TECHNICAL FIELD
[1] The present disclosure relates to the field of pressure reduction devices. Particularly, the present disclosure relates to a pressure reduction device and a heat recovery unit for the pressure reduction device.
BACKGROUND OF THE DISCLOSURE
[2] The information in this section merely provides background information related to the present disclosure and may not constitute prior art(s) for the present disclosure.
[3] In process industries, ejectors are well known in the art. The ejectors work by accelerating a high pressurized stream (motive fluid) through a nozzle that converts the pressure of the steam into a velocity of the steam. Generally, boilers are used in the process industries to generate steam at high pressure and high temperature. The steam can be either saturated or superheated where superheated steam has temperature above saturation level. The high-pressurized steam occupies less volume than the steam at atmospheric or low pressure, thus, requiring pipes having small diameters to transfer high-pressurized steam from the boiler to the other equipment in the process industries. The superheated steam contains high energy that may be utilized for various applications like driving the steam turbines, motive fluid in ejectors etc.
[4] Typically, the process industries utilize steam at low pressure and low temperature compared to steam generated in boilers and sometimes at saturated conditions, primarily due to various reasons viz. heat transfer efficiency, size and thickness of equipment etc., that are caused to keep the installation (CAPEX) and operation costs lower. Saturated steam has the highest heat transfer compared to superheated steam as the latent heat is transferred.
[5] In some process industries, there may be various process units in which steam, boiler feed water, and power are required and produced at various locations. The steam pressure and temperature for each process unit of the process units may be the same or different depending on the type of operations being performed thereon. The steam may be produced across the process unit at various locations in the waste heat boilers. The waste heat boilers produce the steam by heating boiler feed water. The boiler feed water may be heated through waste heat generated during different operations of the process

units. However, the steam produced through the waste heat boilers may not be able to meet the entire load of the process units. Therefore, the steam is generated with high pressure and in a superheated state at a centralized location from where the steam can be readily distributed to all the process units. The steam is generated close to a boiler house and distributed to the individual process unit therefrom. The boiler house includes a plurality of boilers to generate steam. The steam is sometimes reduced and conditioned to the desired operating pressure and temperature. The steam is generated with a single pressure level or maybe more than one based on a steam system design. Mainly, terminologies such as HP steam, MP, steam, and LP steam are used in the process industries, where HP steam stands for High-pressure steam, MP steam stands for Medium-pressure steam, and LP steam stands for Low-pressure steam. These terminologies are defined based on the level of pressure of the steam that is generated and utilized in the process industries.
[6] The devices that are configured to reduce the pressure of the steam from high pressure to medium or low pressure or any intermediate pressure level therebetween are called pressure reduction devices. In some configurations, the pressure reduction devices are also centrally located close to the boiler house where the steam is generated. The steam produced in the boiler is reduced within the boiler house to individual steam levels and distributed in respective steam headers across a process industry. The pressure reduction devices may be distributed across the process industry or even simply at the place of their application. The pressure reduction device is thus required to reduce the high pressure to desired pressure for different operations.
[7] The pressure reduction valve may also be referred to as a pressure regulator valve. The pressure regulator valve utilizes spring pressure against a diaphragm to open the valve. As the pressure at the outlet drops below the pre-defined pressure, the spring pressure overcomes the outlet pressure and forces a valve stem downward and the valve opens up respectively. Additionally, there is another device i.e. the Pressure Reducing and De-Superheating System (PRDS) configured for conditioning the steam through the reduction in pressure and temperature of the steam. The PRDS has a control valve and atomizing nozzles. The control valve is provided to reduce the pressure of the steam and the atomizing nozzles are provided to control the temperature of the steam.

[8] During operation in the process unit, boiler feed water is sprayed into the steam after pressure reduction for reducing the temperature to meet downstream requirements. As the process is isenthalpic, the mass of the steam goes up as the additional mass of boiler feed water adds up to the total mass of the steam. The above-mentioned conventional devices are widely used in the process industries for the purpose of pressure reduction and/or de-superheating. However, conventional pressure reduction devices are associated with several shortcomings such as these devices having moving parts, thereby the chances of failure are more. Further, these devices serve issues such as blockage of the valve thus restricting steam flow compared to the design flow, degradation of components due to significant forces acting on them, continuous leakages, etc.
[9] Further, the steam is generally produced at saturation conditions in waste heat boilers, and the steam is further super-heated before transferring the steam to other locations through steam pipelines as condensation happens due to heat loss in the steam pipelines and thus chances of water hammering and loss of valuable steam. Generally, steam traps are used to remove the condensate to save the steam in the steam pipelines, however, this is a loss of valuable condensate which sometimes proves to be difficult to recover. To generate sensible heat, a superheater requires a temperature source that can raise the temperature of the steam above the saturation temperature of the steam. Further, this process requires a large size of device to transfer the sensible heat, and heat transfer occurs when the heat transfer medium is in the gas phase.
[10] With increasing energy costs, process industries try to recover as much energy as possible that is economically viable. However, due to poor economics, heat at a low level is generally discarded. The recovery of the low-level heat may reduce energy consumption and saves additional costs which are required for discarding the low-level heat in cooling towers, air coolers etc. Further, the low-level heat recovery reduces greenhouse gases as most of the energy required is sourced from fossil fuels. There are various techniques used in the process of low-level heat recovery. However, conventional low-level heat recovery systems are capital extensive and thus not readily adopted by process industries.

[11] The present disclosure is directed to overcome one or more limitations stated above or any other limitations associated with the prior art.
SUMMARY OF THE DISCLOSURE
[12] The one or more shortcomings of the prior art are overcome by the system/assembly as claimed, and additional advantages are provided through the provision of the system/assembly/method as claimed in the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.
[13] In one non-limiting embodiment of the present disclosure, a pressure reduction device with heat recovery system is disclosed. The device includes a first nozzle having a first inlet and a first outlet, a second nozzle having a second inlet and a second outlet. The second inlet fluidly is connected to the first outlet to flow a steam between the first inlet and the second outlet. The device includes a heat recovery unit comprising a heat recovery chamber enclosing at least one portion of the first nozzle and at least one portion of the second nozzle. The heat recovery chamber is defined with an inlet and an outlet. The heat recovery chamber is configured to receive a heating medium fluid from the inlet for flowing over an outer surface of said at least one portion of the first nozzle and said at least one portion of the second nozzle to exchange heat between said heating medium fluid and the steam flowing between the first inlet and the second outlet.
[14] In an embodiment of the present disclosure, the first nozzle includes a first converging region having the first inlet, a first throat region fluidly connected to the first converging region, and a first diverging region having the first outlet and fluidly connected to the first throat region.
[15] In an embodiment of the present disclosure, the second nozzle includes a second converging region having the second inlet, a second throat region fluidly connected with the second converging region, and a second diverging region having the second outlet and fluidly connected with the second throat region.

[16] In an embodiment of the present disclosure, the device comprises a plurality of extended surfaces extending radially outwardly from the outer surface of the at least one portion of the first nozzle and the at least one portion of the second nozzle.
[17] In another non-limiting embodiment of the present disclosure, a heat recovery unit is disclosed. The heat recovery unit includes a heat recovery chamber that is defined with an inlet and an outlet. The heat recovery chamber encloses at least one portion of a first nozzle and at least one portion of a second nozzle of the pressure reduction device. The heat recovery chamber is configured to receive a heating medium fluid from the inlet for flowing over an outer surface of said at least one portion of the first nozzle and said at least one portion of the second nozzle to exchange heat between said heating medium fluid and a steam flowing through the at least one portion of the first nozzle and the at least one portion of the second nozzle.
[18] In an embodiment of the present disclosure, the heat recovery chamber encloses at least one portion of each of a first diverging region of the first nozzle, a second converging region and a second throat region of the second nozzle.
[19] In an embodiment of the present disclosure, the heat recovery chamber is positioned coaxially to the first nozzle and the second nozzle.
[20] In an embodiment of the present disclosure, comprising a plurality of extended surfaces extending radially outwardly from the outer surface of the at least one portion of the first nozzle and the at least one portion of the second nozzle.
[21] In another non-limiting embodiment of the present disclosure, a multistage pressure reduction device is disclosed. The device includes a plurality of pressure reduction devices. Each pressure reduction device of the plurality of pressure reduction devices includes a first nozzle having a first inlet and a first outlet, a second nozzle having a second inlet and a second outlet, the second inlet fluidly connected to the first outlet to flow a steam between the first inlet and the second outlet, a heat recovery unit comprising a heat recovery chamber enclosing at least one portion of the first nozzle and at least one portion of the second nozzle, the heat recovery chamber is defined with an inlet and an outlet, the heat recovery chamber is configured to receive a heating

medium fluid from the inlet for flowing over an outer surface of said at least one portion of the first nozzle and at least one portion of the second nozzle to exchange heat between said heating medium fluid and the steam flowing between the first inlet and the second outlet. The outlet of the heat recovery chamber of one pressure reduction device of the plurality of pressure reduction devices is fluidly connected to the inlet of the heat recovery chamber of the other pressure reduction device of the plurality of pressure reduction devices to flow the heating medium fluid from the outlet of the heat recovery chamber of said one pressure reduction device to the inlet of the heat recovery chamber of the other pressure reduction device.
[22] In an embodiment of the present disclosure, the second outlet of one pressure reduction device of the plurality of pressure reduction devices is fluidly connected to the first inlet of the other pressure reduction device of the plurality of pressure reduction devices to flow the steam from the second outlet of said one pressure reduction device to the first inlet of the other pressure reduction device.
[23] It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined together to form a further embodiment of the disclosure.
[24] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[25] The novel features and characteristics of the disclosure are set forth in the description. The disclosure itself, however, as well as a preferred mode of use, further objectives, and advantages thereof, will best be understood by reference to the following description of an illustrative embodiment when read in conjunction with the accompanying drawings. One or more embodiments are now described, by way of example only, with reference to the accompanying drawings wherein like reference numerals represent like elements and in which:

[26] Figure 1 illustrates a schematic view of a pressure reduction device with heat recovery system, according to an embodiment of the present disclosure;
[27] Figure 2 illustrates a schematic view of the pressure reduction device with heat recovery system of Figure 1 including a plurality of extended surfaces, according to an embodiment of the present disclosure;
[28] Figure 3 illustrates a schematic view of a multistage pressure reduction device including two pressure reduction devices fluidly connected to each other to transfer a heat medium fluid from one pressure reduction device to the other pressure reduction device, according to an embodiment of the present disclosure; and
[29] Figure 4 illustrates a schematic view of a multistage pressure reduction device including transferring a steam from one pressure reduction device to the other pressure reduction device, according to an embodiment of the present disclosure.
[30] Skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the drawings may be exaggerated relative to other elements to help improve understanding of embodiments of the present disclosure.
DETAILED DESCRIPTION
[31] While the disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the Figures and are described in detail below. However, it should be understood that it is not intended to limit the disclosure to the particular forms disclosed, on the contrary, the disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure as defined by the appended claims.
[32] Before describing detailed embodiments, it may be observed that the novelty and inventive step that are in accordance with the present disclosure resides in a pressure reduction device with heat recovery system, a heat recovery unit, and a multistage pressure reduction device. It is to be noted that a person skilled in the art can be motivated by the present disclosure and modify the various constructions of the

device. However, such modification should be construed within the scope of the present disclosure. Accordingly, the drawings show only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.
[33] In the present disclosure, the term "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.
[34] The terms "comprises", "comprising", or any other variations thereof, are intended to cover non-exclusive inclusions, such that a device that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such setup or device. In other words, one or more elements in a system or apparatus proceeded by "comprises... " does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus.

We claim:

1. A pressure reduction device with heat recovery system (1), the device (1)
comprising:
a first nozzle (3) having a first inlet and a first outlet;
a second nozzle (7) having a second inlet and a second outlet, the second inlet fluidly connected to the first outlet to flow a steam (2) between the first inlet and the second outlet,
a heat recovery unit (100) comprising a heat recovery chamber (11) enclosing at least one portion of the first nozzle (3) and at least one portion of the second nozzle
(7),
wherein the heat recovery chamber (11) is defined with an inlet (12) and an outlet (13),
wherein the heat recovery chamber (11) is configured to receive a heating medium fluid (15) from the inlet (12) for flowing over an outer surface of said at least one portion of the first nozzle (3) and said at least one portion of the second nozzle (13) to exchange heat between said heating medium fluid (15) and the steam (2) flowing between the first inlet and the second outlet.
2. The device (1) as claimed in claim 1, wherein the first nozzle (3) comprises:
a first converging region (4) having the first inlet,
a first throat region (5) fluidly connected to the first converging region (4), and a first diverging region (6) having the first outlet and fluidly connected to the first throat region (5).
3. The device (1) as claimed in claim 1, wherein the second nozzle (7) comprises:
a second converging region (8) having the second inlet,
a second throat region (9) fluidly connected with the second converging region (8), and
a second diverging region (10) having the second outlet and fluidly connected with the second throat region (9).

4. The device (1) as claimed in claim 1, comprising a plurality of extended surfaces (16) extending radially outwardly from the outer surface of the at least one portion of the first nozzle (3) and the at least one portion of the second nozzle (7).
5. A heat recovery unit (100) for a pressure reduction device (1), the unit (100) comprising:
a heat recovery chamber (11) defined with an inlet (12) and an outlet (13), wherein the heat recovery chamber (11) encloses at least one portion of a first nozzle (3) and at least one portion of a second nozzle (7) of the pressure reduction device (1),
wherein the heat recovery chamber (11) is configured to receive a heating medium fluid (15) from the inlet (12) for flowing over an outer surface of said at least one portion of the first nozzle (3) and said at least one portion of the second nozzle (7) to exchange heat between said heating medium fluid (15) and a steam (2) flowing through the at least one portion of the first nozzle (3) and the at least one portion of the second nozzle (7).
6. The unit (100) as claimed in claim 5, wherein the heat recovery chamber (11)
encloses at least one portion of each of a first diverging region (6) of the first nozzle
(3), a second converging region (8) and a second throat region (9) of the second nozzle
(7).
7. The unit (100) as claimed in claim 5, wherein the heat recovery chamber (11) is
positioned coaxially to the first nozzle (3) and the second nozzle (7).
8. A multistage pressure reduction device (200), the device (200) comprising:
a plurality of pressure reduction devices,
wherein each pressure reduction device (1) of the plurality of pressure reduction devices comprises:
a first nozzle (3) having a first inlet and a first outlet;
a second nozzle (7) having a second inlet and a second outlet, the second inlet fluidly connected to the first outlet to flow a steam (2) between the first inlet and the second outlet,

a heat recovery unit (100) comprising a heat recovery chamber (11) enclosing at least one portion of the first nozzle (3) and at least one portion of the second nozzle (7),
the heat recovery chamber (11) is defined with an inlet (12) and an outlet
(13),
the heat recovery chamber (11) is configured to receive a heating medium fluid (15) from the inlet (12) for flowing over an outer surface of said at least one portion of the first nozzle (3) and at least one portion of the second nozzle (7) to exchange heat between said heating medium fluid (15) and the steam (2) flowing between the first inlet and the second outlet,
the outlet (13) of the heat recovery chamber (11) of one pressure reduction device (1) of the plurality of pressure reduction devices is fiuidly connected to the inlet (12) of the heat recovery chamber (11) of the other pressure reduction device (1) of the plurality of pressure reduction devices to transfer the heating medium fluid (15) from the outlet (13) of the heat recovery chamber (11) of said one pressure reduction device (1) to the inlet (12) of the heat recovery chamber (11) of the other pressure reduction device (1).
9. The device (200) as claimed in claim 8, wherein the second outlet of one
pressure reduction device (1) of the plurality of pressure reduction devices is fiuidly connected to the first inlet of the other pressure reduction device (1) of the plurality of pressure reduction devices to transfer the steam (2) from the second outlet of said one pressure reduction device (1) to the first inlet of the other pressure reduction device (1).