1.1 GENERAL
As in any application there is fluctuation in heat load, this fluctuation affects optimal values of efficiency which causes decrement in system's overall efficiency.
1.2 HISTORY AND BACKGROUND
Heat exchangers are equipments that ease the exchange heat between two fluids which are at different temperatures while keeping them apart from mixing with each other. Heat exchangers in their purest sense have been around for as long as man has been cooking in pots and ovens. To understand this, one can remember that there are three types of heat transfer from on fluid to another: conduction, convection and radiation. The typical stew pot or clay oven exchanges heat between the heat source and the food through conduction.
The most common
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Controlled heat transfer is obtained in heat exchanger by inducing turbulence in fluid (either one or both) to maintain effectiveness of component and maintain overall efficiency of plant.
1.4 ADVANTAGES
By using variable load shell and tube type heat exchanger, controlled heat is transfer between two fluids. It will help to run the pump at constant load and mass flow rate. It will maintain overall efficiency of the pump and save auxiliary power of the whole plant.
1.5
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It has been widely reported in literature that heat transfer rates in helical coils are higher as compared to those straight tubes. Due to compact structure and high heat transfer coefficient, helical coil heat exchangers find wide range of application. The heat transfer is enhanced by turbulence is governed by Reynolds number and Nusselt number. Experimental analysis for a helical coil heat exchanger was carried out and the results are compared with the straight coil under similar geometrical and operating conditions. The helical tube allows the fluid to be in contact for greater period of time so that there is an enhanced heat transfer compared to that of straight tube. The swirl of flow helps decrease the boundary layer thickness of the hot air flow and increase residence time of hot air in the inner tube. The enhancement efficiency and Nusselt number increase with decrease in pitch of wire. The most common type of heat exchanger in industrial applications is the shell-and-tube heat exchanger, shown in Figure. Shell-and-tube heat exchangers contain a large number of tubes (sometimes several hundred) packed in a shell with their axes parallel to that of the shell. Heat transfer takes place as one fluid flows inside the tubes while the other fluid flows outside the tubes through the shell. As the turbulence is increase rate of heat transfer between system to surrounding is increases. Often
Two equations were used in this experiment to determine the initial temperature of the hot water. The first equation
Superior Pump 91250 by Superior Pump is a utility pump designed to handle day-to-day chores smartly. This ultra-compact pump is convertible into a backup sump pump by connecting a float switch to it. In addition, the pump is highly portable and has rugged thermoplastic casing making its use as well as handling reliable. It helps in clearing water from basements, waterfalls, and even pools. It indeed is one handy companion to count on.
Standard Air Conditioner There are a number of standard air conditioner systems that are available on the market. One is a unitary system. The one room air conditioners sit in a window or wall opening, with interior controls. A large house or building may have several units, permitting each room to be cooled separately. Another type is the basic central air conditioning unit, which offers whole house-house cooling. It is usually a large, loud, mechanism that sits outside of the home. Although these standard air conditioners may be effective, they come with drawbacks. According to the U.S. Department of Energy, Americans spend $22 billion a year and use more than 183 billion kilowatt-hours of electricity to cool their homes with standard air conditioning. Also those air conditioners release about 100 million tons of carbon dioxide into the air annually -- two tons for each home that has one.
Refrigeration, the production of cold, is an essential practice for present-day living. It is used in a many place like the processing and preservation of food, conditioning of air for comfort, manufacture of chemicals and other materials, cooling of concrete, medical applications etc. Refrigeration is defined as the science of maintaining the temperature of a particular space lower than its surrounding space. Refrigeration and air conditioning involves various processes such as compression, expansion, cooling, heating, humidification, de-humidification, air purification, air distribution etc. In all these processes, there is an exchange of mass, momentum and energy. All these exchanges are subject to certain fundamental laws. Hence to understand and analyses the refrigeration and air conditioning systems, a basic knowledge of the laws of thermodynamics, fluid mechanics and heat transfer is essential.
good emitter of heat radiation so a lot of heat will be lost to the
The thermal performance of a heat exchanger depends upon various parameters like inlet temperature of a hot fluid, type of hot fluid, type of cold fluid, shape of baffles, material of baffles, baffles angle and property of ribs. Basically fluid flow and heat transfer characteristics are largely depends upon the Reynolds number (Re). Reynolds number is basically the ratio of inertia force to viscous force. Re is only the factor by which we can decide whether the fluid is laminar or turbulent in shell and tube type of heat exchanger. Heat exchanger is an adiabatic device in which heat is transferred from one fluid to another fluid across a plate surface. In this paper we have introduced some special type of triangular baffles with rectangular channels. The purpose
example, in Table 2 if one of the two fluids is a gas and the other a liquid, then it is
A process flow diagram of the pump system is shown in Figure 1. The main components of the system are a centrifugal pump with a 4½-inch impeller, a 2-horsepower motor, a piping system with an effective length of about 285 feet, a rotameter for low liquid flow rates (0-2 gpm), a magnetic flow meter for high liquid flow rates (0-90 gpm), and a tank.
fuel, heat loss and shape of the type of wick. The type of fuel, heat loss will be the variables to change. We will measure to control the temperature of the water using a
The multiphase pump is a pump which can transport liquid as well as gas. The multiphase pumping doesn’t require separation of oil, gas or water. Production from field can be gathered and transported to a central processing area without requiring separate flow lines, separators, heat treaters, tanks, flares, stock pumps and compressor make this technology a simpler and economical compare to conventional methods. It is an isothermal machine in which the heat generated by compressing gas is carried away by the flow stream through the pump, contrary to a compressor, which is an adiabatic machine and requires additional cooling. The pictorial representation showing advantage of multiphase pump over conventional system is shown below:
These resources can be classified as low temperature (less than 194 degrees F), moderate temperature (194 – 302 degrees F), and also high temperature (greater than 302 degrees F). The uses to which these resources are applied are also influenced by temperature. If the reservoir is to be used for direct-heat application, the geothermal water is usually fed to a heat exchanger before being injected back into the earth. Heated domestic water from the output side of the heat exchanger is used for home heating, greenhouse heating, vegetable drying and a wide variety of other uses.
... temperature of 112 0C also and a pressure 2.5 bar. Cooling water is used to condense the vapor exiting column. Remaining methane and hydrogen are separated in reflux drum where the vapor stream is combined with other gases streams. The overhead of first and second separator are combined to form fuel gas. The liquid stream exiting in the bottoms of the reflux drum is pumped at pressure of 3.3 bar for discharging pressure. The pump stream is separated in two streams. One stream is to feed to tray one of the column and the other one stream is cooled down to 38 0C in heat exchanger. Then, the cooled product stream is sent to storage.
Solar water heaters work by using energy from the sun. There are two types of systems for solar water heaters, an open system and a closed system (“Tapping into the Sun”). These systems depend on the type of climates they are installed in (“Tapping into the Sun”). Open systems are worth the installation if the weather is year round sunny, closed systems are better if the weather gets cold. The water cannot be run during winter so the system will be switched to fuel and in the summertime when it is warm, so the sy...
In thermodynamics Refrigeration is the major application area, in which the heat is transferred from a lower temperature region to a higher temperature region. The devices which produce refrigeration are known as Refrigerators and the cycle on which it operates are called refrigeration cycles. Vapour compression refrigeration cycle is the most regularly used refrigeration cycle in which the refrigerant is alternately vaporized and condensed and in the vapor phase it is compressed. Gas refrigeration cycle is the well-known refrigeration cycle in which cycle refrigerant remains in the gaseous phase throughout the cycle. Cascade refrigeration are the other refrigeration cycles discussed in this chapter; absorption refrigeration is the one more refrigeration cycle which is used where the refrigerant is dissolved in liquid before it is compressed. One more refrigeration in which refrigeration is produced by passing the electric current through two dissimilar materials is called as the thermoelectric refrigeration.
turbine via interceptor valves and control valves and after expanding enters the L.P. turbine stage via 2 numbers of cross over pipes. In the L.P. stage the steam expands in axially opposite direction to counteract the trust and enters the condenser placed directly below the L.P. turbine. The cooling water flowing throughout the condenser tubes condenses the steam and the condensate collected in the hot well of the condenser. The condensate collected is pumped by means of 3*50% duty condensate pumps through L.P. heaters to deaerator from where the boiler feed pump delivers the water to boiler through H.P. heaters thus forming a closed