Method and apparatus for solar energy storage system using gas and rock

Abstract

A method and Apparatus for solar energy storage system uses gas for thermal transport for central tower solar thermal electric power plant to provide high quality, low cost, and continuously electric power generation. The storage contains a number of storage modules that each module can store energy for a given period of time. The thermal energy from central tower charges the modules one by one during the sunny time, while the thermal electric power plant discharge the modules one by one as long as it works. A control and a connection valve system control and connect the charge and discharge modules with the central tower and the power plant according to pre-arranged sequences. Fans at the cool side of the storage system push the circulation gas into the central tower or the thermal storage modules. In the discharge system, the hot gas from storage system is send to the heat exchange system, and to generate steam and to super heat steam for the power plant. In the charge system, the cold gas is pushed into the central receiver thermal exchange unit and to be heated, and the hot gas is then circulated back to storage system to charge up the storage system.

1 . A solar energy thermal storage system contains at the least two thermal storage modules and a thermal storage charge system and discharge system;
 (a) A thermal storage module is made of small rocks in a large sealed, thermal isolated container for thermal storage and gas freely flow between rocks for the thermal transport;   (b) A thermal charge system and discharge system can select to charge and discharge thermal storage modules at the same time, and are controlled by the thermal storage charge and discharge controller;   (c) A charge and discharge controller is programmed in such a way that allows the maximizing the thermal energy storage from central solar tower while discharge the thermal energy to the power plant as smooth as possible;   (d) A monitoring system for charge and discharge system with sensors is monitoring the temperature of the rocks, the gas, and as well the pressure, and the contaminations of the gas;   (e) A filter system in the gas loop is used to filtering out the dusts or other un-wanted compounds of the gas;   (f) An heat exchanger with the hot liquid metal transport solar thermal energy from the solar central receiver on one side is heating the charging gas on the other side;   (g) A gas loop circulation fan is installed at the cool side of the charging gas loop and another is installed at the cool side of the discharging loop;   
     
     
         2 . The solar energy thermal storage system of  claim 1  wherein said thermal storage modules means a large size container filled with rocks of suitable sizes with cool gas in and out pipe from one side and hot gas in and out pipe from another side, and covered with thermal isolation material. The cold gas pipe and hot gas pipe of the container are connected with valves that the storage unit can switch the connections between the charge and discharge system, 
     
     
         3 . The solar energy thermal storage system of  claim 1  wherein said a charge system has hot side and cold side pipes and valves which allow each storage unit connect to or cut off from the charge system, and at the cold side, a fan blows the cooler gas to the central solar tower receiver's heat exchange and push the hot gas out from the hot side of the exchange, and circulating back to thermal storage unit's hot side; 
     
     
         4 . The solar energy thermal storage system of  claim 1  wherein said a discharge systems have hot side and cold side pipes and valves which allow each storage unit connect to or cut off from the discharge system, and at the cold side, a fan flows cooler gas to thermal storage and push the hot gas out from the hot side of the thermal storage unit and send to the heat exchange of the power plant for power generation; 
     
     
         5 . The solar energy thermal storage system of  claim 1  wherein said a thermal storage charge and discharge controller contains electric valves, computers, and sensors, and sensors monitoring the status of the thermal storage units, computers analyzing the data from the sensors, and valves connect the thermal storage units on or off or partial open and partial close from the charge system and on or off from the discharge system; 
     
     
         6 . The solar energy thermal storage system of  claim 1  wherein said a discharge systems have filters installed at the output of the system to protect the heat exchangers. The filters filter dusts being based on gravity and centrifuge force.