Industrial Refrigeration System Evaluation

Transcription

1 Industrial Refrigeration System Evaluation A Tiered Approach to Assessing Industrial Refrigeration Systems by the Industrial Refrigeration Consortium 1415 Engineering Drive, Suite 2342 Madison, WI (866)

2 Industrial Refrigeration System Evaluations Background Refrigeration is a major consumer of electricity in the industrial sector. For example, refrigeration is the single largest electrical load and is responsible for the bulk of energyrelated costs in most food processing and distribution facilities. Typically, industrial refrigeration systems are large vapor compression systems that utilize ammonia as a refrigerant. These systems are prime candidates for targeted programs to improve their performance and efficiency. Virtually all industrial refrigeration installations are field-erected custom engineered refrigeration systems comprised of separate components provided by different original equipment manufacturers. The individual components for each system must be carefully selected and integrated by both the refrigeration design engineer and mechanical contractor to achieve the performance and efficiency targets set forth by the system s application specifications. In sizing individual components, designers rely heavily on past experience as well as on catalog performance information furnished by component manufacturers. For several reasons, the current refrigeration procurement process can lead to sub-optimal systems - in terms of both capacity/productivity and efficiency. First, the catalog data provided by manufacturers are often incomplete, particularly for off-design conditions. Second, optimal system performance requires a design optimization study of the entire system because the best performance can often occur at a set of operating conditions where none of the individual components are at their peak efficiency. Third, controls that cycle equipment on and off can introduce transient effects that reduce the equipment's efficiency and life. These weaknesses create a real opportunity to significantly improve performance and efficiency of industrial refrigeration systems. Many owners and operators of industrial refrigeration systems are interested in techniques that will allow them to 1. decrease their energy use and energy costs 2. increase their production capability 3. maintain stored product quality 4. maximize capital utilization 5. enhance system reliability 6. improve product flow 7. reduce maintenance costs 8. minimize environmental impacts (i.e. EPA Risk Management) 9. minimize lost work days (i.e. OSHA Process Safety Management) The IRC has established a program of tiered refrigeration system evaluations or audits that, primarily, focus on helping end-users better understand: the current state of their refrigeration systems, approaches to improving their system energy efficiency and 1

3 performance, strategies to improve system safety, and methods to enhance both the reliability and life-cycle costs of their refrigeration systems. This document outlines high-level scopes and budgets for conducting evaluations at three progressively detailed levels. The variable detail provides clients with options to gain the greatest cost/benefit for the efforts expended in this area. In all cases, the scope of the evaluation is structured to deliver results that will benefit the client. Level 0 Industrial Refrigeration System Evaluation The Level 0 evaluation is the simplest and least detailed evaluation option available. The purpose of the Level 0 evaluation is to provide an overview of the existing refrigeration system and to identify those opportunities that are most likely to provide significant benefits to the owner. The primary deliverable from the Level 0 evaluation is a letter report documenting the findings of the pre-site visit analysis and the site visit findings. Task List and Deliverables There are three basic tasks for a Level 0 evaluation: 1. Pre-Site Visit Preparation Prior to conducting a site visit, IRC staff will establish a pre-visit review, which may include analyzing energy-billing data for the target facility, reviewing incident investigations, or review of system documentation in preparation for the site visit. A work plan is then prepared to maximize our productivity while conducting the site visit. In the case of energy efficiency evaluations, facility energy consumption profiles are required for pre-visit analysis. The energy billing data should cover a period extending at least 12 months in length. The energy use and billing data will give the audit staff an opportunity to better understand the as-operated load characteristics of this facility. 2. Site Visit Staff will visit the target facility and meet with the owner's personnel to review the scope of the investigation and discuss concerns, such as energy use, refrigeration capacity shortfalls, operational problems, maintenance issues, etc. The site staff briefing is a key element of the visit. Along with site personnel, the IRC staff will then walk through the facility and observe the layout, configuration, and operating conditions of the 2

4 refrigeration system. The walk-through will focus particular attention on areas of client concern previously identified as well as areas that have potential to achieve significant refrigeration system improvements (based on our past experience in similar facilities). The audit staff will spend approximately one-half day on site for the meeting and walk-through. 3. Report Development Based on the findings from Task 1 and the information gathered during the walk-through phase (Task 2), the investigators will provide a letter report summarizing the findings and listing recommendations for the client to consider pursuing. Level 1 Industrial Refrigeration System Evaluation The Level 1 evaluation involves a more detailed investigation and evaluation when compared to the Level 0 evaluation. The Level 1 evaluation will offer additional presite visit analysis, on-site time expenditure, and an increased level of post-site visit analysis to identify opportunities to improve the facilities refrigeration system. Goals often include enhancing plant energy efficiency, reducing equipment-related maintenance, improving refrigeration system safety, and/or overall refrigeration system performance. The primary deliverable from the Level 1 evaluation will be a report documenting and discussing the findings of the walk-through and subsequent analyses. Task List and Deliverables There are three basic tasks for a Level 1 evaluation: 1. Site Visit Preparation Prior to conducting a site visit, the IRC staff will establish a more detailed pre-visit review, which may include analyzing energy-billing data for the target facility, reviewing incident investigations, or review of system documentation in preparation for the site visit. A work plan is then prepared to maximize our productivity while conducting the site visit. A detailed list of documentation and data needed for the site visit preparation phase of the project will be forwarded to the client shortly after reaching an agreement on the project scope. 3

5 2. Site Visit The purpose of the site visit task is to gather information on the existing system and its operation, and on the concerns and priorities of the plant s staff. Specific activities include: Meeting with the plant s operating staff, refrigeration staff, energy manager, and any other relevant individuals to discuss their concerns and ideas relating to the refrigeration system. Review documentation such as construction drawings, control drawings, system logs, equipment manuals, etc. that are relevant to the investigation. View the plant on a simple walk-through investigation of the plant layout, problem areas, and areas of potential improvement as identified by IRC and plant staff. The scope of this task includes approximately one and one-half days for onsite observation and review. This time will be allocated to put the highest priority on the issues considered most important by the client. 3. Report The deliverable will be a report that documents the information gathered and specific recommendations that result from the site visit and subsequent analyses conducted by IRC staff. Our intention will be to provide a document that the client s staff can use to guide them through the next steps in investigating improvements to the refrigeration system. The report will emphasize areas for possible improvements that were identified in Tasks 1 & 2. Priority will be given to those items that appear to provide the largest benefit for the amount of implementation effort required. Level 2 Industrial Refrigeration System Evaluation A Level 2 audit extends the scope and depth of the Level 1 evaluation. While still focusing on areas of concern identified by the owner (e.g. identifying energy efficiency opportunities at a somewhat high level), the Level 2 evaluation will include more in-depth analysis of system performance and economic implications.. Where possible, criteria such as capital cost and simple paybacks will be estimated and included in the final report. Many of the opportunities will emphasize implementation of "best practice engineering" in the design, construction, and operation of refrigeration equipment. In many cases, owners are interested in learning knowing more about opportunities that will lead to: improved plant energy efficiency, reduced equipment maintenance requirements, and improved plant performance. 4

6 Concepts and ideas generated as a result of the Level 2 evaluation, along with feedback from the client, will provide the framework for conducting detailed followon engineering evaluations. Task List and Deliverables There are three basic tasks for the Level 2 audit that include: 1. Site Visit Preparation Prior to conducting a site visit, the IRC staff will establish a detailed pre-visit review, which may include analyzing energy-billing data for the target facility, reviewing incident investigations, or review of system documentation in preparation for the site visit. A detailed work plan is prepared to maximize our productivity while conducting the site visit. A list of documentation and data needed for the site visit preparation phase of the project will be forwarded to the client shortly after reaching an agreement on the project scope. 2. Site Visit Staff will visit the site and discuss any system-related concerns with the owner s personnel (refrigeration mechanics, managers, facility engineers, safety managers, plant managers, etc) and other staff. The visit will include a thorough facility walk-through to focus on areas of concern identified by the client. Possible items to be considered during a Level 2 evaluation include: a) techniques to minimize high compressor discharge pressures b) opportunities for efficiency improvements c) comparisons to best practices d) Process Safety Management, and Risk Management Program e) coil defrost and defrost strategies f) heat rejection systems and controls g) compressor oil cooling system layout and operation h) refrigeration system heat recovery i) energy management and control systems j) refrigeration system reliability/redundancy risks k) temperature and moisture control of spaces including dock areas, freezer corridors, and holding freezers 5

7 3. Report Development The investigators will conduct appropriate analyses, further develop ideas, and refine the opportunities identified during Tasks 1 and 2. The report will document findings in each of the areas identified above. During the course of report development, we may request additional information (PFDs, schedules, logs, etc.) and input from site staff. Although the final report will likely contain line schematics and system-level drawings, the contents of the final report should not be construed as a design. However, the documentation provided in the report will often provide a basis for the design of future modifications and additions to the facility and its equipment. The deliverable from the Level 2 evaluation will be a report documenting and discussing the findings of the site visit and subsequent analyses. The report will document our findings and provide feedback on approaches for project implementation. The report will provide recommendations in three categories: implement without further study, implementation will require further study, and do not pursue further. To follow-up the Level 2 evaluation, investigators will be available for a conference call with the client to discuss the findings and recommendations detailed in the report. Budget Contact us for information on the current rate structure for a level 0, 1 or 2 audit of your facility. Feel free to contact us at: Industrial Refrigeration Consortium U.W. Madison 1415 Engineering Dr., Rm. #2342 Madison, WI (toll free) (fax) info@irc.wisc.edu ( ) (website) 6