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The sensitivity of differential‐pressure flow meters to the quality of the approaching flow continues to be a cause for concern to flow meter manufacturers and users. Distortions to the approaching velocity profiles generated by pipe fittings and installations located upstream of a flow meter, can lead to considerable errors in flow metering. This cannot be ignored because of the likely cost and process efficiency implications. This paper describes the effects of various entrance flow velocity profiles on the performance of an orifice flow meter with and without flow conditioning. Asymmetric swirling velocity profiles were generated by a ball valve. These caused significant shifts to the meter’s calibration. The use of a vaned‐plate flow conditioner, consisting of six vanes attached to a 70 per cent porosity plate, greatly improved the performance of the meter. Thus, the device can be used as part of a flow metering package that will have considerably reduced installation lengths. The less‐sophisticated NEL plate proved to be a good flow straightener, i.e. a good swirl remover, but was not an efficient flow conditioner.

The sensitivity of orifice plate metering to poorly conditioned and swirling flows are subjects of concerns to flow meter users and manufacturers. The distortions caused by pipe fittings and pipe installations upstream of the orifice plate are major sources of this type of non‐standard flows. These distortions will alter the accuracy of metering up to an unacceptable degree.Design/methodology/approach – The design of orifice plate meters that are independent of the initial flow conditions of the upstream is a major object of flow metering. Either using a long straight pipe or a flow conditioner upstream of an orifice plate usually achieves this goal. The effect of cone swirler flow conditioner for both standard and non‐standard flow conditions has been carried out in the experimental rig. The measuring of mass flow rate under different conditions and different Reynolds numbers were used to establish a change in discharge coefficient relative to a standard one.Findings – The experimental results using the cone swirler flow conditioner showed that the combination of an orifice plate and cone swirler flow conditioner is broadly insensitive to upstream disturbances. The results clearly show that this flow conditioner can attenuate the effect of both swirling and asymmetric flows on metering to an acceptable level.Originality/value – Previous work on the orifice plate has shown that the concept has promise. The results of using a combination of a cone swirler and orifice plate for non‐standard flow conditions including swirling flow and asymmetric flow show this package can preserve the accuracy of metering up to the level required in the standards, providing that a new discharge coefficient is used for the combined swirler and orifice plate.

Looks at the development of a new ultrasonic meter for the gas supply industry and explaining the transit time measurement principle on which it works and the performance characteristics of the new meter. Concludes that the ultrasound gas meter could also have medical applications including anaesthetics and hospital ward monitoring. There have been limited production runs of the new gas meter and extensive trials are taking place in several countries.

The purpose of this paper is to extend the possibilities of using the earlier developed indirect method of fluid flow rate measurement in circular pipes to the square-section channels with elbows installed.

The idea of the method is based on selecting such a value of the Reynolds number assumed as a coefficient in fluid flow equations, which fulfills with set accuracy the condition of equality between the measured and computed pressure difference at the end points of the secant of the elbow arch. The numerical calculus takes into consideration the exact geometry of the flow space and the measured temperature of the fluid, on the basis of which its thermo–physical properties are determined. To implement the proposed method in practice, a special test stand was built. The numerical computations were carried out using the software package FLUENT.

The results of calculations were compared with corresponding results of measurements achieved on the stand, as well as those found in the literature. The comparative analysis of the obtained numerical and experimental results shows a high grade of consistence.

The discussed elbow flow meter, implementing the extended indirect measuring method, can be applied to determine the flow rate of gases, as well as liquids and suspensions.

The indirect method used to measure the volumetric flow rate of the fluid is characterized by high accuracy and repeatability. The high accuracy is possible because of a very realistic mathematical model of the complex flow in the curved duct. The indirect method eliminates the necessity of frequent calibration of the flow meter. The discussed extended indirect measuring method can be applied to determine the flow rate of gases as well as liquids and suspensions. The fluid flow rate measurement based on the method considered in this paper can be particularly useful in newly designed as well as already operated ducts.

Outlines the four main types of flow metering technology and their various applications, covering electromagnetic flowmeters, coriolis mass flowmeters, vortex flowmeters and ultrasonic flowmeters. Looks at the future of flowmeters with regard to quality control standards, signal converters and serial communication. Concludes that since the basic problems surrounding flow measurements have been solved there will be no quantum leap in flowmeter technology, however the four basic flowmeter measuring techniques will be gradually developed and the level of intelligence in each unit will be further enhanced.

To examine the possibilities for dry calibration or in situ calibration for flowmeters in the field.

Reviews history and current situation with regard to in situ/dry calibration of flowmeters. Its acceptability for modern flowmeters is considered. Various options are considered to achieve dry calibration or in situ calibration. The possibility of action at a distance via the internet, for example, naturally follows from these developments.

The paper concludes that this development is likely to be of importance to manufacturers. It will need to be addressed by certification authorities.

The concepts will reduce the cost of calibration and the discussion should be of value to research workers, industry and government.

This paper aims to show that by using air source heat pump (ASHP) water heater in the residential sector, the energy consumption from sanitary hot water production can be reduced by more than 50 per cent. Hence, this study quantitatively and qualitatively confirms that domestic ASHP water heater is a renewable and energy efficient device for sanitary hot water production.

Design and building of a data acquisition system comprises a data logger, power meters, flow meters, temperature sensors, ambient and relative humidity sensor and an electronic input pulse adapter to monitor the ASHP water heater performance. All the sensors are accommodated by the U30-NRC data logger. The temperature sensors are installed on the inlet pipe containing a flow meter and the outlet pipe of the ASHP unit, the vicinity of both evaporator and expel cold air. An additional temperature sensor and a flow meter that cater for hot water drawn off measurements are incorporated into the data acquisition system (DAS).

The result from a specific monitoring split type ASHP water heater gives an average daily coefficient of performance (COP) of 2.36 and the total electrical energy of 4.15 kWh, and volume of hot water drawn off was 273 L. These results were influenced by ambient temperature and relative humidity.

The cost involved in purchasing the entire sensors and data logger limits the number and categories of ASHP water heaters whose performance were going to be monitored. Pressure sensors were excluded in the data acquisition system.

The data acquisition system can easily be designed and the logger can also be easily programed. Hence, no high technical or computer skills are needed to install the DAS and to be able to read out the results.

Hence, the data acquisition system can be installed on the entire domestic Eskom roll out air source heat pump water heaters to effectively determine the coefficient of performance and demand reductions.

This DAS is the first of its kind to be built in South Africa to be used to determine the performance of an ASHP water heater with high accuracy and precision. DAS is also robust.

To present a new generation of liquid flow sensors that is capable of meeting the requirements as imposed by the life science, analysis, biotech and other markets.Design/methodology/approach – A description of the design and development of low flow rate measuring system and typical applications.Findings – The system described uses tubes made of silica, stainless steel or PEEK, and either constant power or constant temperature methods in conjunction with a heater and temperature sensor. The tested instruments were capable of measuring flow ranges between 25‐500 nl/min (smallest flow range) and 100‐2000 μl/min (largest flow range) water, with operating pressures up to 100 bar (up to 400 bar for flow meters with flow ranges below 100 μl/min).Originality/value – Presents information on a new generation of liquid flow sensors.

Claims that, although the use of adhesives in automated assembly is common, the use of structural adhesives is not so. Indeed, the use of structural adhesives can be termed a “new technology”. Offers advice on their use and concludes that the benefits outweigh the threat of failure.

The purpose of this paper is to look more closely at incentives for a landlord to use individual metering and charging of heat and water. This paper also aims to look at the possible reasons for the differences in use of individual metering and charging between Sweden and Germany.

The research in this paper is based on a questionnaire and interviews with landlords, in Sweden, using individual metering and charging.

The two main incentives for the landlords in the survey to use individual metering are the possibility to save energy and the possibility to create a fair allocation of heating cost between tenants. Sweden has a long history of heat and water included in the rent leading to a possibly tougher transition to individual metering.

To see the overall picture and understand the purpose of individual metering is important to avoid conflicts between landlords and tenants. The paper aids this process.