US 5,073,862 A · Method and apparatus for diagnosing problems with the thermodynamic performance of a heat engine

Abstract

A method and apparatus measured and calculates the derived thermodynamic state of a heat-pump or air conditioning system using information from transducers sensing elementary thermodynamic variables in the system. Elementary signals such as pressure, temperature, power, humidity, air flow, and others as required are derived using transducers from closed and open portions of the thermodynamic system, and which signals are then transmitted using appropriate transmission media. These signals are input to a computer, which could take many forms (electrical analog, electrical digital, pneumatic, hydraulic, and others), and these signal inputs along with known and tabulated thermodynamic characteristics of the working fluid (refrigerant) and psychrometric properties of the cooled media (air for example), are used to calculate thermodynamic output variables such as entropy, enthalpy, pressure, temperature, and volume at various states in the thermodynamic cycle. The output variables can be presented in tabulated or graphic form for clear understanding such as pressure vs. volume, temperature vs. entropy, or pressure vs. enthalpy graphs of the working system. The derived data can be used to determine efficiency and operating condition of the heat-pump or air-conditioning system and can be used as an aid in the diagnosis of the cause of a malfunctioning or inefficient system. Using artificial intelligence in an "expert" system, diagnosis could be completely automated.

Claims14

Dependent claims

In the operation of a heat engine having an evaporator and a condenser, a method of diagnosing and evaluating actual thermodynamic performance of the heat engine comprising:

a) sensing evaporator localized data and producing output signals corresponding to the sensed evaporator localized data;
b) sensing condenser localized data and producing output signals corresponding to the sensed condenser localized data;
c) sensing indoor psychrometric data in an environment controlled by the heat engine and producing output signals corresponding to the sensed psychrometric data;
d) transmitting the output signals corresponding to the sensed evaporator localized data, condenser localized data, and psychrometric data to a processing means and calculating a performance data set indicative of the actual thermodynamic performance of the heat engine;
e) storing a predefined performance data set in a memory device operatively connected to the processing means, the predefined performance data set being representative of a normal thermodynamic performance of the heat engine;
f) comparing the calculated performance data set with the predefined performance data set stored in memory to yield a comparative result indicative of whether the heat engine is operating normally;
and
g) displaying the comparative result.

5 more elements

Dependencies are inferred from the claim text.

Method and apparatus for diagnosing problems with the thermodynamic performance of a heat engine

Life of this patent

Method and apparatus for diagnosing problems with the thermodynamic performance of a heat engine

Life of this patent

Abstract

Claims14