A test device for a centrifugal steam heat pump unit

Abstract

The present invention relates to the technical field of centrifugal steam heat pump unit testing, and discloses a testing device for a centrifugal steam heat pump unit, comprising a centrifugal compressor, a steam generator, a regenerator and an evaporator connected in sequence, wherein the steam generator is connected to a steam separator, and further comprising a steam heater and a water reservoir, wherein a steam outlet of the steam separator is connected to the steam heater, and when the centrifugal steam heat pump unit is started, the steam heater, the evaporator and the water reservoir are connected in series; when the centrifugal steam heat pump unit is in stable operation, the steam heater and the evaporator are connected in series. When the centrifugal steam heat pump unit is in stable operation, water flowing out of the evaporator directly enters the steam heater for heating, and then is transported to the evaporator. Since water is no longer added from the water reservoir during the stable operation of the unit, the water temperature and flow rate entering the evaporator are effectively controlled, and the stability of the water temperature entering the evaporator is ensured, thereby improving the accuracy of the unit test results.

Description

Technical Field

[0001] The invention relates to the technical field of centrifugal steam heat pump unit testing, and in particular to a testing device for a centrifugal steam heat pump unit. Background Art

[0002] Heat pump technology has significantly reduced greenhouse gas emissions. In the face of complex market demands, the trend of large-scale heat pump technology has gradually attracted more attention. Heat pump units absorb low-temperature heat energy from the environment and convert it into high-temperature heat energy, thereby generating water vapor. This technology not only improves energy utilization efficiency, but is also of great significance for promoting sustainable development.

[0003] Because of the advantages of large-scale heat pump technology, more and more companies are beginning to research this field. The following problems have become the difficulties faced by everyone:

[0004] (1) Lack of stable heat source: The user site proposes design requirements based on stable operating parameters, including flow rate and temperature. However, the factory often does not have the heat source conditions at the user site, and the evaporator lacks a continuous and stable heat load, and cannot be tested according to the design conditions. How to test the heat pump unit according to the actual situation becomes a problem.

[0005] (2) Startup of large heat pump units: When a large heat pump unit is started from a shutdown state, a certain amount of initial heat source load is required to realize the conversion of the refrigerant from liquid to vapor in the evaporator until water vapor is generated. How to provide a stable initial heat source load for the heat pump unit becomes a key issue.

[0006] (3) Stability of operating conditions: Due to its high efficiency and high flow rate characteristics, centrifugal units require more heat source medium to circulate and achieve circulation. However, the operating temperature of heat pumps is much higher than the ambient temperature. The test system is complex and heat loss and other reasons lead to large temperature fluctuations of the heat source medium at the inlet and outlet of the evaporator. The system parameters are not easy to stabilize, which affects the accuracy of the test results of the unit's power consumption, efficiency, etc.

[0007] (4) Test cycle of large heat pump units: Due to the thermal inertia of the heat pump and the test system, the stabilization time under the heat pump test condition is long and the test efficiency is low. Since the heat source needs to be preheated when starting from a shutdown state, it is time-consuming and energy-consuming, and the test preparation time is long. Summary of the invention

[0008] In view of the existing technical problems, the present invention provides a testing device for a centrifugal steam heat pump unit.

[0009] The technical solution of the present invention for solving the above technical problems is as follows: a testing device for a centrifugal steam heat pump unit, comprising a centrifugal compressor, a steam generator, a regenerator and an evaporator connected in sequence, wherein the steam generator is connected to a steam separator, and further comprising a steam heater and a water reservoir, wherein the steam outlet of the steam separator is connected to the steam heater, and when the centrifugal steam heat pump unit is started, the steam heater, the evaporator and the water reservoir are connected in series; when the centrifugal steam heat pump unit is running stably, the steam heater is connected in series with the evaporator.

[0010] On the basis of the above technical solution, the present invention can also be improved as follows:

[0011] Preferably, a steam condenser is further included, and the steam condenser is connected in parallel with the steam heater.

[0012] Preferably, when the centrifugal steam heat pump unit is started, the water reservoir is connected to the water inlet of the evaporator, the water outlet of the evaporator is connected to the steam heater, and the outlet of the steam heater is connected to the water reservoir.

[0013] Preferably, the water reservoir is connected to the water inlet of the evaporator through the fifth branch and the third branch, a second switching valve is installed on the fifth branch, the water outlet of the evaporator is connected to the steam heater through the fourth branch, the outlet of the steam heater is connected to the water reservoir through the sixth branch, and a third switching valve is installed on the sixth branch.

[0014] Preferably, a diffuser is connected to the outlet of the sixth branch, and the diffuser is located in the water reservoir.

[0015] Preferably, a one-way valve is provided at the inlet of the fifth branch.

[0016] Preferably, when the centrifugal steam heat pump unit is operating stably, the steam heater is connected to the water inlet of the evaporator through a third branch, a first switching valve, an expansion water tank and a water pump are installed on the third branch, and the water outlet of the evaporator is connected to the steam heater through a fourth branch.

[0017] Preferably, the third branch is connected in parallel with a first bypass branch, the first bypass branch is connected to the outlet of the steam heater, and a water regulating valve is installed on the first bypass branch.

[0018] Preferably, the fourth branch is connected to the third branch via a second bypass branch, a water temperature regulating valve is installed on the second bypass branch, and a back pressure regulating valve is installed on the fourth branch, and the back pressure regulating valve is used to increase the pressure on both sides of the water temperature regulating valve.

[0019] Preferably, a steam superheater is provided on the steam outlet pipeline of the steam separator.

[0020] The beneficial effects of the present invention are as follows: when the centrifugal steam heat pump unit is started, the water in the water reservoir is added to the evaporator to realize the circulation of water and ensure that there is enough water for heat exchange; when the centrifugal steam heat pump unit is running stably, the water flowing out of the evaporator directly enters the steam heater for heating and then returns to the evaporator. Since no water is added from the water reservoir during the stable operation of the unit, it can ensure that the steam heater heats the water to a stable temperature, realizes effective control of the water temperature and flow rate entering the evaporator, is no longer limited by the ambient temperature, meets the requirements of the evaporator for heat source conditions during the heat pump test, meets the test requirements of the unit under various heat source conditions, and ensures the accuracy and stability of the unit test results, solves the problem of inaccurate test results caused by fluctuations in the water temperature entering the evaporator. When the centrifugal steam heat pump unit is ready to shut down, part of the water in the centrifugal steam heat pump unit is transported to the water reservoir, the water in the water reservoir is heated, the heat is recovered, and the next startup time of the centrifugal steam heat pump unit is reduced, thereby improving work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of a testing device for a centrifugal steam heat pump unit of the present invention.

[0022] The accompanying drawings are marked as follows: 1. Steam outlet pipeline; 2. First branch; 3. Second branch; 4. First bypass branch; 5. Third branch; 6. Second bypass branch; 7. Fourth branch; 71. Back pressure regulating valve; 8. Fifth branch; 9. Sixth branch; 10. Expansion water tank; 11. Centrifugal compressor; 12. Steam generator; 13. Steam separator; 14. Regenerator; 15. Evaporator; 16. Steam heater; 17. Steam condenser; 18. Steam superheater; 19. Diffuser; 20. Water reservoir; 21. First switching valve; 22. Second switching valve; 23. Third switching valve; 24. Water pump; 25. Water supply pipeline; 26. First flow meter; 27. Second flow meter. DETAILED DESCRIPTION

[0023] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0024] like Figure 1As shown, the present invention discloses a test device for a centrifugal steam heat pump unit, comprising a centrifugal compressor 11, a steam generator 12, a regenerator 14 and an evaporator 15 connected in sequence, wherein the steam generator 12 is connected to a steam separator 13, and the height of the steam separator 13 is greater than the height of the steam generator 12, the steam generated by the steam generator 12 rises upward and flows into the steam separator 13, and the separated hot water returns to the steam generator 12 under the action of gravity, realizing a siphon cycle and improving the comprehensive heat exchange efficiency, and further comprising a steam heater 16 and a water storage Pool 20, the steam outlet of the steam separator 13 is connected to the steam heater 16 through the steam outlet pipeline 1, and the steam outlet pipeline 1 is installed with a first flow meter 26, a temperature sensor and a pressure sensor, wherein "TT" in the attached figure represents a temperature sensor and "PT" represents a pressure sensor, to ensure the accuracy of the unit test results. When the centrifugal steam heat pump unit is started, the steam heater 16, the evaporator 15 and the water reservoir 20 are connected in series; when the centrifugal steam heat pump unit is running stably, the steam heater 16 is connected in series with the evaporator 15. The steam heater 16 heats the water entering the evaporator 15 to ensure the stability of the water temperature, thereby ensuring the stability and accuracy of the unit test results. And the water temperature is no longer limited by factors such as seasonality, and the water temperature can be heated to a specified temperature to meet the test requirements under different working conditions and reduce the test cost.

[0025] The test device also includes a steam condenser 17, which is connected in parallel with the steam heater 16. Specifically, the steam outlet pipeline 1 connected to the outlet of the steam separator 13 is connected to the steam condenser 17 through the first branch 2, and a steam condensation regulating valve is installed on the first branch 2 to regulate the steam entering the steam condenser 17. The steam outlet pipeline 1 is connected to the steam heater 16 through the second branch 3, and a steam heating regulating valve is installed on the second branch 3 to regulate the steam entering the steam heater 16. The steam condenser 17 plays a bypass role for the water vapor, so as to facilitate the control of the amount entering the steam heater 16, ensure that the water is heated to the set temperature, and ensure the accuracy of the test results.

[0026] Furthermore, a steam superheater 18 is provided on the steam outlet pipeline 1 of the steam separator 13. The steam superheater 18 is used to further heat the water micro-clusters contained in the water vapor flowing out of the steam separator 13 to form superheated water vapor, thereby ensuring the heating effect on the water entering the evaporator 15. Pressure sensors and temperature sensors are installed on the pipelines on both sides of the steam superheater 18 to detect the heating effect of the steam superheater 18 on the steam.

[0027] In this embodiment, when the centrifugal steam heat pump unit is started, the water reservoir 20 is connected to the water inlet of the evaporator 15, the water outlet of the evaporator 15 is connected to the steam heater 16, and the outlet of the steam heater 16 is connected to the water reservoir 20. The water in the water reservoir 20 is added to the evaporator 15 to ensure that the centrifugal steam heat pump unit contains sufficient water for heat exchange circulation and the accuracy of the test results.

[0028] Specifically, the water reservoir 20 is connected to the water inlet of the evaporator 15 through the fifth branch 8 and the third branch 5, and the second switching valve 22 is installed on the fifth branch 8. The outlet of the steam heater 16 is connected to the water reservoir 20 through the sixth branch 9, and the third switching valve 23 is installed on the sixth branch 9. When in use, the first switching valve 21 on the third branch 5 is closed, and the second switching valve 22 and the third switching valve 23 are opened. The water in the water reservoir 20 enters the evaporator 15 through the fifth branch 8 and the third branch 5. After heat exchange in the evaporator 15, the water flows into the steam heater 16 through the fourth branch 7. The water flowing out of the steam heater 16 flows into the water reservoir 20 through the sixth branch 9, so that the water in the water reservoir 20 is added to the evaporator 15 and circulates.

[0029] When the water vapor flowing out of the steam separator 13 reaches the set temperature, it indicates that the centrifugal steam heat pump unit enters a stable operation state, and the temperature measured by the temperature sensor on the steam outlet pipeline 1 can be used to determine whether the set temperature has been reached.

[0030] When the centrifugal steam heat pump unit is running stably, the first switching valve 21 is opened, the second switching valve 22 and the third switching valve 23 are closed, the steam heater 16 is connected to the water inlet of the evaporator 15 through the third branch 5, the third branch 5 is equipped with an expansion water tank 10 and a water pump 24, the expansion water tank 10 plays a buffering role to ensure the stability of the system pressure, the water outlet of the evaporator 15 is connected to the steam heater 16 through the fourth branch 7, and the fourth branch 7 is equipped with a second flow meter 27. Since water is no longer added to the system from the water reservoir 20 at this time, it can be ensured that the steam heater 16 heats the water to a stable temperature, and the water temperature and flow rate entering the evaporator 15 are effectively controlled to ensure the stability of the water temperature entering the evaporator 15, thereby improving the accuracy and stability of the test results of the centrifugal steam heat pump unit.

[0031] In this embodiment, the third branch 5 is connected in parallel with the first bypass branch 4, the first bypass branch 4 is connected to the outlet of the steam heater 16, and a water flow regulating valve is installed on the first bypass branch 4. The inlet water flow of the evaporator 15 is regulated by the first bypass branch 4. When the water flow entering the water inlet of the evaporator 15 is large, the opening of the regulating valve of the first bypass branch 4 is adjusted to make part of the water in the third branch 5 return to the outlet of the steam heater 16 through the first bypass branch 4, so as to control the water flow entering the evaporator 15 and further ensure the stability of the centrifugal steam heat pump unit.

[0032] In this embodiment, the fourth branch 7 is connected to the third branch 5 through the second bypass branch 6, a water temperature regulating valve is installed on the second bypass branch 6, and a back pressure regulating valve 71 is installed on the fourth branch 7, and the back pressure regulating valve 71 is used to increase the pressure on both sides of the water temperature regulating valve. The second bypass branch 6 is used to further control the water temperature entering the evaporator 15 to ensure the stability of the water temperature. Specifically, when the temperature of the water inlet of the evaporator 15 is high, by adjusting the opening of the water temperature regulating valve of the second bypass branch 6, part of the water flowing out of the evaporator 15 directly flows into the water inlet of the evaporator 15. Since this part of the water is not heated by the steam heater 16, the temperature of the water inlet entering the evaporator 15 can be reduced, further ensuring the stability of the water temperature.

[0033] By effectively controlling the water temperature and flow rate entering the evaporator 15, it is no longer limited by the ambient temperature, and the requirements of the evaporator 15 for heat source conditions during the test of the centrifugal steam heat pump unit are met; various regulating valves are used to ensure that the flow rate, temperature and pressure of water or water vapor in each pipeline or branch are in a stable state, so that the centrifugal steam heat pump unit can operate stably and the accuracy of the test results of performance parameters such as the thermal efficiency of the centrifugal steam heat pump unit can be guaranteed.

[0034] When the centrifugal steam heat pump unit is ready to shut down, the first switching valve 21, the second switching valve 22 and the third switching valve 23 are all opened to a certain degree, among which the first switching valve 21 has the largest opening and the second switching valve 22 has the smallest opening, so as to control the fluctuation of the water temperature entering the evaporator 15. A part of the hot water flowing out of the steam heater 16 directly enters the evaporator 15 through the first switching valve 21, and the other part enters the water reservoir 20 through the third switching valve 23, so as to heat the water in the water reservoir 20. The water in the water reservoir 20 flows to the evaporator 15 through the second switching valve 22, so that the water circulates among the evaporator 15, the steam heater 16 and the water reservoir 20. By flowing part of the water in the centrifugal steam heat pump unit to the water reservoir 20, the water in the water reservoir 20 is continuously heated, thereby reducing the next startup time of the centrifugal steam heat pump unit, improving working efficiency, realizing heat recovery and energy saving. When the temperature sensor on the fifth branch 8 or the water reservoir 20 reaches the set temperature, the centrifugal steam heat pump unit shuts down.

[0035] Furthermore, a diffuser 19 is connected to the outlet of the sixth branch 9, and the diffuser 19 is located in the water reservoir 20. The diffuser 19 allows the water flowing out of the steam heater 16 to be evenly diffused in the water reservoir 20, thereby improving the uniformity of the water temperature in the water reservoir 20 and increasing the temperature in the water reservoir 20.

[0036] Furthermore, a one-way valve is provided at the entrance of the fifth branch 8. The one-way valve allows water to flow only from the water reservoir 20 to the evaporator 15 and not in the reverse direction. Therefore, when the machine is shut down, a certain amount of water can be stored in the third branch 5 where the water pump 24 is located, ensuring that the water pump 24 can be started normally next time.

[0037] Furthermore, the steam separator 13 is connected to a water supply pipeline 25 , on which a pressure sensor, a temperature sensor, a flow meter and a water supply regulating valve are installed, so as to timely supply an appropriate amount of water into the steam separator 13 and ensure that sufficient water vapor is generated.

[0038] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A test device for a centrifugal steam heat pump unit, comprising a centrifugal compressor (11), a steam generator (12), a regenerator (14) and an evaporator (15) connected in sequence, wherein the steam generator (12) is connected to a steam separator (13), and characterized in that: It also comprises a steam heater (16) and a water reservoir (20), wherein the steam outlet of the steam separator (13) is connected to the steam heater (16), and when the centrifugal steam heat pump unit is started, the steam heater (16), the evaporator (15) and the water reservoir (20) are connected in series: the water reservoir (20) is connected to the water inlet of the evaporator (15), the water outlet of the evaporator (15) is connected to the steam heater (16), and the outlet of the steam heater (16) is connected to the water reservoir (20); When the centrifugal steam heat pump unit is in stable operation, the steam heater (16) is connected in series with the evaporator (15): the steam heater (16) is connected to the water inlet of the evaporator (15) via the third branch (5); a first switching valve (21), an expansion water tank (10) and a water pump (24) are installed on the third branch (5); and the water outlet of the evaporator (15) is connected to the steam heater (16) via the fourth branch (7); When the centrifugal steam heat pump unit is ready to shut down, part of the water in the centrifugal steam heat pump unit is transported to the water reservoir (20) to heat the water in the water reservoir (20).

2. The testing device for a centrifugal steam heat pump unit according to claim 1, characterized in that: It also includes a steam condenser (17), wherein the steam condenser (17) is connected in parallel with the steam heater (16).

3. The testing device for a centrifugal steam heat pump unit according to claim 1, characterized in that: The water reservoir (20) is connected to the water inlet of the evaporator (15) via a fifth branch (8) and a third branch (5); a second switching valve (22) is installed on the fifth branch (8); a water outlet of the evaporator (15) is connected to the steam heater (16) via a fourth branch (7); an outlet of the steam heater (16) is connected to the water reservoir (20) via a sixth branch (9); a third switching valve (23) is installed on the sixth branch (9).

4. The testing device for a centrifugal steam heat pump unit according to claim 3, characterized in that: The outlet of the sixth branch (9) is connected to a diffuser (19), and the diffuser (19) is located in the water reservoir (20).

5. The testing device for a centrifugal steam heat pump unit according to claim 3, characterized in that: A one-way valve is provided at the inlet of the fifth branch (8).

6. The testing device for a centrifugal steam heat pump unit according to claim 1, characterized in that: The third branch (5) is connected in parallel with a first bypass branch (4), the first bypass branch (4) is connected to the outlet of the steam heater (16), and a water flow regulating valve is installed on the first bypass branch (4).

7. The testing device for a centrifugal steam heat pump unit according to claim 1 or 6, characterized in that: The fourth branch (7) is connected to the third branch (5) via a second bypass branch (6); a water temperature regulating valve is installed on the second bypass branch (6); a back pressure regulating valve (71) is installed on the fourth branch (7); the back pressure regulating valve (71) is used to increase the pressure on both sides of the water temperature regulating valve.

8. The testing device for a centrifugal steam heat pump unit according to claim 1, characterized in that: A steam superheater (18) is provided on the steam outlet pipeline (1) of the steam separator (13).

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