الهندسة والمعرفة

الأساسيات والهندسة

بناء المضخة (الجزء الأول)

In 1689 the physicist Denis Papin invented the centrifugal pump and today this kind of pump is the most used around the world. The centrifugal pump is built on a simple principle: Liquid is led to the impeller hub and by means of the centrifugal force it is flung towards the periphery of the impellers. The construction is fairly inexpensive, robust and simple and its high speed makes it possible to connect the pump directly to an asynchronous motor.

اختيار صمامات التمدد

The expansion valve regulates the amount of compressed liquid refrigerant moving into the evaporator. It removes pressure from the liquid refrigerant to allow expansion or change of state from a liquid to a gas in the evaporator. In order to properly select Expansion Valves one should pay attention to the items that we mention in this post.

ما هو التآكل؟

Corrosion is usually referred to as the degradation of the metal by chemical or electrochemical reaction with its environment, see figure 1. When considered broadly, corrosion may be looked upon as the tendency of the metal to revert to its natural state similar to the oxide from which it was originally melted. Only precious metals, such as gold and platinum are found in nature in their metallic state. – Types of corrosion – Uniform corrosion – Pitting corrosion – Crevice corrosion – Intergranular corrosion – Selective corrosion – Erosion corrosion – Cavitation corrosion – Stress corrosion cracking (SCC) – Corrosion fatigue – Galvanic corrosion

مطرقة الماء (الجزء الأول)

Under unfavorable circumstances, damage due to water hammer may occur in pipelines measuring more than one hundred meters and conveying only several tenths of a liter per second. But even very short, unsupported pipelines in pumping stations can be damaged by resonant vibrations if they are not properly anchored. By contrast, the phenomenon is not very common in building services systems, e.g. in heating and drinking water supply pipelines, which typically are short in length and have a small cross-section.

أنبوب الماء مقابل غلايات أنبوب النار

غلايات أنبوب المياه ومراجل أنبوب النار هي نوعان مختلفان من غلايات البخار التي تستخدم عادة في التطبيقات الصناعية والتجارية. يستخدم كلا النوعين من الغلايات نظامًا من الأنابيب لتوليد البخار ، لكنهما يختلفان في الطريقة التي يتم بها ترتيب الأنابيب والطريقة التي تمر بها الغازات الساخنة من الموقد عبر الأنابيب.

Capillary Tube Refrigeration

A refrigeration capillary tube is a small, narrow tube that is used in refrigeration systems to control the flow of refrigerant. It is typically made of copper or other highly conductive metal, and is used in conjunction with a compressor, evaporator, and condenser to transfer heat from one location to another. The capillary tube is placed between the evaporator and the compressor in the refrigeration system, and it acts as a metering device to control the flow of refrigerant.

صيغ التبريد والحسابات

These formulas are commonly used in the field of refrigeration and air conditioning to calculate various performance parameters of a refrigeration system such as compression work, compression power, coefficient of performance, net refrigeration effect, capacity, compressor displacement, heat of compression, volumetric efficiency, and compression ratio. These formulas are based on the thermodynamics principles and are generally used to evaluate the performance of the refrigeration system and to optimize its design.

The coefficient of velocity (Cv)

Cv, or coefficient of velocity, is a measure of the flow capacity of a valve. It represents the number of gallons per minute (GPM) of water at 60°F that will flow through a valve with a one-inch opening at a pressure drop of one pound per square inch (PSI). Cv can be calculated using various formulas, such as the one based on water at 60F and one that takes into account the specific gravity of the fluid. Cv is a theoretical value and it may vary depending on the actual conditions of the valve. When selecting a valve for a specific application, it is important to consider the Cv in relation to the flow rate and pressure drop requirements of the system, as well as other factors such as ease of maintenance, cost, and safety.

دليل عزل الأنابيب

يعد عزل الأنابيب أمرًا بالغ الأهمية للحفاظ على كفاءة الطاقة ، والتحكم في درجة الحرارة ، والتحكم في التكثيف ، وتقليل الضوضاء ، والسلامة. يوفر ASHRAE توصيات سماكة محددة لأحجام الأنابيب المختلفة ونطاقات درجة الحرارة في 90.1 القياسية. عند اختيار عزل الأنابيب بناءً على معايير ASHRAE ، من المهم مراعاة درجة الحرارة وحجم الأنبوب والاعتبارات البيئية ومقاومة الحرائق وكفاءة الطاقة.

أنابيب التبريد - الجزء 2

In this post, we will be continuing our comprehensive training on how to size refrigerant piping. We will cover all the important aspects of this process, including determining the pipe size, pressure drop, and other factors. We will also discuss topics such as sizing refrigerant lines, equivalent length for refrigerant lines, and how to determine equivalent length. With this training, you will have the knowledge and confidence to size refrigerant piping accurately and correctly in any situation.

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المعايير والامتثال

HVAC Load Estimation: Internal Heat Gain from Infrastructure Components (Pipes, Ducts, Tanks, AC Motors)

Complete guide to internal heat gain from HVAC infrastructure components including pipes, ducts, tanks, and motors using Carrier standards for accurate load estimation and system design.

تقدير حمل التدفئة والتهوية وتكييف الهواء: كسب الحرارة الداخلية من المعدات والأجهزة

Complete guide to internal heat gain from equipment and appliances in HVAC load estimation using ASHRAE, CIBSE, and Carrier standards for accurate system sizing and equipment integration.

تقدير حمل HVAC: زيادة الحرارة الداخلية من الإضاءة

Complete guide to internal heat gain from lighting systems in HVAC load estimation using ASHRAE, CIBSE, and Carrier standards for accurate system sizing and lighting-HVAC integration.

تقدير حمل HVAC: زيادة الحرارة الداخلية من الأشخاص والركاب

Complete guide to internal heat gain from people and occupants in HVAC load estimation using ASHRAE, CIBSE, Carrier, and NFPA standards for accurate system sizing and design.

تقدير تحميل HVAC: القيم الزجاجية u وقيم معامل التظليل (SC)

Complete guide to glazing U-values and shading coefficients for HVAC load estimation using ASHRAE, CIBSE, and Carrier standards for accurate fenestration thermal and solar analysis.

تقدير أحمال التدفئة والتهوية وتكييف الهواء: قيم البناء للجدران والأسقف والفواصل

Complete guide to construction U-values for walls, roofs, and partitions in HVAC load estimation using ASHRAE, CIBSE, and Carrier standards for accurate thermal analysis.

عمليات القياس النفسي لأنظمة التدفئة والتهوية وتكييف الهواء: الرسوم البيانية والحسابات وتطبيقات معالجة الهواء

Complete guide to psychrometric processes in HVAC design covering sensible/latent cooling, heating, humidification, dehumidification, and evaporative cooling using ASHRAE and CIBSE standards.

HVAC Cooling and Heating Load Estimation: Outdoor Conditions and Climate Data

Comprehensive guide to outdoor climate data for HVAC load estimation using ASHRAE, CIBSE, and Carrier standards. Essential weather parameters for accurate system sizing and energy analysis.

استراتيجية اختيار وتصميم نظام التدفئة والتهوية وتكييف الهواء: المعايير والمبادئ التوجيهية المهنية

Comprehensive guide to HVAC system selection and design strategy using ASHRAE, SMACNA, and Carrier standards. Learn professional methodologies for optimal system selection and performance optimization.

معادلات تصميم التدفئة والتهوية وتكييف الهواء: حسابات الهواء والمروحة والمضخة والنظام الهيدروليكي

Comprehensive guide to essential HVAC design equations covering air, fan, pump, and hydronic system calculations. Reference standards from SMACNA, ASHRAE, and Carrier for professional engineering applications.

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الأدوات والموارد الرقمية

تصنيف كفاءة مرشحات الهواء

ASHRAE 52.2: Filter testing was originated from America in 1930 (ASHVE and AFI code). It was then reviewed and modified in 1967 and 1968. ASRHAE collaborated with American National Standard Institude (ANSI) in 1992 to create ASHRAE-ANSI 52.1. Finally updated to ASHRAE 52.2 in 2007.

وظائف البرمجة السيكرومترية

ibrary of psychrometric functions to calculate thermodynamic properties of air for Python, C, C#, Fortran, JavaScript and VBA/Excel

المبردات في عام 2025: الخصائص والتطبيقات والتوافق

As the HVAC and refrigeration industry continues to evolve with environmental regulations and technological advancements, understanding refrigerant properties remains crucial for engineers, technicians, and facility managers. This comprehensive guide provides an updated overview of common refrigerants, their compositions, and applications in today’s market.

برامج هاب الناقل

Carrier’s Hourly Analysis Program is two powerful tools in one package – versatile features for designing HVAC systems for commercial buildings AND powerful energy analysis capabilities for comparing energy consumption and operating costs of design alternatives.

برنامج Trace 700

TRACE 700 enables building designers to optimize the building, system and equipment designs on the basis of energy utilization and life-cycle cost. The Trane software for TRACE 700 facilitates analysis of the energy and economic effects of virtually any chiller plant configuration by allowing users to manipulate a wide range of variables and create a profile of their specific building.

تنزيل EVAP-COND 5.0: أداة محاكاة المبادل الحراري النهائية لمهندسي التدفئة والتهوية وتكييف الهواء (HVAC).

سواء كنت تصمم مبادلًا حراريًا جديدًا، أو تعمل على تحسين نظام موجود، أو تبحث عن مبردات بديلة، فإن EVAP-COND يوفر إمكانات التحليل التفصيلي اللازمة لاتخاذ قرارات مستنيرة. أنا أشجع جميع مهندسي وباحثي التدفئة والتهوية وتكييف الهواء (HVAC) على استكشاف أداة المحاكاة القوية هذه وتجربة كيفية تحويل أسلوبك في تصميم المبادلات الحرارية بشكل مباشر.

تنزيل كتاب نقل الحرارة

The book is meant for juniors, seniors, and first-year graduate students. And to those who choose to learn the subject on their own, and to practicing engineers who use it as a reference. Whether one studies alone or with a class, learning means posing, then answering, one’s own questions.

Flexible Duct Calculator

Flexible Duct Calculator based on four different methods. Based on Friction Loss, Based on Duct Diameter, Equivalent Rectangular Duct, Equivalent Round Duct Diameter. Also table of Maximum Recommended Supply Velocity.

تغيير الهواء Cfm حاسبة

The rate at which air is exchanged (in the premises) represents another method of measuring ventilation capacity & effectiveness. Air exchange rate is typically expressed in Air Changes per Hour – “ACH”. Air changes per hour can be estimated by determining the total air supplied to, and removed from, the premises “total air exchange” or the outdoor (fresh) air supplied to, and removed from, the premises “outdoor air exchange”. We invite you to experience how this calculator can transform your workflow. Whether you’re specifying a new system, troubleshooting an existing installation, or teaching the next generation of HVAC professionals, this tool was built with your needs in mind.

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