Improper opening detection method of multiple suction reciprocating compressor suction valve

Abstract

A method for detecting an improper opening of a multiple suction reciprocating compressor suction valve of a reciprocating compressor includes monitoring, by an electronic processing core, a variable proportional to torque of an electrical engine that cooperates with a piston of the reciprocating compressor, the variable being measured by a sensor. A detection of the improper opening of the suction valve is made by a detection of at least one peak of the variable proportional to torque of the electrical engine during power of the electromagnetic field generator element.

Claims

1. Method of detecting improper opening of a multiple suction reciprocating compressor suction valve of a reciprocating compressor, the reciprocating compressor comprising: at least one compression mechanism comprising at least one compression cylinder, at least one piston configured for reciprocating linear movement inside the cylinder, at least one valve-port set fluidly coupled to the compression cylinder integrated by at least one suction port, at least one actuating suction valve cooperating with its respective suction port, and at least one electrical magnetic generator element configured to interact selectively with the suction valve; an electrical engine cooperating with said piston; at least one electronic processing core; and at least one sensor configured to measure at least one variable proportional to torque of said electrical engine; the method characterized by monitoring, by the electronic processing core, the at least one variable proportional to torque of said electrical engine measured by the sensor; wherein the detection of improper opening of the suction valve is made by the detection of at least one peak of said variable proportional to torque of said electrical engine during power of the electromagnetic field generator element.

2. Method, of claim 1, wherein the variable proportional to torque of said electrical engine comprises the electrical current that runs by a coil of the electrical engine.

3. Method, of claim 1, wherein the variable proportional to torque of said electrical engine comprises the electrical power of the electrical engine.

4. Method, of claim 1, wherein the variable proportional to torque of said electrical engine monitored comprises the speed of the engine resulting from the improper opening of suction valve.

Description

BRIEF SUMMARY OF THE DRAWING

(1) FIGS. 1A and 1B illustrates mere conceptual examples of part of the compression mechanisms of double or multiple suction reciprocating compressors; and

(2) FIG. 2 shows a relational graphic between the high pressure suction valve state and the engine electrical current of the double and multiple suction reciprocating compressor.

DETAILED DESCRIPTION OF THE INVENTION

(3) As shown on FIG. 1A, from document BRPI10013598, current state of the art comprises double or multiple suction compressors, in which comprises one single compression mechanism capable of operate, exclusively, with one among at least two suction lines of different pressures.

(4) Thus, such compression mechanism comprises at least two suction sets and integrated, each one, by a actuating suction valve coopering with its respective suction port and at least one exhaust set.

(5) In case of document BRPI10013598, both suction sets are disposed in one single plate-valve belonging to the compression mechanism. In case of document BR1020140072594, both suction sets are disposed in distinct components of the compression mechanism, as exemplified on FIG. 1B, where one of the suction sets is disposed on the compression cylinder of reciprocating compressor, as the other suction set is disposed on the plate-valve of reciprocating compressor.

(6) Independently of the physical location of suction sets (so called), it is noted that one of them is also integrated by an electromagnetic field generator element capable of help and/or hinder switch of the suction valve operation state, allowing said suction valve to be electronically actuated (by electromagnetic field generator element) and/or automatically actuated (by pressure differential of compression chamber.

(7) The valve in which suction set is free of any type of electromagnetic field generator element is normally named automatic valve (or low valve), after all, it has its operational state altered only depending on the pressure differential of the compression chamber. The valve in which the suction set is integrated by the electrical field generator element (electrical coil) is normally named semi controlled (or high valve), finally, it has its operational state altered automatically and/or controlled.

(8) From a functional point of view, and according to detailed description on documents BRPI10013598 and BR1020140072594, it is noted that the low valve and high valve operate exclusively, this is, they do not operate simultaneously.

(9) Therefore, when it is desired to select (work with) the high valve, it is just not actuate the electrical field generator element. In this circumstance, the pressure of the suction line itself (high pressure) keeps the high valve open and, additionally, a low valve closed.

(10) On the other hand, when it is desired to select (work with) the low valve, simply press the electromagnetic field generator element. In this circumstance, the magnetic field generated by this element makes the high valve to be attracted obstructing its suction port, blocking its suction line (high pressure) and allowing the other suction line (low pressure) to keep the low valve opened related to its suction port.

(11) However, it is possible that the pressure of the suction line (high pressure) of high valve is greater than the attraction strength produced by the electromagnetic field generator element. In this case, there is a possibility of the high valve open during a low pressure suction cycle (when it is desired to work just with the low valve).

(12) This problem or malfunctioningcaused by improper opening of the high valveis extremely harmful to compressor efficiency, besides damaging the concept of double or multiple suction, after all, the improper opening of the high valve interrupts unduly the operation of low valve.

(13) Thus, and having in mind the importance of checking the improper opening of the high valve, it is presented the method of the invention, which has the objective to detect the improper opening of the suction valve from the multiple section reciprocating compressor.

(14) Preliminarily, It remains clear that the subject method is specially dedicated to reciprocating compressions integrated by a compression mechanism basically composed by a compression cylinder, a piston capable of make reciprocating linear movement inside the cylinder, and at least one valve-port set that, fluidly associated with the compression cylinder, is integrated by at least one suction port 11, at least one suction valve 12 actuating cooperatively with its respective suction port 11, and an electromagnetic field generator element 13 capable of selectively interact with the suction valve 12. Possible embodiments of this compression mechanisms are shown on FIGS. 1A and 2B.

(15) Obviously, said reciprocating compressor is further integrated by electrical engine (not shown) cooperating with said piston and at least one electronic central of processing (not shown). As above mentioned, reciprocating compressor capable of receive the method revealed comprises a compressor already known by specialist on the art.

(16) In this scenario, stands out the present invention because it proposes a method in which monitoring is made by at least one variable proportional to torque of said electrical engine by means of at least one sensor electrically connected to electronic central of processing, wherein the improper opening detection of the suction valve 12 made from detection of at least one peak of said variable proportional to torque of said electrical engine during electromagnetic field generator element 13 energization.

(17) In this way, it is worth to say that said sensor capable of measure at least one variable proportional to torque of said electrical engine can comprise, in example, the own engine, a shunt resistor, a resistive voltage divider, among other sensors already known and, eventually, called sensorless.

(18) According to the invention concerned, the variable proportional to torque of said electrical engine comprises an electrical current that runs by at least one of the coils from electrical engine. Specifically, the variable proportional to torque of said electrical engine comprises the electrical engine electric power.

(19) The proposed method is better understood based on FIG. 2.

(20) In this figure it is observed that during mechanical laps from low pressure suction, formed by suction and exhaust cycles S1D1, S2D2, S3D3 the engine current presents certain level. In this condition the valve is properly closed. In occurring an improper opening, indicated by disturb d_ivs3 on the coil current during the suction cycle S3, the gas of high pressure encroaches the barrel and causes a significant increase on the engine current during compression cycle D3 indicated by l_md3.

(21) The current during this compression cycle is pointedly higher than the current from previous compression cycles D1, D2 in which the valve was closed. This sudden increase on the current during the functioning of low pressure can be used as indication of valve improper opening.

(22) Still on the figure, other improper openings d_ivs4, d_ivs5 occur on suction cycles S4, S5 and cause the currents to increase l_md4, l_md5 during the following exhaust cycles D4, D5.

(23) Thus, can be seen that the peak of said variable proportional to torque of said electrical engine occurs on the compression cycle immediately after the suction cycle in which occurred valve improper opening.

(24) The variable of electrical engine monitored comprises the speed when occurs the improper opening of suction valve the engine speed will present a peak (negative).

(25) The advantages of proposed method related to the technics already knowncapable of reach the same resultis the fact that do not need further sensor of valve coil current, once its uses the engine current for the same function.