Artículo Académico / Academic Paper

Recibido: 27-10-2023, Aprobado tras revisión: 18-12-2023

Forma sugerida de citación: Rivera, A., Quitiaquez, W., Simbaña, I. y Quitiaquez, P. (2024). “Study of Steam Generation and

Distribution in a Hospital to Improve Energy Efficiency Using Thermography, Ultrasound, and Gas Analyzer”. Revista Técnica

“energía”. No. 20, Issue II, Pp. 72-80

ISSN On-line: 2602-8492 - ISSN Impreso: 1390-5074

Doi: https://doi.org/10.37116/revistaenergia.v20.n2.2024.601

Esta publicación es de acceso abierto bajo una licencia Creative Commons

Study of Steam Generation and Distribution in a Hospital to Improve Energy

Efficiency Using Thermography, Ultrasound, and Gas Analyzer

Estudio de la Generación y Distribución de Vapor en un Hospital para la

Mejora de Eficiencia Energética mediante Termografía, Ultrasonido y

Analizador de Gases

A. Rivera1

0009-0004-4721-1427

W. Quitiaquez1

0000-0001-9430-2082

I. Simbaña2

0000-0002-3324-3071

P. Quitiaquez1

0000-0003-0472-7154

1Universidad Politécnica Salesiana, Grupo de Investigación en Ingeniería, Productividad y Simulación Industrial

(GIIPSI), Quito, Ecuador

E-mail: ariverac2@est.ups, wquitiaquez@ups.edu.ec, rquitiaquez@ups.edu.ec

2Instituto Superior Universitario Sucre, Grupo de Investigación en Ingeniería Mecánica y Pedagogía de la Carrera de

Electromecánica (GIIMPCEM), Quito, Ecuador

E-mail: isimbana@tecnologicosucre.edu.ec

Abstract

This investigation studied the energy efficiency of a

steam system in a hospital, considering the procedure in

ASME EA-3-2009 standard. This is the standard for the

energy assessment of industrial steam systems and aims

to enhance the energy efficiency and sustainability of

industrial steam systems by identifying opportunities

and providing recommendations to optimize system

performance. The obtained boiler energy efficiency was

80.29 %, by applying an energy balance, reaching

15.33 kW for heat losses in the distribution pipes. Two

consistent improvement alternatives were proposed,

starting by unifying the pipe diameter of the kitchen

area of 5 m, generating a reduction of heat loss from 828

to 600 W, which represented a total annual energy

saving of around 2.4 GJ/year. The investment cost is

USD 47.40, considering the achievement of the break-

even point after 9 months, where the insulation of the

pipes with glass wool was considered second and it

generated a reduction in losses of 5.98 kW, representing

a total annual energy saving of about 62.91 GJ/year,

which corresponds to approximately USD 1 672. The

expenditure for insulating a 49 m pipe amounted to

USD 462, factoring in both the NPV calculation and

potential savings. The breakeven point was achieved

within roughly 4 months, underscoring the economic

advantage of implementing the two suggested

improvement measures.

Resumen

En esta investigación se analizó la eficiencia energética

de un sistema de vapor en un hospital, considerando la

norma ASME EA-3-2009. Esta norma se utiliza para la

evaluación energética de los sistemas de vapor

industriales y busca mejorar la eficiencia energética y la

sostenibilidad de estos sistemas identificando

oportunidades y proponiendo medidas para optimizar el

rendimiento. Se obtuvo una eficiencia energética de la

caldera de 80.29 % mediante un balance de energías y

las pérdidas de calor en las tuberías de distribución

alcanzaron 15.33 kW. Se plantearon dos alternativas de

mejora consistentes, iniciando con unificar el diámetro

de tubería del área de cocina de 5 m, generando una

reducción de pérdida de calor de 828 hasta 600 W, que

representó un ahorro de energía anual total de

2.4 GJ/año, aproximadamente. El costo de inversión es

de USD 47.40, considerando como alcanzable el punto

de equilibrio a los 9 meses, donde se planteó en segundo

lugar el aislamiento de las tuberías mediante lana de

vidrio y generó la disminución de pérdidas en 5.98 kW,

representando un ahorro de energía anual total de

alrededor de 62.91 GJ/año, lo que corresponde a

USD 1 672, aproximadamente. La inversión para el

aislamiento de tuberías con una longitud de 49 m fue de

USD 462, considerando el cálculo del VAN y los

posibles ahorros, además el punto de equilibrio se

alcanza a los 4 meses, aproximadamente, e indica

el beneficio económico de aplicar las dos opciones de

mejora planteadas.

Index terms—Energy efficiency, shell boiler, heat

transfer, steam, NPV.

Palabras clave— Eficiencia energética, caldera

pirotubular, transferencia de calor, vapor, VAN.

Edición No. 20, Issue II, Enero 2024

1. INTRODUCTION

Steam systems in hospitals are essential since they

produce saturated steam for the operation of equipment,

such as autoclaves, boilers, boilers, industrial washers,

industrial dryers, steam irons, and water heaters. A steam

system is formed by the boiler, the distribution pipes, and

the consuming equipment, which interact with each

other, therefore, if any of them fails, it damages the whole

system, producing energy losses, related to costs [1].

Nowadays, steam is one of the most important factors

when industrial costs are analyzed. According to Palacios

et al. [2], steam leaks stand out as one of the most

expensive issues in a hospital. Notably, steam trap leaks

can elevate operating expenses by as much as 33%.

Consequently, initiatives aimed at conserving energy

should commence with a thorough examination of these

traps. It is crucial to recognize that even the slightest leak

can result in annual costs of up to USD 7 000 [3].

Energy efficiency applied to steam systems is

fundamental since it allows the steam to be used in the

correct way, generating most of the heat for the different

processes. Yogesh et al. [4] indicate that, by having good

energy efficiency, fuel savings are generated and it helps

the environment, reducing pollution. Mandrela et al. [5]

conducted an energy audit of a food company in which

they used thermography and ultrasound techniques to

reduce energy losses and produce savings for the steam

system.

In the last decades, several studies have been carried

out, such as Ocaña et al. [6], who performed an energy

analysis in a hospital steam system, applying the

procedure established by the ASME EA-3-2009 standard

for energy evaluation. The objective of the study was to

assess the thermal losses resulting from the lack of

thermal insulation on the steam and condensate return

pipes in the four areas exhibiting the highest steam

consumption. The findings revealed a cumulative energy

loss of 513 GJ per year, equivalent to approximately

USD 4 060. By implementing insulation in the pipes, a

loss reduction of 195 GJ/year was achieved, representing

38 %, by completely insulating the pipes, which

generated savings of USD 1 542 per year. The estimated

cost of insulating the system with glass wool was USD 3

400, recoverable in a period of 2 years and 7 months,

considering for the calculations a subsidized Ecuadorian

diesel price of USD 1 037 per gallon.

The energy analysis of a boiler for reducing fuel

expenditure was presented by Caetano et al. [7]. The

methodology was to analyze an ATA 14 H 3N boiler

model, with a capacity of 33.3 kg/s of steam. The data

were obtained by measurements with a thermographic

camera and a flue gas analyzer. The energy efficiency of

the generator was 74.65 %. The most significant thermal

losses were found in the combustion gases, with 11.18 %,

radiation and convection losses reached 4 %, presenting

a total boiler loss of 25.35 %. Two improvement

alternatives are concluded, the first one is to reduce the

excess air and the second one is to place thermal

insulation in the non-insulated pipes. Perez et al. [8]

carried out an analysis of a steam system of a meat

factory, showing that the boiler efficiency was 90.7 %

and the losses of the pipes without thermal insulation

were 207.09 kW. Two improvement alternatives were

proposed, the first was the thermal insulation of the

distribution pipes with glass wool insulation and the

second was the design of a water preheater at 70 ºC to

feed the steam generator. The implementation of glass

wool in the pipes generated a reduction of thermal losses

by 92.30 %, the design of the water preheater generated

a reduction of fuel consumption of 64 186.51 L per year,

and the investment for the improvements was USD 450,

this investment will be recovered in 1.4 months.

Ibrahim et al. [9] conducted a study on energy savings

in the industrial steam system of a palm oil mill. During

the development, we employed the steam SSAT system

assessment tool along with the 3E Plus insulation

program software. The outcomes revealed multiple

sources of energy losses contributing to increased costs

for the plant, notably with a low boiler efficiency of only

68.6 %. The study identified potential enhancements,

specifically through the installation of a water

economizer and a reduction in steam generator

blowdowns. These improvements elevated the system's

efficiency to 77 % from its initial operational state.

Consequently, steam quality was enhanced, leading to

annual energy savings of 75.28 GJ and fuel savings

amounting to 598.3 tons per year.

The energy efficiency analysis of 5 boilers was

performed by Santana et al. [10]. Surface temperature

values of the insulated and uninsulated pipes were

obtained using a Testo 875 thermographic camera. The

study involved the determination of useful heat within the

cooking system and a thorough analysis of thermal losses

occurring in the distribution pipes. The transmission

losses in the insulated pipes were 13.32 and 4.22 kW for

uninsulated ones, for a total of 17.53 kW of heat losses.

The analysis determined that the total heat loss of the

installation was 14.43 kW, with respect to 243.02 kW

which represented the available heat, obtaining a system

efficiency of 94 %.

The thermo-energetic study of a thermoelectric plant

with a capacity of 49 MW was developed by Retirado et

al. [11]. The applied methodology utilized an algorithm

to assess both the gross and exergetic thermal

performances of the boilers. The findings revealed a

notable efficiency in thermal energy utilization coupled

with a relatively low capacity for exergy use in the

installations. Specifically, the thermal efficiency of the

system reached 90.1%, while the exergy efficiency was

recorded at 45.5%. Suntivarakorn et al. [12] proposed

enhancing boiler efficiency through heat recovery and

the implementation of an automatic combustion control

system. This improvement harnessed the heat from

chimney gases for fuel drying, air preheating, and

Rivera et al. / Study of Steam Generation and Distribution in a Hospital to Improve Energy Efficiency

regulating the burner air intake using a fuzzy logic

control algorithm. Experimental findings demonstrated

that heat recovery and fuel drying reduced fuel moisture

content by 3 wt.%, leading to a 0.41 % increase in boiler

efficiency. Air preheating resulted in a 35 °C temperature

rise, contributing to a 0.72 % boost in efficiency. The

fuzzy logic-controlled air system exhibited an accuracy

of 89.15 %, correlating with a 4.34 % efficiency increase.

When all three systems operated concurrently, a

collective boiler efficiency increase of 5.15 % was

achieved, translating to annual fuel savings of

246.88 tons.

Erbas [13]. conducted a comprehensive study on the

thermal performance of a coal-fired boiler, employing the

energy balance method in accordance with the ASME

PTC 4 standard. The analysis focused on a 75-ton-per-

hour capacity boiler installed in the mining industry. The

performance test revealed an impressive boiler efficiency

of 93.07 %. Utilizing the indirect method, the top three

contributors to the overall losses in the boiler were

identified as water heat loss in the fuel at 4.03 %, dry flue

gas loss at 3.23 %, and the proportion of unburned coal

in the waste products at the end of combustion at 1.65 %.

Sagaf et al. [14] performed a prediction on the

efficiency deterioration of two boilers in two power

plants, with an individual capacity of 660 MW in

Indonesia. ASME PTC 4 guidelines and linear regression

method were followed. The findings highlight that the

primary sources of thermal losses stem from hydrogen

burning moisture in the fuel and heat loss attributable to

moisture in the fuel. Notably, the degradation in boiler

efficiency is measured at 0.19 and 0.4 % per year for the

first and second units, respectively. One of the causes of

the boiler efficiency deterioration is the use of coal of

variable quality and the accumulation of ash in the

economizer that reduces heat transfer.

This work aims to propose energy efficiency

improvements by analyzing the boiler and distribution

piping system, applying energy management techniques,

and obtaining operating parameters to determine

improvements. This document is divided as follows,

Materials and Methods detail the utilized methodology to

develop the study, focusing on energy management

techniques to achieve outcomes. Results study the data in

order to determine the improvements in the system.

Finally, in Conclusion, the qualitative and quantitative

information is synthesized to demonstrate the fulfillment

of this work.

2. MATERIALS AND METHODS

2.1 Steam generation, distribution and consumption

The steam generation and distribution system for the

study is a hospital in the province of Chimborazo, with

an altitude of 2 760 m above sea level, the average annual

temperature is 15 °C and the atmospheric pressure is

71.33 kPa, according to statistical data from the National

Institute of Meteorology and Hydrology (INAMHI) [15].

Steam generation is carried out in a vertical boiler Model

V1X69-150-9, with a power of 30 BHP, which runs on

diesel and has the capacity to generate 469.47 kg/h of

steam, working at a nominal pressure of 620.5 kPa.

The process begins when raw water from the public

network is sent to two 64 m3 tanks, from which point the

fluid is sent by a pumping system to the water treatment

process, where it is softened with cationic resins. Then,

the water is sent to the storage tank, where it is mixed

with the condensate that returns from the process. The

water is then supplied by a multi-stage pump to feed the

boiler, usually at a temperature of 60 ºC. On the other

hand, the fuel is stored in a 7 570-liter main tank, and

from there, it is pumped to the secondary tank that feeds

the boiler. Subsequently, it is distributed by gravity to the

burner, having an average fuel consumption of

18.93 liters per hour, at a fuel oil temperature of 18 ºC.

Fig. 1 shows the distribution of steam generated to a

storage manifold and to the consuming areas of the

hospital steam system. The Laundry area consists of three

sections, the Garment Drying area which is composed of

an industrial dryer with a capacity of 60 kg, the Garment

Washing area with two industrial washers of 45 kg

capacity and the Ironing area with a 3 HP ironer. The next

area is the Kitchen with 115-liter kettles, followed by the

Sterilization area, which consists of two Autoclaves with

180 kW power. The last area is the Power House which

consists of a water heater capable of generating

13.25 liters per minute.

Figure 1: Diagram of the hospital's steam system

2.2 Technical system status

The steam system has a main boiler and a reserve

boiler and its thermal insulation is in good physical

condition. Several sections of the steam and condensate

return piping are not insulated, generating heat loss to the

environment and energy costs, and also causing poor

steam quality. The areas where most of the insulation is

missing are the laundry and sterilization areas. Table 1

shows a review of the condensate distribution and return

system. The external diameter (do), insulated (La) and

Edición No. 20, Issue II, Enero 2024

Table 1: Data for insulated and non-insulated pipes and temperatures

Pipe section

do [mm]

La [m]

Lp [m]

dp [%]

ta [mm]

Tsup [K]

Tp [K]

Ta [K]

Boiler to Manifold

38.1

12.5

0.8

318.15

428.15

296.15

Manifold to the kitchen

19.05

313.2

410

294.2

31.75

100

425

294.2

Manifold to laundry

31.75

314.15

419.15

294.15

Manifold to steam autoclave

25.4

320.15

418.15

294.15

Manifold to water heater

25.4

318.15

417.15

294.15

Manifold to condensate return

31.75

107

311.15

368.15

294.15

non-insulated pipe length (Lp), insulation thickness (ta),

ambient temperature (Ta), surface temperature outside

the insulated (Tsup) and non-insulated (Tp) pipes were

measured. For these records, a SATIR thermographic

camera was used, taking measurements in 6 sections. To

gather operating parameters of the system, pressure

gauges and thermometers are strategically installed at

key points of interest, complemented by the use of a

DN100 electromagnetic flowmeter.

2.3 Technical system status

For the steam system diagnosis and subsequent

energy efficiency improvement proposals, the

recommendations of the ASME-EA-3-2009 standard

[16] were followed. It is utilized for energy evaluation of

steam systems, which suggests collecting and analyzing

design, operation, energy use, and system performance

data to identify opportunities for energy efficiency

improvement. Efficiency was evaluated by the energy

balance method [17]. Fig. 2 lists the causes for heat

losses, due to dry flue gas loss (a), H2 loss (b), fuel

moisture (c), moisture in the air (d), CO loss (e), fly ash

loss (f ), surface loss (g) and bottom ash loss (h).

Figure 2: Schematic diagram of boiler configuration for Platzer

efficiency calculation [18]

The calculation of the boiler efficiency is performed

following the procedure outlined in Platzer [18]. For this,

the stoichiometric air/fuel ratio and the excess air

supplied, described in equations (1) and (2), respectively,

are determined. To perform these calculations, the fuel

properties must be considered, in this case, the boiler uses

diesel fuel No. 2. It is also necessary to know the

constitution of the combustion gases, by considering the

measurements of the main boiler, that were made with a

Bacharach ECA 450 gas analyzer:

11.6 34.8 4.35

100

air theoretical

C H S





 +  − + 









(1)

Where Mair, theoretical is the theoretical air quantity per

fuel quantity. Excess air (EA) is obtained from gas

analysis data by applying equation (2):

%100

21 gas analysis

EA Data

O

=



−

(2)

Then the amount of actual air mass (Ma) entering, per

amount of fuel, is determined [18]:

1100

a air theorical



= + 





(3)

The mass of dry flue gas (m) is then determined:

( )

20.77

100 100 100

0.23

a air theorical

C PMCO N S

PMC



= + + + 

+  −

(4)

It is essential to identify the diverse thermal losses

associated with the boiler, commencing with the

determination of heat loss due to dry flue gas (L1). This

loss, considered the primary one for the boiler, is derived

using equation (5):

( )

1100

p gas a

m C T T

LPCI

  −

=

(5)

The thermal loss due to the evaporation of water

formed by H2 in the fuel (L2) is related to the combustion

of hydrogen, which causes a heat loss because the

combustion product is water, which is converted into

steam and is calculated with the equation (6):

( )

9 584 100

p gases a

H C T T

LPCI



 +  −



=

(6)

To determine the loss due to the moisture present in

the fuel (L3), it is considered that the moisture that enters

with the fuel produces a superheated steam, and it is

determined by equation (7):

( )

584 100

combustible gases a

H O Cpv T T

LPCI



 +  −



=

(7)

Rivera et al. / Study of Steam Generation and Distribution in a Hospital to Improve Energy Efficiency

In computing the loss attributed to moisture in the air

(L4), the mass of vapor in the air is ascertained using

psychrometric charts. The quantification of this

moisture-related loss is achieved through the application

of equation (8):

()

100

a H O air pv gas a

M M C T T

LPCI

   −

=

(8)

Heat losses due to incomplete combustion (L5) are the

products containing CO, H2, and hydrocarbons that are in

the combustion, value determined with equation (9):

% 5744 100

CO C

LCO CO PCI



=  

(9)

The surface losses (L6) are calculated by knowing the

boiler surface area and temperature:

( )

1.25

0.548 55.55 55.55

196.85 68.9

1.957 68.9

s boiler a







=−











+



+  − 



(10)

Once the different heat losses have been determined,

the boiler efficiency is determined by equation (11) [19]:

( )

100

caldera

n Totallosses



=−





(11)

2.4 Calculation of heat losses in pipelines

Fig. 3 presents the calculation method established in

the scientific literature to determine losses in insulated

steam pipes, based on NOM-009-ENER-1995 [20].

Figure 3: Methodology of thermal losses in insulated pipes

In the equations presented in Fig. 3, the dimensionless

geometric coefficient for pipes (C) is denoted as 1.016.

The variable V represents wind speed, which, in this

scenario, is assigned a value of zero due to the entirety of

the installation being situated within the confines of a

building. Additionally, E and kinsulation correspond to the

emissivity and conductivity of the insulation,

respectively, while Top signifies the operating

temperature of the boiler.

In the absence of insulating material, pipes are

regarded as horizontal cylindrical surfaces that dissipate

energy through a combination of convection and natural

radiation. The calculation method established in the

scientific literature to calculate the losses in non-

insulated steam pipes was considered with the modeling

proposed by Cengel [21]. The operating conditions are

considered to be stationary and the formulation

synthesized and systematized in Fig. 4 is used.

Figure 4: Methodology of thermal losses in non-insulated pipes

2.5 Calculation of heat losses in pipelines

The primary alternatives proposed include pipe

diameter standardization and thermal insulation, with the

initial focus on pipe diameter standardization. The steam

pipes within the hospital exhibit varying diameters,

spanning from 12.7 mm (0.5 in) to 38.1 mm (1.5 in).

Certain sections necessitate this range of diameters to

meet the steam demand of the associated equipment.

However, in the section from the steam manifold to the

boiling pans located in the kitchen, 2 sizes of pipe

Edición No. 20, Issue II, Enero 2024

diameters prevail, due to the lack of adequate couplings

to maintain a single pipe diameter, which generates a

greater heat loss. For this pipe section, the diameter is

unified by acquiring the fittings and pipe of the same size,

and the calculation is made in the pipe section, by

applying the calculation model shown in Fig. 4. After

calculating the pipe loss by unifying the diameter, the

loss due to the variety of diameters is determined by

means of equation (12):

diameter diameter,variety diameter,unified

q q q=−

(12)

In addition, it is proposed to implement thermal

insulation in the non-insulated distribution pipe sections.

Initially, the thermal losses for each uninsulated pipe

section are reassessed by introducing thermal insulation.

The calculations adhere to the methodology outlined in

Fig. 4. Given that the surface temperature outside the

insulation (Tsup) is not known, an initial temperature

value is assumed, and the corresponding thermal losses

(qa) are then determined. To obtain that the calculated

thermal losses (qa) are admissible, the iterative approach

suggested in NOM-009-ENER-1995 [20] is used, with

equation (13):

2aa

sc op

insulation o

TT Kd



= − 



(13)

This equation determines if the calculated value is

acceptable, by obtaining the calculated surface

temperature (Tsc) and comparing it with the surface

temperature of the insulation, initially assumed for the

calculation of losses in the insulated pipes. If Tsc is equal

to Tsup, then the heat losses are acceptable, if Tsc is

different from Tsup then the qa calculations must be

repeated, equaling Tsc to Tsup, and then the temperatures

are compared again. After determining the losses of the

insulated pipes, the heat loss due to lack of insulation is

determined with equation (14):

,insulation lack non insulated insulated

q q q

−

=−

(14)

3. RESULTS

3.1 Boiler energy efficiency analysis

Table 2 details the results of heat losses after

calculating the boiler efficiency, with the objective of

finding opportunities for improvement.

Table 2: Steam generator energy efficiency calculation

Heat Losses

Value [%]

10.41

7.52

0.03

0.21

0.01

1.54

80.29

It is observed that the highest loss is due to dry

combustion gases, with a percentage of 10.41 %, due to

the excess of air present in the combustion equal to 15 %,

followed by the loss of hydrogen in the fuel with 7.52 %.

The heat loss by radiation and convection is within the

parameters, according to Saidur et al. [22], which

indicates that these losses represent a maximum value of

2 %. Finally, a boiler efficiency of 80.29 % is obtained,

which is a value that can be considered tolerable,

although it can also be improved for the type of fuel used,

according to Retirado et al. [23].

3.2 Thermal loss analysis of the piping system

The analysis aimed to identify opportunities for

improvement by assessing thermal losses in both

insulated and non-insulated pipes within the system. The

pipes were segmented into six sections, and characteristic

geometric values of the pipe system, along with surface

temperatures in both insulated and non-insulated pipes,

were measured. Surface temperatures ranged from 40 °C

for insulated pipes to a maximum of 150 °C for non-

insulated pipes values falling within the application range

for glass wool as per ASTM C-552 [24] and

C-1696 [25]. Table 3 outlines the losses per section, with

the total loss calculated at 15.33 kW.

Table 3: Steam generator

Heat Losses

[kW]

Boiler to Manifold

Manifold to the kitchen

Manifold to laundry

Manifold to steam

autoclave

Manifold to water heater

Manifold to condensate

return

In insulated pipes

0.41

0.50

1.52

2.17

0.19

3.19

In uninsulated

pipes

0.22

1.31

4.20

0.85

0.17

0.62

Total, in sections

0.63

1.81

5.72

3.02

0.35

3.81

Total, in pipes

15.33

Fig. 5 presents the actual loss values for the insulated

and uninsulated pipes in each section. The current total

heat loss of the piping system is 15.33 kW, of which, 7.36

kW is lost in the uninsulated pipes, representing 48 % of

the total losses. Currently, the steam system falls outside

the parameters defined by the NEC energy efficiency

standard regulations [26], as it exceeds the permissible

maximum energy loss of 4% attributable to inadequate

insulation [27].

Figure 5: Section losses in insulated and non-insulated pipes

Rivera et al. / Study of Steam Generation and Distribution in a Hospital to Improve Energy Efficiency

3.3 Steam system efficiency improvements

The piping section from the steam manifold to the

kitchen area is made up of two diameters, due to the lack

of fittings and piping, identifying a 5 m section with

different diameters. It generates greater heat loss,

therefore, the effect of unifying the pipe diameter is

considered. The analysis is carried out regarding the

installation of 19 mm (0.75 in) pipe, of the same diameter

as the other pipes in this section. In this manner, a heat

loss reduction of 228 W is generated and represents a

total annual energy saving of about 2.4 GJ per year,

which corresponds to USD 64. Fig. 6 compares the heat

loss in the section without unifying the pipe diameter and

unifying the diameter, which was calculated considering

that the steam distribution system works

8 hours per day, the whole year.

Figure 6: Loss per diameter cross-section

3.4 Insulation of distribution pipeline

For the analysis, it is proposed to install an insulator

with the same characteristics as those installed in the

insulated pipes. The insulators possess the characteristic

of being composed of glass wool material featuring an

aluminum coating adhered to it, with insulation thickness

ranging from 25 to 33 mm. Through measurements with

a thermographic camera, it was determined that these

insulation thicknesses guarantee that the surface

temperature is within the parameters allowed in Cengel

[21], where the surface temperature should not be higher

than 60 °C. Fig. 7 shows the effect of insulating the pipe

sections without thermal insulation.

Figure 7: Comparison of thermal losses in distribution pipelines

In the Boiler to Manifold section, there was a loss

reduction of 0.19 kW. Next, for the Manifold to the

kitchen section, a reduction of 0.88 kW was obtained, in

the Manifold to laundry, 3.63 kW, in the Manifold to

steam autoclave section, 0.71 kW, in the Manifold to

water heater section, 0.14 kW, and in the Manifold to

condensate return section, 0.44 W. All these savings

produce a total reduction of 5.99 kW, and represent a

total annual energy saving of 62.91 GJ per year, which

corresponds to approximately USD 1 672, value that was

calculated considering that the distribution system works

8 hours per day during 365 days of the year.

A financial analysis was conducted to assess the

project, aiming to determine the necessary investment

costs and the anticipated payback time. Hence, the

estimated implementation cost for insulating the steam

piping system amounts to USD 9.43 per meter. When

taking into account the Net Present Value (NPV) and

potential savings, the break-even point becomes

achievable within 4 months. Beyond this timeframe, the

initial investment proves worthwhile, generating

additional income. This rapid payoff not only recoups the

investment but also generates surplus funds that can be

directed toward further investments in hospital

machinery and infrastructure. Additionally, an analysis

was conducted by implementing pipe diameter

standardization. The examination revealed that the

investment required to standardize the pipe diameter in

the Manifold to kitchen section, covering a distance of

5 m and including the acquisition of necessary pipes and

accessories, amounts to USD 47.40. According to NPV

calculations, the break-even point for this investment

could be realized after 9 months.

4. CONCLUSIONS

The efficiency of the boiler was obtained by

calculating the six thermal losses present in the

combustion, determining an efficiency of 80 %. The

greatest loss is produced by the dry combustion gases,

representing 10.41 %, attributed to the excess air that has

a presence in the combustion of 15 %. To produce

improvements, excess air can be reduced to 10 % by

increasing the frequency of burner maintenance. By

improving the excess air, the flue gas temperature is also

reduced, which was 295 °C, data that were recorded

using technological equipment, such as a thermographic

camera and gas analyzer. The heat losses of the 6 sections

of the system were 15.33 kW, of which 7.36 kW is lost

in the uninsulated pipes, representing 48 % of the total

thermal losses.

With the unification of the pipe section from the

Manifold to the kitchen, a reduction of heat loss from 828

to 600 W is generated. It represents a total annual energy

saving of 2.4 GJ per year, which corresponds to

approximately USD 64. The thermal insulation of the

pipes with glass wool represents a total annual energy

saving of 62.91 GJ per year, related to USD 1 672, both

scenarios were calculated considering that the system

operates 8 hours per day during the 365 days of the year.

The expenditure for insulating a 49-meter pipe is

USD 462. This cost, factoring in the NPV of the

investment and potential savings, leads to the break-even

Edición No. 20, Issue II, Enero 2024

point being achieved after 4 months. Similarly, for the

standardization of the pipe diameter in a 5-meter section,

involving the purchase of necessary pipes and fittings at

a cost of USD 47.40, the NPV analysis suggests the

break-even point could be attained within 9 months.

These findings underscore the economic benefits

associated with implementing the proposed improvement

options.

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Biografías

Alex Rivera.- He was born in

Chimborazo, Ecuador. He received

his title of Technologist in

Maintenance and Repair of Diesel

and Gasoline Engines from the

Instituto Superior Tecnológico

Carlos Cisneros in 2001, his

Engineering Degree in

Maintenance Engineering from the Escuela Superior

Politécnica de Chimborazo in 2019, and his Master’s

Degree in Mechanical Engineering Mention Design of

Mechanical, Hydraulic, and Thermal Systems from the

Universidad Politécnica Salesiana in 2023. His research

field focuses on maintenance management.

William Quitiaquez.- He was born

in Quito, Ecuador, in 1988.

He received his Mechanical

Engineering degree from the

Universidad Politécnica Salesiana

in 2011; a Master's Degree in

Energy Management from the

Universidad Técnica de Cotopaxi,

in 2015; Master of Engineering from the Universidad

Pontificia Bolivariana de Medellín, in 2019; Ph.D. in

Engineering from the Universidad Pontificia Bolivariana

de Medellín, in 2022. He is the coordinator of the

Productivity and Industrial Simulation Research Group

(GIIPSI) of the Universidad Politécnica Salesiana. His

research field is related to Renewable Energy Sources,

Thermodynamics, Heat Transfer, and Simulation.

Isaac Simbaña.- He was born in

Quito, Ecuador, in 1990.

He received his Mechanical

Engineering Degree from the

Universidad Politécnica Salesiana,

in 2018; his Master's Degree

in Mathematical Methods and

Numerical Simulation in

Engineering from the Universidad Politécnica Salesiana

in 2022; his Master's Degree in Education from the

Universidad Politécnica Salesiana, in 2023. He currently

works in the Electromechanical Career at the Instituto

Superior Universitario Sucre. His research fields are

related to Numerical and Statistical Analysis, as well as

Thermodynamics, Manufacturing Processes, Materials

Science, and Educational Innovation.

Patricio Quitiaquez.- He was born

in Quito in 1969. He received his

Mechanical Engineer degree from

the Escuela Politécnica Nacional in

2002; and his Master's Degree in

Production Management from the

Universidad Técnica de Cotopaxi,

in 2007. His research field is related

to Operations Management, Structural Design,

Manufacturing Processes, and Simulation.