System and method for controlling molten salt temperature

Patent metadata

Field	Value
Publication number	US-9605879-B2
Application number	US-201314074782-A
Country	US
Kind code	B2
Filing date	Nov 8, 2013
Priority date	Nov 8, 2013
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

The molten salt solar tower system 100 is provided for controlling molten salt temperature in a solar receiver 130 for effective operation of the system 100 while without degrading physical properties of molten salt. The system 100 includes two circuits, first 140 and second 150 . The first circuit 140 is configured to supply relatively cold molten salt in the solar receiver 130 for heating, and the second circuit 150 is configured to supply a predetermined amount of the relatively cold molten salt in the first circuit 140 , as and when the temperature of the relatively hot molten salt circulating through the solar receiver 130 exceeds a predetermined set temperature value thereof.

First claim

The invention claimed is:

1. A method for controlling temperature of a molten salt in a molten salt solar tower system, the method comprising:
heating relatively cold molten salt in a solar receiver arrangement to obtain relatively hot molten salt heated up to a predetermined set temperature value, the solar receiver arrangement having an inlet port, a plurality of panels from panel 1 to panel N−1, and an outlet port;
supplying a predetermined amount of the relatively cold molten salt at least at the outlet port and at least at one location in-between the plurality of panels, as and when the temperature of the relatively hot molten salt circulating through the solar receiver arrangement exceeds the predetermined set temperature value of the relatively hot molten salt in order to maintain the predetermined set temperature value of the relatively hot molten salt exiting from the outlet port of the solar receiver arrangement for being stored to be utilized for producing electricity;
supplying the relatively cold molten salt upstream from a first temperature measuring point disposed at the outlet port to control the temperature of the molten salt to the predetermined set temperature value at the outlet port by:
(1) controlling a temperature of the hot molten salt at a second temperature point disposed at an inlet to panel N by regulation of a supply from second circuit disposed between an outlet from panel N−1 and the second temperature measurement point, and
(2) controlling a differential temperature across a third temperature measurement point disposed at an outlet from a panel N−1 upstream from the second temperature measurement point.

2. The method as claimed in claim 1 further comprising electronically controlling and checking supply of the predetermined amount of the relatively cold molten salt in order to maintain the predetermined set temperature value of the relatively hot molten salt exiting from the outlet port of the solar receiver arrangement.

3. The method as claimed in claim 1 further comprising electronically controlling and balancing,
the solar energy provided to the solar receiver arrangement, and
the flow of the relatively cold molten salt in the solar receiver arrangement in order to preclude exceeding of the relatively hot molten salt temperature above the predetermined set temperature value.

4. A molten salt solar tower system for capturing solar energy and controlling molten salt temperature, the molten salt solar tower system, comprising:
first and second storage tanks adapted to store molten salt, wherein the first storage tank is configured to store relatively cold molten salt, and the second storage tank is configured to store relatively hot molten salt at a predetermined set temperature value;
a solar receiver arrangement configured to receive solar energy from a solar source, the solar receiver arrangement having an inlet port, a plurality of panels from panel 1 to panel N, and an outlet port to enable the molten salt to flow therefrom;
a first circuit configured to supply the relatively cold molten salt from the first storage tank to the solar receiver arrangement to enable the relatively cold molten salt to be heated up to produce relatively hot molten salt at the predetermined set temperature value, and supply the relatively hot molten salt from the solar receiver arrangement to the second storage tank at the predetermined set temperature value;
a second circuit configured to supply a predetermined amount of the relatively cold molten salt in the first circuit, at least at the outlet port and at least at one location in-between the plurality of panels, when the temperature of the relatively hot molten salt circulating through the solar receiver arrangement exceeds the predetermined set temperature value in order to maintain the relatively hot molten salt exiting from the outlet port of the solar receiver arrangement at the predetermined set temperature value for being stored in the second storage tank;
a plurality of temperature measurement points in the first circuit to measure the temperature of the molten salt flowing though the solar receiver arrangement, wherein:
a first temperature measurement point is disposed at an outlet from panel N to detect the temperature of the hot molten salt at the outlet port;
a second temperature measurement point is disposed at an inlet to panel N;
a third temperature measurement point is disposed at an outlet from a panel N−1 upstream from the second temperature measurement point;

a supply from the second circuit is disposed between an outlet from panel N−1 and the second temperature measurement point; and
the predetermined set temperature value of the hot molten salt is maintained at the first temperature measurement point by (1) controlling temperature of the hot molten salt at the second temperature point by regulation of the supply from the second circuit, and (2) controlling a differential temperature across the third temperature measurement point.

5. The molten salt solar tower system as claimed in claim 4 further comprising a control logic arrangement configured to the first and second circuits wherein the control logic arrangement based on the temperature value of the relatively hot molten salt exceeding the predetermined set temperature value enables the relatively cold molten salt from the second circuit to flow in the first circuit at the position to maintain the relatively hot molten salt exiting the solar receiver arrangement at the predetermined set temperature value.

6. The molten salt solar tower system as claimed in claim 5 , wherein flow of the relatively cold molten salt from the second circuit to the first circuit is controlled via a valve arrangement, wherein the valve arrangement is electrically controlled by the control logic arrangement.

7. The molten salt solar tower system as claimed in claim 4 further comprising a controller unit configured to the first and second circuits, wherein the controller unit is configured to electronically control and balance,
the solar energy provided to the solar receiver arrangement, and
the flow of the relatively cold molten salt from the second circuit to the first circuit in order to preclude exceeding of the relatively hot molten salt temperature above the predetermined set temperature value.

Assignees

• Alstom Technology Ltd
• Alstom Technology Ltd

Inventors

• Joshi Abhinaya
• Mccombe James A
• Yang Shizhong

Classifications

• F03G6/06 Primary

  with solar energy concentrating means · CPC title

• Y02E70/30

  Systems combining energy storage with energy generation of non-fossil origin · CPC title

• F01K3/12 Primary

  having two or more accumulators · CPC title

• Y02E10/46

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

• F22B1/006

  using solar heat · CPC title