Technical Field
[0001] The present invention relates to performance improvement of the fan used in no frost
refrigerators by means of changing the angle and position thereof with respect to
the evaporator and replacement of the material forming the air channels and fan mounting
surface with a material having better heat and sound insulation.
Background of the Invention
[0002] Currently, evaporator is the section of the refrigerators where the low temperature
and low pressure liquid from the throttling valve evaporates by the heat of the cabin.
Heat transfer between the air and the evaporator surface is realized by means of natural
or forced convection. Natural convection creates problems even with the small resistances
encountered. Thus, air circulation obtained by means of forced convection using a
fan is preferred. Here, the evaporator fan is used for forced distribution of the
low temperature air provided in the evaporator into the sub sections. Fan motor is
connected in series to the lower and upper door buttons. Motor disengages when any
of the doors is opened. Thus, leakage of cold air to outside is prevented. The compressor
stops when thermostat of the cooler switches off the circuit. In this case, fan motor
also stops for preventing the temperature rise in the freezer section. On the other
side, when the timer is in defrost position, fan motor is also disengaged for not
sending the warm and moist air provided in the evaporator volume to the other parts
of the cooler during melting of the ice in the evaporator section. Evaporator fan
is placed in the rear section of the evaporator, near the protective aluminum sheet
walls.
[0003] In the prior art, placement of the fan providing flow in the air channels of the
no frost type refrigerators is realized in a way to increase pressure drop and benefit
ineffectively from the evaporator. Fan and evaporator are provided in the same direction.
[0004] In the prior art, fan is surrounded by polypropylene material, natural white color
material obtained by polymerization (small molecules combine to form larger molecules)
of propylene molecules obtained from "naptha", one of the crude oil derivatives. The
availability and prices of said material directly depend on the availability and prices
of the world crude oil reserves since, on average, crude oil derivatives of 97% are
utilized in manufacturing thereof.
[0005] Improvements, for suiting different places of use and purposes, can be made on the
physical properties such as flexibility, heat resistance and brittleness of polypropylene
raw material by introducing ethylene molecules into the propylene molecules resulting
from a complex series of chemical processes. Propylene gas and ethylene gas are reacted
under specific conditions in a reactor and introduction of ethylene molecules into
the propylene molecules is achieved. Percentage of said ethylene introduced and placement
positions thereof between the propylene molecules determine the physical properties
of the obtained material. Polypropylene raw material is more expensive than other
plastic materials. In addition, UV radiation resistance of polypropylene material
is small and it exhibits high thermal expansion. Painting and coating thereof is difficult.
It has low resistance to external weather conditions, it is prone to oxidation. It
is flammable and interacts with chlorine containing solvents.
[0006] Expanded polystyrene, i.e. EPS, is a lightweight, rigid plastic foam insulation material
made of solid polystyrene particles. Expansion thereof is obtained with small amounts
of pentane gas dissolved in the polystyrene base material during manufacturing. The
gas expands by means of the heat applied in the form of steam to form EPS cells enclosed
excellently. Said cells occupy as much as approximately 40 times of the polystyrene
particle's volume. EPS is molded in respective shapes according to the particle applications.
[0007] EPS is an important material for thermal and acoustic isolation of walls, roofs or
floors. It is an easy to use, ideal and cost effective material in all types of buildings.
EPS material is used as lightweight filler or a space forming material. It is also
used as floating material. EPS material consists of 98% air, thus, it is a high quality
thermal insulator. In addition, EPS material absorbs sound of impact in floating floors
as well as sound generated in the walls. For this reason, it is a proven acoustic
insulator.
[0008] In the current state of the art, the material surrounding the fan is a polypropylene
derivative. Said material cannot absorb the noise generated by the fan as required.
[0009] One of the patent applications in the literature related with the subject matter
is the patent
TR 2007/08742, titled 'a refrigerator'. Following is stated in the abstract of said patent application:
The present invention relates to a refrigerator comprising a heat insulated wall,
a storage compartment, an evaporator, an air conveying channel comprising air outlet
vents opening to the storage compartment, a fan providing blowing of air from the
evaporator towards the conveying channel, a vacuum opening positioned on said conveying
channel and carrying out air vacuum by means of the static pressure drop occurring
in the conveying channel walls during fan's blowing of air inside the conveying channel
to the storage compartment through the air outlet vents, a condensation chamber conveying
the air to the vacuum opening and at least one condenser element positioned inside
said condensation chamber. Another application related with the subject matter is
the patent application
JP 2010230286. The fan installation according to said application is intended to provide ease of
installation and reduce fan noise.
[0010] Consequently, fan systems of no frost refrigerators are improved, thus, new structures,
which would eliminate the aforementioned drawbacks and offer solutions to the existing
systems are needed.
Objects of the Invention
[0011] The present invention, which meets the aforementioned requirements, eliminates all
the drawbacks and provides some additional advantages, relates to performance improvement
of the fan used in no frost refrigerators by means of changing the angle and position
thereof with respect to the evaporator and replacement of the material forming the
air channels and fan mounting surface with a material having better heat and sound
insulation.
[0012] An object of the present invention is to reduce pressure drop formed on the fan in
the no frost refrigerators.
[0013] Another object of the present invention is to enable effective heat transfer of the
air sucked out of the evaporator with all surfaces of the evaporator in the no frost
refrigerators.
[0014] Another object of the present invention is to provide quieter operation by increasing
sound insulation through surrounding the fan with EPS material.
[0015] Another object of the present invention is to increase thermodynamic efficiency by
the fan assembly according to the present invention.
[0016] The present invention, for the purpose of providing all the advantages, which are
described above and will be understood from the detailed description given below,
relates to fan assembly structure used in the no frost refrigerators, comprising a
fan and evaporator, wherein it comprises fan mounting angle reducing pressure drop
forming on the fan between the fan and the evaporator and increasing thermodynamic
efficiency by enhancing heat transfer effectiveness of the air sucked over the evaporator
with all surfaces of the evaporator.
[0017] The present invention, in order to achieve all objects thereof, comprises EPS (expanded
polystyrene rigid foam) material allowing for forming air channel by surrounding said
fan and realizing heat and sound insulation.
[0018] The structural and the characteristic features and all advantages of the present
invention will be understood more clearly with the detailed description written by
referring to the following figures and therefore, the evaluation needs to be done
by taking these figures and the detailed description into consideration.
Brief Description of the Figures
[0019] Embodiment of the present invention and advantages thereof with the additional components
must be considered together with the figures explained below in order to be fully
understood.
Figure 1: Two dimensional side view of the inclined mounted fan structure according to the
present invention.
Figure 2: Two dimensional side view of the prior art fan structure.
[0020] Scaling of drawings is not absolutely required and details, which are not needed
for understanding the present invention, can be neglected. Furthermore, elements,
which are at least substantially identical or have at least substantially identical
functions, are indicated with the same number.
Reference Numbers
[0021]
- 1. Fan
- 2. Insulating material
- 3. Evaporator
- 4. Fan mounting angle
Detailed Description of the Invention
[0022] In this detailed description, subject of the invention and preferred embodiments
thereof are described only for a better understanding of the subject without constituting
any restrictive effect.
[0023] The present invention, in general, comprises fan (1) having reduced pressure drop
and enabling more effective use of the evaporator. Position of said fan (1) with respect
to the evaporator (3) is changed as shown in Figure 1. A fan mounting angle (4) is
formed between the fan (1) and the evaporator (3) in order to improve flow and heat
transfer properties. In addition, an evaporator (3) operating as heat exchanger is
provided in the present invention. Said evaporator (3) cools the air circulating inside
the refrigerator by means of the refrigerant gas. Another feature of the inclined
mounted fan (1) structure according to the present invention is the insulating material
(2) employed. Said insulating material (2) is made of EPS (expanded polystyrene rigid
foam) forming air channel by surrounding the fan (1) and with good sound insulating
feature.
[0024] Said fan mounting angle (4) of the inclined mounted fan structure according to the
present invention is not provided in the prior art shown in Figure 2. The fan mounting
angle (4) according to the present invention is formed such that the fan (1) has an
inclination in the clockwise (+) direction with respect to the evaporator (3). In
this case, said fan mounting angle (4) has values greater than 90° and less than 180°,
wherein it may be in preferred magnitudes so as to increase the thermodynamic efficiency.
Operating principle of the present invention is as follows.
[0025] In today's no frost refrigerators, refrigerated air cools the required compartments
by being circulated within the air channels through a fan (1). Said fan (1) cools
the air sucked inside the refrigerator by passing it over the evaporator (3) and then,
resends it back to the refrigerator cooling compartments. The importance of the inclined
mounted fan structure emerges here. At this point, fan mounting angle (4) is formed
between said fan (1) and the evaporator (3). Pressure drop of said fan (1) is reduced
by developing fan mounting angle (4) formed between the fan (1) and the evaporator
(3). In addition, inclined fan (1) mounting also has a significant effect on increasing
the thermodynamic efficiency. Here, air intake prevents full performance operation
of the evaporator (3) when the fan (1) and the evaporator (3) are in the same direction,
i.e. without any angle in between them and in vertical position, because, air tends
to pass over only a portion of the evaporator (3). Yet, fan (1), by means of the inclined
mounted fan structure according to the present invention, carries out suction so as
to utilize all surfaces of the evaporator (3).
[0026] Another important feature given to the fan structure according to the present invention
is the insulating material (2) employed. In the prior art shown in Figure 2, insulating
material (2) forming the air channels and the fan mounting surface is polypropylene
(PP). In the present invention, EPS (expanded polystyrene rigid foam) having better
sound and heat insulation properties is employed instead of polypropylene material.
The EPS mentioned herein, is a lightweight, rigid plastic foam insulation material
made of solid polystyrene particles. EPS is an important material for thermal and
acoustic isolation of walls, roofs or floors. EPS material is also used as lightweight
filler or a space forming material. EPS material absorbs sound of impact in floating
floors as well as sound generated in the walls. For this reason, it is a proven acoustic
insulator. Operation of the fan (1) with less noise is thus achieved by surrounding
thereof with EPS material and discomfort caused thereby to the surroundings thereof
is reduced.
1. A fan (1) mounting structure used in the no frost refrigerators, comprising a fan
(1) and an evaporator (3),
wherein;
- it comprises fan mounting angle (4) reducing pressure drop forming on the fan (1)
between the fan (1) and the evaporator (3) and increasing thermodynamic efficiency
by enhancing heat transfer effectiveness of the air sucked over the evaporator (3)
with all surfaces of the evaporator.
2. Fan (1) mounting structure according to Claim 1, wherein it comprises EPS (expanded polystyrene rigid foam) material allowing for forming
air channel by surrounding said fan (1) and realizing heat and sound insulation.
3. A fan (1) mounting method used in the no frost refrigerators, comprising a fan (1)
and an evaporator (3),
wherein;
- it comprises the process step of positioning the fan by means of forming a fan mounting
angle (4) between said fan (1) and the evaporator (3).
4. Fan (1) mounting method according to Claim 3, wherein it comprises the process step of surrounding said fan (1) with EPS (expanded polystyrene
rigid foam) material allowing for forming air channel and realizing heat and sound
insulation.