US 5,231,841 A · Refrigerant charging system and control system therefor

Abstract

An apparatus and method for controlling the charging of refrigerant into a refrigerant system is disclosed. The apparatus determines the mass amount of refrigerant charged by determining the volume of refrigerant charged, the density of the refrigerant based on its pressure as it is charged, and determines the mass amount charged from the determined density and pressure. The apparatus has a pressure compensated flow valve and determines the volume of refrigerant charged based on the amount of time refrigerant has flowed through the constant flow valve. The type of refrigerant being charged can be selected from a plurality of refrigerant types and the apparatus has a memory in which data related to density and flow characteristics of each refrigerant type is stored. The apparatus uses the data for the selected refrigerant to determine the mass amount of refrigerant charged. The apparatus further determines that the refrigerant supply tank is empty when its pressure decay exceeds a predetermined amount. The apparatus has a manifold in which the constant flow valve is mounted and the apparatus can be made as a portable, hand carried unit. The apparatus can also be used as a mass flowmeter.

Claims33

Dependent claims

An apparatus for charging refrigerant into a refrigerant system, comprising:

(a) a constant flow valve having an inlet for coupling to a source of refrigerant and an outlet port for coupling to an inlet of a refrigerant system;
(b) means coupled to the outlet of the constant flow valve for determining the pressure at the inlet of the refrigerant system when the outlet of the constant flow valve is coupled thereto;
(c) means for determining the density of the refrigerant being charged into the refrigerant system from the pressure determined at the inlet of the refrigerant system;
(d) means for determining the volume of refrigerant that has flowed through the constant flow valve;
(e) means for determining the mass of refrigerant charged into the refrigerant system based upon the volume of refrigerant that has flowed through the constant flow valve and the determined density of the refrigerant.

2 more elements

An apparatus for charging refrigerant into a refrigerant system from a source of refrigerant, comprising:

(a) an inlet port for coupling to the source of refrigerant and an outlet port for coupling to an inlet port of the refrigerant system;
(b) a constant flow valve coupled in series between the inlet port and the outlet port of the apparatus;
(c) control means for determining the mass of refrigerant charged into the refrigerant system based on the volume of refrigerant that flowed through the constant flow valve and the density of that refrigerant, the control means including means for determining the density of the refrigerant based on the pressure of the refrigerant at the outlet port of the apparatus and also including means for determining the volume of refrigerant that flowed through the constant flow valve;
and
(d) a pressure transducer coupled to the outlet port of the apparatus for sensing the pressure of the refrigerant and having an output coupled to an input of the control means.

2 more elements

An apparatus for charging refrigerant into a refrigerant system from a source of refrigerant, comprising:

(a) an inlet port for coupling to the source of refrigerant, a low pressure outlet port for coupling to a low pressure port of the refrigerant system and a high pressure port for coupling to a high pressure port of the refrigerant system;
(b) a constant flow valve coupled in series between the inlet port and the outlet port;
(c) a solenoid valve coupled in series with the constant flow valve between the inlet port and the outlet port;
(d) control means for controlling the flow of refrigerant through the apparatus and determining the amount of refrigerant charged into the refrigerant system;
(e) a first pressure transducer coupled to the outlet port and having an output coupled to the control means;
(f) a second pressure transducer coupled to the high pressure port of the apparatus and having an output coupled to the control means;
(g) refrigerant selection means for selecting the type of refrigerant being charged into the refrigerant system, the refrigerant selection means coupled to the control means;
(h) the control means having a memory for storing data related to density characteristics of refrigerant types that can be selected by the refrigerant selection means;
(i) the control means including means for determining the density of the refrigerant at the outlet port based on the pressure of the refrigerant at the outlet port, means for determining the volume of refrigerant that flowed through the constant flow valve and means for determining the mass amount of refrigerant that has been charged into the refrigerant system from the density of the refrigerant and the volume of refrigerant that has flowed through the constant flow valve;
(j) refrigerant amount display means coupled to the control means for displaying the amount of refrigerant that has been charged into the refrigerant system as determined by the control means;
(k) charge mode selecting means for selecting between a continuous charge mode and a charge to set amount mode, the charge mode selecting means coupled to the control means;
(l) refrigerant amount setting means coupled to the control means for setting an amount of refrigerant to be charged into the refrigerant system;
(m) means coupled to the control means for providing start and stop signals to the control means;
(n) the control means actuating the solenoid valve to open it upon receipt of a start signal to permit refrigerant to flow through the apparatus into the refrigerant system, the control means deactuating the solenoid valve to close it and stop refrigerant flowing through the apparatus into the refrigerant system upon receipt of a stop signal and when in the charge to set amount mode when the control means determines that the amount of refrigerant charged into the refrigerant system has reached the set amount.

11 more elements

In an apparatus for charging refrigerant into a refrigerant system having a constant flow valve through which the refrigerant flows wherein the volume of refrigerant charged into the refrigerant system is determined based on the amount of time refrigerant flowed through the constant flow valve, a method of determining the mass amount of refrigerant charged into the refrigerant system comprising the steps of:

(a) measuring the pressure of the refrigerant as it is charged into the refrigerant system;
(b) determining the density of the refrigerant from the measured pressure;
and
(c) determining the mass amount of refrigerant charged into the refrigerant system based on the determined volume of refrigerant and determined density of the refrigerant.

1 more element

A hand carried apparatus for controlling the charging of refrigerant into a refrigerant system, comprising:

(a) a case adapted to be hand carried;
(b) a manifold mounted in the case;
(c) a controller mounted in the case;
(d) the manifold having an inlet for coupling to a pressurized refrigerant tank and an outlet for coupling to a low pressure port of the refrigerant system and a high pressure port for coupling to a high pressure port of the refrigerant system;
(e) a constant flow valve mounted to the manifold in series between the manifold's inlet and outlet;
(f) a solenoid valve mounted to the manifold in series between the manifold's inlet and outlet;
(g) a first pressure transducer mounted to the manifold and coupled to the manifold's inlet, the first pressure transducer providing an electrical signal at an output indicative of the pressure of refrigerant at the manifold's inlet, the first pressure transducer's output coupled to the controller;
(h) a second pressure transducer mounted to the manifold and coupled to the manifold's outlet, the second pressure transducer providing an electrical signal at an output indicative of the pressure of refrigerant at the manifold's outlet, the second pressure transducer's output coupled to the controller;
(i) a third pressure transducer mounted to the manifold and coupled to the manifold's high pressure port, the third pressure transducer providing an electrical signal at an output indicative of the pressure of refrigerant at the manifold's high pressure port, the third pressure transducer's output coupled to the controller;
(j) means coupled to the controller for setting an amount of refrigerant to be charged into the refrigerant system;
(k) means coupled to the controller for providing a start input to the controller to start the charging of refrigerant into the refrigerant system;
(l) means coupled to the controller for causing the controller to select a type of refrigerant to be charged into the refrigerant system from a plurality of refrigerant types;
(m) the controller including
(i) a memory having data stored therein related to characteristics of the plurality of refrigerant types that can be selected by the refrigerant type selecting means;
(ii) means for periodically determining the pressures at the manifold's inlet, the manifolds' outlet, and the manifold's high pressure port as sensed by the first, second, and third pressure transducer, respectively, from the electrical signals provided by the first, second, and third pressure transducer;
(iii) means for determining the density of the refrigerant at the manifolds' outlet from the pressure of the refrigerant at the manifold's outlet and the stored data related to the characteristics of the selected refrigerant type;
(iv) means for determining the volume of refrigerant that has flowed through the constant flow valve;
(v) means for determining the mass amount of refrigerant that has been charged into the refrigerant system from the determined volume and density of the refrigerant at the manifold's outlet;
(vi) means responsive to the start input for energizing the solenoid valve to start refrigerant flowing from the refrigerant tank into the manifold's inlet and through the solenoid valve and constant flow valve and out of the manifold's outlet and into the low pressure port of the refrigerant system;
(vii) means for comparing the mass amount of refrigerant charged into the refrigerant system with the set amount and deenergizing the solenoid valve to terminate the charging of refrigerant into the refrigerant system when the mass amount of refrigerant charged into the refrigerant system reaches the set amount;
(viii) means for periodically determining a rate of pressure drop at the manifold's inlet and comparing the determined rate of pressure drop to a predetermined rate and determining that the refrigerant tank is empty when the determined rate of pressure drop reaches the predetermined rate and deenergizing the solenoid valve to terminate the charging of refrigerant into the refrigerant system when the refrigerant tank is determined to be empty;
(n) means coupled to the controller for displaying the mass amount of refrigerant charged into the refrigerant system;
(o) means coupled to the controller for displaying the pressure of refrigerant at the manifold's outlet as determined by the controller;
and
(p) means coupled to the controller for displaying the pressure of refrigerant at the manifold's high pressure port as determined by the controller.

22 more elements

An apparatus for charging refrigerant into a refrigerant system, comprising

(a) valve means for controllably coupling a source of refrigerant to the refrigerant system, the valve means having an inlet coupled to the refrigerant source and an outlet coupled to the refrigerant system;
(b) a controller having a memory in which is stored data related to characteristics of a plurality of refrigerant types;
(c) means coupled to the controller for selecting one of the plurality of refrigerant types for which data is stored in the controller's memory, said selected refrigerant type being the type of refrigerant provided by the refrigerant source;
(d) the controller including means for determining the amount of refrigerant that flows through the valve means and determining the amount of refrigerant charged into the refrigerant system from the determined amount of refrigerant that has flowed through the valve means and the stored data related to characteristics of that refrigerant;
(e) and means for coupling the controller to the valve means.

2 more elements

Dependencies are inferred from the claim text.

Refrigerant charging system and control system therefor

Life of this patent

Refrigerant charging system and control system therefor

Life of this patent

Abstract

Claims33