CHAPTER 1
INTRODUCTION
This chapter discuss about introduction, objectives, scope, and problem statements for this project.
1.1 INTRODUCTION OF THE PROJECT
The purpose of this project is to model and design an expansion valve in a car air- conditioner system. It will be pursued by designing an embedded controller for the
system using PIC. The project involves hardware and firmware parts. This project is a different method for controlling car air-conditioner expansion valve.
A thermostatic expansion valve TXV is precision device used to measure the flow of liquid refrigerant entering the evaporator at a rate that matches the amount of
refrigerant being boiled off in the evaporator, The main purpose is like other measuring devices it also provides a pressure drop in the system, separating the high pressure side
of the system from the low pressure side. Thus allowing low pressure refrigerant to absorb heat onto itself. This project is the combination of electrical, electronics and
mechanical engineering field to represent the new invention which is regarding the design and development process.
1.2 OBJECTIVES
1. To model and design an expansion valve for an air conditioner system.
2. To implement the electrical circuit wiring, PIC programming to control the
sequence of the system and for troubleshooting. 3.
To learn more on troubleshooting and solving problem.
1.3 SCOPE OF WORKS
1. To model and design an expansion valve for car’s air condition system.
2. To design a controller for the system using PIC16F877A.
3. To learn the concept of microcontroller PIC and micro-C programming to get
finest tune. 4.
To use RS-232C serial port as an interface between PIC controller computer system.
1.4 PROBLEM STATEMENT
1. The original expansion valve system consist the 100 mechanical part. There
are no variable situations in operating system. 2.
In the expansion valve system, there have the delay due to the response of the sensing bulb.
1.5 PROBLEM SOLVING
1. Design heat sensor as input and servo motor as output to control valve that are
controlled by PIC controller to allow the system to operate in multi range of heat. 2.
By using PIC controller there have no delay due to response the valve system.
CHAPTER 2
LITERATURE REVIEW
This chapter will explain the theoretical part of the component and information on the overall trends that will use in this project. This chapter also contains previous
work related to this project.
2.1 SIMULATION MODEL OF A VAPOR COMPRESSION
