Exhaust superheat degree control method of refrigerating and heat pump unit

A technology of exhaust superheat and heat pump units, which is applied in the direction of refrigerators, refrigeration components, refrigeration safety arrangements, etc., can solve the problems of high cost and expensive pressure sensors, and achieve the effect of reducing control costs and ensuring safe operation

Inactive Publication Date: 2018-06-15

韩军

14 Cites 4 Cited by

AI-Extracted Technical Summary

Problems solved by technology

[0006] Since the pressure sensor is relatively expensive, t...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine

Abstract

The invention discloses an exhaust superheat degree control method of a refrigerating and heat pump unit. The exhaust superheat degree control method of the refrigerating and heat pump unit comprisesthe following steps that S1, the exhaust temperature of a compressor is collected through an exhaust temperature sensor; S2, the temperature at an air inlet (or a liquid outlet pipe) when an air heatexchanger serves as a condenser or the outlet water temperature when a water-cooling heat exchanger serves as a condenser are measured; S3, the environment temperature corrected value or the water temperature corrected value is calculated; S4, a controller collects the temperatures in the S1, S2 and S3 and calculates the exhaust superheat degree. After the unit runs and goes into a normal state, the controller judges the size relation between the exhaust superheat degree and an exhaust superheat threshold value, and if the exhaust superheat degree is larger than or equal to the exhaust superheat threshold value, the unit is within a safety range; and if the exhaust superheat degree is smaller than the exhaust superheat threshold value, a failure code is reported. According to the exhaust superheat degree control method of the refrigerating and heat pump unit, the exhaust superheat degree can be calculated on the basis that the controller and the sensor are not additionally arranged, and it is guaranteed that the unit safely runs.

Application Domain

Heat pumpsRefrigeration safety arrangement

Technology Topic

EngineeringHeat pump +4

Image

Examples

Experimental program(3)

Example Embodiment

[0044] Example 1

[0045] Such as figure 1 As shown, this embodiment 1 describes a method for controlling the superheat degree of exhaust gas in a refrigeration and heat pump unit. This method is suitable for the situation where there are two air heat exchangers in the refrigeration and heat pump unit at the same time, such as Figure 4 Shown.

[0046] A method for controlling exhaust superheat in a refrigeration and heat pump unit includes the following steps:

[0047] s11. Use the exhaust temperature sensor 2 to collect the exhaust temperature t1 of the compressor 1.

[0048] Wherein, the exhaust temperature sensor 2 is arranged at a position 50-300 mm away from the compressor exhaust port, for example, it may be 50 mm, 100 mm, 150 mm, 200 mm, 250 mm, and so on.

[0049] s12. Use the ambient temperature sensor 3 to measure the temperature t2 at the air inlet when one of the air heat exchangers 5 is used as a condenser. Wherein, the ambient temperature sensor 3 is arranged at the air inlet of the air heat exchanger or in the air environment.

[0050] Of course, it is also possible to replace the ambient temperature sensor 3 with a fin temperature sensor, and use the fin temperature sensor to measure the outlet pipe temperature when the air heat exchanger is used as a condenser, and use the outlet pipe temperature as the temperature t2.

[0051] It should be noted here that the temperature t2 measured by the above two methods is suitable for the exhaust superheat control of the present invention.

[0052] s13. Calculate the ambient temperature correction value t3 under the current heat exchange medium temperature. The calculation formula is as follows:

[0053] Another air heat exchanger 5 is used as an evaporator. It is defined that the heat absorption at the current heat exchange medium temperature is p1, the input power of the compressor at the current heat exchange medium temperature is p2, and the heat transfer area of the evaporator is s, The heat transfer coefficient of the evaporator is k.

[0054] Among them, p1, p2, s, and k are all constant values, and there are: t3=(p1+p2)/(s×k).

[0055] For example: in an environment of 15°C, the heat absorption of the evaporator is 17.5KW, and the input power of the compressor p2 is 7.0KW, so the total heat output of the refrigeration and heat pump unit is p1+p2=24.5KW.

[0056] The heat transfer area of the evaporator is s=70m 2 , Heat transfer coefficient k=70W/℃.m 2.

[0057] Then the ambient temperature correction value at the current temperature t3=24500/(70×70)=5°C.

[0058] When the temperature changes, both the heat absorption p1 of the evaporator and the input power p2 of the compressor will change. Therefore, the ambient temperature correction values corresponding to different ambient temperatures are different.

[0059] And when the ambient air temperature decreases, the heat absorption load of the evaporator decreases, and the ambient temperature correction value decreases.

[0060] s14. The controller collects the above temperatures t1, t2, and t3, and calculates the exhaust gas superheat t, t=t1-t2-t3.

[0061] After the unit enters the normal state, the controller judges the relationship between the exhaust superheat t and the exhaust superheat threshold t4. If the exhaust superheat t is greater than or equal to t4, the unit is in a safe range; if the exhaust superheat t is less than t4, the fault code is reported.

[0062] Among them, exhaust temperature sensor, ambient temperature sensor, fin temperature sensor and controller are all existing components in refrigeration and heat pump units. In the first embodiment, the exhaust gas superheat can be measured by using the existing controller and sensor.

Example Embodiment

[0063] Example 2

[0064] Such as figure 2 As shown, this embodiment 2 also describes a method for controlling the superheat degree of exhaust gas in a refrigeration and heat pump unit. This method is suitable for the situation where there are two water-cooled heat exchangers in the refrigeration and heat pump unit at the same time, such as Figure 5 Shown.

[0065] A method for controlling exhaust superheat in a refrigeration and heat pump unit includes the following steps:

[0066] s21. Use the exhaust temperature sensor to collect the exhaust temperature T1 of the compressor 1.

[0067] Wherein, the exhaust temperature sensor 2 is arranged at a position 50-300 mm away from the compressor exhaust port, for example, it may be 50 mm, 100 mm, 150 mm, 200 mm, 250 mm, and so on.

[0068] s22. Use the cooling outlet water temperature sensor 4 to measure the outlet water temperature T2 when one of the water-cooled heat exchangers 6 is used as a condenser.

[0069] Wherein, the cooling water outlet temperature sensor is arranged at the water outlet of the water-cooled heat exchanger. Of course, the cooling return water temperature sensor can also be used to collect, but the collected temperature needs to add the temperature difference between the return and outlet water to obtain the outlet water temperature T2.

[0070] s23. Calculate the water temperature correction value T3 under the current water temperature. The calculation formula is as follows:

[0071] Another water-cooled heat exchanger 6 is used as an evaporator. It is defined that the heat absorption of the evaporator at the current water temperature is P1, the input power of the compressor at the current water temperature is P2, the heat transfer area of the evaporator is S, and the heat transfer area of the evaporator is S. The heat transfer coefficient is K.

[0072] Among them, P1, P2, S, and K are all constant values, and there are: T3=(P1+P2)/(S×K).

[0073] For specific examples, please refer to the above-mentioned embodiment 1. It can be obtained through examples that the temperature of the cooling water is different, and the water temperature correction value is also different, and when the cooling water temperature decreases, the heat absorption load of the evaporator is reduced, and the water temperature correction value is reduced.

[0074] s24. The controller collects the above temperatures T1, T2, and T3, and calculates the exhaust gas superheat T, T=T1-T2-T3. After the unit enters the normal state, the controller judges the relationship between the exhaust superheat T and the exhaust superheat threshold T4. If the exhaust superheat T is greater than or equal to T4, the unit is in a safe range; if the exhaust superheat T is less than T4, the fault code is reported.

[0075] Among them, the exhaust temperature sensor, the cooling water temperature sensor and the controller are all existing components in the refrigeration and heat pump unit.

Example Embodiment

[0076] Example 3

[0077] Such as image 3 As shown, this embodiment 3 also describes a method for controlling the superheat degree of exhaust gas in a refrigeration and heat pump unit. This method is suitable for the situation where there is a water-cooled heat exchanger and an air heat exchanger in the refrigeration and heat pump unit, such as Image 6 Shown.

[0078] There are two situations in the exhaust superheat control method in the third embodiment:

[0079] The first is that the air heat exchanger 5 is used as a condenser and the water-cooled heat exchanger 6 is used as an evaporator; the second is that the water-cooled heat exchanger 6 is used as a condenser and the air heat exchanger 5 is used as an evaporator. among them:

[0080] In the first case, the exhaust superheat control method is performed according to the following steps:

[0081] s31. Use the exhaust temperature sensor 2 to collect the exhaust temperature L1 of the compressor.

[0082] Wherein, the exhaust temperature sensor 2 is arranged at a position 50-300 mm away from the compressor exhaust port, for example, it may be 50 mm, 100 mm, 150 mm, 200 mm, 250 mm, and so on.

[0083] s32. Use the ambient temperature sensor to measure the temperature L2 at the air inlet when the air heat exchanger is used as a condenser, and go to step s34.

[0084] The ambient temperature sensor is arranged at the air inlet of the air heat exchanger or in the air environment.

[0085] Of course, it is also possible to replace the ambient temperature sensor 3 with a fin temperature sensor, and use the fin temperature sensor to measure the outlet pipe temperature when the air heat exchanger is used as a condenser, and use the outlet pipe temperature as the temperature L2.

[0086] It should be noted here that the temperature L2 measured by the above two methods is suitable for the exhaust superheat control of the present invention.

[0087] s34. Calculate the water temperature correction value L3 at the current water temperature, and go to step s35.

[0088] The method for solving the water temperature correction value in this step s34 can refer to the solving method in the above-mentioned embodiment 2.

[0089] s35. The controller collects the above-mentioned temperatures L1, L2 and L3; and calculates the exhaust superheat L, L=L1-L2-L3; after the unit runs into the normal state, the controller judges the exhaust superheat L and the exhaust superheat threshold The size relationship of L4. If the exhaust superheat L is greater than or equal to L4, the unit is in a safe range; if the exhaust superheat L is less than L4, a fault code will be reported.

[0090] In the second case, the exhaust superheat control method is carried out according to the following steps:

[0091] s31. Use the exhaust temperature sensor 2 to collect the exhaust temperature L1 of the compressor.

[0092] Wherein, the exhaust temperature sensor 2 is arranged at a position 50-300 mm away from the compressor exhaust port, for example, it may be 50 mm, 100 mm, 150 mm, 200 mm, 250 mm, and so on.

[0093] s32. Use the cooling outlet water temperature sensor to measure the outlet water temperature L2 when the water-cooled heat exchanger is used as the condenser, and go to step s33.

[0094] s33. Calculate the ambient temperature correction value L3 under the current heat exchange medium temperature, and go to step s35.

[0095] The method for solving the ambient temperature correction value in step s33 can refer to the method for solving in the above-mentioned embodiment 1.

[0096] s35. The controller collects the above-mentioned temperatures L1, L2 and L3; and calculates the exhaust superheat L, L=L1-L2-L3; after the unit runs into the normal state, the controller judges the exhaust superheat L and the exhaust superheat threshold The size relationship of L4. If the exhaust superheat L is greater than or equal to L4, the unit is in a safe range; if the exhaust superheat L is less than L4, a fault code will be reported.

[0097] It should be noted that the exhaust temperature sensor, ambient temperature sensor, fin temperature sensor, cooling water temperature sensor and controller in the third embodiment are all existing components in the refrigeration and heat pump unit.

[0098] The above embodiments 1, 2, and 3 respectively deal with the exhaust superheat control method proposed when there are two air heat exchangers, two water-cooled heat exchangers, one air heat exchanger and one water-cooled heat exchanger in the refrigeration and unit .

[0099] Through the above method steps, it is not difficult to see that no matter what kind of exhaust superheat control method, the existing components can be used to calculate the exhaust superheat to ensure the safe operation of the unit. Because the pressure sensor is omitted, the cost is controlled. reduce.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine

Login to view more

PUM

Property	Measurement	Unit
Heat transfer area	70.0	m²
tensile		MPa
Particle size		Pa
strength	10

Description & Claims & Application Information

We can also present the details of the Description, Claims and Application information to help users get a comprehensive understanding of the technical details of the patent, such as background art, summary of invention, brief description of drawings, description of embodiments, and other original content. On the other hand, users can also determine the specific scope of protection of the technology through the list of claims; as well as understand the changes in the life cycle of the technology with the presentation of the patent timeline. Login to view more.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine

Login to view more

Classification and recommendation of technical efficacy words

Guaranteed safe operation
Lower control costs

Exhaust superheat degree control method of refrigerating and heat pump unit

AI-Extracted Technical Summary

Problems solved by technology

Abstract

Image

Examples

Example Embodiment

Example Embodiment

Example Embodiment

PUM

Description & Claims & Application Information

Similar technology patents

Method and system for monitoring heat condition of generator stator winding of nuclear power station

Insulation oil pipe with inside and outside reinforcing rib structures

Free-piston type internal combustion engine

Special high temperature-resistant electrical cable and its production method

Elevator system

Classification and recommendation of technical efficacy words

Fiber monitoring system

Anomalous video warning device for ATM

Device for online monitoring and overcurrent limiting power transformer iron core grounding current

Penetration prevention safe tyre cyclic chain sheet belt

Correlation-considered GEPOPF calculation method

Method for preparing edible fungus health-care product

On-line coordination control method for plate shape and plate thickness of strip tandem hot continuous rolling mill

Torque pulse suppression method of brushless DC motor in all speed regulation range

Maximum power tracking control method for small permanent-magnet direct-drive wind power generation system

Functional film composite particle, manufacturing method and filter stick formed by functional film composite particle