Heat pump chilling system and control method therefor

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Solution Overview

Problem

Existing heat pump chilling systems face issues with excessive operating capacity when all devices are activated simultaneously and prolonged activation times when devices are activated sequentially, leading to inefficiencies in restoring heating or cooling capacity after a power outage.

Innovation Solution

A heat pump chilling system and method that calculates the optimal number of devices needed based on individual operating capacities, allowing for simultaneous activation of devices that are neither too large nor too small, ensuring rapid activation and efficient operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If all heat source devices are activated simultaneously, then the requested capacity can be obtained quickly, but the overall operating capacity becomes excessive

Engineering Contradiction:
Improveactivation timeVSAvoidoverall operating capacity
Core Design Contradiction:
Loss of timeVSPower

Solution Approach 1:

The system dynamically adjusts the activation strategy based on real-time conditions. The control device calculates the number of devices to activate based on the requested capacity and current operating states, enabling flexible adaptation between simultaneous and sequential activation modes to optimize both response time and capacity utilization

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control device segments the activation process into two phases: initial simultaneous activation of calculated number of devices to quickly meet capacity requirements, followed by sequential activation of remaining devices. This segmentation allows the system to balance rapid response with controlled capacity buildup

Inventive Principle:
Principle #1Segmentation

2Power

If heat source devices are activated sequentially by a predetermined time period, then the operating capacity is controlled, but it takes too much time to complete activation

Engineering Contradiction:
Improveoperating capacity controlVSAvoidactivation time
Core Design Contradiction:
PowerVSLoss of time

Solution Approach 1:

The system transitions from static sequential activation to dynamic hybrid activation. The control device continuously monitors requested capacity and adjusts the activation sequence in real-time, switching between simultaneous and sequential modes to minimize activation time while maintaining capacity control

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control device performs preliminary calculation of the optimal number of devices to activate simultaneously based on the requested capacity before activation begins. This preliminary action prevents excessive capacity while ensuring rapid response by activating the precise number of devices needed upfront

Inventive Principle:
Principle #10Preliminary action

3Productivity

If a large number of heat pump chilling devices are activated simultaneously, then the requested capacity is met quickly, but the system becomes unstable

Engineering Contradiction:
Improvecapacity restoration speedVSAvoidsystem stability
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The control device implements feedback control by continuously monitoring the operating states of activated devices and the actual capacity output. Based on this feedback, the system adjusts subsequent activation decisions to maintain system stability while achieving rapid capacity restoration

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system uses dynamic activation control where the number and timing of device activations are adjusted in real-time based on system response. This dynamic approach prevents simultaneous activation of too many devices while ensuring rapid capacity buildup through optimized sequencing

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3136013B1Heat pump chilling system and control method therefor
Publication Date: 2023.02.22 MITSUBISHI ELECTRIC CORP
  • EP3136013B1 patent drawingFigure 1
  • EP3136013B1 patent drawingFigure 2~3
  • EP3136013B1 patent drawingFigure 4~5

AI summary

A heat pump chilling system includes an inlet temperature sensor that detects an inlet temperature of a heat medium flowing into a plurality of heat pump chilling devices, an outlet temperature sensor that detects an outlet temperature of flow from the plurality of heat pump chilling devices to a load, and a system control device that controls operation of the plurality of heat pump chilling devices based on the inlet temperature and the outlet temperature. The system control device includes a storage unit that stores an operating capacity for each of the plurality of heat pump chilling devices, a requested-capacity calculating unit that calculates a requested capacity based on the inlet temperature or the outlet temperature and a set target temperature, a number-of-devices calculating unit that calculates the number of devices to be activated among the plurality of heat pump chilling devices satisfying the requested capacity based on the operating capacity of each of the plurality of heat pump chilling devices, and an activation control unit that activates the plurality of heat pump chilling devices of the number of devices to be activated calculated in the number-of-devices calculating unit.