WO2014164799A1

WO2014164799A1 - Water extractor

Info

Publication number: WO2014164799A1
Application number: PCT/US2014/023513
Authority: WO
Inventors: Paul Dinnage
Original assignee: Munters Corporation
Priority date: 2013-03-12
Filing date: 2014-03-11
Publication date: 2014-10-09

Abstract

A water extraction method and moisture extraction system are disclosed. Water is removed from the water vapor laden exhaust of a gas turbine electrical generator by first increasing the concentration of water vapor in that exhaust stream while passing it through a desiccant means to regenerate the desiccant and remove water from the desiccant. The exhaust stream exits the desiccant at a lower temperature and higher vapor content level, and is then passed through one or more heat exchangers to further lower the temperature of the exhaust stream and condense water vapor out of the stream. The condensed water from the heat exchanger is collected and used for other purposes. The turbine exhaust leaving the heat exchanger is then passed through the adsorption region of the desiccant device to transfer water vapor remaining therein to the desiccant to dry the exhaust air stream before exhausting it to the atmosphere.

Description

TITLE WATER EXTRACTOR

BACKGROUND OF THE INVENTION

FIELD OF THE INVENTION

[0001] Modern data centers for large scale computers and/or servers are trending to be powered, in whole or in part, for various reasons, with gas turbine generated electrical power. Much of the reasoning for the use of gas turbines is aimed at reducing the environmental footprint of such facilities. To that end, gas turbines generate substantial quantities of waste heat that could potentially be used for water generation, absorption cooling and other processes using thermodynamic heat exchange.

BRIEF DESCRIPTION OF INVENTION

[0002] In accordance with the present invention water is removed from the water vapor laden exhaust of a gas turbine electrical generator by first increasing the concentration of water vapor in that exhaust stream while passing it through a desiccant means, such as a rotary desiccant wheel, to regenerate the desiccant and remove water from the desiccant. The exhaust stream exits the desiccant at a lower temperature and higher vapor content level, and is then passed through one or more heat exchangers to further lower the temperature of the exhaust stream and condense water vapor out of the stream. This can be done with, for example, a cross flow heat exchanger using ambient air. The condensed water from the heat exchanger is collected and used for other purposes, such as for evaporatively cooling other heat loads in the data center, e.g. the electrical heat load produced by the gas turbine generator.

[0003] The turbine exhaust leaving the heat exchanger is then passed through the adsorption region of the desiccant device to transfer water vapor remaining therein to the desiccant to dry the exhaust air stream before exhausting it to the atmosphere.

DESCRIPTION OF DRAWINGS

Figure 1 is a schematic view of a water extraction system according to the present invention;

Figure 2 is a psychometric chart of the operation of the system of Figure 1 in one embodiment; and

Figure 3 is a state point and process report for the system whose operation is depicted in Figure 2.

DETAILED DESCRIPTION

[0004] Referring now to Figure 1, exhaust air containing water vapor from a gas turbine electrical generator which may or may not be precooled, at a temperature range of 200°F or more, is supplied to a desiccant means, such as a conventional rotary desiccant wheel 12. Other forms of desiccant means or systems may be used as would occur to those skilled in the art.

[0005] The exhaust air stream A acts as a regeneration air stream in a regeneration section of the desiccant system. In passing through the regeneration section of the desiccant means the turbine exhaust air (or supply air stream) is cooled and its moisture content is increased.

[0006] After leaving the regeneration section of the desiccant means the exhaust air stream is supplied to one or more heat exchangers 14. In one embodiment the heat exchangers may be cross flow heat exchangers. As illustrated in the embodiment of Figure 2, two such heat exchangers are used. A cooling ambient or outside air stream B is supplied to the heat exchangers to cool the exhaust air stream and condense water vapor from the exhaust air stream. Although Figure 2 illustrates the use of two cross flow heat exchangers it is also contemplated that a single oversized heat exchanger or one or more counterflow heat exchangers can be used instead.

[0007] As seen in Figure 1 , the exhaust air stream enters the first heat exchanger 14 (HX-2), then passes to the second heat exchanger 14 (HX-1) and is then returned to the adsorption section of desiccant means 12. The outside air stream (having a temperature of 65 °F in this illustrative embodiment) first enters HX-1 and then enters HX-2, in both cases passing in cross flow heat exchange relationship with the exhaust air stream A. As a result water vapor condenses in the heat exchangers and is collected in a receptacle 16 for later use, e.g. in evaporative cooling of another heat load. Thus both the temperature and water content of the exhaust air stream A is reduced, while the temperature of the cooling outside air stream is increased, before it is exhausted to the atmosphere.

[0008] As the exhaust air stream A passes through the adsorption section of the desiccant means, the desiccant removes moisture from that air stream and increases its temperature before it too is exhausted to the atmosphere.

[0009] In the illustrative embodiment assuming 13, 100 SCFM of pre -cooled natural gas turbine exhaust at 200 deg F and at a moisture level of 160 gr/lb (e.g. from a IMW turbine) the system of the present invention can produce almost 700 lb/hr of water whenever the ambient dry bulb temperature is 65°F or lower.

Claims

WHAT IS CLAIMED IS:

1. A water extraction method comprising the steps of:

supplying a hot water vapor laden stream of gas turbine exhaust air to a regeneration section of a desiccant means to regenerate the desiccant means while increasing the water vapor content of the exhaust air stream;

supplying the exhaust air stream from the desiccant' s regeneration section to heat exchanger means;

condensing water vapor from the exhaust air stream in the heat exchanges means while also reducing its temperature;

then supplying the cooled and dried exhaust air stream from the heat exchanger to the adsorption section of the desiccant means; and

reducing the moisture content and increasing the temperature of the exhaust air stream in said adsorption section of the desiccant means.

2. A moisture extraction system comprising:

desiccant means having a regeneration section and an adsorption section for removing moisture in the regeneration section from an air stream and decreasing its temperature and for decreasing the moisture content of the exhaust air stream and increasing its temperature in the adsorption section;

heat exchanger means for receiving the exhaust air stream leaving the regeneration section of the desiccant means, removing moisture from the exhaust air stream by condensing the same, while also reducing its temperature, then

supplying the exhaust air stream from the heat exchanger means to the adsorptions sections of the desiccant means; and

means for collecting water condensation from the heat exchanger for use elsewhere.