A high-efficiency heat pump system with uninterrupted defrosting operation at low ambient temperatures

Abstract

A high-efficiency heat pump system for low ambient temperature operation with uninterrupted defrosting includes a heat pump heating system, a defrosting system, and a thermal storage system. It employs a dual-evaporator design, allowing for switching between single and dual evaporators and system defrosting via a three-way valve and the start / stop of the water pump. The evaporators use hot water from the tank for intermittent defrosting; while one evaporator is defrosting, the other operates normally, ensuring normal operation of the defrosting system. The system uses a parallel dual-evaporator structure, allowing single evaporators to operate intermittently at higher ambient temperatures, and both evaporators to work simultaneously at lower ambient temperatures, thus improving the overall heating capacity of the system at low ambient temperatures.

Description

Technical Field

[0001] This invention relates to the field of heat pump system technology, and in particular to a high-efficiency heat pump system with low ambient temperature that operates continuously during defrosting. Background Technology

[0002] A heat pump system consists of an evaporator, compressor, and condenser connected by pipes. A heat pump is a highly efficient and energy-saving device that fully utilizes low-grade heat energy. The working principle of a heat pump is a mechanical device that forces heat from a low-temperature object to a high-temperature object in a reverse circulation manner. It consumes only a small amount of net reverse circulation work to obtain a large amount of heat supply, effectively utilizing low-grade heat energy that is difficult to apply, thus achieving energy-saving goals. In existing technologies, domestically produced heat pump systems generally require the main unit to be shut down during defrosting, and their energy efficiency is generally low when operating in low-temperature environments. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to address the shortcomings of the existing technology by proposing a high-efficiency heat pump system with uninterrupted defrosting operation at low ambient temperature to improve the system's energy efficiency.

[0004] The technical problem to be solved by the present invention is achieved through the following technical solution: a high-efficiency heat pump system with uninterrupted defrosting operation at low ambient temperature, characterized by:

[0005] It includes a first circulation system, a second circulation system, a third circulation system, and a heat exchanger; the first circulation system is a heat pump heating system, the second circulation system is a defrosting system, and the third circulation system is a heat storage system;

[0006] The first circulation system includes an evaporator, a compressor, a heat exchanger, an electronic expansion valve, and compression and expansion lines; the compressor is installed on the compression line, and the electronic expansion valve is installed on the expansion line.

[0007] The third circulation system includes a heat exchanger, a hot water storage tank, a three-system circulation pump, and three-system circulation piping;

[0008] The second circulation system includes an evaporator, a secondary circulation pump, a hot water storage tank, and defrost inlet and defrost return pipes.

[0009] The first circulation system and the second circulation system share the same set of evaporators; the third circulation system and the second circulation system share the same hot water storage tank; the heat exchanger in the first circulation system and the heat exchanger in the third circulation system are the same heat exchanger, wherein the compression pipeline and expansion pipeline heat exchanger of the first circulation system are connected to the heating side of the heat exchanger, and the three-system circulation pipeline of the third circulation system is connected to the heat exchange side of the heat exchanger.

[0010] The evaporators are evaporator I and evaporator II connected in parallel. The heating ends of evaporator I and evaporator II are connected in parallel to the compression pipeline. A regulating valve assembly is installed between the return ends of evaporator I and evaporator II and the expansion pipeline.

[0011] The defrost inlets of evaporator I and evaporator II are connected to the defrost inlet pipe via a defrost three-way reversing valve, and the defrost outlets of evaporator I and evaporator II are connected to the defrost return pipe; evaporator I and evaporator II defrost at intervals to maintain normal system operation;

[0012] The regulating valve group includes at least four three-way reversing valves. The first three-way reversing valve is connected to the return end of evaporator I, the second three-way reversing valve is connected to the return end of evaporator II, the third three-way reversing valve is connected between the first and second three-way reversing valves, and the fourth three-way reversing valve is connected between the first and third three-way reversing valves. One port of the fourth and second three-way reversing valves is connected to the expansion pipeline. The switching between the three-way reversing valves in the regulating valve group enables the conversion between the intermittent operation state and the simultaneous operation state of the two evaporators.

[0013] The technical problem to be solved by the present invention can also be further achieved by the following technical solution: a start / stop solenoid valve is installed on the defrosting water inlet pipe.

[0014] Compared with the prior art, the present invention adopts a dual evaporator design, in which the evaporators use hot water from the water tank for defrosting at intervals. When one evaporator is defrosting, the other evaporator is operating normally, thus realizing the normal operation of the defrosting system. The system adopts a dual evaporator parallel structure, in which the single evaporator operates at intervals when the ambient temperature is high, and the two evaporators work simultaneously when the ambient temperature is low, thereby improving the overall heating capacity of the system in low ambient temperature conditions. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the system composition of the present invention;

[0016] Figure 2 This is a schematic diagram of the operating principle of a low-ambient-temperature dual evaporator.

[0017] Figure 3 Operating principle of high ambient temperature single evaporator Figure 1 ;

[0018] Figure 4 Operating principle of high ambient temperature single evaporator Figure 2 ;

[0019] Figure 5 Schematic diagram of defrosting operation principle for evaporator 1;

[0020] Figure 6 This is a schematic diagram of the defrosting operation principle of evaporator 2.

[0021] in:

[0022] 1 is the unified evaporator I, 2 is the unified evaporator II, 3 is the compressor, 4 is the second system circulation pump, 5 is the heat exchanger, 6 is the hot water storage tank, 7 is the third system circulation pump, 8 is the electronic expansion valve; 9, 10, 11, 12, and 13 are three-way reversing valves, and 14 is the start / stop solenoid valve. Detailed Implementation

[0023] The specific technical solutions of the present invention are further described below. To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, and to facilitate a better understanding of the present invention by those skilled in the art, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments, and do not constitute a limitation on its rights. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0024] A high-efficiency heat pump system with low ambient temperature that operates continuously during defrosting includes a first circulation system, a second circulation system, a third circulation system, and a heat exchanger; the first circulation system is a heat pump heating system, the second circulation system is a defrosting system, and the third circulation system is a heat storage system.

[0025] The first circulation system includes an evaporator, a compressor, a heat exchanger, an electronic expansion valve, and compression and expansion lines; the compressor is installed on the compression line, and the electronic expansion valve is installed on the expansion line.

[0026] The third circulation system includes a heat exchanger, a hot water storage tank, a three-system circulation pump, and three-system circulation pipelines; the second circulation system includes an evaporator, a two-system circulation pump, a hot water storage tank, a defrost inlet pipe, and a defrost return pipe.

[0027] The first and second circulation systems share the same set of evaporators; the third and second circulation systems share the same hot water storage tank; the heat exchanger in the first circulation system and the heat exchanger in the third circulation system are the same heat exchanger, wherein the compression pipeline and expansion pipeline heat exchanger of the first circulation system are connected to the heating side of the heat exchanger, and the three-system circulation pipeline of the third circulation system is connected to the heat exchange side of the heat exchanger.

[0028] The evaporators are evaporator I and evaporator II connected in parallel. The heating ends of evaporator I and evaporator II are connected in parallel to the compression pipeline. A regulating valve group is installed between the return ends of evaporator I and evaporator II and the expansion pipeline. The defrost inlet of evaporator I and evaporator II is connected to the defrost water inlet pipe through a defrost three-way reversing valve. The defrost outlet of evaporator I and evaporator II is connected to the defrost return water pipe. Evaporator I and evaporator II defrost at intervals to maintain normal system operation.

[0029] The regulating valve group includes at least four three-way reversing valves. The first three-way reversing valve is connected to the return end of evaporator I, the second three-way reversing valve is connected to the return end of evaporator II, the third three-way reversing valve is connected between the first and second three-way reversing valves, and the fourth three-way reversing valve is connected between the first and third three-way reversing valves. One port of the fourth and second three-way reversing valves is connected to the expansion pipeline. The switching between the three-way reversing valves in the regulating valve group enables the conversion between the intermittent operation state and the simultaneous operation state of the two evaporators.

[0030] The defrosting water inlet pipe is equipped with a start / stop solenoid valve.

[0031] This invention adopts a dual-evaporator structure design, which can realize the system defrosting while the system outputs normally; it uses a dual-medium evaporator, and the defrosting heat source is taken from the terminal pressurized water tank, which does not affect the normal operation of the system; it operates with a single evaporator at high ambient temperature and with dual evaporators at low ambient temperature, which improves the operating capacity and energy efficiency of the low-temperature system.

[0032] Low temperature operation: such as Figure 2 As shown, when the ambient temperature is low, the system operates with dual evaporators. Terminals a and c of three-way reversing valve 9, three-way reversing valve 11, and three-way reversing valve 12 are connected; terminals a and b of solenoid valve 14 are closed; compressor 3 and circulating water pump 7 operate. Compressor 3, evaporator 1, evaporator 2, heat exchanger 5, and electronic expansion valve 8 constitute the primary system. The primary system transfers heat to the tertiary system through heat exchanger 5; the secondary system (defrosting) does not operate.

[0033] High-temperature operation 1: such as Figure 3 As shown, when the ambient temperature is high, the system operates with only the evaporator. Terminals a and b of three-way reversing valve 9 are connected, terminals b and c of three-way reversing valve 10 are connected, terminals a and b of three-way reversing valve 11 are connected, terminals b and c of three-way reversing valve 12 are connected, and terminals a and b of solenoid valve 14 are closed. Compressor 3 and circulating water pump 7 operate. Compressor 3, evaporator 2, heat exchanger 5, and electronic expansion valve 8 constitute the primary system. The primary system transfers heat to the tertiary system through heat exchanger 5. The secondary system (defrosting) does not operate.

[0034] High-temperature operation 2: such as Figure 4As shown, when the ambient temperature is high, the system operates with only one evaporator. Terminals a and b of three-way reversing valve 9, three-way reversing valve 10, three-way reversing valve 11, and three-way reversing valve 12 are connected. Terminals a and b of solenoid valve 14 are closed, and compressor 3 operates. Compressor 3, evaporator 1, heat exchanger 5, and electronic expansion valve 8 constitute the primary system. The primary system transfers heat to the tertiary system through heat exchanger 5. The secondary system (defrosting) does not operate. Evaporator 1 and evaporator 2 are switched on and off based on a loss balancing mechanism.

[0035] Evaporator 1 defrosting: such as Figure 5 As shown, when the system reaches the defrosting conditions, evaporator 1 first starts the defrosting mode. Terminals a and b of three-way reversing valve 9, terminals b and c of three-way reversing valve 10, terminals a and b of three-way reversing valve 11, terminals a and c of three-way reversing valve 13, and terminals a and b of solenoid valve 14 are connected. Compressor 1 runs, and circulating water pumps 4 and 7 start. Compressor 3, evaporator 2, heat exchanger 5, and electronic expansion valve 8 form the primary system. The primary system transfers heat to the tertiary system through heat exchanger 5, and the secondary (defrosting) system operates.

[0036] Evaporator 2 defrosting: such as Figure 6 As shown, when the system reaches the defrosting conditions and evaporator 1 completes defrosting, evaporator 2 starts defrosting mode. Terminals a and b of three-way reversing valve 9, three-way reversing valve 10, three-way reversing valve 11, and three-way reversing valve 13 are connected, as are terminals a and b of solenoid valve 14. Compressor 1 runs, and circulating water pumps 4 and 7 start. Compressor 3, evaporator 2, heat exchanger 5, and electronic expansion valve 8 form the primary system. The primary system transfers heat to the tertiary system through heat exchanger 5, and the secondary (defrosting) system operates.

Claims

1. A high-efficiency heat pump system with uninterrupted defrosting operation at low ambient temperature, characterized in that: It includes a first circulation system, a second circulation system, a third circulation system, and a heat exchanger; the first circulation system is a heat pump heating system, the second circulation system is a defrosting system, and the third circulation system is a heat storage system; The first circulation system includes an evaporator, a compressor, a heat exchanger, an electronic expansion valve, and compression and expansion lines; the compressor is installed on the compression line, and the electronic expansion valve is installed on the expansion line. The third circulation system includes a heat exchanger, a hot water storage tank, a three-system circulation pump, and three-system circulation piping; The second circulation system includes an evaporator, a secondary circulation pump, a hot water storage tank, and defrost inlet and defrost return pipes. The first circulation system and the second circulation system share the same set of evaporators; the third circulation system and the second circulation system share the same hot water storage tank; the heat exchanger in the first circulation system and the heat exchanger in the third circulation system are the same heat exchanger, wherein the compression pipeline and expansion pipeline heat exchanger of the first circulation system are connected to the heating side of the heat exchanger, and the three-system circulation pipeline of the third circulation system is connected to the heat exchange side of the heat exchanger. The evaporators are evaporator I and evaporator II connected in parallel. The heating ends of evaporator I and evaporator II are connected in parallel to the compression pipeline. A regulating valve assembly is installed between the return ends of evaporator I and evaporator II and the expansion pipeline. The defrost inlets of evaporator I and evaporator II are connected to the defrost inlet pipe via a defrost three-way reversing valve, and the defrost outlets of evaporator I and evaporator II are connected to the defrost return pipe; evaporator I and evaporator II defrost at intervals to maintain normal system operation; The regulating valve group includes at least four three-way reversing valves. The first three-way reversing valve is connected to the return end of evaporator I, the second three-way reversing valve is connected to the return end of evaporator II, the third three-way reversing valve is connected between the first and second three-way reversing valves, and the fourth three-way reversing valve is connected between the first and third three-way reversing valves. One port of the fourth and second three-way reversing valves is connected to the expansion pipeline. The switching between the three-way reversing valves in the regulating valve group enables the conversion between the intermittent operation state and the simultaneous operation state of the two evaporators.

2. The high-efficiency heat pump system with uninterrupted defrosting operation at low ambient temperature according to claim 1, characterized in that: The defrosting water inlet pipe is equipped with a start / stop solenoid valve.

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