W/FT2 to 1W/FT2 and should be managed with control modules (motion sensors) to avoid unnecessary loads. These loads will significantly impact the energy balance of the plant. See figure 6 for an illustration of warehouse lighting. Conclusion There are several elements to consider when addressing improvements on a refrigerated facility or process. One of these considerations is available funds. Several of the issues described above can have a direct impact in the bottom line of a refrigerated plant s operating costs and the decision to expend capital and effort on a system. Using the Mass and Energy Balance (MEB) as a tool to help examine such system characteristics as the maximum load; the minimum load; maximum and spare piping and vessel capacities; and spare engine room equipment capacity can help determine if new equipment or piping is required. Alternatively, the examination of the MEB versus the actual conditions can serve to highlight parameters of a system or an environment that is operating out of the range of expectations. If these types of issues can be resolved, capital costs and energy costs will be saved and systems and Technical Paper #7 IIAR

16 2010 IIAR Industrial Refrigeration Conference & Exhibition, San Diego, California environments can perform better and yield a better product. When it is considered that a typical refrigerated facility will spend 60% to 70% of its energy costs operating its refrigeration equipment, it is prudent to use all resources available to examine the refrigeration system thoroughly. Using the MEB is a good step in that process. By using the MEB, decision makers can easily become familiar with a system and make comparisons, troubleshoot systems, and understand the capacities and capabilities of the system often very quickly. Sustainability and carbon foot print are often discussed in the context of new technologies such as wind and solar power, for example. We should not forget that understanding or optimizing the operation of existing refrigeration equipment (Capacity) with the process and operation (Energy and Mass Flow) of the plant can provide an immediate impact on these important components and also fewer unplanned shutdowns. 14 IIAR 2010 Technical Paper #7

17 How the PSM Mass and Energy Balance Relates to Your Plant s Energy Usage Appendix A First Law of Thermodynamics and MEB Typical Drawing Formula; Delta E = Q + W where, Delta E Internal Energy Increased or Decreased in the Refrigerant at Closed Refrigeration System Q Heat transferred to the Refrigerant or rejected by the Refrigerant W Work done to the Refrigerant Making few simplified assumptions for each component of the Refrigeration System we have: Q = Delta E for Evaporators and Condensers (work is negligible) W= Delta E for Compressors (heat transfer is negligible adiabatic) Technical Paper #7 IIAR

18 2010 IIAR Industrial Refrigeration Conference & Exhibition, San Diego, California MEB MASS and ENERGY BALANCE Flow Diagram 16 IIAR 2010 Technical Paper #7

19 How the PSM Mass and Energy Balance Relates to Your Plant s Energy Usage Appendix B Evaporator Load Rating The Total Heat (thermal) Load absorbed by a given evaporator will be then directly proportional to the Differential Temperature = Air Return Temperature Saturated Suction Temperature at the Tubes: Using Q=Mx Cp X Delta T and Q= U x A x LMTD we have Ti => temperature air in To=> temperature air out Ts=> SST (Saturated Suction Temperature) Cp Specific Heat of Air LMTD = (Ti Ts) (To Ts) / ln (Ti Ts)/(To Ts) which simplifies to LMTD = (Ti To) / ln (Ti Ts)/(To Ts) Q => Heat load M=> mass air flow Q= M x Cp (Ti To) and Q= U x A x (Ti To)/ ln (Ti Ts)/(To Ts) so, U x A = M x Cp x ln (Ti Ts)/(To Ts) Ti Ts / To Ts = e^(u x A / M x Cp) so, To Ts = (Ti Ts) x e^ (U x A / M x Cp) and (Ti To) = Q / (M x Cp) Technical Paper #7 IIAR

20 2010 IIAR Industrial Refrigeration Conference & Exhibition, San Diego, California making substitutions on (To Ts) = ((Ti To) (Ti Ts)) Then: (Ti Ts) x e^ (U x A / M x Cp) = (Q / ( M x Cp) (Ti Ts)) Q = M x Cp x ((Ts Ti) x e ^ ( U x A / M x CP) + (Ti Ts)) Q = M x Cp x ( 1 e^ (- U x A / M x Cp)) x ( Ti Ts) Q = CONSTANT x (Ti Ts) where Ti = Air inlet at coil and Ts = SST Reference: Industrial Refrigeration Handbook by Wilbert F. Stoecker 18 IIAR 2010 Technical Paper #7

21 How the PSM Mass and Energy Balance Relates to Your Plant s Energy Usage Appendix C Roll Up / Sliding Door Opening Losses Door Infiltration Load (based on 95 Degrees F and 55% RH). No Pressurization. Door Sizes and Passages Estimated Cost per Hour at 1.3 BHP/TR and $.08/KWh Door # F H (ft) 34F/80% 15F/80% 5F/80% 0F/80% n10f/80% n20f/80% $2.26 $3.02 $3.40 $3.58 $4.02 $ $2.76 $3.69 $4.15 $4.38 $4.91 $ $3.31 $4.43 $4.98 $5.25 $5.89 $ $3.95 $5.29 $5.95 $6.27 $7.03 $ $4.63 $6.19 $6.96 $7.34 $8.23 $ $3.86 $5.17 $5.81 $6.13 $6.87 $ $4.61 $6.17 $6.94 $7.32 $8.20 $ $5.40 $7.22 $8.13 $8.57 $9.61 $ $4.42 $5.91 $6.64 $7.01 $7.86 $ $5.27 $7.05 $7.93 $8.36 $9.37 $ $6.17 $8.26 $9.29 $9.79 $10.98 $ $7.71 $10.32 $11.61 $12.24 $13.72 $ $10.14 $13.57 $15.26 $16.09 $18.04 $ $12.78 $17.10 $19.23 $20.28 $22.73 $ $12.17 $16.28 $18.31 $19.31 $21.65 $ $15.33 $20.52 $23.07 $24.33 $27.28 $ $18.74 $25.07 $28.19 $29.73 $33.33 $35.73 Passages/hr 60.0 Up (sec) 5.0 Down (sec) 5.0 Fully open (sec) 30.0 Opening 58.3% Technical Paper #7 IIAR

22 2010 IIAR Industrial Refrigeration Conference & Exhibition, San Diego, California Reference: ASHRAE Fundamentals 20 IIAR 2010 Technical Paper #7

23 How the PSM Mass and Energy Balance Relates to Your Plant s Energy Usage Appendix D Insulation Losses ROOF ENERGY LOSSES R value and Perm Influence Outside Condition 95 F 55% RH Vapor Pressure in Hg A) PERM = 0.02 grains(h20)/hr/sq.ft/inches Hg Original R value = 48 hr ft2 F / Btu US$/TR/HR= 0.1 Number of Hours = 1000 (1.7 bhp/tr x.745 KWH/ hp x US$ 0.08/KWH) Area (FT2) neg 10 F Total Gallons Water neg 20 F Total Gallons Water neg 30 F Total Gallons Water 34 F Total Gallons Water Technical Paper #7 IIAR

24 2010 IIAR Industrial Refrigeration Conference & Exhibition, San Diego, California THERMAL LOAD CONDUCTION LOSSES Area (FT2) neg 10 F Thermal Losses US$/ 1000 HR neg 20 F Thermal Losses US$/ 1000 HR neg 30 F Thermal Losses US$/ 1000 HR 34 F Thermal Losses US$/ 1000 HR BTU/HR BTU/HR BTU/HR BTU/HR ,188 $18 2,396 $20 2,604 $22 1,271 $ ,938 $91 11,979 $100 13,021 $109 6,354 $ ,875 $182 23,958 $200 26,042 $217 12,708 $ ,625 $547 71,875 $599 78,125 $651 38,125 $ ,500 $729 95,833 $ ,167 $868 50,833 $ ,375 $ ,792 $ ,208 $1,085 63,542 $ ,250 $1, ,750 $1, ,250 $1,302 76,250 $ ,125 $1, ,708 $1, ,292 $1,519 88,958 $ ,000 $1, ,667 $1, ,333 $1, ,667 $ ,875 $1, ,625 $1, ,375 $1, ,375 $ ,750 $1, ,583 $1, ,417 $2, ,083 $1, ,500 $3, ,167 $3, ,833 $4, ,167 $2, ,250 $5, ,750 $5, ,250 $6, ,250 $3, ,000 $7, ,333 $7,986 1,041,667 $8, ,333 $4, ,093,750 $9,115 1,197,917 $9,983 1,302,083 $10, ,417 $5, ,640,625 $13,672 1,796,875 $14,974 1,953,125 $16, ,125 $7, ,187,500 $18,229 2,395,833 $19,965 2,604,167 $21,701 1,270,833 $10, IIAR 2010 Technical Paper #7

25 How the PSM Mass and Energy Balance Relates to Your Plant s Energy Usage B) PERM grains(h20)/ hr/sq.ft/inches Hg = 1 Deteriorated R value = 5 hr ft2 F / Btu Area (FT2) neg 10 F Total Gallons neg 20 F Total Gallons neg 30 F Total Gallons 34 F Total Gallons Water Water Water Water ,075 1,084 1, ,229 1,239 1,245 1, ,382 1,394 1,401 1, ,536 1,549 1,556 1, ,072 3,098 3,113 2, ,608 4,646 4,669 3, ,144 6,195 6,226 5, ,679 7,744 7,782 6, ,519 11,616 11,674 9, ,359 15,488 15,565 12,984 Technical Paper #7 IIAR

26 2010 IIAR Industrial Refrigeration Conference & Exhibition, San Diego, California THERMAL LOAD CONDUCTION LOSSES Area (FT2) neg 10 F Thermal Losses US$/ 1000 HR neg 20 F Thermal Losses US$/ 1000 HR neg 30 F Thermal Losses US$/ 1000 HR 34 F Thermal Losses US$/ 1000 HR BTU/HR BTU/HR BTU/HR BTU/HR ,000 $175 23,000 $192 25,000 $208 12,200 $ ,000 $ ,000 $ ,000 $1,042 61,000 $ ,000 $1, ,000 $1, ,000 $2, ,000 $1, ,000 $5, ,000 $5, ,000 $6, ,000 $3, ,000 $7, ,000 $7,667 1,000,000 $8, ,000 $4, ,050,000 $8,750 1,150,000 $9,583 1,250,000 $10, ,000 $5, ,260,000 $10,500 1,380,000 $11,500 1,500,000 $12, ,000 $6, ,470,000 $12,250 1,610,000 $13,417 1,750,000 $14, ,000 $7, ,680,000 $14,000 1,840,000 $15,333 2,000,000 $16, ,000 $8, ,890,000 $15,750 2,070,000 $17,250 2,250,000 $18,750 1,098,000 $9, ,100,000 $17,500 2,300,000 $19,167 2,500,000 $20,833 1,220,000 $10, ,200,000 $35,000 4,600,000 $38,333 5,000,000 $41,667 2,440,000 $20, ,300,000 $52,500 6,900,000 $57,500 7,500,000 $62,500 3,660,000 $30, ,400,000 $70,000 9,200,000 $76,667 10,000,000 $83,333 4,880,000 $40, ,500,000 $87,500 11,500,000 $95,833 12,500,000 $104,167 6,100,000 $50, ,750,000 $131,250 17,250,000 $143,750 18,750,000 $156,250 9,150,000 $76, ,000,000 $175,000 23,000,000 $191,667 25,000,000 $208,333 12,200,000 $101, IIAR 2010 Technical Paper #7

27 How the PSM Mass and Energy Balance Relates to Your Plant s Energy Usage Appendix E PRESSURIZATION COSTS / Infiltration Load (based on 95 Degrees F and 55% RH Outside and 34 F 80% RH Inside) Pressure 0.01 inches of water Velocity Opening Area (FT2) CFM MPH US$/hr Technical Paper #7 IIAR

28 2010 IIAR Industrial Refrigeration Conference & Exhibition, San Diego, California Pressure 0.1 Inches Velocity Opening Area (FT2) CFM MPH US$/hr IIAR 2010 Technical Paper #7

29 How the PSM Mass and Energy Balance Relates to Your Plant s Energy Usage References: Industrial Refrigeration Handbook Wilbert F. Stoecker 2009 ASHRAE Fundamentals Handbook Energy Savings Using Air Curtains Installed in High Traffic Doorways ASHRAE paper by Eric B. Lawton /Ronal H. Howell, Ph.D., PE Technical Paper #7 IIAR

30 2010 IIAR Industrial Refrigeration Conference & Exhibition, San Diego, California Figure 1: Doors that are not shut Figure 2: Losses in insulation 28 IIAR 2010 Technical Paper #7

31 How the PSM Mass and Energy Balance Relates to Your Plant s Energy Usage Figure 3: Losses in insulation Figure 4: Compressors with capacity control issues Technical Paper #7 IIAR

32 2010 IIAR Industrial Refrigeration Conference & Exhibition, San Diego, California Figure 5: Heavily frosted coil Figure 6: Lighting fixtures 30 IIAR 2010 Technical Paper #7

33 How the PSM Mass and Energy Balance Relates to Your Plant s Energy Usage Figure 7: Hot Products Technical Paper #7 IIAR

34 2010 IIAR Industrial Refrigeration Conference & Exhibition, San Diego, California Notes: 32 IIAR 2010 Technical Paper #7