WO2021230736A1

WO2021230736A1 - Improved commercial refrigerator

Info

Publication number: WO2021230736A1
Application number: PCT/MA2021/000007
Authority: WO
Inventors: Ezzitouni KHIYARI
Original assignee: Khiyari Ezzitouni
Priority date: 2020-05-14
Filing date: 2021-06-04
Publication date: 2021-11-18
Also published as: MA49801B1; MA49801A1

Abstract

The present invention relates to an improved commercial refrigerator which makes it possible to improve current commercial refrigerators and to ensure continuity of service thereof even in the event of a failure of the fan, of the condenser or in the event of a gas leak from the defrosting water evaporation coil, and to ensure good efficiency thereof.

Description

Improved commercial refrigerator

Technical field of the invention

The invention relates to commercial refrigeration devices with an integrated cooling unit.

The technical problem addressed by the invention

Commercial refrigeration units on the market have several problems.

Most of them contain integrated cooling units, and the condenser can be found either at the front (drawing 2) or at the rear of the unit (drawing 1).

When the condenser is installed at the rear (drawing 1), and the rear end of the cooling device is on the side of the wall, in most cases there is not enough space between the wall and the 'device to ensure that the quantity of air that the condenser needs is given to it or to empty the air leaving the condenser. If installed at the front of the unit, the fan draws in from the front and exhausts hot air from the back, with the wall behind, air begins to accumulate there, and the fan finds a difficulty and its effectiveness decreases. These two fan installation methods lead to an increase in the gas condensing temperature and the condensing pressure, and also to an increase in the consumption of electrical energy.

It is also known that in commercial refrigeration devices operating with compact units, the coiled tube exiting the compressor, called a coil, is used at high pressure and high temperature to evaporate the water coming from the forced air evaporator during cooling. defrost process, and in this coil gas leaks often occur. In this case of a leak, the appliance loses the total amount of gas it contains and shuts down permanently, and there are sensitive appliances such as freezers, and the appliance may suddenly stop in the absence of the user of the device, which causes material loss for the user, and also a lot of losses and technical malfunctions in the device in the absence of a protection device with a safety to stop the device when a gas leak occurs. Indeed, the gas leak can cause the water to be absorbed in the tank by the compressor and the circuit also contaminated by air and humidity, and the compressor continues to operate without gas until it is destroyed, not to mention the negative impact of the gases used in refrigeration equipment on the environment, which causes global warming.

It is also known that the air that feeds the condenser is often polluted with dust, and this dust is difficult to remove, which means that the condenser requires maintenance from one period to another. During the time between these maintenance periods, the dust settles on the condenser, which induces a gradual increase in the pressure and the temperature necessary for the condensation of the gas. In addition, studies have shown that when the temperature required for gas condensation increases by 5 °, the efficiency decreases by 7%, and the consumption of electrical energy increases by 16%.

It also happens that the fan of the forced air condenser stops due to a malfunction, while the compressor continues to operate without condenser ventilation, as a result, the pressure and amperage of the compressor increase, causing the compressor to increase. 'shutdown by the appliance's safety system, this can cause several damages, for example in the case of a food refrigerator during holidays and when the owner is away.

During winter and when the air temperature drops, the gas condensing pressure is not stable. Another problem encountered in the conventional refrigeration circuit is that when changing the compressor for maintenance, for example, the gas may be discharged into the air, and this is very harmful for the environment.

State of the prior art

Document CN 104567158 A discloses a refrigeration circuit and a method for controlling the amount of leakage of a refrigerant with refrigerant fluid. The invention uses an arrangement of sectional separation valves to control the leakage of the refrigerant and not to reach a combustible and explosive point.

This prior art document does not go so far as to ensure the operation of the refrigeration circuit even in the event of a leak, and this is among the advantages of the present invention.

Advantages and description of the invention

To overcome these problems, the invention is a commercial refrigerator with a compact and integrated refrigeration unit, with full specifications and cost savings.

The invention consists in installing in a commercial refrigerator:

- At least one turbine or centrifugal fan (3b) to ventilate the condenser

- An auxiliary fan (3b-1) if the main fan (3-b) does not work.

- These fans have an orifice (20) with control motor (17)

- An air filter (19) installed in front of the condenser with a control system.

- Electromagnetic valves to isolate the coil (5)

- A defrost pan (6) comprising a resistance (14) and a water level control member (15). - Valves at the inlet and outlet of the compressor (4) to isolate the compressor when it is changed.

Below is the detailed description of the elements of the commercial refrigerator.

A square fan (3) is installed in the circuit and works with the auxiliary fan, one to the right of the condenser and the second to the other side, which sucks in the hot air discharged by the forced air condenser (1) if the latter is installed at the front of the appliance and vice versa, the additional fans supply the fan of the forced air condenser if it is installed at the rear of the appliance. This is a technique that adapts with the devices currently in place, whether the condenser in front (drawing 2) or backward (drawing 1), and also a technique allowing to eliminate this problem of setting up. place the unit in stores and not provide ventilation to properly cool the condenser.

For the condenser installed on the front face, the additional fans suck in and extract the hot air delivered by the condenser (drawing 5). In drawing 4, where the condenser is behind, fans are placed to supply the condenser with cold air, and after its supply, the forced air condenser delivers it to the outside of the device.

Another embodiment is to put fans, whether it is a turbine fan or a centrifugal fan, by installing one of these fans from the rear of the condenser. Thus, the fan draws in from the front of the unit and cools the air in the condenser, and this fan discharges the air towards the front of the unit, whether the condenser is installed at the front or at the back. back of the unit, and it is better to install the compressor on the back to install the compressor in front of the condenser, so that before the air enters the condenser, it goes through the compressor to cool it.

Turbine fans (3b) or centrifugal fans have been used, because the advantage of these fans is that the direction of the air inlet is the direction of its discharge. (drawing 7), which means that the air is not discharged to the rear of the appliance from the side of the wall. The condenser is installed on the front of the unit and the fan is located behind the condenser and draws air from the front and pushes it out of the unit from the front.

To ensure the continuity of the condenser ventilation even in the event of a fan malfunction, an auxiliary fan (3b-1) is added in addition to the 1st main fan (3b).

If the main fan (3b) is installed sideways, the auxiliary fan (3b-1) is installed in parallel (drawing 7). If the main fan (3b) is installed on the upper side, the auxiliary fan (3b-1) is installed at the bottom parallel to the main one.

An auxiliary turbine or centrifugal fan operates automatically in the event of a fan failure. The operation of the auxiliary fan is activated with an alarm system.

For the problem of the gradual accumulation of dust between the periods of maintenance of the device, the proposed solution is to place an air filter (19, drawing 7) of dust in front of the condenser and monitor the presence of dust in the filter by high pressure switch (10) or thermostat, placed to monitor the temperature of the gas leaving the condenser in the liquid state and going towards the expansion valve. In the event of dust accumulation on the air filter (19) of the condenser (1), the pressure and temperature of the gas condensate rise and the thermostat or high pressure switch gives the command to an audible alarm and to an indicator light to warn the user of the device. This warning can take place in two ways. The first is to turn on the warning lamp and sound the alarm continuously, and the second is to automatically turn on the warning lamp and the audible alarm alternately. When the thermostat or the control pressure switch (10) triggers an alarm, if the user after checking finds that the filter is in good condition, then in this case the alarm would be caused by the increase in the ambient temperature. A switch is put on to stop the alarm by the user in this situation. This means that the user of the device maintains the capacitor of his device himself and chooses the method to be informed automatically.

It is known that pressure switches, and thermostats are used for regulation or protection. In this invention, they are used to inform or alert for maintenance of the condenser.

By placing the filter (19), the condenser (1) is kept in good condition because the dust remains in the filter.

To regulate and maintain the gas condensing pressure in a stable state in winter or in the event of a drop in the air temperature during the night, for example, a hot air recirculation orifice (20) which opens automatically is placed at the fan outlet, it is opened by means of a motor (17) controlled by a thermostat (16) or high pressure switch to control the temperature or the pressure of the gas leaving the condenser, to reinject a quantity of heat leaving the condenser to return, to take advantage of its energy in order to increase the gas condensing pressure (drawing 7).

As for the coiled tube called coil (5) in the defrosting water tank (6) to evaporate the water, in which gas leaks occur, the solution is to install the coiled tube (5) inside tank (6) by installing it between a solenoid valve (12) at its inlet leaving the compressor (4), and at its outlet there is a non-return valve (13). A solenoid valve (12 ') is installed in parallel with the inlet of the solenoid valve (12) installed at the inlet of the coil (5), and the outlet of this valve is installed in front of the outlet of the non-return valve (13) ) (drawing 7, drawing 8-1). These valves make it possible to cancel the coiled tube called a coil (5), and thus the gas is directed directly to the condenser (1). The opening of this valve and the closing of the one at the inlet of the coil is done by a low pressure pressure switch with manual reset (11).

In normal operation, the pressure switch supplies power to the solenoid valve

(12) entering the coiled tube called coil (5) inside the tank (6) which collects the water, and the gas passes through this valve to pass through the non-return valve

(13), heading towards the condenser (1) after passing through the tank (6), for the evaporation of the water at high temperature of the gas

In the event that the gas pressure decreases in the circuit, when the coil (5) contains a hole, the pressure switch stops the electromagnetic valve (12) and supplies the valve (12 ') installed in parallel to cancel the coil (5 ), and the gas passes directly to the condenser (1) to ensure the continuity of the operation of the appliance in the event that the coil inside the tank (6) contains one or more holes. This is how the coil is isolated from the circuit by the 1st electromagnetic valve (12) and the non-return valve (13). This is done automatically by a manually reset low pressure switch (11).

This solution has the advantage of allowing the device to remain operational continuously while waiting for the technician to intervene to resolve the coil problem. The user receives a signal informing them that the device has a problem. An electrical resistance (14) is installed in the tank (6) to allow water to evaporate during the change of the coil (5), so that water does not accumulate in this tank (6). Said resistance (14) is monitored by a level detection system (15) of water in the tank. In this way, the device continues to operate without the problem of water overflow.

Using valves 12 and 12 ', and adding a solenoid valve (12-1) on the suction side of the compressor, the compressor can be isolated from both sides, and thus ensure the change of said compressor while keeping the gas in the cooling circuit. These valves work at the same time with the compressor (4). This also makes it possible to save money during the technician's intervention time when changing the compressor, and a large percentage of gas is preserved in the circuit. During the compressor change process, only the amount of gas vapor present in the compressor that is lost, this also ensures the operation of the compressor at the end of the refrigeration cycle under the evaporating pressure of the gas. which gives a decrease in the intensity of the operating current at start-up or at the end of the cooling cycle.

Thanks to this solution, we obtain a complete device, unique and economical compared to existing commercial refrigerators.

Description of the Drawings and Embodiments Drawing 1 illustrates a commercial refrigerator with a condenser (1) installed at the rear of the appliance.

Drawing 2 shows a commercial refrigerator with a condenser (1) installed on the front of the appliance.

1: forced air condenser 2: the direction of air flow to the outside

Figure 3 shows three commercial refrigerators at different condenser installations

F: commercial refrigerator with condenser installed at the back of the device, its condenser is supplied with air from other refrigerators F1: refrigerator with condenser installed on the front of the device

Drawing 4 shows a commercial refrigerator with the square fan motorcycles for supplying the condenser installed at the rear of the unit. 3: square condenser supply fan with air at room temperature.

Drawing 5 shows a commercial refrigerator with motorcycles square fans for the discharge of hot air from the condenser

1: condenser installed on the front of the device 2: the direction of air flow towards the wall

3: square fan for the discharge of hot air from the condenser Drawing 6 shows a turbine fan 3b: turbine fan 7: intake air direction

Drawing 7 shows the refrigeration circuit of a commercial refrigerator with the continuity of operation of the appliance in the event of a leak in the defrost water vaporization coil, the air filter saturation control system with dust, use of the main and auxiliary turbine fan and regulation of the condensing temperature and pressure using hot air recirculation from the condenser, and the compressor insulation with valves to ensure the compressor change without loss of gas and compressor start-up under evaporating pressure.

Drawing 8 is the electrical circuit for refrigeration circuit 7.

Drawing 8-1 is a continuation of drawing 8.

Figure 9 shows the use of valves at the inlet and outlet of the compressor to ensure start-up under evaporating pressure and change without gas recovery.

Fig 1 of drawing 9 shows the compressor with the elements of the invention. Fig 2 of drawing 9 shows a normal compressor without the elements of the present invention.

For drawings 7, and 9, the legend is as follows: 3b: turbine fan

3b-1: auxiliary turbine fan 4: compressor

5: defrost water vaporization coil 6: defrost water tank 7: direction of flow of air drawn in with the turbine fan 8: filter drier 9: liquid line to the expansion valve

10: high pressure pressure switch for controlling the saturation of the air filter 11: low pressure pressure switch with manual reset of the inversion of the solenoid valves in the event of a leak in the defrost water vaporization coil

12: electromagnetic valve ensures the passage of gas through the water vaporization coil in normal operation

12 ': electromagnetic valve ensures the passage of gas directly to the condenser in the event of a leak in the coil

12-1: electromagnetic valve on the suction side of the compressor, ensures isolation between the circuit and the compressor for ease of changing the compressor without evacuating the circuit using the other electromagnetic valves 12 'and 12. 13: check valve return 14: defrost water vaporization resistance in the event of isolation and separation between the refrigeration circuit and the coil, using a solenoid valve and the valve and also in the event of water increase in the tank defrost water 15: water level control unit in the defrost water tank 16: thermostat for controlling the gas temperature at the condenser outlet for the regulation of the temperature and the condensing pressure 17: electric motor of the hot air recirculation port of the condenser for the regulation of the temperature and the condensing pressure 18: air flow control unit at the outlet of the turbine fan to protect the compressor in the event of damage to the fan ensured shutdown of the device 19: air filter

20: hot air recycling orifice for temperature regulation and condensation pressure

21: safety door against entry of mice into the fan duct and the separation between the blower outlets of the turbine fan to ensure the passage of air to the condenser

22: low pressure gauge to show the difference between the current state and with the innovation

23: high pressure manometer

Drawing 8 is the electrical circuit of refrigeration circuit 7. Here is its caption:

N-L: power supply S1: on / off switch

H1: voltage indicator light B1: regulation thermostat M1: compressor motor

F1: magneto thermal circuit breaker for main turbine fan protection F2: magneto thermal circuit breaker for auxiliary turbine fan protection

M2: main turbine fan motor M3: auxiliary turbine fan motor

B2: temperature and condensing pressure regulation thermostat M4 and M5: condenser hot air recirculation port motors for temperature and condensing pressure regulation

B3 high pressure pressure switch for controlling filter saturation with dust and auxiliary fan on

KA1: dust filter saturation alarm system power relay and auxiliary fan start S2: alarm system stop switch K: alarm system

H2: saturated filter saturation indicator light and auxiliary fan on

Drawing 8-1 is the continuation of drawing 8. Below is its caption:

B4: low pressure pressure switch with manual reversal of the solenoid valves in the event of a leak in the defrost water vaporization coil Y1: solenoid valve operating in normal mode with defrost water vaporization with coil

Y2: electromagnetic valve operates in the event of a leak in the defrost water vaporization coil

Y3: electromagnetic suction valve

H3: indicator light when the appliance is operating without a coil B5: device for regulating the operation of the defrosting water vaporization resistance in the event of a leak in the coil or an increase in water at the level of the bac

R: defrost water vaporization resistance H4: resistance on indicator light

Drawing 10 shows the electrical circuit of drawing 9. Below is its legend:

L-N: power supply

H1: indicator light under voltage S1: on / off switch B1: regulation thermostat

F2: low pressure safety pressure switch in the event of blocking of the solenoid valves in the closed position Y1 and Y2: solenoid valves which operate in parallel with the compressor.

Claims

1. Improved commercial refrigerator characterized in that it contains with the forced air condenser (1), the compressor (4), the coil (5), the evaporator and the expansion valve, the following elements:

- at least one fan (3b) for cooling the condenser (1);

- an air filter (19) for dust placed in front of the condenser (1);

- a pressure switch (10) or high pressure thermostat to control the saturation of the air filter (19);

- audible alarm and indicator light connected to the pressure switch (10) or to the thermostat;

- a thermostat (16) for controlling the temperature of the gas at the outlet of the condenser (1) for regulating the temperature and the condensing pressure;

- an electromagnetic valve (12-1) on the suction side of the compressor (4);

- An electromagnetic valve (12) at the inlet of the coil (5);

- An electromagnetic valve (12 ') parallel to the valve (12);

- A non-return valve (13) at the outlet of the defrost pan (6);

- low pressure switch (11) with manual reset of the inversion of the solenoid valves in the event of a leak at the level of the defrost water vaporization coil (5);

- A defrost water vaporization resistance (14) inside the defrost water tank (6);

- a member (15) for controlling the water level in said defrost pan (6);

- An orifice (20) for recycling hot air at the delivery port of at least one fan (3b);

2. Refrigerator according to claim 1 characterized in that the fan is a square fan (3) for sucking the hot air discharged by the condenser (1).

3. Refrigerator according to claim 1 characterized in that the fan is a turbine fan.

4. Refrigerator according to claim 1 characterized in that the fan is a centrifugal fan. 5. Refrigerator according to claims 3 or 4 comprising a control member

(18) air flow at the outlet of the fan (3b) for the protection of the compressor

(4).

6. Refrigerator according to claims 3 or 4 characterized by an auxiliary fan (3b-1) parallel to the fan (3b). 7. Refrigerator according to claim 6 characterized in that the auxiliary fan (3b-1) is connected to a pressure switch (B3) which triggers it.