Pressure type flow control system with flow monitoring, and method for detecting anomaly in fluid supply system and handling method at abnormal monitoring flow rate using the same

Patent metadata

Field	Value
Publication number	US-9632511-B2
Application number	US-201314075890-A
Country	US
Kind code	B2
Filing date	Nov 8, 2013
Priority date	May 10, 2011
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

A pressure type flow control system with flow monitoring includes an inlet, a control valve including a pressure flow control unit connected downstream of the inlet, a thermal flow sensor connected downstream of the control valve, an orifice installed on a fluid passage communicatively connected downstream of the thermal flow sensor, a temperature sensor provided near the fluid passage between the control valve and orifice, a pressure sensor provided for the fluid passage between the control valve and orifice, an outlet communicatively connected to the orifice, and a control unit including a pressure type flow rate arithmetic and control unit receiving a pressure signal from the pressure sensor and a temperature signal from the temperature sensor, and a flow sensor control unit to which a flow rate signal from the thermal flow sensor is input.

First claim

What is claimed is:

1. A pressure type flow control system with flow monitoring, comprising:
(a) an inlet side passage for fluid;
(b) a control valve and a valve drive unit of a pressure type flow control unit that is connected to a downstream side of the inlet side passage;
(c) a thermal type flow sensor that is connected to a downstream side of the control valve;
(d) an orifice that is installed on a first fluid passage communicatively connected to a downstream side of the thermal type flow sensor;
(e) a temperature sensor that is provided near the first fluid passage between the control valve and the orifice to measure temperature of fluid in the first fluid passage;
(f) a pressure sensor that is provided for the first fluid passage between the control valve and the orifice to measure pressure of fluid in the first fluid passage;
(g) an outlet side passage that is communicatively connected to the orifice; and
(h) a first control unit comprising
(i) a pressure type flow rate arithmetic and control unit to which a pressure signal from the pressure sensor and a temperature signal from the temperature sensor are input, and the pressure type flow rate arithmetic and control unit computes a first flow rate value Q of fluid flowing through the orifice based on the input pressure signal, and the pressure type flow rate arithmetic and control unit outputs a control signal Pd for performing a feedback control to the valve drive unit that brings the control valve into an opening or closing action in a direction in which a difference between the computed first flow rate value and a set flow rate value is decreased; and
(ii) a flow sensor control unit to which a flow rate signal from the thermal type flow sensor is input, and the flow sensor control unit computes a second flow rate of the fluid flowing through the orifice according to the flow rate signal to indicate an actual flow rate of the fluid flowing through the orifice,

wherein, when a difference between the first flow rate of the fluid computed by the flow sensor control unit and the second flow rate of the fluid computed by the pressure type flow rate arithmetic and control unit exceeds a set value, then the first control unit performs an alarm indication;
wherein the control valve is a nearest control valve to the orifice on an upstream side, and there are no other control valves between the control valve and the orifice.

2. The pressure type flow control system with flow monitoring according to claim 1 , wherein the pressure sensor is provided between an outlet side of the control valve and an inlet side of the thermal type flow sensor.

3. The pressure type flow control system with flow monitoring according to claim 2 , wherein when a difference between the first flow rate of the fluid computed by the flow sensor control unit and the second flow rate of the fluid computed by the pressure type flow rate arithmetic and control unit exceeds a set value, then the first control unit performs an alarm indication.

4. The pressure type flow control system with flow monitoring according to claim 1 , wherein the control valve, the thermal type flow sensor, the orifice, the pressure sensor, the temperature sensor, the inlet side passage, and the outlet side passage, are integrally assembled in one body, and the first fluid passage is integrally formed in the one body.

5. The pressure type flow control system with flow monitoring according to claim 1 , wherein the pressure sensor is provided between the thermal flow type sensor and the orifice.

6. A pressure type flow control system with flow monitoring, comprising:
(a) an inlet side passage for fluid;
(b) a control valve and a valve drive unit of a pressure type flow control unit that is connected to a downstream side of the inlet side passage;
(c) a thermal type flow sensor that is connected to a downstream side of the control valve;
(d) an orifice that is installed on a first fluid passage communicatively connected to a downstream side of the thermal type flow sensor;
(e) a temperature sensor that is provided near the first fluid passage between the control valve and the orifice to measure temperature of fluid in the first fluid passage;
(f) a first pressure sensor that is provided for the first fluid passage between the control valve and the orifice to measure pressure of fluid in the first fluid passage;
(g) an outlet side passage that is communicatively connected to the orifice; and
(h) a control unit comprising
(i) a pressure type flow rate arithmetic and control unit to which pressure signals from the first pressure sensor and a temperature signal from the temperature sensor are input, and the pressure type flow rate arithmetic and control unit monitors critical expansions conditions of fluid flowing through the orifice and computes a first flow rate value Q of the fluid flowing through the orifice based on the input pressure signal, and the pressure type flow rate arithmetic and control unit outputs a control signal Pd for performing a feedback control to the valve drive unit that brings the control valve into an opening or closing action in a direction in which a difference between the computed first flow rate value and a set flow rate value is decreased; and
(ii) a flow sensor control unit to which a flow rate signal from the thermal type flow sensor is input, and the flow sensor control unit computes a second flow rate of the fluid flowing through the orifice according to the flow rate signal to indicate an actual flow rate of the fluid flowing through the orifice,

wherein, when a difference between the first flow rate of the fluid computed by the flow sensor control unit and the second flow rate of the fluid computed by the pressure type flow rate arithmetic and control unit exceeds a set value, then the first control unit performs an alarm indication;
wherein the control valve is a nearest control valve to the orifice on an upstream side, and there are on other control valves between the control valve and the orifice.

7. The pressure type flow control system with flow monitoring according to claim 6 , wherein the first control unit performs an alarm indication when the fluid flowing through the orifice is out of the critical expansion conditions.

8. The pressure type flow control system with flow monitoring according to claim 6 , wherein the control valve, the thermal type flow sensor, the orifice, the first pressure sensor, the temperature sensor, the inlet side passage, and the outlet side passage, are integrally assembled in one body, and the first fluid passage is integrally formed in the one body.

9. The pressure type flow control system with flow monitoring according to claim 6 , wherein a second pressure sensor is provided for the outlet side passage on the downstream side of the orifice to measure pressure of fluid on the downstream side of the orifice, and wherein the control unit further comprises the second pressure sensor.

10. The pressure type flow control system with flow monitoring according to claim 9 , wherein the control valve, the thermal type flow sensor, the orifice, the first pressure sensor, the temperature sensor, the inlet side passage, the outlet side passage, and the second pressure sensor, are integrally assembled in one body, and the first fluid passage is integrally formed in the one body.

11. The pressure type flow control system with flow monitoring according to claim 6 , wherein the pressure sensor is provided between the thermal flow type sensor and the orifice.

Assignees

• Fujikin Kk

Inventors

• Hirata Kaoru
• Dohi Ryousuke
• Nishino Kouji
• Ikeda Nobukazu
• Sugita Katsuyuki

Classifications

• G05D7/0617

  specially adapted for fluid materials · CPC title

• Y10T137/0368

  By speed of fluid · CPC title

• G01F1/6965

  comprising means to store calibration data for flow signal calculation or correction · CPC title

• G01F1/363

  with electrical or electro-mechanical indication (G01F1/37 and G01F1/38 take precedence) · CPC title

• F16K37/0083

  by measuring valve parameters · CPC title