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NBSIR 85-3242

A Report on the NBS-DOE

May 1 984 Workshop on Thermal

Meteri ng

George E. Mattingly

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

Center for Chemical Engineering

Chemical Process Metrology Division

Gaithersburg, MD 20899

November 1985

Proqared for: QC

100

• U56

85-3242

1985

. Department of Energy

ice of Conservation

shington, DC 20585

NBSIR 85-3242

A REPORT ON THE NBS-DOE

MAY 9184 WORKSHOP ON THERMAL

METERING

NBS sEsmcK n-vTonTAnou

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George E. Mattingly

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

Center for Chemical Engineering

Chemical Process Metrology Division

Gaithersburg, MD 20899

November 1985

Prepared for: U.S. Department of Energy

Office of Conservation

Washington, DC 20585

U.S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS
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A REPORT ON THE NBS-DOE MAY L984 WORKSHOP ON THERMAL METERING

George E. Mattingly

Chemical Process Metrology Division

Center for Chemical Engineering

National Bureau of Standards

Gaithersburg, MD 20899

A workshop on thermal metering (i.e., the flow of steam or of

hot or chilled water) was convened in Gaithersburg, MD, May 21-22,

1984 to discuss and prioritize measurement problems and research

programs which could lead to improved energy conservation through

the development and use of district heating and cooling systems.

The workshop brought together 60 attendees whose expertise spanned

a broad range of interests. Included were flowmeter manufacturers,

meter users, standards personnel, academicians, and consultants.

Attendees listed current problem areas and measurement needs in

thermal metering, discussed appropriate responses to these needs,

and prioritized these according to their perceived potential for

impacting thermal metering practice. Leading this list are:

® "paper" standards with special emphasis on "meter

installation requirements",

® research on two-phase flow and its measurement,

* two-phase flow technology transfer and information

dissemination.

Key Words: district heating and cooling; energy conservation; flow;

standards; thermal metering; two-phase flow.

Workshop Summary

This report is the summary of a two-day workshop held on May 21-22, 1984 by

the National Bureau of Standards (NBS) in Gaithersburg, MD. The workshop was sponsored by the Department of Energy's Office of Conservation and NBS. Its

purpose was to discuss and prioritize the flowrate measurement problems,

technical issues, research areas, which could enable energy conservation

measures to be realized through the development and use of district heating and

cooling (DHC) systems.

The workshop attendees were welcomed by Dr. Jarda J. Ulbrecht, Chief of the

Chemical Process Metrology Division at NBS. Dr. Ulbrecht said:

"The National Bureau of Standards established a role for itself in

developing fluid metering technology in the early 1900' s. In the area of

orifice metering, NBS staff members Mr. Howard S. Bean and Dr. Edgar Buckingham

together with others, and especially in collaboration with Professor Samuel R.

Bel tier of Ohio State supervised and/or consulted in orifice testing programs

over three decades from the 1920' s. The result of this combination of testing

programs, with others in the U.S. and abroad have produced the state-of-the-art

in orifice metering as we know it - even today in the 1980 's.
"Even today, calibration- testing programs continue to be conducted in the

U.S. and in several countries in Europe to corroborate or to upgrade the levels

of uncertainty associated with orifice metering. It is also beginning to be

recognized that, in addition to this type of calibration testing and empirical

approaches, other research tools - especially laser velocimetry and computer

modeling techniques are available for studying fluid flows in orifice and other

metering geometries.

"It is the purpose of this workshop to discuss the fluid flowrate issues

that affect thermal metering, to suggest research programs to address these

issues, and to prioritize them. The task seems clear, at least in principle; it

is certainly most timely and appropriate; and I wish you every success in

carrying out the goals of this workshop - I shall look forward to your

results."

Mr. Jacob Kaminsky of the U.S. Department of Energy's Office of

Conservation followed Dr. Ulbrecht's welcome with the following statement of

purpose for the workshop:

"doe's Office of Conservation is continuously looking for ways to conserve

energy in the U.S. - both in the industrial and private sectors. One of the

promising ways to do this can be through the advantageous economies of scale

offered via District Heating and Cooling (DHC) Systems.

The economic feasibility of DHC systems is based upon the equitable custody

transfer of energy between vendor and user. This transfer is carried out

through an accounting chain based upon thermal measurements - i.e., the energy

content in a fluid stream. Fluids range from wet and dry steam to heated and

chilled water. Flowrates and pipeline sizes span a wide range. Measurement

precision and accuracy is desired to be at or below the 1% level. The costs - capital and operating - for the thermal measurement systems are to be kept at a reasonable level."

The purpose of this workshop is to; (I) determine the barriers - technical

and otherwise - that currently prevent this level of thermal metering, (2)

discuss these, (3) list them in priority order, and (4) suggest what should be

done to improve matters.

To introduce the subject matter of the workshop, brief overviews will

describe the state-of-the-art in thermal metering and the state-of-the-art in

fluid metering research. These overviews were given by:

Mr. Norman R. Taylor

Executive Director

International District Heating Association (IDHA)

Washington, DC

Mr. Peter L. Turchi

Chairman, Fluid Meter Committee of IDHA, and

ADCONS, Inc.

Baltimore, MD

2
Mr. CllntOQ W. Phillips

Board Member

North American District Heating and Cooling Institute

Washington, DC

Dr. George E. Mattingly

Senior Scientist for Fluid Measurements

National Bureau of Standards

Gaithersburg, MD

Written summaries of these overviews are given in Appendices 1-4.

The Task Group Facilitators invited to lead discussion in the five topical

areas were introduced by Dr. Mattingly. The topic areas and the respective

facilitators are listed as follows:

Task Group 1 - Installation Effects

Professor William Durgin

Department of Mechanical Engineering

Worcester Polytechnic Institute

Worcester, MA

Task Group 2 - Measurement Techniques

Professor James Murdock

Department of Mechanical Engineering

Drexel University

Philadelphia, PA

Task Group 3 - New Technologies

Professor Dirse Sallet

Department of Mechanical Engineering

University of Maryland

College Park, MD

Task Group 4 - Standards and Calibration

Professor Thomas Amberg

Department of Mechanical Engineering

University of Colorado - Denver

and

Colorado Engineering Experiment Station, Inc. (CEESI)

Nunn , CO

Task Group 5 - Control Systems

Dr. James Hill

Chief, Building Equipment Division

Center for Building Technology

NBS - Gaithersburg, MD

3
and

Mr. Narender Reddy

Energy and Environmental Systems

Argonne National Laboratory

Argonne, XL

Messrs. Kaminsky and Mattingly reviewed the fact that the letter sent

inviting each of the attendees Included a section which requested input

regarding perceived:

” suggestions

® key issues

** items needing resolution

... that affect thermal metering and should receive attention during the

workshop. This letter is included as Appendix No. 5.

The responses received are listed in Appendix No. 6. These responses are also provided to the respective Task Group Facilitators. Additionally, each

attendee was provided a listing so that all participants have a set of the

topics with which to begin their discussions in their respective areas.

The instructions to Task Group Facilitators were to add or subtract items

from their listings as they deemed appropriate. Task groups were then asked to

organize their topics, discuss these according to their pertinence for improving

cost-effective thermal metering, and describing what should be done about them.

As per the workshop schedule, see Appendix No. 7, the progress of each Task

Group would be summarized by its facilitator for all the workshop attendees on

the morning of the second day of the workshop. The discussion after each of the

summary presentations will provide the opportunity for "cross-fertilization"

among the Task Groups.

A listing of the workshop attendees is given in Appendix 8.

Task Group Summaries

The products from the Task Group deliberations are presented in summary

form by the respective Facilitator as follows;

Task Group 1. Installation Effects -

Chairman; Professor W. W. Durgin

Department of Mechanical Engineering

Worcester Polytechnic Institute

Worcester, MA

Problem areas and issues will be identified, sub-divided into components, and

the recommended responses given by the designated group or agency, in

parentheses

.

4
I. Measurement of Energy Transport in Wet Steam.

A. Identify Problem. (Trade association should respond to this

issue)

.

B. Develop Measurement Methodology. (Response to this issue should be

by DOE, academia, and the national labs).

C. Utilize Existing Tes t/ Development Facilities, if possible.

(Response to this issue should be by DOE, academia, and industry).

II. Reproducible Baseline Input Profiles. (Response to all these issues

should be by DOE, academia, national labs, and MBS).

A. Fluid characteristics - Velocity (including swirl), temperature,

and density.

B. Achievement in practice, flow conditioning.

III. Conduct Interlabora tory Fluid Metering Comparisons Programs. (Response

should be by DOE, industry, and NBS).

A. Several laboratories are needed for cross-checks, these should use different methods for calibrating flowmeters.

IV. Write Thermal Meter Standards. (Response should be by professional

societies and NBS).

A. Utilize existing standards where possible.

B. Develop new documents incorporating new technology as necessary.

V. Dissemination of Thermal Metering Technology and Information.

(Response should be by national labs and NBS).

A. Existing fluid and thermal metering codes and standards (trade

associa tions)

.

B. Bibliography of pertinent texts, publications and reports (trade

associations)

.

C. Short Courses on thermal measurement and related subjects should be

generated, publicized, and presented on a regular basis.

D. Question and Answer Surveys regarding thermal measurements should

be prepared, used, and results disseminated to inform all on problems and solutions (trade associations).

E. Thermal metering operating and maintenance guidelines (trade

associations, vendors, and users).

F. Thermal metering installation guidelines (trade associations,

vendors, and users).

5
G. PubLlcatloa of thermal measurement case studies (Trade

Associations)

.

Task Group 2 - Thermal Metering

Chairman: Professor James Murdock

Department of Mechanical Engineering

Drexel University

Philadelphia, PA

Problem areas and issues will be identified, described briefly, and the

recommended responses given by the designated group or agency, in parentheses.

I. Standards for thermal metering, including related system design

considerations. (Response to this issue should be by such professional

societies as ASME and ASTM with trade association cooperation.)

II. Independent laboratories should be established with capabilities for

calibrating thermal meters (including steam). These laboratories should

have their measurement processes traceable to NBS. (Response to this

issue should be by DOE with "seed funding" and by industry funding with

the steam trap industry).

III. Research in thermal metering of two-phase flows. (Response to this issue

should be by DOE with "seed funding" by NBS, by academia, and by industry.

Task Group 3 - New Technologies

Chairman: Professor Dirse Salle

t

Department of Mechanical Engineering

University of Maryland

College Park, MD

Problem areas and issues are identified, briefly described, and the recommended

response given by the designated group or agency, in parentheses.

I. Basic research is needed to characterize the regimes of two-phase pipe

flow. (Response to this issue should be initiated by DOE, academia,

industry, and NBS).

II. Improve the capability of "Standard Metering Techniques" to make thermal

metering cost effective. Measurements in one and two phase thermal

streams. (Response should be by DOE and industry). By "Standard Metering

Techniques" is meant turbine, vortex shedding, and differential pressure

type devices, etc.

III. Determine "Prospective New Techniques" and schemes for thermal metering

and assess these according to their cost effectiveness for making the

desired levels of thermal measurement. (Trade association support). By

"Prospective New Techniques" is meant such techniques as magnetic

resonance, pulsed neutron activation, ultrasonic, angular momentum, etc.

6
Task Group 4 - Standards and Traceability

Chairman: Professor Thomas Amberg

Department of Mechanical Engineering

University of Colorado - Denver

and

Colorado Engineering Experiment Station, Inc. (CEESI)

Munn, CO

Problem areas and issues are identified, briefly described, and the recommended

responses given by the designated group or agency, in parentheses.

A. "Paper" Products:

I. Thermal metering performance standards. (Response should be by

trade association). Thermal metering testing standards.

(Response should be by professional societies).

II. Application and installation manual. (Response should be by

trade associations).

III. "In-si tu" testing technique manual. (Response should be by

professional society).

IV. Certification program - manual. (Response should be by trade

association)

.

B. "Hardware" Products;

V. Manufacturer's testing. (Response by industry).

VI. Certification - commercial testing laboratory. (Response should

be by industry).

VII. "In-situ" testing device development. (Response should be by NBS

and academia.

Task Group 5

- Control Systems

Co-Chairmen; Dr. J. E. Hill

Center for Building Technology

MBS - Gaithersburg, MD

and

Mr. Narender Reddy

Energy and Environmental Systems

Argonne National Laboratory

Argonne , IL

A. Problem Areas;

1. Current district heating systems are being designed with siioplified

control algorithms that result in suboptimum efficiency of the plant

and no load management.

7
2 . Current district heating control systems are not operating as intended.

3.

Utilities refuse to purchase excess electricity from total energy

plants that feed district heating systems.

B. Proposed Research:

Response to the above-numbered problem areas:

1. Develop and verify algorithms for advanced district heating and cooling

control and load management.

2. None - Industry should follow-up to see that existing systems are checked out and operated properly; operators are trained properly.

3. ?

C. Other Issues:

1. The problem of building submetering and control systems (e.g.

distribution of steam to apartments from a central source) are is

similar to the problems confronting those attempting to build DH

(district heating) systems.

2. The link between metering and instrumentation and control system is the same regardless of whether current control or advanced control

algorithms are used.

D. Effect of Proposed Research:

1. Increased plant efficiency.

2. Improved Load management.

3. Enhanced safety and reliability.

4. Lower operating costs.

5. Automated data acquisition for metering and billing.

8
Prioritization Results

After presentation of Task Group deliberations by the respective

Facilitator, the results of the individual groups were surveyed to determine

identical or similar issues. This effort produced the following listing of

prioritized issues that were approved by ballot of the attendees.

1. Thermal metering standards with special emphasis on installation

requirements.

2. Certification techniques (calibration facilities) adequate to and

including the verification needed to assure the needed levels of

measuremen t.

3. Two-phase flow measurement research to assess and develop accurate, low

cost techniques.

4. Devices to perform "in-si tu" checks on thermal measurements.

5. Generic flow sensor development programs.

6. Dissemination systems for thermal measurement information and

technology transfer.

The above issues might be regrouped under three headings:

1. Standards - installation requirements, operation techniques, levels of

perfomance, etc.

II. Calibration Facilities - laboratory, "in-situ" proving, traceability, etc.

III. Research - flow and related sensor development for accurate, low-cost

thermal measurements.

This order of priority (I, II, III) reflects the consensus researched in the

final session of the workshop.

9

Appendix I

Metering Issues in District Heating and Cooling

N. R. Taylor

Executive Director

International District Heating and Cooling Association (IDHCA)

Washington, D.C.

The sale of any commodity to the consumer generally has some form of

regulation as to quantity or quality. Scales in markets must be certified,

gasoline pump meters are checked to assure accuracy, electrical materials bear

labels of approval, as do most food products. The thermal heating/cooling

business is no different and there exists well defined rules and regulations for

the transfer of these products to the consumer in exchange for dollars. Most

often such standards are established by state regulatory offices and may be

referred to as "PUC Regulations".

Examining a cross section of such regulations prepared in general, for

steam distribution companies, we find some basics that give us a foundation for

our discussion of thermal metering. Some of the essentials are:

Meter. The word "meter", when used in these regulations without other

qualification, shall be construed to mean any meter or device which is installed

by the utility for measuring the quantity of service rendered to a customer.

Meter Accuracy . Ail meters shall be adjusted before installation so as to register with an error of not more than 2%, and this adjustment shall be

maintained as nearly as possible in meters which are in service. If any meter

in service is found to register with an error of more than 3% when subjected to tests, as outlined below, it shall be deemed inaccurate.

Meter Tests . There are many types of tests that can be applied to meters

in a variety of situations both in the field, in the shops of the supplier, at

the facilities of the regulatory body, or at an independent laboratory. Some

"test" definitions are:

Laboratory Test

Service Test

Installation Test

Periodic Test

Request Tes t Referee Test

Office Test

Repair Test

Inspec tion

Check Tes t Special Test

Facilities for Testing . Each utility, unless specifically excused by the

Commission, provides such laboratory meter testing equipment and facilities as may be necessary to make the tests required of it by these rules or any orders

of the commission. The apparatus and equipment so provided shall be subject to

the approval of the commission, and it shall be available at all times for

inspection or used by any member or authorized representative of the commission

That various gauges, scales, thermometers, etc., used in make test, shall be

calibrated as frequently as necessary for maintenance of accuracy.

Al.l
The types of meters are recognized by most regulations and specific tests are designated:

Condensation Meters . Condensation meters shall be tested by passing a known quantity of water through the meter. In the case of rotating type meters,

one test shall be made at not more than 25% of rated capacity, using in no case

less than 20 pounds of water, and one test at not less than 75% of capacity.

The arithmetical average of the accuracies at these test points shall be deemed

the accuracy of the meter. However, the variation in accuracy at different

ratings shall not exceed 3%.

Flow Meters . Flow meter shall be tested on the consumer's premises by

careful measurement of orifice size, static pressure and pressure differential.

Check of differential pressure at any point shall be made with increasing and

decreasing flows, using the average as the calibration pressure for that flow

point. In the case of the graphic or chart typemeters, the chart record shall

be checked against the static pressure and pressure differential as determined

by test. Such checks shall be made at not less than three points, as follows:

1. At approximately 25% of chart range, with a permissible accuracy tolerance

of + 3%.

2. At a point not less than 50% nor more than 75% of chart range, with a permissible accuracy tolerance of + 2%.

3. At approximately full scale, with a permissible accuracy of + 2%.

Other Meters . Any other type meter shall be tested in accordance with the

manufacturer's recommendations and as approved by the commission and shall

insure accuracy commensurate with that of flow meters.

Most regulations also specify conditions by which the supplier can furnish

data to a regulatory agency as to the quantity and quality of the product.

Station and Consumption Records . Each utility shall maintain such

instruments and meters at each generating station as may be necessary to obtain

a daily record of the load and a monthly record of the output and to show

continuously the character of service being rendered therefrom.

These rules, together with the standard operating procedure of the supplier

provide the background for reasonable cost accounting between the customer and

the company. How much money the company pays for the meter, what type is

purchased, where it is installed and how it is utilized, is generally left to

the company. The same capacity steam meter may cost $200 or $5000, it is a matter of conditions of supply and utilization.

Metering any product is largely a decision making process.

A1.2
Appendix 2

Mr. Peter L. Turchi

Chairman, IDHA Committee on Fluid Metering

and

ADCONS, Inc.

Baltimore, MD

As representatives from the thermal metering community, we are here to discuss thermal measurement and its meaning to the customer and the non-utility

selling agency. It is quite evident that anytime that you have a billing

adjustment that is estimated the feeling is buyer beware. On the other hand, if we can measure with confidence over the entire range with an accepted accuracy

to both parties, then any loss of measurement is accepted by the seller as a pro-rated system loss.

It becomes very evident that any meter based on "range accuracy" rather

than "reading accuracy" can be in greater error at the lower end of the scale,

depending upon rangeability of the instrument. That can be a detriment to either the customer or the seller. We do not believe that any customer would

not be willing to pay for a utility that he feels has an accurate accountability.

Standards for metering, especially steam are either based on water or air.

As a note, when we measure BTU's for either hot or chilled water systems, we measure the differential temperature of the fluid and in most cases, flow on the

inlet side. Makeup is rarely accounted for. Ue believe there is a fallacy in

steam measurement systems in that a total amount of steam sent to a customer is

billed and where there is a condensate return system, that is not metered.

Consequently, the customer is paying for 100% of the energy transported to him.

On the other hand, where the condensate is measured, the seller is not at the

mercy of any trap losses and other leaks in the customer's system.

It becomes obvious that in protection of the seller and customer, total

energy usage can best be measured by the meter on the inlet and the meter on the

outlet of the customer system. It then behooves both parties to maintain their

individual systems. In the case of the customer, if he doesn' t it results in a higher billing. In the case of the seller, it now becomes the responsibility of

a governing body or public service utility to govern the percentage of losses

that can be accounted or added to the customer's bill.

What is our part? Our part is to look for those areas that need development in order to achieve the best metering system possible which not only

includes the meter, but also piping, controls and whatever else we should

develop at this meeting. Over the years, I have learned that there is no stopping the learning process and each of us can learn from each other. With

that in mind, I feel certain that collectively we will all come out of these

next two days with far more questions that need to be answered than we have

today.

Thank you.

PLT

A2.1

Appendix 3

Mr. C. W, Phillips

Technical Director

North American District Heating and Cooling Institute (NADHCI)

Washington, D.C.

Good morning. I am Clint Phillips - Member of the Board of the North

American District Heating and Cooling Institute, and the person responsible to pull together NADHCI* s metering standards and related R&D efforts.

We are all here, hopefully, because we want to help enhance the expanded

role of DHC in America's cities, and recognize the key role of metering in that

regard.

Our Executive Director, Dick Eckfield, had hoped to be here with us this

morning, in fact was to have made this opening statement. He knows many of you,

and in addition to the substance covered at these meetings, because they also

provide a good opportunity to make new acquaintances and renew acquaintenances

,

he is sorry to miss this opportunity.

However, there is another issue that is also key to DHC development, and

that is the creation of favorable tax incentives for DHC development - and the

key person here is House Ways and Means Chairman Dan Rostenkowsy.

To organize the educational briefings for Chairman Rostenkowsky it has been

necessary for us to work with the key-opinion leaders in Chicago to share with

them our vision for DHC. That effort has culminated in a half-day seminar for

the key city officials and the major Chicago area developers. That meeting,

which Dick Eckfield is keynoting, is today in Chicago. Thus, he is there - and

I am pleased to be with you here today - to add our support for the purposes of

this meeting. I want to take a couple of minutes to tell you why we at NADHCI

place such importance on metering.

I. Accurate metering will be a key ingredient in the development of the

DHC market in American cities.

® We expect to see much of the new DHC development to be sponsored by

private entrepreneurs, or public and quasi-public institutions (such as universities) who will embrace system expansion and metering for entrepreneurial

reasons.

In all Instances, the system developer will need to recover all the revenue

possible. Thus, accurate metering for billing purposes is essential.

In a highly competitive market where economics of the cost of energy will

determine new customer hook-ups, there will be little room for error in the

metering, and in a cost-conscious environment there is little room for 'gilding*

of the individual meters.

Thus, in what may appear to be a contradiction - we need meters that are

the most accurate possible - which must be installed at the lowest possible

cost.

A3.1
2. We know that strong reliable standards ~ both performance and testing - are important if we are to be able to build accurate yet inexpensive metering

devices

.

" We have spoken to several of you about the perceived need to develop such

standards for the measurement of both the flow and the temperature differential - thermal measurement - for hot water, chilled water, and steam meters. We

have contacted ANSI in regard to the development of such standards. They appear

to be needed. We have been in contact with ASHRAE regarding our collaboration

in the development of such standards. One of the things we will be looking for,

particularly from our members, is feedback from this meeting on what the scope

of such standard(s) should be.

3. One last item of more immediate interest is the effort NADHCl is

putting together with the public housing administration in HUD regarding master

metering and tenant sub-metering of public housing units.

^ A few months ago, as some of you know, we began to work out the scope of

a public housing metering demonstration effort. 1 participated in the first

meeting - which lasted all morning - with the Assistant Secretary for Public

Housing (Warren Lindquist - March 23).

I can tell you definitely there is interest in our proposal - and we at

NADHCl place a special importance on this segment of the total industry ... as a major key to DHC expansion in American cities ... and improved metering is

necessary for that effort to succeed.

We were pleased to work with the development of this meeting today. We

look forward to the results.

A3.

2
Appendix 4

Improved Thermal Metering; New Research

Tools and New Opportunities

G. E. MattinglySenior Scientist for Fluid Measurements

Chemical Process Metrology Division

Center for Chemical Engineering

National Bureau of Standards

Gaithersburg, MD 20899

S umma ry

To realize the potential energy conservation benefits offered by District

Heating and Cooling (DHC) schemes that are based on equitable custody transfer

of thermal energy, cost-effective measurement capabilities are essential. The

required measurement capabilities to achieve the 2% accuracy levels described

previously by Mr. Norman R. Taylor are very difficult to achieve in the wide

range of metering conditions that confront (and confound!) users. For example,

the installation specifications called for by meter vendors to achieve stated

levels of meter performance can not always be met in practical situations. In

many cases, meters are installed too near elbows, valves, and piping reducers or enlargements. Few, if any, of these installation situations have been

calibrated and, as a result, meter performance has been found to deviate widely

from predictions.

To remedy this situation there are available now new research tools for

conducting metering research. These differ radically from the methods used in

the past i.e., calibration testing. The new tools - laser Doppler velocimetry

(LDV) , computer modeling, and high speed flow visualization enable a new strategy in metering studies - determining the flow field into and inside a metering geometry, understanding this flow, and arranging the operation of the

meter to achieve and assure the desired level of performance.

These research tools and this strategy enable significant improvements in

thermal metering to be made in efficiently arranged and sponsored projects.

Results would be disseminated to meter vendors and users alike. Concurrently,

results would be incorporated into metering standards and specifications. The

ultimate result would be the attainment of metering performance that is adequate

and satisfactory to both the buyers and sellers of energy in DHC systems.

INTRODUCTION

To attain the potential energy conservation benefits from District Heating

and Cooling (DHC) schemes that involve custody transfer of thermal energy,

cost-effective measurement capabilities are essential. In fact, the acceptance

of such concepts, the implementation and use of such systems hinges critically

on the accuracy, precision, and costs of both capital and operating of the

ins tr\imentation necessary to make these thermal measurement systems economically

viable.

A4.1
Thermal Metering Requirements , Thermal measurements systems are needed

over the widely ranging conditions of operations described above by Taylor and

Turchi. Throughout these ranges of conditions, fluid metering research programs

will be needed to improve existing methods of thermal measurement and to

evaluate the feasibility of new techniques which show potential for these tasks.

In what follows, emphasis will be placed upon the measurement of fluid

volumetric flowrate; the determination of temperature, pressure, or the energy

content of the fluid stream will be considered an auxiliary one. Emphasis will

also be placed upon the newly available research tools and how these can produce

more detailed understanding of fluid meter performance than could be attained

using the "research" methods of the past.

Historical Perspective . In the past, fluid metering research was carried

out by calibration techniques - using discharge coefficients and meter factors

and the variations of these as performance indicators. Upstream piping

configurations, meter variations, fluids, and flowrates were arranged and the

installed meter was calibrated. Individually, the parameters were varied and

calibration was repeated until a satisfactory range of conditions was covered by

the calibrations. The resulting data was analyzed to determine the nature and

amount of variation that occurred in the discharge coefficient or meter factor.

Calibration Benefits . This approach had considerable practical value - provided the conditions of the calibrations precisely duplicated a meter

installation, and provided the accuracy and precision desired of the meter did

not exceed that obtained in the calibration. Additionally, in the past the

fluid research tools needed to go beyond this "calibration - produced"

understanding of meter performance did not exist. Consequently, it was not

possible to make detailed measurements of flow velocity into or through the

meter geometry; it was not possible to understand the instantaneous

distributions of fluid pressure or temperature in the meter's flow field. As a result, when meter installation conditions differed from those of a known

calibration, or when changes in meter conditions - such as orifice edge

sharpness, pipe roughness, or secondary instruments i.e., manometry or transducer systems occurred, it became uncertain how to predict the nature and

amount of change in meter performance. Similarly, when the need arose to reduce

metering uncertainty. Little guidance was given via the calibration data as to which of the many variables controlling meter performance should be changed (and

how much) so as to achieve the desired improvement. Therefore, it is concluded

that an improved level of understanding be established so that hierarchy of the

factors that affect meter performance are understood. Using this understanding,

meter standards for installations can be specified and operating procedures laid

out so that desired performance can be attained. To achieve this understanding

will require significant metering research.

FLUID METERING RESEARCH

The purpose and strategy for fluid metering research have several

components, as shown in Table 1:
Table I. Fluid Metering Research

L. Purpose ;

A. Improve existing metering techniques

B. Assess and establish new metering technologies

2. S tra tegy ;

A. Focus fluid mechanical expertise on the salient phenomena

governing meter performance

B. Apply new fluid dynamical research tools to meter flows

The details as to how these are achieved are to result from the discussions of

this workshop.

Thermal Metering . A number of flow measurement devices offer potential for

thermal metering. These can be subdivided as to their potential for making

volumetric or mass flow rate measurements, as shown in Table 2. Rather than

address each of these devices and describe or infer how its performance can

deviate from "the ideal", it will be sufficient to select the prevalently used

orifice meter and use it as a generic example. The essential point to be made

is that before the performance of any metering device is optimized, the factors

that significantly affect it must be thoroughly understood.

Ideal Orifice Performance . The time-averaged, ideal orifice flow field, shown

in Figure 1, has been the focal point of many studies and a recent workshop

organized to determine the fundamental research issues in orifice technology,

see (1).* References (2-22) describe a range of orifice studies and some of the

results obtained from them. These have shown conclusively that the orifice flow

field is altered by a number of effects. For example, the ideal flow pattern

can be perturbed by fluid dynamic instabilities, coherent structures,

turbulence, pulsations, etc. These sources of deviations affect the flow and

pressure distributions shown in Figure 1, causing them to deviate from those

assumed in deriving the metering equations in use. This affects the accuracies

and performance of the orifice meter. Performance deviation due to individual

effects varies in magnitude and when multiple effects are present, the combined

effect can be diminished or enhanced. Because instabilities and coherent

structures can develop naturally in the orifice jet and because the turbulence

distributions in the flow field are inherent to the flow in this geometry, we shall confine our attention to these aspects.

Pulsation effects as transmitted from specific sources, such as valves,

pumps, and compressors, etc. are dependent on the characteristics of these sources. For this reason, these will not be dealt with in the discussion that

follows. References (23-27) present current descriptions of the effects of

pulsations on orifice meters and on other differential pressure type meters.

*Integers in parentheses refer to references given below.

A4.3
Table 2. Flow Measurement Devices

I. Volumetric Flow Rate

1. Differential Pressure Type

a) Orifice

b) Nozzle

c) Venturi

d) Pitot

e) Laminar

2. Turbine

a) Full bore

b) Insertion

c) Paddle

3. Vortex

a) Shedding- type

b) Swirl meter

4. Electromagnetic

5. Acoustic

6. Positive Displacement

7. Force Type

a) Target

b) Variable area

11. Mass Flow Rate

1. Angular momentum

2. Coriolis

3. Acoustic

4. Thermal

A4.4
Because the fluid inertial effects in most pipelines far exceed viscous

effects, orifice flows are predominantly turbulent. As a result, the pressure

distributions along the pipewalls have a corresponding randomly varying

component which can significantly affect the level of uncertainty and the

accuracy of flow measurements with orifice meters.

For incompressible, one -dimensional, steady flow, the conservation of mass

and energy relationships can be used to produce the theoretical mass or volumetric flowrate that will occur through the orifice construction from a high

pressure upstream to a lower pressure downstream. The actual flow rate can be

computed using a discharge coefficient, Cq and the theoretical flowrate as follows:

Q

= Vd /2AP

P

where, in compatible units, Q is the volumetric flowrate, is the orifice

hole area, 3 is the orifice hole to pipe diameter ratio, AP is the pressure

difference, and P is the fluid density. The discharge coefficient is dependent

on the orifice geometry, a sequence of dimensionless flow parameters, and the

specific installation. The deviation of the discharge coefficient from unity can be considered to be a measure of the deviation of actual conditions from the

assumptions involved in applying the above described conservation equations to

orifice flow.

Perturbations on Ideal Orifice Performance . Deviations from ideal conditions- can result from anomalies in pipe geometry, plate geometry, and inlet flow.

Examples of each of these are given in Table 3, see also Figs. 2-3. Piping

configurations can produce perturbations on the performance of meters placed too

closely to elbows, pipe diameter changes, or partially opened valves, see Figs.

4(a) and (b). As well, these results form the basis for recommending meter

installations where these perturbing influences have been diffused either

naturally or through flow conditioning, see (28-35).

Flow Conditioning . Flow conditioning philosophies vary as do the associated

devices. A detailed review is given in (36). A prevalent flow conditioning

philosophy is to remove artificially those flow anomalies which affect orifice

meter performance.

Tube bundle flow straighteners, which consist of large numbers of small

tubes are quite prevalent. These bundles, which are several pipe diameters in

length, are placed upstream of orifice meters so that, through "wave-guiding"

action, they reduce secondary motions such as sketched in Figs. 4(a) or 4(b).

The tube bundle's effectiveness in reducing swirl reduces the need for long

lengths of straight pipe. Similar to tube bundle straighteners are the

"slat- type" and the "Etoile" straighteners. These use wave-guiding action

produced by small square or triangle passages produced by assemblies of flat

plates.

A4.5
Table 3. Causes for Deviations from Ideal

Anomalies in

® Pipe Geometry

Size

Shape

Roughness

Alignment

* Plate Geometry

Size

Shape

Roughness

Flatness

Sharpness

Goncentrici ty

® Inlet Flow

Linear Velocity Profile

Swirl Velocity Profile

» Pulsations

A4.6
Sprenkle* flow coadltloaers consist of multiple discs, usually three,

having large numbers of small holes drilled through them. These discs are supported across the cross-sectional area of a pipe flow to produce highly

turbulent wakes. These wakes are designed to mix the fluid kinetic energy so that swirl is diffused and the streamwise component of the velocity profile

closely resembles a "fully developed" pipe flow profile - i.e., that which would

evolve oatually via very long lengths of straight pipe.

A Zanker-type flow conditioner is basically a combination of a single

Sprenkle disc followed by a "slat- type" straightener. It is designed to

construct a "fully developed" pipe flow distribution through selected disc hole

sizings aligned with each channel of the straightener, see (37). A design

somewhat similar to the Zanker type device is becoming known as the Mitsubishi

flow conditioner (38).

Using computer modeling techniques to calculate the flow fields through

reasonably simple flow conditioning geometries, NBS staff have produced a configuration that shows good conditioning potential. This conditioner turns

the pipe flow through four 90® turns and includes passing the flow through a cylindrical surface containing small holes. The resulting tortuosity produces

very repeatable flow profiles in only a few diameters downstream of this device

regardless of the anomalies in the distribution of the streamwise flow velocity

entering the device, (39). This approach uses the second conditioning

philosophy of attempting to produce an extremely repeatable flow profile

regardless of that which enters the conditioner. In this manner, once the flow

conditioner and meter are calibrated (or otherwise characterized) as a unit, the

combination can be expected to produce extremely reliable measurements.

Thus, our short review shows that orifice discharge coefficients can be

affected by a number of factors. These can interact with one another to produce

combined effects which, in turn, can either enhance or offset their individual

effects on the discharge coefficient. Assessing the significance of these

effects individually is very difficult - especially if only calibration and

testing procedures are used. Assessing their significance in combination is

virtually impossible in light of the extremely large number of separate tests

then required. Since these effects readily interact with one another through

the fluid medium, their effects on prevailing discharge coefficients should be

significant.

As mentioned above, testing programs have been extensively used to

characterize the performance of meters. This is understandable in light of the

fact that the capabilities available in fluid research for observing the

fundamental fluid phenomena inside flow meters were severely limited. It is our

purpose here to show that this is not the case today and that new research

opportunities are now available to measure, study and understand these phenomena

and their effects on meter performance on a fundamental level.

New Research Opportunities . To understand the basic fluid phenomena that

control meter performance, it will be necesary to understand how the sources of

the various performance perturbations affect the operation of the meter. To do

this, new techniques will be needed, especially the experimental and

computational ones that are now available for these studies.

^Device patented by R. E. Sprenkle at the Bailey Meter Co., Wycliffe, Ohio.

A4.7
Experimental Techniques . Some of the experimental techniques intrude into the

flow field to obtain desired measurement; others do not. Table 4 lists a number

of each type.

It is pertinent here to describe these further.

Pitot tubes, shown schematically in Figure 5 have the capabilities of

measuring the streamwise component of the mean flow velocity distributions, see

(40). Care should be taken to measure the fluid velocity without disturbing it.

For example, a pitot tube inserted downstream of the orifice plate could disrupt

the normal dynamics which occur in the eddy system which resides there.

Anemometry techniques which use heat transfer from small elements - hot

wires for gas flows and hot films for conducting liquids like water *• can

measure one or more components of the velocity and are capable of very high

frequency response, see (40, 23). As such, these can be used to measure flow

instabilities, coherent structures, and turbulence. As with pitot tubes,

however, care must be used to minimize the intrusive nature of the sensors

involved. Figure 6 sketches the way in which the technique could be used to measure streamwise velocity components.

Many visualization techniques have been developed in recent years. Among

these, the smoke wire visualization technique is well-suited for use in orifice

geometries. Figure 7 shows a configuration that can produce photos of the fluid

dynamics in the orifice jet where instabilities and coherent structures can

occur. Figure 8 shows typical results using this smoke wire technique. Note

the vortices generated at the edge of the orifice jet. The cyclic pulsations

produced by these can be transmitted directly to the downstream pressure tap.

Dye injection techniques have been used in orifice meter research (23).

Figure 9 shows several arrangements that can be used to picture the fluid

dynamics upstream or downstream of the plate.

The hydrogen bubble flow visualization technique uses the electrolysis of

water to produce small hydrogen bubbles that, with proper lighting, can be

viewed with the naked eye or photographed (41). These small bubbles have a buoyancy to drag ratio that is proportional to the bubble diameter. For

sufficiently small bubbles, buoyancy becomes negligible making them ideal

tracers to portray fluid motions. By placing the cathode terminal in the form

of a thin wire supported where bubble injection is desired and the anode

terminal in an inconspicuous location in the flow, visible bubbles can be

generated at the cathode using pulsed or d-c excitation. Figure 10 sketches

both the electrode arrangements to generate bubbles in a diametral plane as well

as the bubble patterns that can be produced.

Laser Doppler velociraetry (LDV) is an ideal technique for use in orifice

research, see (42). Figure 11 sketches an arrangement of components to measure

the streamwise component of the fluid velocity. It is capable of measuring in a non-intrusive manner, one or more components of the fluid velocity in a field

inside the orifice geometry. Because the technique is based on light scattering

phenomena, it is capable of very high frequency response. In addition, by using

multiple sensing schemes, this technique makes it possible to perform the

correlation measurements needed to describe turbulent flow fields properly. LDV

is an ideal experimental research tool with which to measure orifice flows.

A4.8
Table 4. Experimental Techniques for Orifice Flow

A. Intrusive

1. Pitot Tubes

2. Anemometry

* Hot Wire

® Hot Film

3. Visualization

Smoke Wire

® Electrolysis

B. Non-Intrusive

1. Visualization

® Dye Injection

2. Optical

® Interferometry

3. Laser Doppler Velocimetry

A4.9
Figure 12 presents typical results from some preliminary velocity traverses

measured at NBS.

In compressible orifice flow where fluid density variations occur,

interferometry is capable of producing, in an non-intrusive manner, both

qualitative and quantitative records for orifice flow. Figure 12 sketches an arrangement through which interferometry can be used to give the density field

in an orifice flow (40).

These techniques offer tremendous potential for experimentally measuring

and understanding metering flows. Additionally, there are computational

techniques which can be applied to studying metering flows.

Computational Techniques . Computational approaches to understanding orifice

flow offer tremendous potential because they enable one factor to be changed at

a time while holding others fixed and generating the entire metering flow field.

In fact, these computations offer the possibility of making such changes and

producing the associated flow quite rapidly. In this way, the influence of the

various factors on the flow field can be individually assessed in a time period

which is short in comparison to the time required to conduct the analogous

experiment. Examples of computational techniques can be found in (43-47). When

coupled with experimental investigations that are essential to both guide and

verify computational procedures and results, this dual approach offers the

maximum potential for understanding orifice flow. A description of this

powerful research tool is given by Professor K. Ghia and U. Ghia in (1).

Techniques such as those discussed briefly above, when used in conjunction

with corresponding computer modeling efforts, offer immense potential for the

attainment of a fundamental understanding of orifice flow. Experimental

results, especially those obtained via non-intrusive measurement techniques such

as LDV, now enable quantitative descriptions of orifice flow phenomena that were not possible previously. These descriptions will have the three-fold benefit

of: 1 - increasing the current knowledge of orifice phenomena, 2 - providing

essential input to the initiation of computer modeling efforts designed to compute orifice flow, and 3 - validating the predictions of the computer model.

Once the two approaches (i.e., fundamental flow experiments and computer

modeling) are underway, the interactive collaborative efforts are expected to be

highly productive in establishing a credible understanding of the factors

affecting orifice performance. This understanding, implemented in practice both

nationally and internationally via codes and standards, should improve orifice

measurements significantly.

CONCLUSIONS

We have attempted to show that new research efforts are now needed to produce an understanding of the fundamental fluid dynamic phenomena that control

the performance of thermal metering devices. This understanding and how those

phenomena controlling meter performance are affected by the parameters involved

in metering practice will lead to improved standards, improved installations, as well as improvements in fluid measurement technology. This, in turn should

produce the improved levels of measurement accuracy currently demanded by

industry. The new experimental research tools needed for these efforts exist

and are available . These efforts, in conjunction with collaborative

computational counterparts, offer maximal potential to establish the

A4.10
understanding needed. When a collaborative testing program is added, to confirm

practical metering performance the way to dramatically improve metering practice

becomes clear. All that is needed is the commitment by science and industry to pursue the task at hand and to reap the resulting scientific and industrial

rewards

.

References

1. Mattingly, G.E., Spencer, E.A. , and Klein, M. - Workshop on Fundamental

Research Issues in Orifice Metering; Gas Research Inst. Rept. 84-0190, Oct.

1984. 156 p.

2. Rouse, H. and Abul-Fetouh, A., "Characteristics of Irrotational Flow

through Axially Symmetric Orifices", Joum. of Appl. Mechs. , Trans. ASME

,

Vol. 17, No. 4, 1950, pp. 421-426.

3. Chen, Y.L., "Inviscid Rotational Axisymmetric Flow through a Sharp Edged

Concentric Orifice in a Circular Pipe", PhD. dissertation, Univ. of Rhode

Island, Kingston, RI , 1973.

4. Teyssandier, R.G., "Internal Separated Flows-Expansions , Nozzles, and

Orifices", PhD. dissertation, Univ. of Rhode Island, 1973.

5. Teyssandier, R.G. and Wilson, M.P., "An Analysis of Flow through Sudden

Enlargements in Pipes", Journal of Fluid Mechanics , Vol. 64, Part I, 1974,

pp. 85-95.

6. Wilson, M.P. and Teyssandier, R.G. , "The Paradox of the Vena Contracta,"

Journal of Fluids Engr. , Trans. ASME, Sept. 1975, pp. 366-371.

7. Mills, R.D., "Numerical Solutions of Viscous Flow through a Pipe Orifice at

Low Reynolds Numbers", Journal of Mech. Engr. Sci., 10, No. 2, 1968, pp.

133-140.

8. Greenspan, D. , "Numerical Studies of Viscous Incompressible Flow through an Orifice for Arbitrary Reynolds Number", Int'l. Journal for Numerical

Methods in Engineering , 6, 1973, pp. 489-496.

9. Dowdell, R.B. and Wilson, M.P., "Status of the Analysis of Flow through

Concentric Square Edged Orifices", ASME Paper 75 WA/FM-4, Houston, TX,

1975.

10. Dyban, Y.P. and Epik, E.Y. , "Effects of Turbulence on Calculating Heat

Transfer Downstream of an Orifice in a Tube", Heat Transfer, Soviet

Research , Vol. 2, No. 1, Jan. 1970, pp. 11-16.

11. Chaturvedi, M.C. , "Flow Characteristics of Axisymmetric Expansions",

Journal of Hydraulics Div. , ASCE, May 1963, pp. 61-92.

12. Lipstein, N.J., "Low Velocity, Sudden Expansion Pipe Flow", ASHRAE Journal,

Vol. 4, 1962, pp. 43-47.

A4.11
13. Bourque, C. and Newman, B. G., "Reattachment of a Two-Dimensional

Incompressible Jet to an Adjacent Flat Plate", The Aero Quarterly , Vol. XI,

Aug. 1960, pp. 201-232.

14. Ackeret, J. , "Aspects of Internal Flow", Fluid Mechanics of Internal Flow , G. Sovrin, ed. , Elsevier, Amsterdam, 1967, pp. 1-26.

15. Jeppson, P. W. , "Inverse Formulation and Finite Difference Solution for

Flow from a Circular Orifice", J . Fluid Mech. , Vol. 40, part 1, 1970, pp.

215-223.

16. Hunt, B. y. , "Numerical Solution of an Integral Equation for Flow from a Circular Orifice", J. Fluid Mech. , Vol. 31, 1968, pp. 361-77.

17. Ghazi, H, S., "A Pressure Index for Predicting, the Effect of the Flow

Profiles on Orifice Meter Performance", Paper No. 65-WA/FM-3, Journal of

Basic Engr. , Trans. ASME.

18. Steams, R. F. , et al., "Flow Measurement with Orifice Meters", D. Van

Nostrand Co., 1951.

19. Scott, R.W.W., "Developments in Flow Measurement - I", Applied Science

Publishing, London, 1982.

20. Miller, R. W. , "Flow Measurement Engineering Handbook", McGraw-Hill, New

York, 1983.

21. Brennan, J., et al., "An Evaluation of Selected Cryogenic Flowmeters", NBS

TN 650, 1974.

22. Bean, H. S. (ed.), "Fluid Meters - Their Theory and Application", 6th

Edition, ASME, New York, 1971.

23. Bajura, R. A., and Pellegrin, M. T. , "Studies of Pulsating Incompressible

Flow Through Orifice Meters", NBS SP 484, Oct. 1977.

24. Keyser, D. R. , "Unsteady Orifice Flow Measurements, Its Theory and

Observations", In: Flow - Its Measurement and Control in Science and

Industry, Vol. 2, 1981, ASME, ISA, NBS Conference, St. Louis, MO,

published by ISA, Raleigh, NC.

25. Mottram, R. C. , "Measuring Pulsating Flow with a Differential Pressure

Meter", In: Flow - Its Measurement and Control in Science and Industry,

Vol. 2, 1981, ASME, ISA, NBS Conference, St. Louis, MO, published by ISA,

Raleigh, NC.

26. Toyota, H. , "Pressure Fluctuations and Pulsation Error of Differential

Pressure Gas Flow Meters", IMEKO Tokyo Flow Symposium, Nov. 1979, published

by SICE, Tokyo, Japan.

27. Caen, R. and Pignemal, J. , "Errors in Differential Pressure Flowmeters Due

to Pressure Fluctuations", FLOMEKO, Groningen, The Netherlands, Sept. 1978,

published by Nor th-Holland Publishing Co., Amsterdam.

A4.12
28 . Rayle, R. E. , "Influence of Orifice Geometry on Static Pressure

Measurements", ASME Paper 59-A-234, 1959.

29. Benedict, R. P. , "Fundamentals of Temperature, Pressure, and Flow

Measurement", Wiley, New York, 1977.

30. Gorter, J. , "Deformation of Orifice Plates; Theory and Practice", FLOMEKO

,

Groningen, The Netherlands, September 1978.

31. Report of the Joint AGA-ASME Orifice Coefficient Committee, 1935. (This

document has been reprinted by the Thermodynamics Research Center of Texas

AStM University, 1981.

32. American Gas Association, Orifice Metering of Natural Gas, Report No. 3,

Chapter 14, Section 3, (also referred to as American Petroleum Institute

Manual of Petrolexm Measurement Standards, American National Standards

Ins ti tute/American Petroleum Institute 2530), 1978.

33. Irving, S. J. , "The Effects of Bends on the Discharge Coefficient of

Orifice Plates", FLOMEKO, Groningen, The Netherlands, September 1978,

published by North Holland Publishing Co., Amsterdam.

34. Starrett, P. S., Nottage, H. B., and Halfpenny, P. F., "Survey of

Information Concerning the Effects of Non-Standard Approach Conditions Upon

Orifice and Venturi Meters", ISA Reprint of ASME Ppaer 65-WA/FM-5, 1966.

35. Martin, C.N.B., "Effects of Upstream Bends and Valves on Orifice Plate

Pressure Distributions and Discharge Coefficients", International Journal

of Heat and Fluid Flow, Vol. 3, No. 3, Sept. 1982.

36. Kinghom, F. C. , "Flow Measurement in Swirling or Asymmetric Flow - A

Review", Flow-con 77 Proceedings, Institute of Measurement and Control,

Gatton and Kent, U.K. , 1977.

37. Zanker, K. J., "The Development of a Flow Straightener for Use with Orifice

Flow Meters in Disturbed Flow", Symposium on Flow Measurement in Closed

Conduits, paper D-2, NEL , East Kilbride, Scotland, U.K. , 1959.

38. Akashi, K. , et al. , "Development of a New Flow Rectifier for Shortening

Upstream Straight Pipe Lengths in Front of Flow Meters", IMEKO-Tokyo Flow

Symposium, November 1979, published by SICE, Tokyo, Japan.

39. Davis, R. W. , Moore, E. F., and Mattingly, G. E. , "Designing Tortuous Flow

Conditioners Using Computer Modeling Techniques", (unpublished results)

NBS, 1978.

40. Goldstein, R. J., "Fluid Mechanics Measurements", Hemisphere Publishing

Corp. , 1983.

41. Mattingly, G. E. , "The Hydrogen Bubble Flow Visualization Technique", U.S.

Navy DTMB Rept. 2146, 1964.

A4.13
42. Bates, C. J., "LDA Measurements of the Flow Through an Orifice Plate", In:

Flow - Its Measurement and Control in Science and Industry, Vol. 2, St.

Louis, MO, 1981, published by ISA, Raleigh, NC.

43. Mattingly, G, E, and Davis, R. W. , "Numerical Solutions for Laminar Orifice

Flow", ASME Paper 77-WA/FE-13, Dec. 1977.

44. Davis, R. W. and Mattingly, G. E. , "Numerical Modeling of Turbulent Flow

Through Thin Orifice Plates' , NBS SP 484, Oct. 1977.

45. Ashmawey, M. F., "Investigation of Laminar Flow Through a Flow Meter", MSME

Thesis, Univ. of Alexandria, Alexandria, Egypt, 1982.

46. Davis, R. W. and Moore, E. F., "A Numerical Study of Vortex Shedding from

Rectangles", Journal of Fluid Mechanics, Vol. 116, pp. 475-502, 1982.

47. Davis, R. W., Moore, E. F., and Purtell, L. P. , "A Numerical-Experimental

Study of Confined Flow Around Rectangular Cylinders", Physics of Fluids, 27

(1), Jan. 1984.

48. Yeh, T. T. , Robertson, B., and Matter, W. M., "LDV Measurements Near a Vortex Shedding Strut Mounted in a Pipe", Jouimal of Fluids Engineering,

ASME, Vol. 105, pp. 185-196, June 1983.

A4.14
LIST OF TABLES

Table

L

2

3

4

Title

Fluid Metering Research

Flow Measurement Devices

Causes for Deviations from Ideal Orifice Performance

Experimental Techniques for Orifice Flow

A4.15
LIST OF FIGURES

Table

1

2(a)

2(b)

3

4(a)

4(b)

5

6

7

8

9

10

11

12

13

Title

Orifice Flow-The Axisymmetric Ideal

Plate Bending Effects

Plate Beveling Effects

Inlet Flow - Linear Velocity

Inlet Flow - Swirl Velocity - The Effects of an Elbow

Inlet Flow - Swirl Velocity - The Effects of Two Elbows

Pi to t Tubes

Anemome try

Visualization - Smoke Wire

Smoke Wire Results

Visualization - Dye Injection

Visualization - Electrolysis - Hydrogen Bubble

Laser Doppler Velocimetry (LDV)

LDV Orifice Profiles

Optical Techniques - Interferometry

A4.16
DISTANCE

Fig* 1* Orifice Flow-The Axisymmetric Ideal

A4.17
A4.18

Fig*

2(a).

Plate

Bending

Effects
A4.19

Plate

Beveling

Effects
Effects of Pipe Transitions

Fig. 3. Inlet Flow - Linear Velocity

A4.20
A4.21

Fig.

4(a).

Inlet

Flow

-

Swirl

Velocity

-

The

Fffects

of

an

Elbow
^ J J ^ ^ 7 y

Fig* ^i(b). Inlet Flow - Swirl Velocity

The Effects of Two Elbows

A4.22
ADVANTAGES

1) Simple

2) Cheap

3) Rugged

4) Multiholed versions

FOR SECONDARY FLOW

DISADVANTAGES

1) Large sensing volume

2) Non linear principle

3) Slow response

4) Low velocity limit

5) Calibration needed

Fig. 5. Pitot Tube

A4.23
HOT WIRE AN1> HOT FILM

y X

0

y / /

t

Vy V. \ V \ V ?

o

o

/

• L/ VJ

ADVANTAGES

1) Small sensing volume

2) Frequency response - very good

3) Multisensor probes

DISADVANTAGES

1) Non linear principle

2) Sensors are delicate

3) Low VELOCITY LIMIT

4) Calibration needed

Fig. 6. Anemometry
_r-L

c/5 UJ

</) t-U

UJu.

u.

o

Ui3

aet- UJ 2 >

H-

-I <

< H- Z — — _J Z < — 3

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oo

LU

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C/3 C3

Z

O Q CO —> UJ UJ

U. H- £

z — —

— £ _

< —

-J« o z

H- Z 3 O Z

a —

UJ CO

h- 3 H- _ U. Z

£ U. O — — X

kOO

UJz

UJo

3: oo

I

A4.25
AIR FLOW

A IN. DIA- PIPE

BETA = 0-5

REd = 3000

Fig- 8* Smoke Wire Kesults

A4.2fi
ADVANTAGES

1) Simple

2) Cheap

DISADVANTAGES

1) Diffusion Limited

2) Contaminates Fluid

Fig. 9. Visualization - Dye Injection

A4.27
<9

iUz

Ul

a > H •• X

(A H- ^ < z U

Ul

— Z

tk ^ > Ul Ik z ^ - Ul < CO «/» < c/> a a UJ

UJ zoo o a Ul < Z — o z > — O Ul H- <o z — H- a •< H> o z < o oe z M > Ul u Ul o

H* Ul

O <A

a ^ ^ —Z ><J — < ^ — o CO 2 Ul Z K <o a — ^ < Ul <o a O _J < ^ Ul ^ Ul * — < -1 z > — ^ Z 03 a < - z < Ul a Ul — — a a. a h- O SOOOQ — Ul O Z Z ^ - —• M UJ —Hcvjro iiiI

Fig.

10.

Visualization -

Electrolysis -

Hydrogen

Bubble
UJO

z

UJ

CLUJ UJ o »- z z < — o (Jmm >- - mJ »- — UJ — Crt a

u o

O 0. z

-1 z o

UJ o Q —

> u oo UJ »— oo O UJ z <

UJ O (/} Of L9 — »-

iS> o UJ o <s: 3 Z

<c O CC H— 3 UJ 3 ^ O Z UJ Z

>• </> UJ UJ <C Z 3

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AA.29

Laser

Doppler

Velocimetry

(LDV)
R

(a) D/2 upstream of plate

(b) d/2 downstream of plate

PEjj = 5 X 10^

Fi6- 12 - LDV Orifice Profiles

A4.30
MONOCHROMATIC

ADVANTAGES

1) Frequency response - good

2) Qualitative and quantitative

DISADVANTAGES

1) Results are averaged along light path

Fig. 13. Optical Techniques - Interferometry

Appendix 5

UNITED STATES DEPARTMENT DF COMMERCE

Nacional Bureau af Standards

Gaithersburg, Maryland SOS99

March 23, 1984

Dear:

You, or your representative, are invited to participate in a workshop

being planned to address industrial concerns in thermal metering - i.e., the flow of steam and water (both hot and chilled). The

workshop, sponsored by the Department of Energy (DOE) and the National

Bureau of Standards (NBS) with the assistance of industry

representatives (IDEA and NADHCI) , will be convened for two days. May

21-22, 1984 at the Sheraton Potomac Inn, Rockville, MD near NBS.

Attendance is being planned so that a broad range of interests will be

represented. Specifically, U.S. meter manufacturers, meter users,

academicians, and appropriate standards personnel will be present.

The workshop will not involve product advertisements,, exhibits, or hardware items from any manufacturer. Consequently, manufacturers are encouraged to choose a representative from their technical staff (as

opposed to their sales staff) who will be able to contribute to

discussions of issxies and potential solutions required to improve

thermal metering.

Currently, it is planned for attendees to form into task groups to

address five topical areas as follows:

Topic 1 - Installation Effects

Topic 2 - Measurement Techniques for Thermal/BTU Flow and Performance

Characteristics

Topic 3 - New Technologies

Topic 4 - Traceability of and Standards for Measurements for

Thermal/BTU Flow

Topic 5 - Control Systems Management

A5.1
- 2 “

Within each of these topical areas, such aspects as costs, benefits,

effects on accuracy, technology, etc. will be discussed.

The two day format is sketched as follows:

Day 1 - May 21 Day 2 - May 22

Opening - Welcome

Statement of Workshop Purpose

Identification and

Discussion of Issues

Lunch

Attendees formed into

Task Groups

Task Group Sessions

Adjourn

Task Group Chairmen present results

to all attendees

Discussion by all attendees of results

("cross-fert ilization")

Lunch

Task Groups reconvene

Final Session ** Summaries and

Balloting to Prioritize Issues

Adjourn

A wine and cheese get-together is scheduled for Sunday evening. May 19,

at 7:00 PM at the Sheraton Potomac Inn.

On Wednesday morning. May 23, a brief tour of the NBS Fluid Mechanics

and other laboratories is offered for those interested.

We will appreciate it if you would return the enclosed form so that we can finalize plans. It is essential that we receive your response by

April 20, 1984 .

There will be a $35.00 registration fee to cover reception, coffee, two

lunches (May 21 and 22) and a dinner on May 21. Each participant will

have to pay for lodging, other meals, etc. Please make reservations by

May 1 by calling 800-638-8559 making sure to mention that your room is

in the block of rooms reserved for the "NBS-DOE Conference” to obtain

the discount room rate.

Should you have questions, please feel free to contact me,

S inanely.

lior Scientist for Fluid Measurements

Chemical Process Metrology Division

Center for Chemical Engineering

Enclosure

A5.2
Thermal Metering Workshop

1. I suggest that the folloviag items be added to the topical areas given above:

2. I believe that the key issues (i.e., cost, accuracy, etc.) in

thermal metering are:

1 .

2 .

3.

3. In my view the things that are needed to resolve the above issues

(i.e., research, meter performance standards, etc.) are:

1 .

2 .

3.

4. / ! Yes, I am interested in attending this two-day (May 21-22,

1984) workshop.

5. My prioritized preferences for my task group participation are:

1. Installation Effects o

2. Measurement Techniques o

3. New Technologies o

4. Traceability and Standards o

5. Control Systems /”/

6. / / No, I will not be able to attend.

7. / / Yes, I would like to receive the report resulting from this

workshop.

Name:

Address

Phone

A5.3

Appendix 6

DOE-NBS THERMAL METERING WORKSHOP

The following are responses received from the letter inviting you to this

workshop.

1. Compended ’’Suggestions” ; (Question 1)

Identify flow measurement accuracy required for various user areas.

International standards vs. U. S. Standards.

Telemetering/computer interfaces.

Develop standards and guidelines for thermal meters.

Small, commercial (multi-family) master metering.

Establishing standards for BTU meters.

Minimum cost instrumentation.

Maintenance requirements.

Maintenance and calibration-setting up a two-meter shop.

2. Compended **Key Issues” ; (Question 2)

Research on valid operating

principals

Field testing of meter accuracy

Feedback from users - building

owners, tenants, utilities

Installation practice

1*

*

* Pressure and temperature

compensation

Accuracy 11

Rangeability 11

Costs 1111

Traceability

* Standardization

Set accuracy standards for

different meter usages

Selection of meters and sizing

Handling of meters

Predictability

* Variability of performance due to

installation and operational

factors

.

* ROI

Processes

Precision 1

* Recording medium

* Reliability 1

^Marks denote repeats

A6.1
Economic s 1 Minimum cost flow meters

Standardization * Ease of installation and

interfacing to controls 1

* Accuracy as related to cost

* Frequency of repair

* In place calibration

3. Compended “Needs” ; (Question 3)

* System performance standards (not BTU meter standards).

Standardized identification of performance capabilities of'various

metering systems.

* Recommended proper installation for each metering system.

* Fluid condition effects (steam, etc.)

Commitment to research

Standards and standardization

Performance standards 11*

* Performance recommendations

R&D to develop a reliable cost, efficient meter.

Research 111

Utilization of Field Experience

Performance testing

* R & D

Testing of all BTU meters with established testing methods.

* Standards

Sharing of information among users

System optimization

*Marks denote repeats

A6.2
Appendix 7

DOE-NBS Thermal Metering Workshop

Sheraton-Potomac Inn

Gaithersburg, MD

AGENDA

MONDAY, MAY 21 TUESDAY, MAY 22

8:30 BALLROOM A - Coffee 8:30 BALLROOM A - Coffee

9:00 BALLROOM A

NBS Opening (G. E. Mattingly)

NBS Welcome (J. J, Ulbrecht,

Chief, Chemical Process Metrology

Division)

DOE Welcome and Introduction

(J. Kaminsky, Office of

Conservation)

Issues:

Overview - J. Kaminsky

Metering Issues in District

Heating and Cooling ; N. R. Taylor, Int'l. Dist.

Heat. Assoc. (IDHA),

P. L. Turchi, Chrmn. IDHA

Comm, on Fluid Metering and

ADCONS, Inc.,

C. W. Phillips, NADHCI.

Fluid Metering Research: New

Tools and New <^pportunit ies ; G. E. Mattingly

Coffee Break

Responses to Invitation

Discussions

12:00 LUNCH - ATRIUM

1:00 BALLROOM A - Task Group Formation

1:30 BREAKOUT ROOMS - Task Group

Sessions

3:00 Coffee - BALLROOOM A

5:00 Adjourn

7:00 DINNER - ATRIUM

9:00 BALLROOM A - Task Group

Presentations of Results - "Cross-Fertilization” and

Discussions

Coffee Break (midway)

2:00 LUNCH - ATRIUM

1:00 BREAKOUT ROOMS - Implementation

of "Cross-Fertilization" and

Production of Major Issues and

Associated Research Projects

3:00 Coffee - BALLROOM A

3:20 BALLROOM A - Final Session - Grand Ballot

4:30 Adjourn

A7.1
THERMAL METERING WORKSHOP

TasljC Group Facilitators

Task Group 1 - Installation Effects

Professor William Durgin

Department of Mechanical Engineering

Worcester Polytechnic Institute

Worcester, MA

Task Group 2 ~ Measurement Techniques

Professor James Murdock

Department of Mechanical Engineering

Drexel University

Philadelphia, PA

Task Group 3 - New Technologies

Professor Dirse Sallet

Departments of Mechanical Engineering and

Chemical and Nuclear Engineering

University of Maryland

College Park, MD

Task Group 4 - Traceability and Standards

Professor Thomas Arnberg

Department of Mechanical Engineering

University of Colorado - Denver

and

Colorado Engineering Experiment Station, Inc. (CEESI)

Nunn, CO

Task Group 5 ~ Control Systems

Dr. James Hill

Chief, Building Equipment Division

Center for Building Technology

National Bureau of Standards

Gaithersburg, MD

and

Mr. Narender Reddy

Energy & Environmental Systems

Argonne National Laboratory

Argonne, IL

A7.2
Appendix 8

List of Attendees

THERMAL METERING WORKSHOP

May 21-22, 1984

Wallace Alspach Professor R. V. Calabrese

EMCO Dept. Chem. & Nuc. Enginee

Longmont, CO University of Maryland

Norman Alston Harry C. Cartledge

Dieterich Standard Corp. Schuylkill General Station

Boulder, CO Philadelphia, PA

Bernhard Amstutz Michael Celinski

ISTA Energy Systems Brooklyn Union Gas

Roselle, NJ Brooklyn, NY

Jim Anderson Richard Cheatham

EG&G Idaho EFF Co.

Idaho Falls, ID Dallas, TX

Professor T. Arnberg Frank Childs

University of Colorado-Denver EG&G Idaho

and CEESI Idaho Falls, ID

Nunn , CO

Gary Corpron

Bernard H. Barnett Rosemount

Sonseboz Corp.

Plainview, NY

Eden Prairie, MN

Nicholas R. Destefano

Ken Benson BIF

NBS West Warwick, RI

Dr. Martin Bernard Professor William Durgin

Argonne National Lab Worcester Polytechnic Inst

Argonne, IL Worcester, MA

John Brennan E. V. Erjavaec

Spence Engineering Co. Meriam

Walden, NY Cleveland, OH

Professor E. F. Brown Albert G. Ferron

VPI Sc SU Alden Research Lab

Blacksburg, VA Holden, MA

Thomas H. Burgess Robert T. Fretz

Fischer & Porter Co. Arlington, VA

Warminster, PA

Charles Fuller

Alfredo Cacaindin Wilgood Corp.

Arlington, VA Chesapeake, VA

A8.1
Dr. Adolfas GaigaLas

NBS

Dr. Gerald Guinn

Alabama Solar Center

Huntsville, AL

Terri Hahn

Arlington, VA

Peter Herzl

Fischer & Porter Co.

Warminster, PA

James Hill

NBS

Rudolf Hoffman

Spence Engineering Co.

Walden, NY

Thomas Holland

Minnesota Honeywell

Roseville, MN

Professor Y. Y. Hsu

Dept, of Chem. & Nuc. Engrg.

University of Maryland

College Park, MD

Paul Hughes

Omaha, NB

Jacob Kaminsky

DOE

Allen S. Kennedy

Argonne National Lab

Argonne , IL

David Keyset

NADC

Warminster, PA

Robert Kirchner

Armstrong International

Three Rivers, MN

Ronald N. Koch

North American Rockwell

Pittsburgh, PA

Tom Larsen

EG&G Idaho

Idaho Falls, ID

Dr. Gerald Lewis

Argonne National Lab

Argonne, IL

Danny Lim

DOE

D. R. MacKay

NBS

George E. Mattingly

NBS

Richard K. Messock

NAVENENSVA

Port Hueneme, CA

Alan Mitchell

Philadelphia Electric Co.

Schuylkill General Station

Philadelphia, PA

Professor J. Murdock

Dept, of Mechanical Engineering

Drexel University

Philadelphia, PA

Hans 0. Nyman

District Heating Development

St. Paul, MN

John Petze

Andover Controls

Andover, MA

Charles Tilford

NBS

Clinton Phillips

NADHCI

A8.2
Nareader Reddy

Argonne National Lab

Argonne, XL

Dr. B. Robertson

NBS

Professor Dirse W. Sallet

Dept, of Mechanical Engineering

University of Maryland

College Park, MD

Toshio Satori

Yokogawa Corp. of U.S.

Shenandoah, GA

Kirk Smith

EMCO

Longmont, CO

Robert Soulen

NBS

Clifford Spiegelman

NBS

David Spitzer

Nepara Chemical Co.

Harriman, NY

Edward P. Stephenson

Kent Meter

Ocala, FL

Norman R. Taylor

IDHA

Washington, DDCC

Stuart W. Temple

Hartford Steam Service

Hartford, CT

Peter L. Turchi

EMCO

ADCONS

Baltimore, MD

Dr. J. J. Ulbrecht

NBS

Willard Veeder

University of Rochester

Central Utilities

Rochester, NY

Chris Watson

ITT-Barton

City of Industry, CA

Larry M. Windingland

USA-CERL-ES

Champaign, XL

Ted Winick

Controlotron

Hauppauge, NY

Kan N. Yam

Con. Ed.

New York, NY

A8.3
HBS»n4A <REv. 2-<oi U.3. OCPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET (See instructions)

1. PUBLICATION OR

REPORT NO.

NBSIR 85-3242

2. Perfonnint Orsan. Report No. 3. Publication Date DECEMBER 1985

4.

TITLE AND SUBTITLE

5. A Report on the NBS-DOE May 1984 Workshop on Thermal Metering

AUTHOR(S)

G. E. Mattingly

6.

PERFORMING ORGANIZATION (If Joint or other than NBS, see instructions)

national bureau OP STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

7. Con tract/ Grant No.

t. Type of Report & Period Covered

Final

9.

SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. State. ZIP)

U.S. Department of Energy

Office of Conservation

Washington, DC 20585

10.

SUPPLEMENTARY NOTES

I

' 1 Document describes a computer program; SF-I8S, FlPS Software Summary, is attached.

11.

ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

bibliography or literature survey, mention it here) A workshop on thermal metering (i.e., the flow of steam or of hot or chilled water) was convened in Gaithersburg, MD, May 21-22, 1984 to discuss and prioritize flowrate

measurement problems and research programs which could lead to improved energy

conservation through the development, acceptance, and use of district heating and

cooling systems. The workshop brought together 60 attendees whose expertise spanned

a broad range of interests. Included were flowmeter manufacturers, meter users,

standards personnel, academicians, and consultants. Attendees listed current

problem areas and measurement needs in thermal metering, discussed appropriate

responses to these needs, and prioritized these according to their perceived

potential for impacting thermal metering practice. Leading this list are:

° "paper” standards with special emphasis on "meter installation requirements",

° research on two-phase flow and its measurement,

° two-phase flow technology transfer and information dissemination.

I

12. KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolons)

district heating and cooling; energy conservation; flow; standards; thermal

metering; two-phase flow

13. AVAILABILITY 14. NO. OF

1 X| Unlimited

1 1 For Official Distribution. Do Not Release to NTIS

PRINTED PAGES

58

1 1 Order From Suoerintendent of Documents, U.S. Government Printing Office, Washington, D.C.

20402. 15. Price

1 xl Order From National Technical Information Service (NTIS), Springfield,. VA. 22161 $11.95

USCOMM'OC 9O43-P0O