gistfile1.js

// ==UserScript==
// @name         My Fancy New Userscript
// @namespace    http://your.homepage/
// @version      0.1
// @description  enter something useful
// @author       You
// @match        http://tableau1.eocng.org/views/CallCenterLive/*
// @grant        none
// ==/UserScript==

var refresh = function() {
 var clickEvent  = document.createEvent ("HTMLEvents");
        clickEvent.initEvent ("click", true, true);
        $("span.tab-icon-refresh")[0].dispatchEvent (clickEvent);
  
    setTimeout(refresh, 15000);
};

setTimeout(refresh, 15000);