Sprinkler Performance Research Articles

Modes of operation of network pumps with shielded asynchronous motors in small irrigation systems with artificial pressure

The paper proposes a scheme and describes the operating modes of pumping equipment for a finely dispersed irrigation system with artificial pressure for the operating ranges of the performance of sprinklers in terms of flow. For the accepted ratio, which determines the kinetic energy of a drop per unit area, the law of drop motion in air under the action of gravity is obtained. The above network diagram in the process of regulation provides water supply for irrigation, taking into account the measured values of the sprinkler performance over time. Regulation using a centrifugal pump with a shielded asynchronous motor of the current values of water flow in the distribution pipeline connected to the sprinkler provides the technical possibility of implementing the mode corresponding to the inverted (turbine) mode of operation of the pump. The transfer of the engine to the generator mode of operation, allows you to get an autonomous three-phase source of electrical energy for the system’s own needs.

Using Probabilistic Zone Model Simulations to Investigate the Deterministic Assumptions of UK Residential Corridor Smoke Control Design

The modelling of common corridor smoke control systems in residential buildings is one of the most frequently undertaken performance-based assessments by fire engineers in the UK. However, there is limited understanding of how the deterministic assumptions provided in modelling guidance are derived, and to what extent these are representative of a range of possible outcomes. To place these assumptions into context, the Monte Carlo method is applied using the zone modelling software B-RISK for an exemplar residential arrangement. Distribution functions are adopted to inform inputs for fire parameters, sprinkler performance, and occupant behavioural characteristics. An output distribution for the corridor smoke clearance time is determined and compared to the clearance time of an equivalent set of deterministic simulations applying the assumptions of modelling guidance. The probabilistic study indicates that modelling guidance assumptions typically result in a scenario severity greater than the 99th percentile of possible outcomes. The work also considers the sensitivity of individual input parameters, ranking these based on their impact. These sensitivity analyses highlight the importance of occupant behavioural assumptions around the pre-evacuation time and door open time, and the significance of fire parameters including the elevation of the fuel bed, soot yield, and fire growth rate. Sprinkler parameters are shown to have a lesser impact on the corridor clearance time. The work therefore provides practitioners with an indication of which parameters are worth considering in greater detail when assessing scenario sensitivity.

WATER SPREAD TEST ON IOT (Internet of Things) BASED AUTOMATIC IRRIGATION SYSTEM

This research is intended to determine the performance of the tools in the sprinkler irrigation system using controls (android). This activity was carried out in an experimental garden in the laboratory Enviro-Hydro of the Civil Engineering Faculty of Engineering, University of Islamic Malang, covering an area of 80 m². There are two variables used as a reference for sprinkler performance, namely automatic and manual with each valve opening 45°-90°, on 4 sprinklers installed on the land with a distance of 1 m each other. Water flows from 2 tadons that are placed parallel. The method used to analyze the data using the T test which compares the observation results of water distribution from automatic and manual sprinkler openings. The results of measuring the distribution of automatic and manual sprinkler water show that the results are not much different, only a difference of 1% so that the performance of both automatic and manual sprinklers has not different results.

Effect of Nozzles design on the performance of Impact Sprinklers in sprinkler irrigation system

Water is limited resource. This is considered to be one of the main challenges for future water policy. Saving water and energy is a requirement to ensure the viability of pressurized irrigation systems. Designing and optimizing sprinkler irrigation systems are mainly based on achieving appropriate hydraulic performance. Spray nozzles being very often a critical component in determining the final quality of the product or the sprinkler irrigation efficiency process. The engineering design factors of sprinkler affect sprinkler system performance. So, this study focuses on some engineering design factors (three different nozzle characteristics (1, 2 and 3) and operating pressures from 150 to 250 kPa), comparing with designed nozzle (No 4) to improve brass impact sprinkler performance. This study sited on Giza region at National Laboratory for testing the components of irrigation networks and field drainage, Agricultural Engineering Research Institute AEnRI, Agricultural Research Center ARC. The result of Christiansen uniformity coefficient CU indicated that designed nozzle No 4 achieving good performance according to American society of Agricultural and Biological Engineers ASABE 2001 starting with operating pressure 150 kPa 74.05 % while nozzle No 3 starting with 175 kPa achieved 75.23 %. Also it was found that nozzle No 4 increasing flow rate by 43.48 %, precipitation rate by 19.92 %, rotation speed by 24.96 %, decreasing coverage radius by 28.38 % and the jet breaks up sufficiently to achieve an adequate water distribution pattern and obtained good droplet size comparing with nozzle No 3. It was found that sprinkler layouts 9m Х 9m overlapping achieved acceptable uniformity at operating pressure 150 kPa. Also the result indicated that nozzle No 4 saved operating time ratio by 26.87 % and decreased over minimum application targeted irrigation depth by 66.7 % at the same overlapping distances and at the same operating pressure 150 kPa.

Fire safety design of open plan apartments in England

ABSTRACT A review has been undertaken which focusses on the fire safety document ‘Open plan flat layouts’ (NF 19), where the review identifies that NF 19 comes with limitations in its representation of sprinkler performance and its adopted values for door closing behaviours, location of fires, heat release rate and number of occupants when compared to more recent literature. To assess the impact of assumptions for door closing behaviours and fire location specifically, an event tree analysis of exemplar apartments has been undertaken, comparing NF 19 assumptions to data from literature. This analysis indicates that the previous assumptions for these parameters would not be expected to alter the conclusions of NF 19. As a result of the review and analysis, recommendations are made for the design of open plan apartments. The paper ultimately lays the groundwork for future studies, where additional assessments are needed to consider other NF 19 assumptions, including sprinkler performance, as well as to reassess existing guidance limitations derived from NF 19.

Simplified method for estimating throw radius of rotating sprinklers on sloping land

Radius of throw is an important index for assessing sprinkler performance. In the design of a sprinkler system, lateral and sprinkler spacings are determined on the basis of the radius of throw and the precipitation profile. Previous studies on sprinkler radius of throw focused on flat ground. Limited by experimental conditions, radius of throw on sloping land is difficult to measure. The calculation of throw radius is an important issue in the design of sprinkler irrigation systems on sloping land. In this study, a simplified method for calculating radius of throw for rotating sprinklers on sloping land is presented in the form of a model and was experimentally verified. The model is valid for land slopes below 0.20. The effects of sprinkler operating pressure, nozzle size and slope on radius of throw were analyzed using the model, and the results showed that operating pressure significantly affects radius of throw on sloping land, with a 95% confidence interval. Nozzle size and land slope were also found to be factors that affect the radius of throw. It is recommended that in the design of sprinkler irrigation systems on sloping land, the sprinkler should not be rotated through a whole circle when the slope exceeds 0.10, and the proper combination of pressure and nozzle size must be applied. These results are helpful to determine lateral spacing and sprinkler spacing for sprinkler system design on sloping lands.

Evaluating the Adequacy Performance of Sprinkler Irrigation Systems at Finchaa Sugar Cane Plantation, Eastern Wollega Zone (Ethiopia)

AbstractThe success of a sprinkler irrigation system largely depends on its actual performance in field conditions. Although the uniformity of water application is the most important aspect of the sprinkler system's performance, adequacy better explains the performance of the system. In this study, the adequacy of irrigation performance was measured in field conditions considering three operating hydrant pressures (4.0, 4.5 and 5.0 bars) and two sprinkler nozzle sizes (2.4 × 4.4 and 2.4 × 4.8 mm). The main objective of this study was to determine the level of current adequacy of irrigation performance in relation to predicted performance during the design period. Three different aspects of adequacy performance (delivery, infiltration and storage) were determined from the measurements of the two important basic sprinkler performance parameters: discharge and uniformity. The study result indicates excess irrigation water application more than the crop net irrigation requirement and soil moisture deficit, especially for the 2.4 × 4.8 mm nozzles sprinkler at all pressure ranges considered. In line with this, tremendous losses in terms of deep percolation (≅ 40%) have been observed, the consequence of which is leaching of soluble nutrients, loss of valuable water resources, reduced crop yield and rise of the groundwater table. The latter might lead to drainage problems, which require construction of expensive drainage systems and can also lead to the overall waterlogging, salinization and alkalization of the area. Copyright © 2016 John Wiley & Sons, Ltd.

Effect on Hydraulic Performance of Low-Pressure Sprinkler by an Intermittent Water Dispersion Device

An intermittent water dispersion device disperses the water outflow from the nozzle of a sprinkler discontinuously. The shape, location, and number of the dispersion teeth have significant effects on the hydraulic performance of low-pressure sprinklers. In this study, the shortest spray distance (R) and affected area angle (I±) were chosen as indexes of the effect on the sprinkler‘s hydraulic performance caused by dispersion teeth, and a method to calculate R was established. An orthogonal experiment was carried out for sprinklers having the following parameters: tooth width (a), insertion depth of tooth into the water jet (h), and distance from the outlet nozzle to the tooth (c). The optimum sprinkler performance was obtained with a = 1.6 mm, h = -1 mm, and c = 4 mm (test 1) and with a = 1.6 mm, h = 0 mm, and c = 9 mm (test 4). Dynamic water distribution curves for different tooth parameters were obtained by rotationally adding the static radial water distribution curves using MATLAB. The results show that the calculated values agreed well with the experimental values. The lowest working pressure was 230 kPa for nine teeth in test 1 and 180 kPa for eleven teeth in test 1, which means that uniform low-pressure irrigation can be implemented by increasing the number of dispersion teeth to compensate for the decrease in uniformity that results from lowering the pressure.

An experimental study on the spray characteristics of residential sprinklers under low-flow and low-pressure conditions

An experimental investigation to explore the characteristics of the initial drop screen which was formed by sprinkler heads at low water pressures was carried out. Two commercially available sprinkler heads (with thin and massive frame arms) were modified, not only in terms of deflector plate design, but also with respect to the orifice diameter, in order to decrease the flow and study the effect on liquid sheet thickness, initial sheet angle, sheet breakup distance and drop size distributions and their correspondence with the existing mathematical models. It was found that the addition of a boss in the sprinkler design had little impact on the average drop size and sheet breakup distance. The presence of the boss was found to influence the initial angle of the liquid sheet, which was in line with findings of previous researches. Longer slots on the deflector plate did not change the initial angle of the sheet considerably, but did result in an earlier sheet breakup and smaller median drop diameter.A drop combustion sub-model was built, introducing two novel parameters: theoretical heat capacity (THC) and evaporate heat capacity (EHC), which could be used for estimating the actual heat capacity of the spray. In combination with the calculated drop size distribution in a spray screen, the combustion sub-model confirmed that sprinkler performance does not depend merely on provided flow, but rather on the drop size and the number of drops in a drop screen.

A Dynamic-simulation System for Sprinkler Water 3D-distribution Using Multiple Tools Integration

As one of the main water-saving irrigation technologies, sprinkler irrigation is used worldwide due to such advantages as its wide adaptability and easily mechanized operation. Sprinkler uniformity is an important indicator in the evaluation of irrigation quality and sprinkler performance and is an important parameter in the design of sprinkler irrigation systems. Through the MATCOM4.5 interface software, the computer software, Sprinkler Water Distribution Dynamic Simulation and Spacing Optimization System, was developed in this study using both MATLAB and Visual C++. With its powerful functions, this software was able to operate easily without the installation of MATLAB. In addition, this software can quickly compute most types of uniformity coefficients, draw water-distribution maps and determine the best sprinkler combination and spacing according to catch-cans data, sprinkler combination, the interpolation method and interpolation spacing. The software offers great convenience for the evaluation of irrigation quality and sprinkler performance and the design of sprinkler irrigation systems.

Comparing the performance of residential fire sprinklers with other life-safety technologies

Residential fire sprinklers have long proven themselves as life-safety technologies to the fire service community. Yet, about 1% of all one- and two-family dwelling fires occur in homes protected by sprinklers. It has been argued that measured sprinkler performance has ignored factors confounding the relationship between sprinkler use and performance. In this analysis, sprinkler performance is measured by comparing ‘like’ structure fires, while conditioning on smoke detection technology and neighborhood housing and socioeconomic conditions, using propensity score matching. Results show that residential fire sprinklers protect occupant and firefighter health and safety, and are comparable to other life-safety technologies.

Laser Precipitation Monitor for Measurement of Drop Size and Velocity of Moving Spray-Plate Sprinklers

Sprinkler drop size distribution and associated drop velocities have a major influence on sprinkler performance in regards to kinetic energy transferred to the soil surface. A laser instrument commercially marketed for real-time rainfall measurements as a Laser Precipitation Monitor (LPM) was used to measure drop size and velocity from 10 moving spray-plate type sprinklers. Measured drop size and velocity were used to determine sprinkler drop size distribution and kinetic energy applied to the soil by sprinkler discharge. Drop size distributions measured by the LPM were compared to drop size distributions measured in earlier studies using the traditional flour pellet method. Eight of the ten measured drop size distributions were not significantly different between measurement methods. However, the operating conditions when the two methods did not compare well were outside sprinkler manufacturer specifications. Based on this limited study, the results from the two drop size measurement methods can be vastly different for sprinklers under operating conditions that produce relatively compact streams of water drops; which method is more accurate for this condition remains unknown. Kinetic energy values calculated using measured drop size and velocity data were not significantly different from values determined using flour pellet drop size data and a ballistic model for estimating sprinkler droplet tangential velocity. The laser instrument used in this study provided a relatively easy means to obtain reliable estimates of sprinkler kinetic energy per unit volume of applied water for various moving spray-plate sprinkler types and operating conditions. Measured drop size distribution and computed kinetic energy applied by sprinkler discharge is sufficient for practical field application purposes.

The Skip-resistant Sprinkler Concept -- An Experimental Evaluation

A sprinkler with a shield designed to mitigate drop impingement from nearby operating sprinklers is shown experimentally to reduce skipping as compared to the same sprinkler without a shield. As described in a companion article, a model for the response time of a shielded sprinkler has been developed and validated with a Plunge Tunnel apparatus. In this article, results from intermediate-scale spray fire tests employing Froude modeling principles with a 1 : 3 scale ratio are used to evaluate sprinkler performance both with and without the shield. By comparing the operation times of adjacent shielded and unshielded sprinklers, the intermediate-scale tests can identify test arrangements where the shielded sprinkler operates while the unshielded sprinkler does not operate. The identified arrangements are then used in a full-scale environment where a series of pan fire tests serve as a proof-of-concept that proper shielding of a sprinkler can reduce skipping in terms of both the sprinkler operation pattern and total number of sprinkler operations. This study successfully demonstrates that proper shielding of a sprinkler can significantly reduce skipping.

A photographic method for drop characterization in agricultural sprinklers

The characterization of drops resulting from impact sprinkler irrigation has been addressed by a number of techniques. In this article, a new technique based on low-speed photography (1/100 s) is presented and validated. The technique permits to directly measure drop diameter, velocity and angle. The photographic technique was applied to the characterization of drops resulting from an isolated sprinkler equipped with a 4.8 mm nozzle and operating at a pressure of 200 kPa. Sprinkler performance was characterized from photographs of 1,464 drops taken at distances ranging from 1.5 to 12.5 m. It was possible to analyze separately the drops emitted by the main jet and those emitted by the impact arm. The proposed technique does not require specific equipment, although it is labor intensive.

EFFECT OF WIND SPEED AND PRESSURE ON LINEAR MOVE IRRIGATION SYSTEM UNIFORMITY

Use of center pivot and linear move sprinkler irrigation systems is becoming popular in the Southeastern United States. As these systems are used to irrigate increasing acreage, quantitative data are needed on sprinkler performance under local conditions. Two types of low pressure sprinkler nozzles were tested under field conditions, stationary grooved plate (LDN) and off-center wobbling diffuser sprinklers (IWOB). Replicated uniformity measurements were conducted along the axis of a linear move irrigation system at low (<1.7 m/s), medium (3.3-3.9 m/s), and high (5.0-6.6 m/s) wind speeds and at two pressure levels of at least 200 kPa, which was in excess of the pressure regulator discharge pressure and less than 97 kPa, a pressure below nominal regulator discharge pressure. Also, the normal probability distribution was investigated to determine how well it represented the sprinkler field data. The IWOB sprinklers coefficient of uniformity (CU) was consistently 10% to 16% higher than the LDN sprinklers over all conditions and ranged from 87% to 93% and 70% to 85%, respectively. The coefficient of uniformity of the LDN sprinklers was significantly improved at higher wind speeds (5.0-6.6 m/s) under low pressure (<97 kPa) operation from 70% to 85%, while other sprinkler/pressure combinations were not affected by wind speed. It was hypothesized that this improvement was due to the formation of larger drops falling in a more random pattern due to inadequate pressure. Finally, the IWOB sprinklers produced a more uniform application of water compared to the LDN sprinklers under all of the testing conditions in this project and the normal distribution adequately represented the field data except for LDN sprinklers at <97 kPa.

Modelling Aspects of Sprinkler Spray Dynamics in Fires

Sprinklers are used extensively in a variety of fire protection applications. These systems are required to perform effectively over a wide range of extremely harsh and complex operating conditions. The sprinkler performance depends on the initiation, formation, dispersion and surface cooling characteristics of the sprays created by these devices. The behaviour of sprinkler sprays is strongly coupled with the fire dynamics in the surrounding environment, making characterization of these sprays and their corresponding performance quite challenging. The present paper provides a discussion of the important fundamental transport process for sprinkler sprays in fires. Mathematical models are provided for these processes in order to quantitatively characterize sprinkler spray performance. These mathematical models are well suited for incorporation into CFD codes or other fire modelling tools in order to analyze and predict fire suppression performance.

Applications of Drag-Reducing Polymers in Sprinkler Irrigation Systems: Sprinkler Head Performance

The study investigates the effects of polymer additives on sprinkler performance. Experiments were carried out on a medium-pressure sprinkler to determine the effect of polymer additives. Two kinds of polymer additives with several concentrations were used: a low molecular weight polymer, sodium carboxymethylcellulose, and a high molecular weight polymer, polyacrylamide. The results show that with polymer additives the radius of throw and the sprinkler flow rate increase. The jet is slightly affected. Generally, polyacrylamide shows better results than sodium carboxymethylcellulose.

A New Test to Evaluate the Fire Performance of Residential Sprinklers

Fire tests were conducted using the Underwriters Laboratories (UL) UL 1626 Fire Test for residential sprinklers. The results indicated that sprinkler performance in UL 1626 could not be reproduced due to differences in material flammability properties. This conclusion was reached in a cooperative effort with UL. Factory Mutual Research's Approval fire test that had been redesigned based on UL 1626 was thus subject to the same variability. A new fire test was developed using fuel with controlled material flammability parameters based upon the use of the ASTM E2058 Fire Propagation Apparatus. The new fuel package consists of a wood crib (one half the height of the one which was used in UL 1626) supported over a pan with heptane, two polyether foam cushions (about 60% greater in density than the foam previously used in UL 1626) measuring 34 in by 30 in by 3 in (864 mm by 762 mm by 76 mm) and \( \frac{1}{4}\) in (6 mm) Douglas Fir plywood paneling. The new fire test was shown in a series of sprinklered fire tests to provide a reproducible challenge to residential sprinklers comparable to that observed in the Factory Mutual Research and the Los Angeles Residential Test Programs.

Interaction of Sprinklers with Smoke and Heat Vents

There has been an ongoing controversy about the use of sprinklers and smoke/heat vents together, and dozens of position papers have been published over the decades. This paper reviews 13 experimental studies that have some relevance to the claims posed for and against the combined use of sprinklers and smoke/heat vents. These studies are used to evaluate the positive and negative claims that have been made with regard to the combined use of sprinklers and smoke/heat vents. Three of the studies investigate the use of smoke/heat vents alone. Four investigations include sprinklers, but do not include roof vents. Three of these are test series in which perimeter vents were used in the test facility, and the fourth included sprinklers, a partial draft curtain, and no smoke/heat vents. Four test series included sprinklers, smoke/heat vents, and draft curtains, but utilized spray or pool fires which were not subject to extinguishment by the sprinklers. Four test series included sprinklers, smoke/heat vents, draft curtains, and used Class A fuels which were subject to extinguishment. The studies of smoke and heat venting used in conjunction with sprinklers show clearly that venting does not have a negative effect on sprinkler performance. Experimental studies have shown that venting does limit the spread of products of combustion by releasing them from the building within the curtained compartment of fire origin. This improves visibility for building occupants and firefighters who need to find the seat of the fire to complete fire extinguishment. Limiting the spread of smoke and heat also reduces smoke and heat damage to the building. In the event that sprinklers do not operate, venting remains a valuable aid to manual control of the fire. The experimental studies have shown that early vent activation has no detrimental effects on sprinkler performance and have also shown that current design practices are likely to limit the number of vents operated to one and vents may in fact not operate at all in very successful sprinkler operations. Design practices should move to methods that assure early operation of vents, and vent operation should be ganged so that the benefit of roof vents is fully realized. Sprinkler design with vents and draft curtains needs to take full account of draft curtains as obstructions. Curtains should be placed in aisles rather than over storage.

Sprinkler performance as affected by nozzle inner contraction angle

The discharge-pressure relationship for the orifice nozzle is essential for developing new sprinkler prototypes and designing sprinkler irrigation systems. In this work, the sprinkler nozzle inner contraction angle was varied from 20° to 90° to establish the relationship between discharge and pressure. The sprinkler nozzle discharge increases exponentially with increasing pressure. The discharge exponent is essentially independent of the nozzle contraction angle and can be taken as 0.5, while the discharge coefficient decreases significantly with increasing contraction angle. Sprinkler rotation speeds measured for different contraction angle nozzles decreased as the angle increased. Water distributions were tested indoors for various contraction angles. Sprinkler nozzles with contraction angles ranging from 20° to 60° produced approximately equal pattern radii and similar water application profiles, but the pattern radius was significantly reduced for contraction angles above 60°. The optimum inner contraction angle is about 30°.