Pump control of closed cycle power generation system

Patent metadata

Field	Value
Publication number	US-10920667-B2
Application number	US-201916260859-A
Country	US
Kind code	B2
Filing date	Jan 29, 2019
Priority date	Dec 28, 2016
Publication date	Feb 16, 2021
Grant date	Feb 16, 2021

Abstract

Disclosed are systems and methods for pump control of a closed thermodynamic cycle system, such as a Brayton cycle. Operational parameters such as working fluid temperature, thermal fluid temperature, stream pressure, and power generation may be the basis for controlling a thermal fluid pump rate.

First claim

We claim:

1. A system comprising:
a closed cycle system comprising a working fluid flowing through, in sequence, a compressor, a recuperative heat exchanger, a first heat exchanger, a turbine, the recuperative heat exchanger, and a second heat exchanger in a discharge mode and the compressor, the first heat exchanger, the recuperative heat exchanger, the turbine, the second heat exchanger, and the recuperative heat exchanger in a charge mode;
a first pump configured to pump a first thermal fluid, at a variable flow rate based on a speed of the first pump, through the first heat exchanger and in thermal contact with the working fluid;
at least one control device operatively connected to the first pump and configured to control the speed of the first pump;
at least one sensor; and
a controller in communication with the at least one control device and the at least one sensor, wherein the controller is configured to (i) determine an operating condition based on data received from the at least one sensor and (ii) direct the at least one control device to adjust the speed of the first pump based at least in part on the operating condition.

2. The system of claim 1 , wherein the working fluid flows through the closed cycle system in the same direction in both the charge mode and the discharge mode.

3. The system of claim 1 ,
wherein the first heat exchanger comprises a working fluid inlet, a working fluid outlet, a thermal fluid inlet, and a thermal fluid outlet,
wherein the controller is operable to determine an approach temperature of the first heat exchanger, and
wherein the controller is configured to, based at least in part on the determined approach temperature, direct the at least one control device to adjust the speed of the first pump.

4. The system of claim 3 , wherein the controller is configured to direct the at least one control device to increase the speed of the first pump when the determined approach temperature is above a first value and to direct the at least one control device to decrease the speed of the first pump when the determined approach temperature is below a second value.

5. The system of claim 1 , further comprising a generator configured to generate a quantity of electrical power and deliver the quantity of electrical power to an energy grid,
wherein the controller is operable to determine a phase difference between a phase value of the energy grid and a phase value of the generated electrical power, and
wherein the controller is configured to, based at least in part on the phase difference, direct the at least one control device to adjust the speed of the first pump.

6. The system of claim 1 , further comprising a generator configured to generate a quantity of electrical power and deliver the quantity of electrical power to an energy grid,
wherein the generator comprises an alternator,
wherein the controller is operable to determine a phase difference between a current phase value at the alternator and a voltage phase value at the alternator, and
wherein the controller is configured to, based at least in part on the phase difference, direct the at least one control device to adjust the speed of the first pump.

7. The system of claim 1 , further comprising a generator configured to generate a quantity of electrical power and deliver the quantity of electrical power to an energy grid,
wherein the generator comprises an alternator and power electronics,
wherein the controller is operable to determine a phase difference between a phase value of the alternator and a phase value of the power electronics, and
wherein the controller is configured to, based at least in part on the phase difference, direct the at least one control device to adjust the speed of the first pump.

8. The system of claim 1 , wherein the first heat exchanger is a hot-side heat exchanger disposed downstream of the compressor and upstream of the turbine.

9. The system of claim 1 , wherein the second heat exchanger is a cold-side heat exchanger disposed downstream of the turbine and upstream of the compressor.

10. The system of claim 1 , further comprising:
a second pump, wherein the second pump pumps a second thermal fluid, at a variable flow rate based on a speed of the second pump, through the second heat exchanger and in thermal contact with the working fluid,
wherein the at least one control device is operatively connected to the second pump and configured to control the speed of the second pump,
wherein the controller is further configured to direct the at least one control device to adjust the speed of the second pump based at least in part on the operating condition.

11. The system of claim 1 , wherein the operating condition is selected from the group consisting of first heat exchanger working fluid inlet temperature, first heat exchanger working fluid outlet temperature, first heat exchanger thermal fluid inlet temperature, first heat exchanger thermal fluid outlet temperature, first heat exchanger approach temperature, second heat exchanger working fluid inlet temperature, second heat exchanger working fluid outlet temperature, second heat exchanger thermal fluid inlet temperature, second heat exchanger thermal fluid outlet temperature, second heat exchanger approach temperature, recuperative heat exchanger inlet temperature, recuperative heat exchanger outlet temperature, recuperative heat exchanger approach temperature, working fluid pressure downstream of the compressor and upstream of the turbine, working fluid pressure downstream of the turbine and upstream of the compressor, compressor torque, turbine torque, generator torque, compressor RPM, turbine RPM, generator RPM, quantity of electrical power, and generated electrical power phase, or a combination thereof.

12. A system comprising:
a closed cycle system comprising a working fluid circulating through, in sequence, a compressor, a recuperative heat exchanger, a hot-side heat exchanger, a turbine, the recuperative heat exchanger, and a cold-side heat exchanger in a discharge mode, and the compressor, the hot-side heat exchanger, the recuperative heat exchanger, the turbine, the cold-side heat exchanger, and the recuperative heat exchanger in a charge mode;
a hot-side pump, wherein the hot-side pump pumps a first thermal fluid, at a first variable flow rate based on a speed of the hot-side pump, through the hot-side heat exchanger and in thermal contact with the working fluid;
a cold-side pump, wherein the cold-side pump pumps a second thermal fluid, at a second variable flow rate based on a speed of the cold-side pump, through the cold-side heat exchanger and in thermal contact with the working fluid;
at least one control device operatively connected to the hot-side pump and the cold-side pump and configured to control the speed of the hot-side pump and the speed of the cold-side pump;
a first sensor configured to report a first temperature at a working fluid outlet of the hot-side heat exchanger;
a second sensor configured to report a second temperature at a thermal fluid inlet of the hot-side heat exchanger;
a third sensor configured to report a third temperature at a working fluid outlet of the cold-side heat exchanger;
a fourth sensor configured to report a fourth temperature at a thermal fluid inlet of the cold-side heat exchanger; and
a controller in communication with the first sensor, the second sensor, the third sensor, the fourth sensor, and the at least one control device, wherein the controller is operable to (i) determine an approach temperature of the hot-side heat exchanger as a difference between the second temperature and the first temperature, (ii) determine an approach tempe

Assignees

• Malta Inc

Inventors

• Apte Raj
• Larochelle Philippe

Classifications

• F03G6/04

  gaseous {(F03G6/064, F03G6/068 take precedence)} · CPC title

• Y02E10/46

  Conversion of thermal power into mechanical power, e.g. Rankine, Stirling or solar thermal engines · CPC title

• F02C1/04 Primary

  the working fluid being heated indirectly {(in a fluidised-bed combustor F02C3/205)} · CPC title

• F02C6/14

  Gas-turbine plants having means for storing energy, e.g. for meeting peak loads · CPC title

• Y02E20/14

  Combined heat and power generation [CHP] · CPC title