An air handling system for providing treated process air to air consumers, a method for controlling an air handling system and a computer program for an air handling system

Abstract

The disclosure relates to an air handling system (100) for providing treated process air to air consumers (S4a,S4b) the air handling system comprising: at least two air handling units (150a,150b) arranged in parallel, each air handling unit (150a,150b) comprising a dehumidifier (140a,140b), a carbon dioxide catcher (100a,100b) and a process air circuit (S1a,S1b); a collector circuit (S3) arranged to collect the treated process air from the at least two air handling units (150a,150b) and distribute it to the air consumers (S4a,S4b); and a master control unit (130) configured to control which of the air handling units (150a,150b) that are active based on a demand of volume of air per hour from the air consumers. The disclosure further relates to a method (200) for controlling an air handling system (100) and a computer program for an air handling system (100).

Description

[0001] An air handling system for providing treated process air to air consumers, a method for controlling an air handling system and a computer program for an air handling system

[0002] Technical field

[0003] The present disclosure relates to an air handling system for providing treated process air to air consumers, a method for controlling an air handling system and a computer program for an air handling system. More specifically, the disclosure relates to an air handling system for providing treated process air to air consumers, a method for controlling an air handling system and a computer program for an air handling system as defined in the introductory parts of the independent claims.

[0004] Background art

[0005] Carbon dioxide (CO2) is a major greenhouse gas contributing to global warming and climate change and various ways of capturing the gas have been developed over the years. Capturing the carbon dioxide, for example from industrial sources, helps reducing the amount of this gas released into the atmosphere, mitigating its impact on the environment. Different types of carbon dioxide capture material are known, for example covalent organic frameworks, metal-organic frameworks, activated carbon, zeolites and carbon nanotubes. Carbon dioxide capture materials are also good at adsorbing water vapor, which can compete with the capturing of carbon dioxide. Carbon dioxide catchers typically comprise one or more reactors with cassettes containing the carbon dioxide capture material. The reactor may also be referred to as an adsorbent and / or absorbent unit. Thus, the reactor is a unit configured to adsorb and / or absorb carbon dioxide in process air conducted through the reactor. Many carbon dioxide capture materials are also good at adsorbing water vapor, which can compete with the carbon dioxide adsorption. Carbon dioxide catcher systems using such materials therefore often comprise dehumidifiers upstream of the carbon dioxide catcher, such that the carbon dioxide capture material can focus on capturing the carbon dioxide more efficiently.

[0006] Summary

[0007] A consumer of dehumidified process air having low a carbon dioxide level may wish for more process air than a single unit comprising a dehumidifier and a carbon dioxide catcher, herein referred to as an air handling unit, can provide. The consumer must then use multiple air handling units to meet the need. It is an object of the present disclosure to mitigate, alleviate or eliminate one or more of the above-identified deficiencies and disadvantages in the prior art and solve at least the above-mentioned problem. In particular, it is an object of the present disclosure to provide solutions for coordination of multiple air handling units.

[0008] According to a first aspect there is provided an air handling system for providing treated process air to air consumers, the air handling system comprising: at least two air handling units arranged in parallel, each air handling unit comprising a dehumidifier, a carbon dioxide catcher and a process air circuit, wherein the dehumidifier is arranged to dehumidify process air upstream of the carbon dioxide catcher and the carbon dioxide catcher is configured to absorb carbon dioxide from the dehumidified process air; a collector circuit arranged to collect the treated process air from the at least two air handling units and distribute it to the air consumers; and a master control unit configured to control which of the air handling units that are active based on a demand of volume of air per hour from the air consumers.

[0009] The air handling system thereby enables connecting multiple air handling units to multiple consumers via a common collector circuit, which allows supply of process air according to demand. An additional technical effect and advantage is that the disclosed air handling system provides redundancy in that if there is a problem with an air handling unit that is currently providing process air, another air handling unit connected to the collector circuit can be activated and take over the responsibility of the air handling unit with the problem. A further technical effect and advantage is that downtime of the system due to maintenance or unexpected disturbances can be significantly reduced.

[0010] According to some examples, the master control unit is configured to control which of the air handling units that are active according to a sequence that sequentially activates available but inactive air handling units. The master control unit thereby scales the supply of process air by the capacity of each added air handling unit according to the demand from the air consumers using the sequentially activated air handling units to each supply process air until the demand is met.

[0011] Air handling units are considered active if they are contributing process air to the air consumers via the collector circuit, such as by opening a valve (active) or closing the valve (inactive), wherein the valve connects the process air circuits of the air handling unit to the collector circuit. Air handling units are considered available if they can be activated and contribute immediately to supply process air to the air consumers. For instance, an air handling unit that is switched off is not available, while an air handling unit that is up and running but not providing process air to the air consumers is considered available. Examples of criteria when the air handling unit is considered unavailable include: an alarm relating to a malfunction or performance problem of the carbon dioxide catcher 100a, 100b has been triggered; at least one valve configured to prevent process air to be provided to the collector air circuit S3 is closed; the carbon dioxide catcher 100a, 100b is not in an autonomous operating mode; the carbon dioxide catcher 100a, 100b is switched off; the process air from the dehumidifier 140a, 140b upstream of the carbon dioxide catcher is redirected such that no process air passes through the carbon dioxide catcher 150a, 150b; and a fan configured to regulate a flow speed of process air exceeds a predetermined operational threshold.

[0012] According to some examples, the air handling system comprises a pressure sensor configured to measure an air pressure in the collector air circuit, wherein the master control unit is further configured to obtain pressure data from the pressure sensor and to control the air handling units based on a difference between the obtained pressure data and a desired pressure set point value relating to the process air demand from the air consumers.

[0013] By monitoring the air pressure in the collector air circuit, the demand from the air consumers can be met without the air consumers having to transmit any data that specifies their demand. The air handling system can thereby be easily connected to various air consumers without the need for changing the systems of the air consumers.

[0014] According to some examples, each air handling unit comprises a process air diverter circuit arranged in fluid communication with the process air circuit downstream of the carbon dioxide catcher, and a valve configured to regulate the amount of process air being diverted from the process air circuit to the process air diverter circuit, wherein the master control unit is configured to control the valves. The process air diverter circuits and the valves facilitate regulation of the amount of process air being delivered by each air handling unit to the air consumers.

[0015] According to some examples, each air handling unit further comprises a dehumidifier control unit for controlling the dehumidifier and a carbon dioxide catcher control unit for controlling the carbon dioxide catcher.

[0016] In addition to controlling which of the air handling units that are active, the master control unit can control operational parameters of the air handling units that have an impact on the supply of process air to the air consumers, such as fan speeds and / or valves regulating air flow within, into and out of the air handling unit.

[0017] According to some examples, each air handling unit further comprises a shut-off valve arranged downstream of the carbon dioxide catcher and configured to prevent air from going back into inactive air handling units when closed and make the air handling unit active when open.

[0018] According to a second aspect there is provided a method for controlling an air handling system according to the first aspect, wherein the method comprises: determining a demand of volume of air from the air consumers; and controlling which of the air handling units that are active based on the demand from the air consumers. The method performs the same functions as the disclosed air handling system of the first aspect and therefore has all the same technical effects and advantages.

[0019] According to some examples, controlling which of the air handling units that are active further comprises: obtaining pressure data from a pressure sensor configured to measure an air pressure in the collector air circuit; and controlling which of the air handling units that are active based on a difference between the obtained pressure data and a desired pressure set point value relating to the process air demand from the air consumers.

[0020] According to some examples, the master control unit is configured to control which of the air handling units that are active according to a sequence that sequentially activates available but inactive air handling units.

[0021] According to a third aspect there is provided a computer program for an air handling system comprising at least two air handling units, a collector circuit and a master control unit with a processor, the computer program comprising computer-readable instructions which, when executed by the processor, causes the air handling system to carry out the steps of the method of the second aspect. The computer program implements the method according to the second aspect and has the corresponding technical effects and advantages.

[0022] According to a fourth aspect there is provided a computer program product for an air handling system according to the first aspect, the computer program product comprising a non-transitory computer-readable storage medium having thereon a computer program comprising program instructions, the computer program being loadable into a processor and configured to cause the processor to perform the method for method for controlling an air handling system according to the first aspect. Effects and features of the second and third aspects are to a large extent analogous to those described above in connection with the first aspect. Examples mentioned in relation to the first aspect are largely compatible with the second and third aspects.

[0023] The present disclosure will become apparent from the detailed description given below. The detailed description and specific examples disclose preferred examples of the disclosure by way of illustration only. Those skilled in the art understand from guidance in the detailed description that changes and modifications may be made within the scope of the disclosure.

[0024] Hence, it is to be understood that the herein disclosed disclosure is not limited to the particular component parts of the device described or steps of the methods described since such device and method may vary. It is also to be understood that the terminology used herein is for purpose of describing particular examples only, and is not intended to be limiting. It should be noted that, as used in the specification and the appended claim, the articles "a", "an", "the", and "said" are intended to mean that there are one or more of the elements unless the context explicitly dictates otherwise. Thus, for example, reference to "a unit" or "the unit" may include several devices, and the like. Furthermore, the words "comprising", "including", "containing" and similar wordings does not exclude other elements or steps.

[0025] We will herein refer to air handling units being active if they are contributing process air to the air consumers via the collector circuit. In most examples, this is implemented by opening a valve (active) or closing the valve (inactive), wherein the valve connects the process air circuits of the air handling unit to the collector circuit.

[0026] Brief of the

[0027] The above objects, as well as additional objects, features and advantages of the present disclosure, will be more fully appreciated by reference to the following illustrative and non-limiting detailed description of example embodiments of the present disclosure, when taken in conjunction with the accompanying drawings.

[0028] Figure 1 shows a schematic illustration of the disclosed air handling system; and

[0029] Figure 2 shows the disclosed method for controlling an air handling system. Detailed

[0030] The present disclosure will now be described with reference to the accompanying drawings, in which preferred examples of the disclosure are shown. The disclosure may, however, be embodied in other forms and should not be construed as limited to the herein disclosed embodiments. The disclosed examples are provided to fully convey the scope of the disclosure to the skilled person.

[0031] Figure 1 shows a schematic illustration of the disclosed air handling system 100 for providing treated process air to air consumers S4a, S4b.The air handling system 100 comprises at least two air handling units 150a, 150b arranged in parallel. Each air handling unit 150a, 150b comprises a dehumidifier 140a, 140b, a carbon dioxide catcher 100a, 100b and a process air circuit Sla, Sib, wherein the dehumidifier 140a, 140b is arranged to dehumidify process air upstream of the carbon dioxide catcher 100a, 100b and the carbon dioxide catcher 100a, 100b is configured to absorb carbon dioxide from the dehumidified process air. The air handling system 100 further comprises a collector circuit S3 arranged to collect the treated process air from the at least two air handling units 150a, 150b and distribute it to the air consumers S4a, S4b. The air handling system 100 also comprises a master control unit 130 configured to control which of the air handling units 150a, 150b that are active based on a demand from the air consumers. Each dehumidifier 140a, 140b and a carbon dioxide catcher 100a, 100b will typically also be connected to respective regeneration air circuits S5a, S5b, S6a, S6b, which are indicated in Fig.l for clarity though they do not constitute an essential technical feature for the subject matter of the present disclosure.

[0032] The air handling system 100 thereby enables connecting multiple air handling units 150a, 150b to multiple consumers S4a, S4b via a common collector circuit S3, which allows supply of process air according to demand. As the air consumers S4a, S4b require more or less process air, the master control unit 130 can activate or deactivate air handling units 150a, 150b as needed. If there is a need to deactivate an active air handling unit, for instance due to maintenance or a disturbance, the master control unit 130 can deactivate that air handling unit and activate another. The disclosed air handling system 100 thereby provides redundancy. The potential downtime of the air handling system 100 due to maintenance or unexpected disturbances can be significantly reduced.

[0033] The amount of process air provided to the air consumers S4a, S4b can be measured directly or indirectly. Examples of direct measurements include measuring the volume of process air being transported to the air consumers, for example by using at least one anemometer. Examples of indirect measurements include fan speeds that correlate with process air flow, and / or pressure measurements in the collector circuit S3.

[0034] Thus, according to some examples the air handling system 100 comprises a pressure sensor 110 configured to measure an air pressure in the collector air circuit S3, wherein the master control unit 130 is further configured to obtain pressure data from the pressure sensor 110 and to control the air handling units 150a, 150b based on a difference between the obtained pressure data and a desired pressure set point value relating to the process air demand from the air consumers.

[0035] By using a pressure sensor 110 and providing process air based on the difference between the obtained pressure data and the desired pressure set point value, the need for the air consumers S4a, S4b to provide information of how much process air is needed is removed, thereby allowing existing air consumer systems to be used without further modification.

[0036] In some examples each air handling unit 150a, 150b further comprises a dehumidifier control unit 142a, 142b for controlling the dehumidifier 140a, 140b and a carbon dioxide catcher control unit 102a, 102b for controlling the carbon dioxide catcher 100a, 100b.

[0037] This provides the master control unit 130 of the air handling system 100 more freedom to adjust the process air provided to the collector circuit S3. In particular, it facilitates coordination of air handling units having different types of internal configurations.

[0038] According to some examples each air handling unit 150a, 150b further comprises a shut-off valve 160a, 160b arranged downstream of the carbon dioxide catcher and configured to prevent air from going back into inactive air handling units when closed and make the air handling unit active when open.

[0039] According to some examples, the master control unit 130 is configured to control which of the air handling units that are active according to a sequence that sequentially activates available but inactive air handling units.

[0040] By sequence we herein mean an ordered list in which available but inactive air handling units are to be activated sequentially based on air consumer S4a, S4b demand. An example illustrating the principle behind sequentially activating available but inactive air handling units is provided below. The numbers for demand and provided air flow are for illustrative purposes only and are not meant to be limiting. Consider a situation where each air consumer S4a, S4b demands at minimum 4100 m3 / h (cubic meters per hour) and requests the minimum demand multiplied by a safety factor adding twenty percent. The demand from the air handling system 100 from each air consumer S4a, S4b thereby being 4920 m3 / h. For illustrative purposes, let's further assume that each air handling unit 150a, 150b provides 8200 m3 / h of treated process air. A single air consumer will then request 4920 m3 / h, which can be supplied by a single air handling unit. Two air consumers will require 9840 m3 / h, thereby exceeding what a single air handling unit can provide. Thus, the next air handling unit in the sequence is activated. In examples implementing activation via shut-off valves 160a, 160b, as described above, the shut-off valve of the next air handling unit in the sequence is opened. If a third air consumer is added, the total demand from the air handling system 100 will be 14760 m3 / h, for which two air handling units 150a, 150b supplying a total of 16400 m3 / h is still sufficient. If a fourth air consumer is added, the total demand of treated process air increases to 19680 m3 / h for which a third air handling unit must be activated, and so on.

[0041] An air handling unit 150a, 150b is not available if its carbon dioxide catcher 100a, 100b meets a predetermined unavailability criterion. In some examples, the predetermined unavailability criterion comprises that an alarm relating to a malfunction or performance problem of the carbon dioxide catcher 100a, 100b has been triggered. In some examples, the predetermined unavailability criterion comprises that at least one valve configured to prevent process air to be provided to the collector air circuit S3 is closed. In some examples, the predetermined unavailability criterion comprises the carbon dioxide catcher 100a, 100b not being in an autonomous operating mode. In some examples, the predetermined unavailability criterion comprises the carbon dioxide catcher 100a, 100b being switched off. In some examples, the predetermined unavailability criterion comprises the process air from the dehumidifier 140a, 140b upstream of the carbon dioxide catcher being redirected such that no process air passes through the carbon dioxide catcher 150a, 150b. In some examples, the predetermined unavailability criterion comprises a fan configured to regulate a flow speed of process air exceeds a predetermined operational threshold. According to some further examples, the air handling system 100 is further configured to signal to the master control unit 130 if any carbon dioxide catcher 150a, 150b meets the predetermined unavailability criterion.

[0042] Figure 2 shows the disclosed method 200 for controlling an air handling system 100. The air handling system 100 is configured as disclosed in Figure 1. The method 200 comprises: determining S100 a demand from the air consumers and controlling S200 which of the air handling units 150a, 150b that are active based on the demand from the air consumers. The method 200 thereby performs the functionality of the air handling system described in relation to Figure 1 above, with all the associated technical effects and advantages.

[0043] In some examples, controlling S200 which of the air handling units that are active further comprises: obtaining S110 pressure data from a pressure sensor 210 configured to measure an air pressure in the collector air circuit S3; and controlling S200 which of the air handling units 150a, 150b that are active based on a difference between the obtained pressure data and a desired pressure set point value relating to the process air demand from the air consumers.

[0044] By basing the selection of active air handling units on the pressure data, the air consumers do not need to provide any additional control signals if there is a change in demand; any change in pressure will indicate the change in demand and the master control unit of the air handling system can activate or deactivate air handling units accordingly.

[0045] The person skilled in the art realizes that the present disclosure is not limited to the preferred examples described above. The person skilled in the art further realizes that modifications and variations are possible within the scope of the appended claims. Additionally, variations to the disclosed examples can be understood and effected by the skilled person in practicing the claimed disclosure, from a study of the drawings, the disclosure, and the appended claims.

Claims

CLAIMS1. An air handling system (100) for providing treated process air to air consumers (S4a, S4b), the air handling system comprising: at least two air handling units (150a, 150b) arranged in parallel, each air handling unit (150a, 150b) comprising a dehumidifier (140a, 140b), a carbon dioxide catcher (100a, 100b) and a process air circuit (Sla, Sib), wherein the dehumidifier (140a, 140b) is arranged to dehumidify process air upstream of the carbon dioxide catcher (100a, 100b) and the carbon dioxide catcher (100a, 100b) is configured to absorb carbon dioxide from the dehumidified process air; a collector circuit (S3) arranged to collect the treated process air from the at least two air handling units (150a, 150b) and distribute it to the air consumers (S4a, S4b); and a master control unit (130) configured to control which of the air handling units (150a, 150b) that are active based on a demand of volume of air per hour from the air consumers.

2. The air handling system (100) according to claim 1, further comprising a pressure sensor (110) configured to measure an air pressure in the collector air circuit (S3), wherein the master control unit (130) is further configured to obtain pressure data from the pressure sensor (110) and to control the air handling units (150a, 150b) based on a difference between the obtained pressure data and a desired pressure set point value relating to the process air demand from the air consumers.

3. The air handling system (100) according to claim 1 or 2, wherein each air handling unit (150a, 150b) further comprises a dehumidifier control unit (142a, 142b) for controlling the dehumidifier (140a, 140b) and a carbon dioxide catcher control unit (102a, 102b) for controlling the carbon dioxide catcher (100a, 100b).

4. The air handling system (100) according to any of the preceding claims, wherein each air handling unit further comprises a shut-off valve (160a, 160b) arranged downstream ofthe carbon dioxide catcher and configured to prevent air from going back into inactive air handling units when closed and make the air handling unit active when open.

5. The air handling system (100) according to any of the preceding claims, wherein the master control unit (130) is configured to control which of the air handling units that are active according to a sequence that sequentially activates available but inactive air handling units.

6. A method (200) for controlling an air handling system (100) according to any one of the preceding claims, wherein the method comprises: determining (S100) a demand of volume of air per hour from the air consumers, and controlling (S200) which of the air handling units (150a, 150b) that are active based on the demand from the air consumers.

7. The method (200) according to claim 6, wherein controlling (S200) which of the air handling units (150a, 150b) that are active comprises: obtaining (S110) pressure data from a pressure sensor (210) configured to measure an air pressure in the collector air circuit (S3); and controlling (S200) which of the air handling units (150a, 150b) that are active based on a difference between the obtained pressure data and a desired pressure set point value relating to the process air demand from the air consumers.

8. A computer program for an air handling system (100) comprising at least two air handling units (150a, 150b), a collector circuit (S3) and a master control unit (130) with a processor (132), the computer program comprising computer-readable instructions which, when executed by the processor (132), causes the air handling system (100) to carry out the steps of the method of any one of the claims 6-7.

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