Component of the HVAC system

To maintain the HVAC system properly, you should understand each component of the HVAC system. Because of the knowledge of the HVAC component you have better knowledge of how it works or run and how much this is important for the building. The main components of the HVAC are as follow;

In old HVAC system, we always hear about three major problems that are the level of noise, consumption of energy as well as new coolants. This problem is overcome in the modern HVAC system. Through as much as twenty percent of today’s model can reduce the noise level. The latest compressor technology is quieter. Because of the shapes of the fan blade noise level is also reduce. As these changes are more beneficial in new or modern HVAC systems as well as there are also many factors which make the model more attractive. The new systems are frequently smaller than the previous systems.

As the HVAC system work on the principle of thermodynamics. The moment of heat is depicted in the thermodynamics. From one object to other the flow of energy is heat. The internal kinetic energy of an object is measure known as temperature. Heat depends on the mass and temperature. The HVAC system is work on the principle of the thermodynamics. There are also further three laws of thermodynamics that apply on the HVAC system. According to first law, energy cannot be destroyed or created but convert from one form to another in the form of energy.  But in real-world applications, the second law of thermodynamics is applicable. From higher state to lower state energy must flow. Heat always flows from warmer place to cooler but not from cooler to warmer.

In the HVAC system number of the sensor have been used. On compressor speed, the speed of the blower, the charge level of refrigerant as well as ambient condition depends on the performance of AACS (automotive air conditioning system). As compared to an effect of the evaporator as well as condenser temperature on it the influence on the mass flow rate of compressor speed of refrigerant was more prominent. Because of increasing the inlet temperature both capacity of cooling as well as system COP increases. In liquid line by a Coriolis type mass flow meter placed the refrigerant mass flow rate through the system is measured. Through the compressor, the mass flow rate depends on its speed, in the system amount of refrigerant as well as through the evaporator air flow.

From the Coriolis mass flow meter, the variation of mass flow rate is obtained. Within 0.75%mass flow rate lays for the presented data set the max error. with the increase of refrigerant charge as well as the compressor speed the mass flow rate increase. It is also observed that mass flow rate variation also observed with the blower speed. Along with the several other control operations, HVAC take care of the operation in the control unit of the engine. By the compressor as well as the blower of the evaporator the energy consume have been targeted as well as different control strategies. Different control strategies are used in HVAC. Under steady state conditions, some initiatives time to time has been taken to study regarding the car air conditioning system performance.

In the HVAC controller, the heating valves were used directly for the action of controlling the system. The reverse action controller was used for the control of normal open heating valves. The heating valve opens with the rise of temperature. The reverse action controller never works properly, particularly in the temperature difference conditions. The open heating valves were used for the identification of direct actions. The correct work of valves depends on the selection of humidification and dehumidification, temperature differences, selection of cooling and heating process, and the upstream and downstream sensors of the controlling devices. The psychrometric conditions for the controller can be occurred by overlapping of steps responses. The graph given below shows the relation between the parameters and reverse action controller.

PART 2

Mechanical system:

Among the Automotive air conditioning system as well as industrial refrigeration or conventional building there is some difference because of compactness, highly variable operating condition, as well as the capacity of the former. In the figure below it has been determined to enlarge a stationary facility of examination by using the all actual automotive or modern component of an automotive air conditioning system the name of a component is as follow like compressor of the swash plate, heat exchangers of the micro channel as well as the thermostatic expansion valve. The other additional component apart from these basic four components is filtered/drier, oil separator, glasses and so on. In a test rig, they provided good monitoring as well as the operation ease. With R-134a the developed test rig is charged in case of original automotive air conditioning system.

At different speeds the swash plate compressor runs as in the car it is determined by the engine. To run the compressor in a variable speed motor drive test facility used instead of the engine through a magnetic clutch as well as v-belt. As the lubricating oil polyalkylene glycol is used. In most of the automotive air conditioning system, oil separator are not present in the test bench the same has been provided.  For pressure equalization through a capillary tube separated oil is made to pass to the suction line.

To facilitate monitoring as well as measurement of the air stream for condenser along with evaporator Separate ducting arrangement has been made. With thick Aeroflex sheet, the outside walls of the ducts are insulated. By means of axial flow fans, fresh air is drawn into the duct as well as passed through the evaporator and condenser. From the automobile battery, the fan motor receives the power supply in the car. By providing a car 12 V battery in the test bench, the same arrangements are replicated. In the original PVC casing, the evaporator was kept in a way that it seems that air circuit flow is like the original. For the air conditioning system to simulate the load, downstream of the evaporator duct, an electrical heater is installed.

Selection and placement of the sensor:

For the steady state as well as dynamic characteristics of the test rig the most crucial and important part is to select as well as placement of the sensor. In this test system, the parameters measured include the speeds of the blower, compressor, and mass flow rate of refrigerator, pressure, and temperature at different strategies point of the refrigerant loop, the temperature of the sir dry bulb as well as relative humidity (RH) at the evaporator outlet as well as an inlet. Through the system, the refrigerator mass flow rate is measured in a liquid line by a Coriolis type mass flow meter placed. At a number of location insertion type of temperature sensor have been used to improve the accuracy of the measurements. By a differential pressure transmitter, the pressure drop across the condenser is measured. Electrical outputs are given by all sensors that are sent to the data acquisition system interfaced to a PC.

Design of the Controller:

HVAC and other controlling operations are taken care of by the ECU (Engine control unit) in a car. Nor an ECU or an engine are not contained in the present test rig. Therefore a suitable controller has been designed. The controller is first ensuring that the blower is running after the AC switch is on. By the thermistor temperature is recorded and also checks the discharge pressure. The system will start running if the temperature is more than 4 degree and the pressure is 2 to 32 bar, compressor clutch will be engaged, and the power is supplied to the fan of the condenser. As protection against frost formation to stop the system, the controller will disengage the clutch of the compressor when the temperature drops to 2 degrees.

As according to the above graph we discuss the difference between manual and updated HVAC system. In the manual you have to give all values and run it but in automatic, once you start it automatically takes the value. But the function of both the manual and automatic are similar HVAC system is used to cool one room, the building also in the vehicle.