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Title: Field Test of Boiler Primary Loop Temperature Controller

Abstract

Beyond these initial system efficiency upgrades are an emerging class of Advanced Load Monitoring (ALM) aftermarket controllers that dynamically respond to the boiler load, with claims of 10% to 30% of fuel savings over a heating season. For hydronic boilers specifically, these devices perform load monitoring, with continuous measurement of supply and in some cases return water temperatures. Energy savings from these ALM controllers are derived from dynamic management of the boiler differential, where a microprocessor with memory of past boiler cycles prevents the boiler from firing for a period of time, to limit cycling losses and inefficient operation during perceived low load conditions. These differ from OTR controllers, which vary boiler setpoint temperatures with ambient conditions while maintaining a fixed differential. PARR installed and monitored the performance of one type of ALM controller, the M2G from Greffen Systems, at multifamily sites in the city of Chicago and its suburb Cary, IL, both with existing OTR control. Results show that energy savings depend on the degree to which boilers are over-sized for their load, represented by cycling rates. Also savings vary over the heating season with cycling rates, with greater savings observed in shoulder months. Over the monitoring period, over-sizedmore » boilers at one site showed reductions in cycling and energy consumption in line with prior laboratory studies, while less over-sized boilers at another site showed muted savings.« less

Authors:
; ; ;
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy Building Technologies Office
OSTI Identifier:
1159356
Report Number(s):
DOE/GO-102014-4457
KNDJ-0-40346-03
DOE Contract Number:
AC36-08GO28308
Resource Type:
Technical Report
Resource Relation:
Related Information: Work performed by Partnership for Advanced Residential Retrofit, Des Plaines, Illinois
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; RESIDENTIAL; RESIDENTIAL BUILDINGS; PARR; BUILDING AMERICA; CENTRAL HEATING; HYDRONIC BOILER; LOW-RISE MULTIFAMILY; OUTDOOR TEMPERATURE RESET; LOAD MONITORING; Buildings

Citation Formats

Glanville, P., Rowley, P., Schroeder, D., and Brand, L. Field Test of Boiler Primary Loop Temperature Controller. United States: N. p., 2014. Web. doi:10.2172/1159356.
Glanville, P., Rowley, P., Schroeder, D., & Brand, L. Field Test of Boiler Primary Loop Temperature Controller. United States. doi:10.2172/1159356.
Glanville, P., Rowley, P., Schroeder, D., and Brand, L. Mon . "Field Test of Boiler Primary Loop Temperature Controller". United States. doi:10.2172/1159356. https://www.osti.gov/servlets/purl/1159356.
@article{osti_1159356,
title = {Field Test of Boiler Primary Loop Temperature Controller},
author = {Glanville, P. and Rowley, P. and Schroeder, D. and Brand, L.},
abstractNote = {Beyond these initial system efficiency upgrades are an emerging class of Advanced Load Monitoring (ALM) aftermarket controllers that dynamically respond to the boiler load, with claims of 10% to 30% of fuel savings over a heating season. For hydronic boilers specifically, these devices perform load monitoring, with continuous measurement of supply and in some cases return water temperatures. Energy savings from these ALM controllers are derived from dynamic management of the boiler differential, where a microprocessor with memory of past boiler cycles prevents the boiler from firing for a period of time, to limit cycling losses and inefficient operation during perceived low load conditions. These differ from OTR controllers, which vary boiler setpoint temperatures with ambient conditions while maintaining a fixed differential. PARR installed and monitored the performance of one type of ALM controller, the M2G from Greffen Systems, at multifamily sites in the city of Chicago and its suburb Cary, IL, both with existing OTR control. Results show that energy savings depend on the degree to which boilers are over-sized for their load, represented by cycling rates. Also savings vary over the heating season with cycling rates, with greater savings observed in shoulder months. Over the monitoring period, over-sized boilers at one site showed reductions in cycling and energy consumption in line with prior laboratory studies, while less over-sized boilers at another site showed muted savings.},
doi = {10.2172/1159356},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Sep 01 00:00:00 EDT 2014},
month = {Mon Sep 01 00:00:00 EDT 2014}
}

Technical Report:

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  • Beyond these initial system efficiency upgrades are an emerging class of Advanced Load Monitoring (ALM) aftermarket controllers that dynamically respond to the boiler load, with claims of 10% to 30% of fuel savings over a heating season. For hydronic boilers specifically, these devices perform load monitoring, with continuous measurement of supply and, in some cases, return water temperatures. Energy savings from these ALM controllers are derived from dynamic management of the boiler differential, where a microprocessor with memory of past boiler cycles prevents the boiler from firing for a period of time, to limit cycling losses and inefficient operation duringmore » perceived low load conditions. These differ from OTR controllers, which vary boiler setpoint temperatures with ambient conditions while maintaining a fixed differential.« less
  • The core flow test loop, which is part of the Gas-Cooled Fast Breeder Reactor Program (GCFR) at ORNL, is a high-pressure, high-temperature, out-of-reactor helium circulation system that is being constructed to permit study of the performance at steady-state and transient conditions of simulated segments of core assemblies for a GCFR demonstration plant. The simulated core segments, which are divided into zones, contain electrical heating elements to simulate the heat generated by fission. To control the power which is applied to a zone, a novel multitapped transformer and zone power control system have been designed and built which satisfy stringent designmore » criteria. The controller can match power output to demand to within better than +-1% over a 900:1 dynamic range and perform full-power transients within 1 s. The power is applied in such a way as to minimize the electromagnetic interference at the bandwidth of the loop instrumentation, and the controller incorporates several error detection techniques, making it inherently fail-safe. The operation manual describes the specifications, operating instructions, error detection capabilities, error recovery, troubleshooting, calibration and QA procedures, and maintenance requirements. Also included are sections on the theory of operation, circuitry description, and a complete set of schematics.« less
  • A rigorous analysis of the ETR with temperature feedback demanded the lnvestigatlon of a separate loop whose function lt is to keep the reactor inlet water temperature constant. It ls to accompllsh thls by regalating the secondary water flow. In lDO-l6648, stability Analysis of the ETR With Reactivity Feedback Through the Temperature Coefficient by S. R. Gossmann, the problems of the stabillty analysis of the ETR would have been impossible lf the present experlment had not heen done, since there were no data quickly avallable on the transient or frequency responses of the components of thls loop. As ihe reportmore » describes, the system dld not lend itself to the frequency methed. The trassient response could be easily measured. The experiment and analysis are presented wlth the resultlng transfer function (derived from the transient response) developed in the form used in IDO-16448. (auth)« less
  • A total of 22 dump tests were run using the facilities of the NPR-PCE Loop in the 189-D building. These were divided into 12 series I tests, to establish quench tank design requirements and maximum safe quench water temperature limit after dumping, and 10 Series II tests, to evaluate various distributor designs. Pressurized water varying in temperature from 600 to 275 deg F, simulating the conditions applying to the primary loop and the initial once-through cooling water respectively, was dumped into a pool of quench water. In all cases the recorded data and visual observations showed that: quench tank vibrationsmore » were negligible for all high temperature tests and for the low temperature tests using the ring and draft tube distributors; agitation and mixing were adequate with all of the distributors; condensation of the pressurized water was complete in all of the tests; and examination of the concrete quench pit after these tests revealed no damage. (auth)« less
  • The report gives methods and results of an environmental assessment test program at an industrial site. The aim of the program was to measure multimedia emissions changes as a result of applying NOx controls. Emissions of trace elements, organic materials, sulfur species, SO/sub 2/, NOx, CO, and particulate matter were measured. These emissions, under normal and controlled (for NOx) operating conditions, were compared. Source operating data were also analyzed so that changes in operating parameters and efficiency could be assessed. This unit is a spreader-stoker coal-fired boiler rated at 38 kg/s (300,000 lb/hr) of steam. The fuel tested was low-sulfurmore » coal. High overfire air firing (constant overall air flow) was used for NOx control. These measures reduced NOx by about 10% from baseline. Increased overfire air levels also improved boiler efficiency. These tests lasted about 5 hours; long-term operation under test conditions was not addressed in this program. Test results suggest that applying combustion modification NOx controls increased particulate and organic emissions.« less