All fresh air T3 working condition roof unit

Abstract

The utility model discloses a full fresh air T3 working condition roof unit which comprises a first refrigerating system and a second refrigerating system, the first refrigerating system comprises a first compressor, a first condenser and a first heat exchanger, and the second refrigerating system comprises a second compressor, a second condenser and a second heat exchanger. The first heat exchanger and the second heat exchanger are arranged in parallel to form a combined evaporator, the first heat exchanger is arranged on the air inlet side, and the second heat exchanger is arranged on the air outlet side. The first refrigerating system and the second refrigerating system are controlled to be used independently or jointly through the electromagnetic valve, the area of the evaporator is switched according to working conditions, the refrigerating effect is improved, and meanwhile the service life of the compressor is prolonged.

Description

Technical Field

[0001] The utility model discloses a rooftop machine with a fresh air T3 working condition, and relates to the technical field of rooftop machines. Background Art

[0002] Rooftop unit is a full air system unit, which can integrate cooling, heating, air supply, air purification and electronic control functions. It is generally installed on the roof of a building, so it is called rooftop unit. Rooftop unit has the advantages of compact structure, wide range of cooling (heating) capacity, convenient debugging and installation, and is widely used in various industries. However, when the rooftop unit is used in the fresh air T3 working condition, the fresh air temperature is high, exceeding 52℃, which often causes the compressor to operate beyond the operating range, greatly reducing the life of the unit and causing poor cooling effect. Utility Model Content

[0003] In view of the defects in the above-mentioned background technology, the utility model provides a rooftop unit with fresh air T3 working condition, switches the heat exchange area of ​​the evaporator, and improves the life of the compressor and the refrigeration effect.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is as follows: a fresh air T3 working condition rooftop unit, comprising a first refrigeration system and a second refrigeration system of the same structure, the first refrigeration system and the second refrigeration system share the same combined heat exchanger; the combined heat exchanger comprises a first heat exchanger and a second heat exchanger;

[0005] When the fresh air temperature is greater than a threshold value, the first refrigeration system independently uses the first heat exchanger in the combined heat exchanger to cool the fresh air, and the second refrigeration system independently uses the second heat exchanger in the combined heat exchanger to cool the fresh air;

[0006] When the fresh air temperature is not greater than a threshold value, the first heat exchanger and the second heat exchanger are connected in series, and both the first refrigeration system and the second refrigeration system use a combined heat exchanger to cool the fresh air.

[0007] Furthermore, the first refrigeration system further includes: a first compressor and a first condenser,

[0008] The exhaust port of the first compressor is connected to the inlet of the first condenser, the outlet of the first condenser is connected to the heat exchange inlet of the first heat exchanger, and the heat exchange outlet of the first heat exchanger is connected to the air inlet of the first compressor;

[0009] The second refrigeration system further comprises: a second compressor and a second condenser,

[0010] The exhaust port of the second compressor is connected to the inlet of the second condenser, the outlet of the second condenser is connected to the heat exchange inlet of the second heat exchanger, and the heat exchange outlet of the second heat exchanger is connected to the air inlet of the second compressor.

[0011] Furthermore, a first solenoid valve is provided between the first condenser outlet and the first heat exchanger inlet;

[0012] A second solenoid valve is provided between the first condenser outlet and the second condenser outlet;

[0013] A third solenoid valve is provided between the one-way valve inlet and the second compressor air inlet;

[0014] A fourth solenoid valve is disposed between the first compressor air inlet and the second compressor air inlet.

[0015] Furthermore, the first compressor is a compressor dedicated to the refrigerant R454B; the second compressor is a compressor dedicated to the refrigerant R454B.

[0016] Furthermore, a first condensing fan is arranged on the side of the first condenser, and a second condensing fan is arranged on the side of the second condenser, for heat dissipation of the condenser.

[0017] Furthermore, the refrigerant flow direction and the air flow direction in the evaporator are set to be counter-flow, thereby improving the refrigeration effect.

[0018] Beneficial effects: The utility model controls the use of the first refrigeration system and the second refrigeration system separately or in combination through the solenoid valve, switches the area size of the evaporator according to the working conditions, improves the refrigeration effect, and at the same time increases the life of the compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the framework of the utility model. DETAILED DESCRIPTION

[0020] The following is a further detailed description of the implementation of the technical solution in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the utility model, and cannot be used to limit the protection scope of the utility model.

[0021] like Figure 1 An embodiment shown: This embodiment provides a fresh air T3 working condition rooftop unit, comprising: a first refrigeration system and a second refrigeration system having the same structure, the first refrigeration system and the second refrigeration system sharing the same combined heat exchanger (7); the combined heat exchanger (7) comprises a first heat exchanger and a second heat exchanger, the first refrigeration system comprises: a first compressor 4, a first condenser 5 and a first heat exchanger,

[0022] The second refrigeration system comprises: a second compressor 1, a second condenser 2 and a second heat exchanger,

[0023] The exhaust port of the first compressor 4 is connected to the inlet of the first condenser 5, the outlet of the first condenser 5 is connected to the heat exchange inlet of the first heat exchanger, and the heat exchange outlet of the first heat exchanger is connected to the air inlet of the first compressor 4;

[0024] The exhaust port of the second compressor 1 is connected to the inlet of the second condenser 2, the outlet of the second condenser 2 is connected to the heat exchange inlet of the second heat exchanger, and the heat exchange outlet of the second heat exchanger is connected to the air inlet of the second compressor 1;

[0025] Under low temperature conditions, the first heat exchanger and the second heat exchanger are connected in series, and both the first refrigeration system and the second refrigeration system use the combined heat exchanger 7 to cool the fresh air.

[0026] Under high temperature conditions, the first refrigeration system independently uses the first heat exchanger in the combined heat exchanger 7 to cool the fresh air, and the second refrigeration system independently uses the second heat exchanger in the combined heat exchanger 7 to cool the fresh air, and the first heat exchanger is set on the air inlet side and the second heat exchanger is set on the air outlet side.

[0027] A first solenoid valve 9 is arranged between the outlet of the first condenser 5 and the first heat exchanger;

[0028] A second solenoid valve 8 is provided between the outlet of the first condenser 5 and the outlet of the second condenser 2;

[0029] A third solenoid valve 10 is provided between the one-way valve inlet and the air inlet of the second compressor 1;

[0030] A fourth solenoid valve 11 is provided between the air inlet of the first compressor 4 and the air inlet of the second compressor 1;

[0031] A one-way valve 12 is provided between the outlet of the second heat exchanger and the inlet of the first heat exchanger.

[0032] The first compressor 4 is a compressor dedicated to the refrigerant R454B; the second compressor 1 is a compressor dedicated to the refrigerant R454B.

[0033] A first condensing fan 6 is arranged on the side of the first condenser 5, and a second condensing fan 3 is arranged on the side of the second condenser 2, for heat dissipation of the condenser.

[0034] The refrigerant flow direction and the air flow direction in the evaporator 7 are set to be countercurrent.

[0035] When the utility model is in high-temperature working condition of fresh air, that is, when the fresh air temperature is greater than 46°C, the solenoid valves 8 and 11 are closed, and the solenoid valves 9 and 10 are opened. The refrigerant flow direction of the first refrigeration system is that the compressor 4 discharges high-temperature and high-pressure refrigerant vapor, and the condensation process is completed through the condenser 5. The refrigerant vapor releases heat and condenses from gas to liquid. After passing through 9, it enters the evaporator 7 first heat exchanger to complete the pre-cooling process. After that, the refrigerant changes from liquid to gas and returns to the compressor 4 to complete the pre-cooling cycle. The refrigerant of the second refrigeration system goes from 1 to 2 to the evaporator 7 second heat exchanger and then returns to the compressor 1 to complete the second refrigeration system. The first refrigeration system uses the first heat exchanger to pre-cool the high-temperature fresh air, and the second refrigeration system re-cools the air after pre-cooling. Due to the smaller area of ​​the evaporator, the evaporation pressure of the first refrigeration system is reduced, ensuring that the compressor operation is always within its operating range. The second refrigeration system performs secondary treatment on the air, and the refrigeration effect is greatly improved.

[0036] In the non-high temperature working condition (low temperature working condition), the utility model closes the solenoid valves 9 and 10, opens the solenoid valves 8 and 11, and the first refrigeration system and the second refrigeration system are combined into one. The refrigerant system flows in a direction that the compressors 4 and 1 discharge high-temperature and high-pressure refrigerant vapor at the same time, and then merge after completing the condensation process of their respective refrigeration systems in the condensers 2 and 5 respectively, first passes through the second heat exchanger of the evaporator 7 and then passes through the first heat exchanger of the evaporator 7. After completing the evaporation process, they return to their respective compressors respectively, and the evaporation area is increased, thereby improving the refrigeration effect in the non-high temperature working condition.

[0037] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A new air T3 working condition rooftop unit, characterized in that: It comprises a first refrigeration system and a second refrigeration system of the same structure, the first refrigeration system and the second refrigeration system share the same combined heat exchanger (7); the combined heat exchanger (7) comprises the first heat exchanger and the second heat exchanger; When the temperature of the fresh air is greater than a threshold value, the first refrigeration system independently uses the first heat exchanger in the combined heat exchanger (7) to cool the fresh air, and the second refrigeration system independently uses the second heat exchanger in the combined heat exchanger (7) to cool the fresh air; When the temperature of the fresh air is not greater than a threshold value, the first heat exchanger and the second heat exchanger are connected in series, and both the first refrigeration system and the second refrigeration system use the combined heat exchanger (7) to cool the fresh air.

2. A fresh air T3 working condition rooftop unit according to claim 1, characterized in that: The first refrigeration system further comprises: a first compressor (4) and a first condenser (5), wherein the exhaust port of the first compressor (4) is connected to the inlet port of the first condenser (5), the outlet port of the first condenser (5) is connected to the heat exchange inlet port of the first heat exchanger, and the heat exchange outlet port of the first heat exchanger is connected to the air inlet port of the first compressor (4); The second refrigeration system further comprises: a second compressor (1) and a second condenser (2), wherein the exhaust port of the second compressor (1) is connected to the inlet port of the second condenser (2), the outlet port of the second condenser (2) is connected to the heat exchange inlet port of the second heat exchanger, and the heat exchange outlet port of the second heat exchanger is connected to the air inlet port of the second compressor (1).

3. A fresh air T3 working condition rooftop unit according to claim 2, characterized in that: A first solenoid valve (9) is arranged between the outlet of the first condenser (5) and the inlet of the first heat exchanger; a second solenoid valve (8) is arranged between the outlet of the first condenser (5) and the outlet of the second condenser (2); a one-way valve (12) is arranged between the outlet of the second heat exchanger and the inlet of the first heat exchanger, and a third solenoid valve (10) is arranged between the inlet of the one-way valve and the air inlet of the second compressor (1); and a fourth solenoid valve (11) is arranged between the air inlet of the first compressor (4) and the air inlet of the second compressor (1).

4. A fresh air T3 working condition rooftop unit according to claim 2, characterized in that: The first compressor (4) is a compressor dedicated to the refrigerant R454B.

5. A fresh air T3 working condition rooftop unit according to claim 2, characterized in that: The second compressor (1) is a compressor dedicated to the refrigerant R454B.

6. A fresh air T3 working condition rooftop unit according to claim 2, characterized in that: A first condensing fan (6) is arranged on the side of the first condenser (5), and a second condensing fan (3) is arranged on the side of the second condenser (2).

7. A fresh air T3 working condition rooftop unit according to claim 1, characterized in that: The refrigerant flow direction and the air flow direction in the combined heat exchanger (7) are arranged to be counter-flow.

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