Multiple pulse charge transfer for capacitive deionization of a fluid

Patent metadata

Field	Value
Publication number	US-10696571-B2
Application number	US-201615299021-A
Country	US
Kind code	B2
Filing date	Oct 20, 2016
Priority date	Oct 20, 2016
Publication date	Jun 30, 2020
Grant date	Jun 30, 2020

Abstract

The present disclosure relates to a capacitive deionization system which makes use of a controller, a first capacitor acting as a first electrode, a second capacitor acting as a second electrode, and a first inductor for storing energy received from the first capacitor, and transferring the stored energy to the second capacitor. A first plurality of electronic switches are controlled by the controller to control communication between the first inductor and the first capacitor, and between the first inductor and the second capacitor. An additional energy transfer subsystem is included which has a second inductor for receiving energy from the first capacitor while the first inductor is transferring stored energy to the second capacitor.

First claim

What is claimed is:

1. A capacitive deionization system comprising:
a controller;
a first capacitor for collecting ions in a fluid flowing through the first capacitor to initially charge the first capacitor;
a second capacitor;
an energy transfer subsystem including:
a first inductor for storing energy received from the first capacitor, and transferring the stored energy to the second capacitor;
a first plurality of electronic switches controlled by the controller for controlling electrical communication between the first inductor and the first capacitor, and the first inductor and the second capacitor, a first one of the first plurality of electronic switches being interposed between the first capacitor and the first inductor to selectively enable and prevent a transfer of stored energy from the first capacitor to the first inductor, and a second one of the first plurality of electronic switches being interposed between the first inductor and the second capacitor to selectively enable and prevent a transfer of stored energy from the first inductor to the second capacitor; and

an additional energy transfer subsystem responsive to the controller, and having a first connection point and a second connection point, the additional energy transfer subsystem coupled directly in parallel across the first and second capacitors to communicate with the first and second capacitors, and such that the first connection point is coupled to the first capacitor and the second connection point is coupled to the second capacitor, the additional energy transfer subsystem including:
a second inductor for receiving energy from the first capacitor while the first inductor is transferring the stored energy to the second capacitor, and for discharging energy from the second inductor to the second capacitor while the first plurality of electronic switches is allowing communication between the first inductor and the first capacitor to again charge the first capacitor, such that the controller controls the additional energy transfer subsystem so that the second inductor is charging only while the first inductor is discharging, and further controls the first plurality of electronic switches so that the first inductor is charging only while the second inductor is discharging.

2. The system of claim 1 , wherein the additional energy transfer subsystem is controlled by the controller.

3. The system of claim 2 , wherein the additional energy transfer subsystem includes a second plurality of electronic switches controlled by the controller.

4. The system of claim 1 , wherein the system comprises at least one of:
a desalination system for removing salt from salt water; or
a deionization system for removing ions from a fluid containing the ions.

5. The system of claim 3 , wherein the first plurality of electronic switches comprises a pair of first transistors, and wherein the second plurality of electronic switches comprises a second pair of transistors.

6. The system of claim 3 , further comprising a current sensing resistor and a voltage detection circuit coupled across the current sensing resistor for monitoring a magnitude of a current flow through the first inductor.

7. The system of claim 6 , wherein an output of the voltage detection circuit is coupled to the controller.

8. The system of claim 3 , wherein the first plurality of electronic switches comprises first and second field effect transistors (FETs), and wherein the second plurality of electronic switches comprises third and fourth FETs, and wherein the first one of the first plurality of electronic switches is the first FET, and is interposed between the first capacitor and the first inductor.

9. A capacitive deionization system comprising:
a controller;
a first capacitor in the system for collecting ions in a fluid flowing through the first capacitor;
a second capacitor in the system to enable discharging of the first capacitor;
a first inductor for storing energy received from the first capacitor, and transferring the stored energy to the second capacitor;
first and second electronic switches controlled by the controller for controlling a transfer of energy from the first capacitor to the first inductor, and from the first inductor to the second capacitor, respectively, the first electronic switch being interposed between the first capacitor and the first inductor to controllably enable and prevent a transfer of charge from the first capacitor to the first inductor, and the second electronic switch being interposed between the first inductor and the second capacitor;
an additional energy transfer subsystem coupled at a first connection point to the first capacitor, and at a second connection point to the second capacitor, such that the additional enemy transfer subsystem is coupled in parallel between the first and second capacitors and communicates directly with the first and second capacitors, the additional energy transferring subsystem including:
a second inductor;
third and fourth electronic switches controlled by the controller, the third electronic switch interposed between the first capacitor and the second inductor to controllably enable and prevent a transfer of charge from the first capacitor to the second inductor, and the fourth electronic switch interposed between the second inductor and the second capacitor to control a transfer of charge from the second inductor to the second capacitor;
the first and third electronic switches further being tied in parallel directly to the first capacitor, and the second and fourth electronic switches further being tied in parallel directly to the second capacitor;
the second inductor for receiving energy from the first capacitor while the third electronic switch is closed and the fourth electronic switch is opened, and for transferring an energy stored in the second inductor to the second capacitor when the third electronic switch is opened and the fourth electronic switch is closed; and
the controller configured to control the first, second, third and fourth electronic switches such that:
the second and third electronic switches are both controlled by the controller to be simultaneously conducting during a first time interval to enable the second inductor to receive energy from the first capacitor while the first inductor is transferring stored energy therein to the second capacitor, and further such that the first and fourth electronic switches are controlled by the controller to be non-conducting during the first time interval to prevent charging of the first inductor while simultaneously preventing communication between the second inductor and the second capacitor, and
further such that during a second time interval subsequent to the first time interval, the controller controls the first and fourth electronic switches to be conducting and the second and third electronic switches to be non-conducting, so that the first inductor receives energy through the first electronic switch from the first capacitor while communication between the first inductor and the second capacitor is prevented by the second electronic switch, and communication between the first capacitor and the second inductor is prevented by the third electronic switch, while enabling the second inductor to transfer energy stored therein through the fourth electronic switch to the second capacitor.

10. The system of claim 9 , further comprising a current sensing resistor configured in series with the first inductor for sensing a current flow through the first inductor.

11. The system of claim 10 , further comprising a voltage detection circuit in communication with the current sensing resistor for detecting a voltage drop across the c

Assignees

• L Livermore Nat Security Llc

Inventors

• Stadermann Michael
• Hunter Steven L

Classifications

• C02F1/4691 Primary

  Capacitive deionisation · CPC title

• C02F2209/005

  Processes using a programmable logic controller [PLC] · CPC title

• C02F2201/4612

  Controlling or monitoring · CPC title